Enso's Text Type (#1166)

.github/workflows/release.yml

@@ -188,6 +188,12 @@ jobs:
         run: |
           cp enso.exe ${{ env.LAUNCHER_DIST_DIR }}/bin/
 
+      - name: Build Base Java Extensions
+        shell: bash
+        run: |
+          cd std-bits
+          mvn package
+
       # The way artifacts are uploaded currently does not preserve the
       # executable bits for Unix. However putting artifacts into a ZIP would
       # create a twice nested ZIP file. For now, users downloading artifacts

.github/workflows/scala.yml

@@ -320,6 +320,12 @@ jobs:
         run: |
           cp enso.exe ${{ env.LAUNCHER_DIST_DIR }}/bin/
 
+      - name: Build Base Java Extensions
+        shell: bash
+        run: |
+          cd std-bits
+          mvn package
+
       # The way artifacts are uploaded currently does not preserve the
       # executable bits for Unix. However putting artifacts into a ZIP would
       # create a twice nested ZIP file. For now, users downloading artifacts

.gitignore

@@ -13,6 +13,7 @@ graal_dumps/
 target/
 *.class
 *.log
+.java-version
 
 ##########
 ## Rust ##
@@ -62,6 +63,7 @@ package-lock.json
 *.swp
 .projections.json
 .nvmrc
+*.iml
 
 ############################
 ## Rendered Documentation ##

build.sbt

@@ -4,6 +4,7 @@ import com.typesafe.sbt.SbtLicenseReport.autoImportImpl.{
   licenseReportNotes,
   licenseReportStyleRules
 }
+import scala.sys.process._
 import org.enso.build.BenchTasks._
 import org.enso.build.WithDebugCommand
 import sbt.Keys.{libraryDependencies, scalacOptions}
@@ -893,6 +894,21 @@ lazy val runtime = (project in file("engine/runtime"))
         .dependsOn(Def.task { (Compile / sourceManaged).value.mkdirs })
         .value
   )
+  .settings(
+    (Test / compile) := (Test / compile)
+        .dependsOn(Def.task {
+          val cmd = Seq("mvn", "package", "-f", "std-bits")
+          val exitCode = if (sys.props("os.name").toLowerCase().contains("win")) {
+            (Seq("cmd", "/c") ++ cmd).!
+          } else {
+            cmd.!
+          }
+          if (exitCode != 0) {
+            throw new RuntimeException("std-bits build failed.")
+          }
+        })
+        .value
+  )
   .settings(
     logBuffered := false,
     bench := (test in Benchmark).tag(Exclusive).value,
@@ -989,12 +1005,12 @@ lazy val runner = project
     commands += WithDebugCommand.withDebug,
     inConfig(Compile)(truffleRunOptionsSettings),
     libraryDependencies ++= Seq(
-        "org.graalvm.sdk"     % "polyglot-tck"   % graalVersion % "provided",
+        "org.graalvm.sdk"     % "polyglot-tck" % graalVersion % "provided",
-        "org.graalvm.truffle" % "truffle-api"    % graalVersion % "provided",
+        "org.graalvm.truffle" % "truffle-api"  % graalVersion % "provided",
-        "commons-cli"         % "commons-cli"    % commonsCliVersion,
+        "commons-cli"         % "commons-cli"  % commonsCliVersion,
-        "com.monovore"       %% "decline"        % declineVersion,
+        "com.monovore"       %% "decline"      % declineVersion,
-        "org.jline"           % "jline"          % jlineVersion,
+        "org.jline"           % "jline"        % jlineVersion,
-        "org.typelevel"      %% "cats-core"      % catsVersion,
+        "org.typelevel"      %% "cats-core"    % catsVersion
       ),
     connectInput in run := true
   )

distribution/std-lib/Base/src/Main.enso

@@ -1,13 +1,15 @@
 import Base.List
 import Base.Vector
 import Base.Number.Extensions
-from Builtins import Unit, Number, Integer
+import Base.Text.Extensions
+from Builtins import Unit, Number, Integer, Any, True, False
 
 from Builtins export all
 
 from Base.List export Nil, Cons
 from Base.Vector export Vector
 from Base.Number.Extensions export all hiding Math
+from Base.Text.Extensions export Text
 
 ## Represents a right-exclusive range of integer values.
 type Range
@@ -44,9 +46,22 @@ type Range
         res = it initial this.start this.end
         res
 
+    ## Checks whether `predicate` is satisfied for every number in this range.
+    every predicate =
+        it start end = if start==end then True else
+            r = predicate start
+            if r then (it start+1 end) else False
+        res = it this.start this.end
+        res
+
 type Math
 
 ## The mathematical constant pi, equal to the ratio of a circle circumference
     to its diameter.
 Math.pi : Decimal
 Math.pi = 3.141592653589793
+
+## Equality definition for types defining `==`.
+
+   TODO remove when operators can be defined in-language.
+Any.equals that = this == that

distribution/std-lib/Base/src/Number/Extensions.enso

@@ -82,4 +82,4 @@ Integer.upto n = Range this n
 
    Returns `True` when `this` and `that` are at most `epsilon` apart.
 Number.equals : Number -> Number -> Boolean
-Number.equals that epsilon = (this - that).abs <= epsilon
+Number.equals that epsilon=0.0 = (this - that).abs <= epsilon

distribution/std-lib/Base/src/System/Platform.enso

@@ -1,4 +1,5 @@
 from Builtins import System
+from Base import all
 
 type Os
     type Linux
@@ -10,7 +11,7 @@ type Os
    Create an Os object from text.
 from_text: Text -> Os
 from_text os =
-    if os == "linux" then Linux else if os == "macos" then MacOS else if os == "windows" then Windows else Unknown
+    if os.equals "linux" then Linux else if os.equals "macos" then MacOS else if os.equals "windows" then Windows else Unknown
 
 ## Return the type of operating system.
 

distribution/std-lib/Base/src/Test.enso

@@ -22,16 +22,18 @@ Suite.is_fail = this.specs.any is_fail
 type Assertion
     type Success
     type Failure message
+    type Pending
 
     is_fail = case this of
         Success -> False
         Failure _ -> True
+        Pending -> False
 
 ## Fail a test with the given message.
 fail message = Panic.throw (Failure message)
 
 ## Asserts that `this` value is equal to the expected value.
-Any.should_equal that = case this == that of
+Any.should_equal that = case this.equals that of
     True -> Success
     False ->
         msg = this.to_text + " did not equal " + that.to_text + "."
@@ -64,6 +66,8 @@ Spec.print_report =
             Failure msg ->
                 IO.print_err ("    - [FAILED] " + behavior.name)
                 IO.print_err ("        Reason: " + msg)
+            Pending ->
+                IO.print_err ("    - [PENDING] " + behavior.name)
 
 ## Creates a new test group, desribing properties of the object
    described by `this`.
@@ -93,16 +97,21 @@ Text.describe ~behaviors =
                      2+3 . should_equal 5
                  it "should define multiplication" <|
                      2*3 . should_equal 6
-Text.it ~behavior =
+Text.it ~behavior pending=False =
+    result = if pending then Pending else here.run_spec behavior
     spec = State.get Spec
+    new_spec = Spec spec.name (Cons (Behavior this result) spec.behaviors)
+    State.put Spec new_spec
+
+run_spec ~behavior =
     maybeExc = case Panic.recover behavior of
         _ -> Success
     result = maybeExc.catch ex->
         case ex of
             Failure _ -> ex
             _ -> Failure ("Unexpected error has been thrown: " + ex.to_text)
-    new_spec = Spec spec.name (Cons (Behavior this result) spec.behaviors)
+    result
-    State.put Spec new_spec
+
 
 ## Runs a suite of tests, consisting of multiple `describe` blocks.
 

distribution/std-lib/Base/src/Text/Extensions.enso

@@ -0,0 +1,105 @@
+from Base import all
+from Builtins import Text, Prim_Text_Helpers
+
+from Builtins export Text
+
+polyglot java import com.ibm.icu.text.BreakIterator
+polyglot java import org.enso.base.Text_Utils
+
+## Applies `function` to each character in `this`.
+
+   A character is defined as an Extended Grapheme Cluster, see
+   [Unicode Standard Annex #29](https://unicode.org/reports/tr29/).
+
+   This is the smallest unit that still has semantic meaning in most
+   text-processing applications.
+Text.each : (Text -> Any) -> Unit
+Text.each function =
+    iterator = BreakIterator.getCharacterInstance []
+    iterator.setText [this]
+
+    fst = iterator.first []
+    nxt = iterator.next []
+
+    iterate prev nxt = if nxt == -1 then Unit else
+        function (Text_Utils.substring [this, prev, nxt])
+        next_nxt = iterator.next []
+        iterate nxt next_nxt
+    iterate fst nxt
+    Unit
+
+## Returns a vector containing all characters in the given text.
+
+   A character is defined as an Extended Grapheme Cluster, see
+   [Unicode Standard Annex #29](https://unicode.org/reports/tr29/).
+
+   This is the smallest unit that still has semantic meaning in most
+   text-processing applications.
+Text.characters : Vector
+Text.characters =
+    bldr = Vector.new_builder
+    this.each bldr.append
+    r = bldr.to_vector
+    r
+
+## Takes a separator string and returns a vector resulting from splitting
+   `this` on each occurence of `separator`.
+
+   > Example
+     In the following example, we'll split the text into a vector of
+     comma-separated items:
+         "ham,eggs,cheese,tomatoes".split_at ","
+     The code above returns:
+         ["ham", "eggs", "cheese", "tomatoes"]
+Text.split_at : Text -> Vector
+Text.split_at separator =
+    Vector.from_polyglot_array (Text_Utils.split_at [this, separator])
+
+## Checks whether `this` is equal to `that`.
+
+   The definition of equality includes Unicode canonicalization. I.e. two texts
+   are equal if they are identical after canonical decomposition. This ensures
+   that different ways of expressing the same character in the underlying
+   binary representation are considered equal.
+
+   > Example
+     The string 'é' (i.e. the character U+00E9, LATIN SMALL LETTER E WITH
+     ACUTE) is canonically the same as the string 'e\u0301' (i.e. the letter
+     `e` followed by U+0301, COMBINING ACUTE ACCENT). Therefore:
+         ('é'.equals 'e\u0301') == True
+Text.equals : Text -> Boolean
+Text.equals that = Text_Utils.equals [this, that]
+
+## Returns a vector containing bytes representing the UTF-8 encoding of the
+   input text.
+
+   This is useful for low-level operations, such as binary data encoding and
+   decoding.
+Text.utf_8 : Vector
+Text.utf_8 = Vector.from_polyglot_array (Text_Utils.get_bytes [this])
+
+## Takes an array of bytes and returns Text resulting from decoding it as
+   UTF-8.
+
+   This is useful for low-level operations, such as binary data encoding and
+   decoding.
+Text.from_utf_8 : Vector -> Text
+Text.from_utf_8 bytes = Text_Utils.from_utf_8 [bytes.to_array]
+
+## Returns a vector containing integers representing the Unicode codepoints of
+   the input text.
+
+   This is useful for low-level operations, such as binary data encoding and
+   decoding.
+Text.codepoints : Vector
+Text.codepoints =
+    Vector.from_polyglot_array (Text_Utils.get_codepoints [this])
+
+## Takes an array of numbers and returns the text resulting from interpreting it
+   as a sequence of Unicode codepoints.
+
+   This is useful for low-level operations, such as binary data encoding and
+   decoding.
+Text.from_codepoints : Vector -> Text
+Text.from_codepoints codepoints = Text_Utils.from_codepoints [codepoints.to_array]
+

distribution/std-lib/Base/src/Vector.enso

@@ -25,6 +25,40 @@ type Vector
     at : Number -> Any
     at index = this.to_array.at index
 
+    ## Creates a new vector builder instance.
+
+       A vector builder is a mutable data structure, that allows for gathering
+       a number of elements and then converting them into a vector. This is
+       particularly useful when the number of elements is not known upfront.
+
+       > Example
+         In the following example we'll read items from the standard input,
+         until the string "end" is entered by the user and then return a vector
+         containing all items.
+             from Base import all
+
+             main =
+                  builder = Vector.new_builder
+                  do_read =
+                      item = IO.readln
+                      if item.equals "end" then Unit else
+                          builder.append item
+                          do_read
+                  do_read
+                  vec = builder.to_vector
+                  IO.println vec
+    new_builder : Builder
+    new_builder = Builder.new
+
+    ## Converts a polyglot value representing an array into a vector. This is
+       useful when wrapping polyglot APIs for further use in Enso.
+    from_polyglot_array : Any -> Vector
+    from_polyglot_array arr =
+        a = Array.new arr.length
+        0.upto arr.length . each i->
+            a.set_at i (arr.at i)
+        Vector a
+
     ## Returns the number of elements stored in this vector.
     length : Number
     length = this.to_array.length
@@ -104,3 +138,71 @@ type Vector
                 folder = str -> ix -> str + ", " + (arr.at ix).to_text
                 tail_elems = 1.upto arr.length . fold "" folder
                 "[" + (arr.at 0 . to_text) + tail_elems + "]"
+
+    ## Checks whether this vector is equal to `that`. Two vectors are considered
+       equal, when they have the same length and their items are pairwise equal.
+    equals : Vector -> Boolean
+    equals that =
+        arr1 = this.to_array
+        arr2 = that.to_array
+        eq_at i = (arr1.at i) . equals (arr2.at i)
+        r = if arr1.length == arr2.length then 0.upto arr1.length . every eq_at else False
+        r
+
+## A builder type for Enso vectors.
+
+   A vector builder is a mutable data structure, that allows to gather a
+   number of elements and then convert them to a vector. This is
+   particularly useful when the number of elements is not known upfront.
+
+   > Example
+     In the following example we'll read items from the standard input,
+     until the string "end" is entered by the user and then return a vector
+     containing all items.
+         from Base import all
+
+         main =
+              builder = Vector.new_builder
+              do_read =
+                  item = IO.readln
+                  if item.equals "end" then Unit else
+                      builder.append item
+                      do_read
+              do_read
+              vec = builder.to_vector
+              IO.println vec
+type Builder
+    type Builder to_array length
+
+    ## Creates a new builder.
+    new = Builder (Array.new 1) 0
+
+    ## Returns the current capacity (i.e. the size of the underlying storage)
+       of this builder.
+    capacity = this.to_array.length
+
+    ## Appends a new element into this builder.
+    append : Any -> Unit
+    append item = case this.capacity > this.length of
+        True ->
+            this.to_array.set_at this.length item
+            Unsafe.set_atom_field this 1 (this.length + 1)
+        False ->
+            old_array = this.to_array
+            new_array = Array.new old_array.length*2
+            0.upto this.length . each i->
+                new_array.set_at i (old_array.at i)
+                Unit
+            Unsafe.set_atom_field this 0 new_array
+            this.append item
+            Unit
+
+    ## Converts this builder to a vector containing all the appended elements.
+    to_vector : Vector
+    to_vector =
+        old_array = this.to_array
+        new_array = Array.new this.length
+        0.upto this.length . each i->
+            new_array.set_at i (old_array.at i)
+            Unit
+        Vector new_array

distribution/std-lib/Base/third-party-licenses/THIRD-PARTY.txt

@@ -0,0 +1,3 @@
+
+Lists of 1 third-party dependencies.
+     (Unicode/ICU License) ICU4J (com.ibm.icu:icu4j:67.1 - http://icu-project.org/)

distribution/std-lib/Base/third-party-licenses/unicode_icu license - license.txt

@@ -0,0 +1,414 @@
+COPYRIGHT AND PERMISSION NOTICE (ICU 58 and later)
+
+Copyright © 1991-2020 Unicode, Inc. All rights reserved.
+Distributed under the Terms of Use in https://www.unicode.org/copyright.html.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Unicode data files and any associated documentation
+(the "Data Files") or Unicode software and any associated documentation
+(the "Software") to deal in the Data Files or Software
+without restriction, including without limitation the rights to use,
+copy, modify, merge, publish, distribute, and/or sell copies of
+the Data Files or Software, and to permit persons to whom the Data Files
+or Software are furnished to do so, provided that either
+(a) this copyright and permission notice appear with all copies
+of the Data Files or Software, or
+(b) this copyright and permission notice appear in associated
+Documentation.
+
+THE DATA FILES AND SOFTWARE ARE PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT OF THIRD PARTY RIGHTS.
+IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN THIS
+NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL
+DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THE DATA FILES OR SOFTWARE.
+
+Except as contained in this notice, the name of a copyright holder
+shall not be used in advertising or otherwise to promote the sale,
+use or other dealings in these Data Files or Software without prior
+written authorization of the copyright holder.
+
+---------------------
+
+Third-Party Software Licenses
+
+This section contains third-party software notices and/or additional
+terms for licensed third-party software components included within ICU
+libraries.
+
+1. ICU License - ICU 1.8.1 to ICU 57.1
+
+COPYRIGHT AND PERMISSION NOTICE
+
+Copyright (c) 1995-2016 International Business Machines Corporation and others
+All rights reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, and/or sell copies of the Software, and to permit persons
+to whom the Software is furnished to do so, provided that the above
+copyright notice(s) and this permission notice appear in all copies of
+the Software and that both the above copyright notice(s) and this
+permission notice appear in supporting documentation.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY
+SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER
+RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+Except as contained in this notice, the name of a copyright holder
+shall not be used in advertising or otherwise to promote the sale, use
+or other dealings in this Software without prior written authorization
+of the copyright holder.
+
+All trademarks and registered trademarks mentioned herein are the
+property of their respective owners.
+
+2. Chinese/Japanese Word Break Dictionary Data (cjdict.txt)
+
+ #     The Google Chrome software developed by Google is licensed under
+ # the BSD license. Other software included in this distribution is
+ # provided under other licenses, as set forth below.
+ #
+ #  The BSD License
+ #  http://opensource.org/licenses/bsd-license.php
+ #  Copyright (C) 2006-2008, Google Inc.
+ #
+ #  All rights reserved.
+ #
+ #  Redistribution and use in source and binary forms, with or without
+ # modification, are permitted provided that the following conditions are met:
+ #
+ #  Redistributions of source code must retain the above copyright notice,
+ # this list of conditions and the following disclaimer.
+ #  Redistributions in binary form must reproduce the above
+ # copyright notice, this list of conditions and the following
+ # disclaimer in the documentation and/or other materials provided with
+ # the distribution.
+ #  Neither the name of  Google Inc. nor the names of its
+ # contributors may be used to endorse or promote products derived from
+ # this software without specific prior written permission.
+ #
+ #
+ #  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ # CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ # INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ # DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ # LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ # BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ # LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ #
+ #
+ #  The word list in cjdict.txt are generated by combining three word lists
+ # listed below with further processing for compound word breaking. The
+ # frequency is generated with an iterative training against Google web
+ # corpora.
+ #
+ #  * Libtabe (Chinese)
+ #    - https://sourceforge.net/project/?group_id=1519
+ #    - Its license terms and conditions are shown below.
+ #
+ #  * IPADIC (Japanese)
+ #    - http://chasen.aist-nara.ac.jp/chasen/distribution.html
+ #    - Its license terms and conditions are shown below.
+ #
+ #  ---------COPYING.libtabe ---- BEGIN--------------------
+ #
+ #  /*
+ #   * Copyright (c) 1999 TaBE Project.
+ #   * Copyright (c) 1999 Pai-Hsiang Hsiao.
+ #   * All rights reserved.
+ #   *
+ #   * Redistribution and use in source and binary forms, with or without
+ #   * modification, are permitted provided that the following conditions
+ #   * are met:
+ #   *
+ #   * . Redistributions of source code must retain the above copyright
+ #   *   notice, this list of conditions and the following disclaimer.
+ #   * . Redistributions in binary form must reproduce the above copyright
+ #   *   notice, this list of conditions and the following disclaimer in
+ #   *   the documentation and/or other materials provided with the
+ #   *   distribution.
+ #   * . Neither the name of the TaBE Project nor the names of its
+ #   *   contributors may be used to endorse or promote products derived
+ #   *   from this software without specific prior written permission.
+ #   *
+ #   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ #   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ #   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ #   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ #   * REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ #   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ #   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ #   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ #   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ #   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ #   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ #   * OF THE POSSIBILITY OF SUCH DAMAGE.
+ #   */
+ #
+ #  /*
+ #   * Copyright (c) 1999 Computer Systems and Communication Lab,
+ #   *                    Institute of Information Science, Academia
+ #       *                    Sinica. All rights reserved.
+ #   *
+ #   * Redistribution and use in source and binary forms, with or without
+ #   * modification, are permitted provided that the following conditions
+ #   * are met:
+ #   *
+ #   * . Redistributions of source code must retain the above copyright
+ #   *   notice, this list of conditions and the following disclaimer.
+ #   * . Redistributions in binary form must reproduce the above copyright
+ #   *   notice, this list of conditions and the following disclaimer in
+ #   *   the documentation and/or other materials provided with the
+ #   *   distribution.
+ #   * . Neither the name of the Computer Systems and Communication Lab
+ #   *   nor the names of its contributors may be used to endorse or
+ #   *   promote products derived from this software without specific
+ #   *   prior written permission.
+ #   *
+ #   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ #   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ #   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ #   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ #   * REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ #   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ #   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ #   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ #   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ #   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ #   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ #   * OF THE POSSIBILITY OF SUCH DAMAGE.
+ #   */
+ #
+ #  Copyright 1996 Chih-Hao Tsai @ Beckman Institute,
+ #      University of Illinois
+ #  c-tsai4@uiuc.edu  http://casper.beckman.uiuc.edu/~c-tsai4
+ #
+ #  ---------------COPYING.libtabe-----END--------------------------------
+ #
+ #
+ #  ---------------COPYING.ipadic-----BEGIN-------------------------------
+ #
+ #  Copyright 2000, 2001, 2002, 2003 Nara Institute of Science
+ #  and Technology.  All Rights Reserved.
+ #
+ #  Use, reproduction, and distribution of this software is permitted.
+ #  Any copy of this software, whether in its original form or modified,
+ #  must include both the above copyright notice and the following
+ #  paragraphs.
+ #
+ #  Nara Institute of Science and Technology (NAIST),
+ #  the copyright holders, disclaims all warranties with regard to this
+ #  software, including all implied warranties of merchantability and
+ #  fitness, in no event shall NAIST be liable for
+ #  any special, indirect or consequential damages or any damages
+ #  whatsoever resulting from loss of use, data or profits, whether in an
+ #  action of contract, negligence or other tortuous action, arising out
+ #  of or in connection with the use or performance of this software.
+ #
+ #  A large portion of the dictionary entries
+ #  originate from ICOT Free Software.  The following conditions for ICOT
+ #  Free Software applies to the current dictionary as well.
+ #
+ #  Each User may also freely distribute the Program, whether in its
+ #  original form or modified, to any third party or parties, PROVIDED
+ #  that the provisions of Section 3 ("NO WARRANTY") will ALWAYS appear
+ #  on, or be attached to, the Program, which is distributed substantially
+ #  in the same form as set out herein and that such intended
+ #  distribution, if actually made, will neither violate or otherwise
+ #  contravene any of the laws and regulations of the countries having
+ #  jurisdiction over the User or the intended distribution itself.
+ #
+ #  NO WARRANTY
+ #
+ #  The program was produced on an experimental basis in the course of the
+ #  research and development conducted during the project and is provided
+ #  to users as so produced on an experimental basis.  Accordingly, the
+ #  program is provided without any warranty whatsoever, whether express,
+ #  implied, statutory or otherwise.  The term "warranty" used herein
+ #  includes, but is not limited to, any warranty of the quality,
+ #  performance, merchantability and fitness for a particular purpose of
+ #  the program and the nonexistence of any infringement or violation of
+ #  any right of any third party.
+ #
+ #  Each user of the program will agree and understand, and be deemed to
+ #  have agreed and understood, that there is no warranty whatsoever for
+ #  the program and, accordingly, the entire risk arising from or
+ #  otherwise connected with the program is assumed by the user.
+ #
+ #  Therefore, neither ICOT, the copyright holder, or any other
+ #  organization that participated in or was otherwise related to the
+ #  development of the program and their respective officials, directors,
+ #  officers and other employees shall be held liable for any and all
+ #  damages, including, without limitation, general, special, incidental
+ #  and consequential damages, arising out of or otherwise in connection
+ #  with the use or inability to use the program or any product, material
+ #  or result produced or otherwise obtained by using the program,
+ #  regardless of whether they have been advised of, or otherwise had
+ #  knowledge of, the possibility of such damages at any time during the
+ #  project or thereafter.  Each user will be deemed to have agreed to the
+ #  foregoing by his or her commencement of use of the program.  The term
+ #  "use" as used herein includes, but is not limited to, the use,
+ #  modification, copying and distribution of the program and the
+ #  production of secondary products from the program.
+ #
+ #  In the case where the program, whether in its original form or
+ #  modified, was distributed or delivered to or received by a user from
+ #  any person, organization or entity other than ICOT, unless it makes or
+ #  grants independently of ICOT any specific warranty to the user in
+ #  writing, such person, organization or entity, will also be exempted
+ #  from and not be held liable to the user for any such damages as noted
+ #  above as far as the program is concerned.
+ #
+ #  ---------------COPYING.ipadic-----END----------------------------------
+
+3. Lao Word Break Dictionary Data (laodict.txt)
+
+ #  Copyright (c) 2013 International Business Machines Corporation
+ #  and others. All Rights Reserved.
+ #
+ # Project: https://github.com/veer66/lao-dictionary
+ # Dictionary: https://github.com/veer66/lao-dictionary/blob/master/Lao-Dictionary.txt
+ # License: https://github.com/veer66/lao-dictionary/blob/master/Lao-Dictionary-LICENSE.txt
+ #              (copied below)
+ #
+ #  This file is derived from the above dictionary, with slight
+ #  modifications.
+ #  ----------------------------------------------------------------------
+ #  Copyright (C) 2013 Brian Eugene Wilson, Robert Martin Campbell.
+ #  All rights reserved.
+ #
+ #  Redistribution and use in source and binary forms, with or without
+ #  modification,
+ #  are permitted provided that the following conditions are met:
+ #
+ #
+ # Redistributions of source code must retain the above copyright notice, this
+ #  list of conditions and the following disclaimer. Redistributions in
+ #  binary form must reproduce the above copyright notice, this list of
+ #  conditions and the following disclaimer in the documentation and/or
+ #  other materials provided with the distribution.
+ #
+ #
+ # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ # FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ # INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ # (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ # SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ # STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ # OF THE POSSIBILITY OF SUCH DAMAGE.
+ #  --------------------------------------------------------------------------
+
+4. Burmese Word Break Dictionary Data (burmesedict.txt)
+
+ #  Copyright (c) 2014 International Business Machines Corporation
+ #  and others. All Rights Reserved.
+ #
+ #  This list is part of a project hosted at:
+ #    github.com/kanyawtech/myanmar-karen-word-lists
+ #
+ #  --------------------------------------------------------------------------
+ #  Copyright (c) 2013, LeRoy Benjamin Sharon
+ #  All rights reserved.
+ #
+ #  Redistribution and use in source and binary forms, with or without
+ #  modification, are permitted provided that the following conditions
+ #  are met: Redistributions of source code must retain the above
+ #  copyright notice, this list of conditions and the following
+ #  disclaimer.  Redistributions in binary form must reproduce the
+ #  above copyright notice, this list of conditions and the following
+ #  disclaimer in the documentation and/or other materials provided
+ #  with the distribution.
+ #
+ #    Neither the name Myanmar Karen Word Lists, nor the names of its
+ #    contributors may be used to endorse or promote products derived
+ #    from this software without specific prior written permission.
+ #
+ #  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ #  CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ #  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ #  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ #  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
+ #  BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ #  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ #  TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ #  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ #  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+ #  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ #  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ #  SUCH DAMAGE.
+ #  --------------------------------------------------------------------------
+
+5. Time Zone Database
+
+  ICU uses the public domain data and code derived from Time Zone
+Database for its time zone support. The ownership of the TZ database
+is explained in BCP 175: Procedure for Maintaining the Time Zone
+Database section 7.
+
+ # 7.  Database Ownership
+ #
+ #    The TZ database itself is not an IETF Contribution or an IETF
+ #    document.  Rather it is a pre-existing and regularly updated work
+ #    that is in the public domain, and is intended to remain in the
+ #    public domain.  Therefore, BCPs 78 [RFC5378] and 79 [RFC3979] do
+ #    not apply to the TZ Database or contributions that individuals make
+ #    to it.  Should any claims be made and substantiated against the TZ
+ #    Database, the organization that is providing the IANA
+ #    Considerations defined in this RFC, under the memorandum of
+ #    understanding with the IETF, currently ICANN, may act in accordance
+ #    with all competent court orders.  No ownership claims will be made
+ #    by ICANN or the IETF Trust on the database or the code.  Any person
+ #    making a contribution to the database or code waives all rights to
+ #    future claims in that contribution or in the TZ Database.
+
+6. Google double-conversion
+
+Copyright 2006-2011, the V8 project authors. All rights reserved.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+    * Neither the name of Google Inc. nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

docs/CONTRIBUTING.md

@@ -138,6 +138,7 @@ In order to build and run Enso you will need the following tools:
 
 - [sbt](https://www.scala-sbt.org/) with the same version as specified in
   [`project/build.properties`](../project/build.properties).
+- [Maven](https://maven.apache.org/) with version at least 3.6.3.
 - [GraalVM](https://www.graalvm.org/) with the same version as described in the
   [`build.sbt`](../build.sbt) file, configured as your default JVM. GraalVM is
   distributed for different Java versions, so you need a GraalVM distribution

docs/distribution/licences.md

@@ -92,6 +92,13 @@ files are included by the CI build within the built artifacts.
 
 ### Engine Components
 
+#### Standard Library
+
+The third-party licenses for Java extensions of the standard library are
+gathered in the `third-party-licenses` directory in the `Base` library. The
+gathering process is automatic, triggered by the `package` goal of the
+associated Maven configuration file.
+
 > The actionables for this section are:
 >
 > - The engine components as distributed as a JAR archive that everyone can

engine/runner/src/main/scala/org/enso/runner/Repl.scala

@@ -4,6 +4,7 @@ import java.io.{InputStream, OutputStream, PrintStream, PrintWriter, Writer}
 import java.util.Scanner
 
 import org.enso.polyglot.debugger.{ReplExecutor, SessionManager}
+import org.jline.reader.impl.DefaultParser
 import org.jline.reader.{LineReader, LineReaderBuilder}
 import org.jline.terminal.{Terminal, TerminalBuilder}
 
@@ -98,8 +99,10 @@ case class SimpleReplIO(in: InputStream, out: OutputStream) extends ReplIO {
 case class TerminalIO() extends ReplIO {
   private val terminal: Terminal =
     TerminalBuilder.builder().system(true).build()
+  private val parser: DefaultParser = new DefaultParser()
+  parser.setEscapeChars(null)
   private val lineReader: LineReader =
-    LineReaderBuilder.builder().terminal(terminal).build()
+    LineReaderBuilder.builder().parser(parser).terminal(terminal).build()
 
   /**
     * Ask user for a line of input, using given prompt

engine/runtime/src/bench/java/org/enso/interpreter/bench/BenchmarksRunner.java

@@ -1,11 +1,5 @@
 package org.enso.interpreter.bench;
 
-import java.io.File;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.stream.Collectors;
-import javax.xml.bind.JAXBException;
 import org.openjdk.jmh.results.RunResult;
 import org.openjdk.jmh.runner.BenchmarkList;
 import org.openjdk.jmh.runner.BenchmarkListEntry;
@@ -14,6 +8,12 @@ import org.openjdk.jmh.runner.RunnerException;
 import org.openjdk.jmh.runner.options.Options;
 import org.openjdk.jmh.runner.options.OptionsBuilder;
 
+import javax.xml.bind.JAXBException;
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
 /** Runner class for the benchmarks. Discovers, runs and reports benchmark results. */
 public class BenchmarksRunner {
   public static final File REPORT_FILE = new File("./bench-report.xml");

engine/runtime/src/bench/java/org/enso/interpreter/bench/benchmarks/semantic/RecursionBenchmarks.java

@@ -1,5 +1,7 @@
 package org.enso.interpreter.bench.benchmarks.semantic;
 
+import java.util.ArrayDeque;
+import java.util.Deque;
 import java.util.concurrent.TimeUnit;
 import org.enso.interpreter.bench.fixtures.semantic.RecursionFixtures;
 import org.enso.interpreter.test.DefaultInterpreterRunner;

engine/runtime/src/main/java/org/enso/interpreter/instrument/ReplDebuggerInstrument.java

@@ -17,11 +17,13 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import org.enso.interpreter.Language;
+import org.enso.interpreter.node.expression.builtin.text.util.ToJavaStringNode;
 import org.enso.interpreter.node.expression.debug.CaptureResultScopeNode;
 import org.enso.interpreter.node.expression.debug.EvalNode;
 import org.enso.interpreter.runtime.builtin.Builtins;
 import org.enso.interpreter.runtime.callable.CallerInfo;
 import org.enso.interpreter.runtime.callable.function.Function;
+import org.enso.interpreter.runtime.data.text.Text;
 import org.enso.interpreter.runtime.scope.FramePointer;
 import org.enso.interpreter.runtime.state.Stateful;
 import org.enso.polyglot.debugger.DebugServerInfo;
@@ -47,28 +49,28 @@ public class ReplDebuggerInstrument extends TruffleInstrument {
   @Override
   protected void onCreate(Env env) {
     SourceSectionFilter filter =
-        SourceSectionFilter.newBuilder().tagIs(DebuggerTags.AlwaysHalt.class)
+        SourceSectionFilter.newBuilder().tagIs(DebuggerTags.AlwaysHalt.class).build();
-            .build();
     this.env = env;
 
     DebuggerMessageHandler handler = new DebuggerMessageHandler();
     try {
-      MessageEndpoint client =
+      MessageEndpoint client = env.startServer(URI.create(DebugServerInfo.URI), handler);
-          env.startServer(URI.create(DebugServerInfo.URI), handler);
       if (client != null) {
         handler.setClient(client);
         Instrumenter instrumenter = env.getInstrumenter();
-        instrumenter.attachExecutionEventFactory(filter, ctx ->
+        instrumenter.attachExecutionEventFactory(
-            new ReplExecutionEventNode(ctx, handler, env.getLogger(ReplExecutionEventNode.class)));
+            filter,
+            ctx ->
+                new ReplExecutionEventNode(
+                    ctx, handler, env.getLogger(ReplExecutionEventNode.class)));
       } else {
         env.getLogger(ReplDebuggerInstrument.class)
-            .warning("ReplDebuggerInstrument was initialized, " +
+            .warning("ReplDebuggerInstrument was initialized, " + "but no client connected");
-                "but no client connected");
       }
     } catch (MessageTransport.VetoException e) {
       env.getLogger(ReplDebuggerInstrument.class)
-          .warning("ReplDebuggerInstrument was initialized, " +
+          .warning(
-              "but client connection has been vetoed");
+              "ReplDebuggerInstrument was initialized, " + "but client connection has been vetoed");
     } catch (IOException e) {
       throw new RuntimeException(e);
     }
@@ -85,6 +87,7 @@ public class ReplDebuggerInstrument extends TruffleInstrument {
   /** The actual node that's installed as a probe on any node the instrument was launched for. */
   public static class ReplExecutionEventNode extends ExecutionEventNode {
     private @Child EvalNode evalNode = EvalNode.buildWithResultScopeCapture();
+    private @Child ToJavaStringNode toJavaStringNode = ToJavaStringNode.build();
 
     private ReplExecutionEventNodeState nodeState;
 
@@ -92,7 +95,8 @@ public class ReplDebuggerInstrument extends TruffleInstrument {
     private DebuggerMessageHandler handler;
     private TruffleLogger logger;
 
-    private ReplExecutionEventNode(EventContext eventContext, DebuggerMessageHandler handler, TruffleLogger logger) {
+    private ReplExecutionEventNode(
+        EventContext eventContext, DebuggerMessageHandler handler, TruffleLogger logger) {
       this.eventContext = eventContext;
       this.handler = handler;
       this.logger = logger;
@@ -116,7 +120,8 @@ public class ReplDebuggerInstrument extends TruffleInstrument {
      * @return a map, where keys are variable names and values are current values of variables.
      */
     public Map<String, Object> listBindings() {
-      Map<String, FramePointer> flatScope = nodeState.getLastScope().getLocalScope().flattenBindings();
+      Map<String, FramePointer> flatScope =
+          nodeState.getLastScope().getLocalScope().flattenBindings();
       Map<String, Object> result = new HashMap<>();
       for (Map.Entry<String, FramePointer> entry : flatScope.entrySet()) {
         result.put(entry.getKey(), getValue(nodeState.getLastScope().getFrame(), entry.getValue()));
@@ -128,20 +133,21 @@ public class ReplDebuggerInstrument extends TruffleInstrument {
      * Evaluates an arbitrary expression in the current execution context.
      *
      * @param expression the expression to evaluate
-     * @return the result of evaluating the expression or an exception that
+     * @return the result of evaluating the expression or an exception that caused failure
-     *          caused failure
      */
     public Either<Exception, Object> evaluate(String expression) {
       ReplExecutionEventNodeState savedState = nodeState;
       try {
-        Stateful result = evalNode.execute(nodeState.getLastScope(), nodeState.getLastState(), expression);
+        Stateful result =
+            evalNode.execute(
+                nodeState.getLastScope(), nodeState.getLastState(), Text.create(expression));
         Object lastState = result.getState();
         CaptureResultScopeNode.WithCallerInfo payload =
             (CaptureResultScopeNode.WithCallerInfo) result.getValue();
         CallerInfo lastScope = payload.getCallerInfo();
         Object lastReturn = payload.getResult();
         nodeState = new ReplExecutionEventNodeState(lastReturn, lastState, lastScope);
-        return new Right<>(lastReturn);
+        return new Right<>(formatObject(lastReturn));
       } catch (Exception e) {
         nodeState = savedState;
         TruffleStackTrace.fillIn(e);
@@ -149,6 +155,14 @@ public class ReplDebuggerInstrument extends TruffleInstrument {
       }
     }
 
+    private Object formatObject(Object o) {
+      if (o instanceof Text) {
+        return toJavaStringNode.execute((Text) o);
+      } else {
+        return o;
+      }
+    }
+
     /**
      * Terminates this REPL session.
      *
@@ -202,8 +216,9 @@ public class ReplDebuggerInstrument extends TruffleInstrument {
       if (handler.hasClient()) {
         handler.startSession(this);
       } else {
-        logger.warning("Debugger session starting, " +
+        logger.warning(
-            "but no client connected, will terminate the session immediately");
+            "Debugger session starting, "
+                + "but no client connected, will terminate the session immediately");
         exit();
       }
     }
@@ -211,9 +226,9 @@ public class ReplDebuggerInstrument extends TruffleInstrument {
     /**
      * State of the execution node.
      *
-     * As the execution nodes are reused by Truffle, the nested nodes share
+     * <p>As the execution nodes are reused by Truffle, the nested nodes share state. If execution
-     * state. If execution of a nested node fails, to ensure consistent state of
+     * of a nested node fails, to ensure consistent state of the parent node, its state has to be
-     * the parent node, its state has to be restored.
+     * restored.
      */
     private static class ReplExecutionEventNodeState {
       private final Object lastReturn;
@@ -239,5 +254,4 @@ public class ReplDebuggerInstrument extends TruffleInstrument {
       }
     }
   }
-
 }

engine/runtime/src/main/java/org/enso/interpreter/node/callable/InteropApplicationNode.java

@@ -9,6 +9,7 @@ import org.enso.interpreter.Constants;
 import org.enso.interpreter.Language;
 import org.enso.interpreter.node.callable.dispatch.IndirectInvokeFunctionNode;
 import org.enso.interpreter.node.callable.dispatch.InvokeFunctionNode;
+import org.enso.interpreter.node.expression.builtin.interop.syntax.HostValueToEnsoNode;
 import org.enso.interpreter.runtime.Context;
 import org.enso.interpreter.runtime.callable.argument.CallArgumentInfo;
 import org.enso.interpreter.runtime.callable.function.Function;
@@ -66,8 +67,13 @@ public abstract class InteropApplicationNode extends Node {
       Object[] arguments,
       @CachedContext(Language.class) Context context,
       @Cached("arguments.length") int cachedArgsLength,
-      @Cached("buildSorter(cachedArgsLength)") InvokeFunctionNode sorterNode) {
+      @Cached("buildSorter(cachedArgsLength)") InvokeFunctionNode sorterNode,
-    return sorterNode.execute(function, null, state, arguments).getValue();
+      @Cached("build()") HostValueToEnsoNode hostValueToEnsoNode) {
+    Object[] args = new Object[cachedArgsLength];
+    for (int i = 0; i < cachedArgsLength; i++) {
+      args[i] = hostValueToEnsoNode.execute(arguments[i]);
+    }
+    return sorterNode.execute(function, null, state, args).getValue();
   }
 
   @Specialization(replaces = "callCached")
@@ -75,13 +81,18 @@ public abstract class InteropApplicationNode extends Node {
       Function function,
       Object state,
       Object[] arguments,
-      @Cached IndirectInvokeFunctionNode indirectInvokeFunctionNode) {
+      @Cached IndirectInvokeFunctionNode indirectInvokeFunctionNode,
+      @Cached("build()") HostValueToEnsoNode hostValueToEnsoNode) {
+    Object[] args = new Object[arguments.length];
+    for (int i = 0; i < arguments.length; i++) {
+      args[i] = hostValueToEnsoNode.execute(arguments[i]);
+    }
     return indirectInvokeFunctionNode
         .execute(
             function,
             null,
             state,
-            arguments,
+            args,
             buildSchema(arguments.length),
             InvokeCallableNode.DefaultsExecutionMode.EXECUTE,
             InvokeCallableNode.ArgumentsExecutionMode.PRE_EXECUTED,

engine/runtime/src/main/java/org/enso/interpreter/node/callable/MethodResolverNode.java

@@ -6,6 +6,8 @@ import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.CachedContext;
 import com.oracle.truffle.api.dsl.GenerateUncached;
 import com.oracle.truffle.api.dsl.Specialization;
+import com.oracle.truffle.api.interop.InteropLibrary;
+import com.oracle.truffle.api.library.CachedLibrary;
 import com.oracle.truffle.api.nodes.Node;
 import com.oracle.truffle.api.nodes.NodeInfo;
 import org.enso.interpreter.Language;
@@ -18,6 +20,7 @@ import org.enso.interpreter.runtime.callable.atom.Atom;
 import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
 import org.enso.interpreter.runtime.callable.function.Function;
 import org.enso.interpreter.runtime.data.Array;
+import org.enso.interpreter.runtime.data.text.Text;
 import org.enso.interpreter.runtime.error.MethodDoesNotExistException;
 import org.enso.interpreter.runtime.error.RuntimeError;
 import org.enso.interpreter.runtime.number.EnsoBigInteger;
@@ -153,7 +156,7 @@ public abstract class MethodResolverNode extends Node {
   @Specialization(guards = "cachedSymbol == symbol")
   Function resolveString(
       UnresolvedSymbol symbol,
-      String self,
+      Text self,
       @Cached(value = "symbol", allowUncached = true) UnresolvedSymbol cachedSymbol,
       @Cached(value = "resolveMethodOnString(cachedSymbol)", allowUncached = true)
           Function function) {
@@ -190,6 +193,19 @@ public abstract class MethodResolverNode extends Node {
     return function;
   }
 
+  @Specialization(
+      guards = {"isPolyglotArrayMethod(cachedSymbol)", "arrays.hasArrayElements(array)"})
+  Function resolvePolyglotArray(
+      UnresolvedSymbol symbol,
+      Object array,
+      @CachedLibrary(limit = "3") InteropLibrary arrays,
+      @Cached(value = "symbol", allowUncached = true) UnresolvedSymbol cachedSymbol,
+      @CachedContext(Language.class) Context ctx,
+      @Cached(value = "resolveMethodOnPolyglotArray(cachedSymbol, ctx)", allowUncached = true)
+          Function function) {
+    return function;
+  }
+
   @Specialization(guards = {"cachedSymbol == symbol", "ctx.getEnvironment().isHostObject(target)"})
   Function resolveHost(
       UnresolvedSymbol symbol,
@@ -262,7 +278,7 @@ public abstract class MethodResolverNode extends Node {
 
   Function resolveMethodOnString(UnresolvedSymbol symbol) {
     return ensureMethodExists(
-        symbol.resolveFor(getBuiltins().text(), getBuiltins().any()), "Text", symbol);
+        symbol.resolveFor(getBuiltins().text().getText(), getBuiltins().any()), "Text", symbol);
   }
 
   Function resolveMethodOnFunction(UnresolvedSymbol symbol) {
@@ -283,9 +299,23 @@ public abstract class MethodResolverNode extends Node {
 
   Function buildHostResolver(UnresolvedSymbol symbol, Context context) {
     if (symbol.getName().equals("new")) {
-      return context.getBuiltins().getConstructorDispatch();
+      return context.getBuiltins().polyglot().getConstructorDispatch();
+    } else if (symbol.getName().equals("to_text")) {
+      return context.getBuiltins().polyglot().getPolyglotToTextFunction();
     } else {
-      return context.getBuiltins().buildPolyglotMethodDispatch(symbol);
+      return context.getBuiltins().polyglot().buildPolyglotMethodDispatch(symbol);
+    }
+  }
+
+  static boolean isPolyglotArrayMethod(UnresolvedSymbol symbol) {
+    return symbol.getName().equals("at") || symbol.getName().equals("length");
+  }
+
+  Function resolveMethodOnPolyglotArray(UnresolvedSymbol symbol, Context context) {
+    if (symbol.getName().equals("length")) {
+      return context.getBuiltins().polyglot().getPolyglotArrayLengthFunction();
+    } else {
+      return context.getBuiltins().polyglot().getPolyglotArrayAtFunction();
     }
   }
 

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/bool/ToTextNode.java

@@ -2,10 +2,13 @@ package org.enso.interpreter.node.expression.builtin.bool;
 
 import com.oracle.truffle.api.nodes.Node;
 import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.runtime.data.text.Text;
 
 @BuiltinMethod(type = "Boolean", name = "to_text", description = "Boolean to text conversion.")
 public class ToTextNode extends Node {
-  String execute(boolean _this) {
+  Text t = Text.create("True");
-    return _this ? "True" : "False";
+  Text f = Text.create("False");
+  Text execute(boolean _this) {
+    return _this ? t : f;
   }
 }

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/debug/DebugEvalNode.java

@@ -5,6 +5,7 @@ import org.enso.interpreter.dsl.BuiltinMethod;
 import org.enso.interpreter.dsl.MonadicState;
 import org.enso.interpreter.node.expression.debug.EvalNode;
 import org.enso.interpreter.runtime.callable.CallerInfo;
+import org.enso.interpreter.runtime.data.text.Text;
 import org.enso.interpreter.runtime.state.Stateful;
 
 /** Root node for the builtin Debug.eval function. */
@@ -21,7 +22,7 @@ public class DebugEvalNode extends Node {
   }
 
   Stateful execute(
-      CallerInfo callerInfo, @MonadicState Object state, Object _this, String expression) {
+      CallerInfo callerInfo, @MonadicState Object state, Object _this, Text expression) {
     return evalNode.execute(callerInfo, state, expression);
   }
 }

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/interop/generic/GetMemberNode.java

@@ -7,6 +7,8 @@ import com.oracle.truffle.api.nodes.Node;
 import com.oracle.truffle.api.profiles.BranchProfile;
 import org.enso.interpreter.Constants;
 import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.node.expression.builtin.text.util.ToJavaStringNode;
+import org.enso.interpreter.runtime.data.text.Text;
 import org.enso.interpreter.runtime.error.PanicException;
 
 @BuiltinMethod(
@@ -16,11 +18,12 @@ import org.enso.interpreter.runtime.error.PanicException;
 public class GetMemberNode extends Node {
   private @Child InteropLibrary library =
       InteropLibrary.getFactory().createDispatched(Constants.CacheSizes.BUILTIN_INTEROP_DISPATCH);
+  private @Child ToJavaStringNode toJavaStringNode = ToJavaStringNode.build();
   private final BranchProfile err = BranchProfile.create();
 
-  Object execute(Object _this, Object object, String member_name) {
+  Object execute(Object _this, Object object, Text member_name) {
     try {
-      return library.readMember(object, member_name);
+      return library.readMember(object, toJavaStringNode.execute(member_name));
     } catch (UnsupportedMessageException | UnknownIdentifierException e) {
       err.enter();
       throw new PanicException(e.getMessage(), this);

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/interop/generic/InvokeNode.java

@@ -5,7 +5,9 @@ import com.oracle.truffle.api.nodes.Node;
 import com.oracle.truffle.api.profiles.BranchProfile;
 import org.enso.interpreter.Constants;
 import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.node.expression.builtin.text.util.ToJavaStringNode;
 import org.enso.interpreter.runtime.data.Array;
+import org.enso.interpreter.runtime.data.text.Text;
 import org.enso.interpreter.runtime.error.PanicException;
 
 @BuiltinMethod(
@@ -15,11 +17,12 @@ import org.enso.interpreter.runtime.error.PanicException;
 public class InvokeNode extends Node {
   private @Child InteropLibrary library =
       InteropLibrary.getFactory().createDispatched(Constants.CacheSizes.BUILTIN_INTEROP_DISPATCH);
+  private @Child ToJavaStringNode toJavaStringNode = ToJavaStringNode.build();
   private final BranchProfile err = BranchProfile.create();
 
-  Object execute(Object _this, Object target, String name, Array arguments) {
+  Object execute(Object _this, Object target, Text name, Array arguments) {
     try {
-      return library.invokeMember(target, name, arguments.getItems());
+      return library.invokeMember(target, toJavaStringNode.execute(name), arguments.getItems());
     } catch (UnsupportedMessageException
         | ArityException
         | UnsupportedTypeException

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/interop/java/AddToClassPathNode.java

@@ -1,11 +1,14 @@
 package org.enso.interpreter.node.expression.builtin.interop.java;
 
+import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.CachedContext;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.nodes.Node;
 import org.enso.interpreter.Language;
 import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.node.expression.builtin.text.util.ToJavaStringNode;
 import org.enso.interpreter.runtime.Context;
+import org.enso.interpreter.runtime.data.text.Text;
 
 import java.io.File;
 
@@ -20,10 +23,16 @@ public abstract class AddToClassPathNode extends Node {
   }
 
   @Specialization
-  Object doExecute(Object _this, String path, @CachedContext(Language.class) Context context) {
+  Object doExecute(
-    context.getEnvironment().addToHostClassPath(context.getTruffleFile(new File(path)));
+      Object _this,
+      Text path,
+      @CachedContext(Language.class) Context context,
+      @Cached("build()") ToJavaStringNode toJavaStringNode) {
+    context
+        .getEnvironment()
+        .addToHostClassPath(context.getTruffleFile(new File(toJavaStringNode.execute(path))));
     return context.getBuiltins().unit();
   }
 
-  abstract Object execute(Object _this, String path);
+  abstract Object execute(Object _this, Text path);
 }

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/interop/java/LookupClassNode.java

@@ -1,11 +1,14 @@
 package org.enso.interpreter.node.expression.builtin.interop.java;
 
+import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.CachedContext;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.nodes.Node;
 import org.enso.interpreter.Language;
 import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.node.expression.builtin.text.util.ToJavaStringNode;
 import org.enso.interpreter.runtime.Context;
+import org.enso.interpreter.runtime.data.text.Text;
 
 @BuiltinMethod(type = "Java", name = "lookup_class", description = "Looks up a Java symbol.")
 public abstract class LookupClassNode extends Node {
@@ -14,9 +17,13 @@ public abstract class LookupClassNode extends Node {
   }
 
   @Specialization
-  Object doExecute(Object _this, String name, @CachedContext(Language.class) Context ctx) {
+  Object doExecute(
-    return ctx.getEnvironment().lookupHostSymbol(name);
+      Object _this,
+      Text name,
+      @CachedContext(Language.class) Context ctx,
+      @Cached("build()") ToJavaStringNode toJavaStringNode) {
+    return ctx.getEnvironment().lookupHostSymbol(toJavaStringNode.execute(name));
   }
 
-  abstract Object execute(Object _this, String name);
+  abstract Object execute(Object _this, Text name);
 }

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/interop/syntax/ArrayLengthNode.java

@@ -0,0 +1,41 @@
+package org.enso.interpreter.node.expression.builtin.interop.syntax;
+
+import com.oracle.truffle.api.frame.VirtualFrame;
+import com.oracle.truffle.api.interop.ArityException;
+import com.oracle.truffle.api.interop.InteropLibrary;
+import com.oracle.truffle.api.interop.UnsupportedMessageException;
+import com.oracle.truffle.api.interop.UnsupportedTypeException;
+import com.oracle.truffle.api.library.CachedLibrary;
+import com.oracle.truffle.api.nodes.Node;
+import com.oracle.truffle.api.nodes.NodeInfo;
+import com.oracle.truffle.api.nodes.UnexpectedResultException;
+import com.oracle.truffle.api.profiles.BranchProfile;
+import org.enso.interpreter.Constants;
+import org.enso.interpreter.Language;
+import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.node.expression.builtin.BuiltinRootNode;
+import org.enso.interpreter.runtime.callable.argument.ArgumentDefinition;
+import org.enso.interpreter.runtime.callable.function.Function;
+import org.enso.interpreter.runtime.callable.function.FunctionSchema.CallStrategy;
+import org.enso.interpreter.runtime.error.PanicException;
+import org.enso.interpreter.runtime.state.Stateful;
+import org.enso.interpreter.runtime.type.TypesGen;
+
+@BuiltinMethod(
+    type = "Any",
+    name = "<polyglot_array_length>",
+    description = "Returns the length of a polyglot array.")
+public class ArrayLengthNode extends Node {
+  private @Child InteropLibrary library =
+      InteropLibrary.getFactory().createDispatched(Constants.CacheSizes.BUILTIN_INTEROP_DISPATCH);
+  private final BranchProfile err = BranchProfile.create();
+
+  public Object execute(Object _this) {
+    try {
+      return library.getArraySize(_this);
+    } catch (UnsupportedMessageException e) {
+      err.enter();
+      throw new PanicException(e.getMessage(), this);
+    }
+  }
+}

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/interop/syntax/GetArrayElementNode.java

@@ -1,4 +1,4 @@
-package org.enso.interpreter.node.expression.builtin.interop.generic;
+package org.enso.interpreter.node.expression.builtin.interop.syntax;
 
 import com.oracle.truffle.api.interop.InteropLibrary;
 import com.oracle.truffle.api.interop.InvalidArrayIndexException;
@@ -10,17 +10,18 @@ import org.enso.interpreter.dsl.BuiltinMethod;
 import org.enso.interpreter.runtime.error.PanicException;
 
 @BuiltinMethod(
-    type = "Polyglot",
+    type = "Any",
-    name = "get_array_element",
+    name = "<polyglot_array_at>",
-    description = "Gets an element by index from a polyglot array.")
+    description = "Returns the element of a polyglot array at a given index.")
 public class GetArrayElementNode extends Node {
   private @Child InteropLibrary library =
       InteropLibrary.getFactory().createDispatched(Constants.CacheSizes.BUILTIN_INTEROP_DISPATCH);
+  private @Child HostValueToEnsoNode hostValueToEnsoNode = HostValueToEnsoNode.build();
   private final BranchProfile err = BranchProfile.create();
 
-  Object execute(Object _this, Object array, long index) {
+  public Object execute(Object _this, long index) {
     try {
-      return library.readArrayElement(array, index);
+      return hostValueToEnsoNode.execute(library.readArrayElement(_this, index));
     } catch (UnsupportedMessageException | InvalidArrayIndexException e) {
       err.enter();
       throw new PanicException(e.getMessage(), this);

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/interop/syntax/HostValueToEnsoNode.java

@@ -1,15 +1,18 @@
 package org.enso.interpreter.node.expression.builtin.interop.syntax;
 
 import com.oracle.truffle.api.dsl.Fallback;
+import com.oracle.truffle.api.dsl.GenerateUncached;
 import com.oracle.truffle.api.dsl.ReportPolymorphism;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.nodes.Node;
+import org.enso.interpreter.runtime.data.text.Text;
 
 /**
  * Converts a value returned by a polyglot call back to a value that can be further used within Enso
  * programs.
  */
 @ReportPolymorphism
+@GenerateUncached
 public abstract class HostValueToEnsoNode extends Node {
   public static HostValueToEnsoNode build() {
     return HostValueToEnsoNodeGen.create();
@@ -48,6 +51,11 @@ public abstract class HostValueToEnsoNode extends Node {
     return i;
   }
 
+  @Specialization
+  Text doString(String txt) {
+    return Text.create(txt);
+  }
+
   @Fallback
   Object doOther(Object o) {
     return o;

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/interop/syntax/PolyglotToTextNode.java

@@ -1,4 +1,4 @@
-package org.enso.interpreter.node.expression.builtin.interop.generic;
+package org.enso.interpreter.node.expression.builtin.interop.syntax;
 
 import com.oracle.truffle.api.interop.InteropLibrary;
 import com.oracle.truffle.api.interop.UnsupportedMessageException;
@@ -6,20 +6,23 @@ import com.oracle.truffle.api.nodes.Node;
 import com.oracle.truffle.api.profiles.BranchProfile;
 import org.enso.interpreter.Constants;
 import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.runtime.data.text.Text;
 import org.enso.interpreter.runtime.error.PanicException;
 
 @BuiltinMethod(
-    type = "Polyglot",
+    type = "Any",
-    name = "get_array_size",
+    name = "<to_text>",
-    description = "Gets the size of a polyglot array.")
+    description = "Returns human-readable representation of a polyglot object.")
-public class GetArraySizeNode extends Node {
+public class PolyglotToTextNode extends Node {
   private @Child InteropLibrary library =
       InteropLibrary.getFactory().createDispatched(Constants.CacheSizes.BUILTIN_INTEROP_DISPATCH);
+  private @Child InteropLibrary strings =
+      InteropLibrary.getFactory().createDispatched(Constants.CacheSizes.BUILTIN_INTEROP_DISPATCH);
   private final BranchProfile err = BranchProfile.create();
 
-  Object execute(Object _this, Object array) {
+  public Text execute(Object _this) {
     try {
-      return library.getArraySize(array);
+      return Text.create(strings.asString(library.toDisplayString(_this)));
     } catch (UnsupportedMessageException e) {
       err.enter();
       throw new PanicException(e.getMessage(), this);

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/io/PrintErrNode.java

@@ -1,12 +1,25 @@
 package org.enso.interpreter.node.expression.builtin.io;
 
+import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
+import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.CachedContext;
 import com.oracle.truffle.api.dsl.Specialization;
+import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.nodes.Node;
 import org.enso.interpreter.Language;
 import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.dsl.MonadicState;
+import org.enso.interpreter.node.callable.InvokeCallableNode;
+import org.enso.interpreter.node.expression.builtin.text.util.ToJavaStringNode;
 import org.enso.interpreter.runtime.Context;
+import org.enso.interpreter.runtime.callable.UnresolvedSymbol;
+import org.enso.interpreter.runtime.callable.argument.CallArgumentInfo;
+import org.enso.interpreter.runtime.data.text.Text;
+import org.enso.interpreter.runtime.state.Stateful;
+import org.enso.interpreter.runtime.type.TypesGen;
+
+import java.io.PrintStream;
 
 @BuiltinMethod(
     type = "IO",
@@ -17,12 +30,53 @@ public abstract class PrintErrNode extends Node {
     return PrintErrNodeGen.create();
   }
 
-  abstract Object execute(Object _this, Object message);
+  abstract Stateful execute(
+      VirtualFrame frame, @MonadicState Object state, Object _this, Object message);
 
   @Specialization
-  @TruffleBoundary
+  Stateful doPrintText(
-  Object doPrint(Object self, Object message, @CachedContext(Language.class) Context ctx) {
+          VirtualFrame frame,
-    ctx.getErr().println(message);
+          Object state,
-    return ctx.getUnit().newInstance();
+          Object self,
+          Text message,
+          @CachedContext(Language.class) Context ctx,
+          @Cached("build()") ToJavaStringNode toJavaStringNode) {
+    print(ctx.getErr(), toJavaStringNode.execute(message));
+    return new Stateful(state, ctx.getUnit().newInstance());
+  }
+
+  @Specialization(guards = "!isText(message)")
+  Stateful doPrint(
+      VirtualFrame frame,
+      Object state,
+      Object self,
+      Object message,
+      @CachedContext(Language.class) Context ctx,
+      @Cached("buildSymbol(ctx)") UnresolvedSymbol symbol,
+      @Cached("buildInvokeCallableNode()") InvokeCallableNode invokeCallableNode,
+      @Cached("build()") ToJavaStringNode toJavaStringNode) {
+    Stateful str = invokeCallableNode.execute(symbol, frame, state, new Object[] {message});
+    print(ctx.getErr(), toJavaStringNode.execute((Text) str.getValue()));
+    return new Stateful(str.getState(), ctx.getUnit().newInstance());
+  }
+
+  @CompilerDirectives.TruffleBoundary
+  private void print(PrintStream err, Object str) {
+    err.println(str);
+  }
+
+  boolean isText(Object o) {
+    return TypesGen.isText(o);
+  }
+
+  InvokeCallableNode buildInvokeCallableNode() {
+    return InvokeCallableNode.build(
+            new CallArgumentInfo[] {new CallArgumentInfo()},
+            InvokeCallableNode.DefaultsExecutionMode.EXECUTE,
+            InvokeCallableNode.ArgumentsExecutionMode.PRE_EXECUTED);
+  }
+
+  UnresolvedSymbol buildSymbol(Context ctx) {
+    return UnresolvedSymbol.build("to_text", ctx.getBuiltins().getScope());
   }
 }

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/io/PrintlnNode.java

@@ -3,6 +3,7 @@ package org.enso.interpreter.node.expression.builtin.io;
 import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.CachedContext;
+import com.oracle.truffle.api.dsl.Fallback;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.nodes.Node;
@@ -11,10 +12,13 @@ import org.enso.interpreter.Language;
 import org.enso.interpreter.dsl.BuiltinMethod;
 import org.enso.interpreter.dsl.MonadicState;
 import org.enso.interpreter.node.callable.InvokeCallableNode;
+import org.enso.interpreter.node.expression.builtin.text.util.ToJavaStringNode;
 import org.enso.interpreter.runtime.Context;
 import org.enso.interpreter.runtime.callable.UnresolvedSymbol;
 import org.enso.interpreter.runtime.callable.argument.CallArgumentInfo;
+import org.enso.interpreter.runtime.data.text.Text;
 import org.enso.interpreter.runtime.state.Stateful;
+import org.enso.interpreter.runtime.type.TypesGen;
 
 @BuiltinMethod(type = "IO", name = "println", description = "Prints its argument to standard out.")
 public abstract class PrintlnNode extends Node {
@@ -28,18 +32,37 @@ public abstract class PrintlnNode extends Node {
       VirtualFrame frame, @MonadicState Object state, Object _this, Object message);
 
   @Specialization
+  Stateful doPrintText(
+      VirtualFrame frame,
+      Object state,
+      Object self,
+      Text message,
+      @CachedContext(Language.class) Context ctx,
+      @Cached("build()") ToJavaStringNode toJavaStringNode) {
+    print(ctx.getOut(), toJavaStringNode.execute(message));
+    return new Stateful(state, ctx.getUnit().newInstance());
+  }
+
+  @Specialization(guards = "!isText(message)")
   Stateful doPrint(
       VirtualFrame frame,
       Object state,
       Object self,
       Object message,
       @CachedContext(Language.class) Context ctx,
-      @Cached("buildSymbol(ctx)") UnresolvedSymbol symbol) {
+      @Cached("buildSymbol(ctx)") UnresolvedSymbol symbol,
+      @Cached("build()") ToJavaStringNode toJavaStringNode,
+      @Cached("buildInvokeCallableNode()") InvokeCallableNode invokeCallableNode) {
     Stateful str = invokeCallableNode.execute(symbol, frame, state, new Object[] {message});
-    print(ctx.getOut(), str.getValue());
+    String strr = toJavaStringNode.execute((Text) str.getValue());
+    print(ctx.getOut(), strr);
     return new Stateful(str.getState(), ctx.getUnit().newInstance());
   }
 
+  boolean isText(Object o) {
+    return TypesGen.isText(o);
+  }
+
   @CompilerDirectives.TruffleBoundary
   private void print(PrintStream out, Object str) {
     out.println(str);
@@ -49,6 +72,13 @@ public abstract class PrintlnNode extends Node {
     return UnresolvedSymbol.build("to_text", ctx.getBuiltins().getScope());
   }
 
+  InvokeCallableNode buildInvokeCallableNode() {
+    return InvokeCallableNode.build(
+        new CallArgumentInfo[] {new CallArgumentInfo()},
+        InvokeCallableNode.DefaultsExecutionMode.EXECUTE,
+        InvokeCallableNode.ArgumentsExecutionMode.PRE_EXECUTED);
+  }
+
   static PrintlnNode build() {
     return PrintlnNodeGen.create();
   }

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/io/ReadlnNode.java

@@ -9,6 +9,8 @@ import java.io.IOException;
 import org.enso.interpreter.Language;
 import org.enso.interpreter.dsl.BuiltinMethod;
 import org.enso.interpreter.runtime.Context;
+import org.enso.interpreter.runtime.data.text.Text;
+import org.enso.interpreter.runtime.error.PanicException;
 import org.enso.interpreter.runtime.error.RuntimeError;
 
 @BuiltinMethod(type = "IO", name = "readln", description = "Reads a line from standard in.")
@@ -21,11 +23,11 @@ public abstract class ReadlnNode extends Node {
 
   @Specialization
   @TruffleBoundary
-  Object doRead(Object _this, @CachedContext(Language.class) Context ctx) {
+  Text doRead(Object _this, @CachedContext(Language.class) Context ctx) {
     try {
-      return ctx.getInReader().readLine();
+      return Text.create(ctx.getInReader().readLine());
     } catch (IOException e) {
-      return new RuntimeError("Empty input stream.");
+      throw new PanicException("Empty input stream", this);
     }
   }
 }

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/system/CreateProcessNode.java

@@ -1,14 +1,17 @@
 package org.enso.interpreter.node.expression.builtin.system;
 
 import com.oracle.truffle.api.CompilerDirectives;
+import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.CachedContext;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.io.TruffleProcessBuilder;
 import com.oracle.truffle.api.nodes.Node;
 import org.enso.interpreter.Language;
 import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.node.expression.builtin.text.util.ToJavaStringNode;
 import org.enso.interpreter.runtime.Context;
 import org.enso.interpreter.runtime.data.Array;
+import org.enso.interpreter.runtime.data.text.Text;
 import org.enso.interpreter.runtime.error.PanicException;
 
 import java.io.*;
@@ -25,9 +28,9 @@ public abstract class CreateProcessNode extends Node {
 
   abstract Object execute(
       Object _this,
-      String command,
+      Text command,
       Array arguments,
-      String input,
+      Text input,
       boolean redirectIn,
       boolean redirectOut,
       boolean redirectErr);
@@ -36,21 +39,25 @@ public abstract class CreateProcessNode extends Node {
   @CompilerDirectives.TruffleBoundary
   Object doCreate(
       Object _this,
-      String command,
+      Text command,
       Array arguments,
-      String input,
+      Text input,
       boolean redirectIn,
       boolean redirectOut,
       boolean redirectErr,
-      @CachedContext(Language.class) Context ctx) {
+      @CachedContext(Language.class) Context ctx,
-    String[] cmd = new String[(int) arguments.getItems().length + 1];
+      @Cached("build()") ToJavaStringNode toJavaStringNode) {
-    cmd[0] = command;
+    String[] cmd = new String[arguments.getItems().length + 1];
-    System.arraycopy(arguments.getItems(), 0, cmd, 1, (int) arguments.getItems().length);
+    cmd[0] = toJavaStringNode.execute(command);
+    for (int i = 1; i <= arguments.getItems().length; i++) {
+      cmd[i] = toJavaStringNode.execute((Text) arguments.getItems()[i - 1]);
+    }
     TruffleProcessBuilder pb = ctx.getEnvironment().newProcessBuilder(cmd);
 
     try {
       Process p = pb.start();
-      ByteArrayInputStream in = new ByteArrayInputStream(input.getBytes());
+      ByteArrayInputStream in =
+          new ByteArrayInputStream(toJavaStringNode.execute(input).getBytes());
       ByteArrayOutputStream out = new ByteArrayOutputStream();
       ByteArrayOutputStream err = new ByteArrayOutputStream();
 
@@ -106,8 +113,8 @@ public abstract class CreateProcessNode extends Node {
       }
 
       long exitCode = p.exitValue();
-      String returnOut = new String(out.toByteArray());
+      Text returnOut = Text.create(new String(out.toByteArray()));
-      String returnErr = new String(err.toByteArray());
+      Text returnErr = Text.create(new String(err.toByteArray()));
 
       return ctx.getBuiltins()
           .system()

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/system/OsNode.java

@@ -3,6 +3,7 @@ package org.enso.interpreter.node.expression.builtin.system;
 import com.oracle.truffle.api.nodes.Node;
 import org.apache.commons.lang3.SystemUtils;
 import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.runtime.data.text.Text;
 
 @BuiltinMethod(
     type = "System",
@@ -10,12 +11,12 @@ import org.enso.interpreter.dsl.BuiltinMethod;
     description = "Get the type of operating system.")
 public final class OsNode extends Node {
 
-  private final String LINUX = "linux";
+  private final Text LINUX = Text.create("linux");
-  private final String MACOS = "macos";
+  private final Text MACOS = Text.create("macos");
-  private final String WINDOWS = "windows";
+  private final Text WINDOWS = Text.create("windows");
-  private final String UNKNOWN = "unknown";
+  private final Text UNKNOWN = Text.create("unknown");
 
-  String execute(Object _this) {
+  Text execute(Object _this) {
     if (SystemUtils.IS_OS_LINUX) return LINUX;
     if (SystemUtils.IS_OS_MAC_OSX) return MACOS;
     if (SystemUtils.IS_OS_WINDOWS) return WINDOWS;

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/text/AnyToTextNode.java

@@ -1,13 +1,67 @@
 package org.enso.interpreter.node.expression.builtin.text;
 
 import com.oracle.truffle.api.CompilerDirectives;
+import com.oracle.truffle.api.dsl.Cached;
+import com.oracle.truffle.api.dsl.Fallback;
+import com.oracle.truffle.api.dsl.Specialization;
+import com.oracle.truffle.api.interop.InteropLibrary;
+import com.oracle.truffle.api.interop.UnsupportedMessageException;
+import com.oracle.truffle.api.library.CachedLibrary;
 import com.oracle.truffle.api.nodes.Node;
 import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.runtime.callable.atom.Atom;
+import org.enso.interpreter.runtime.data.text.Text;
+import org.enso.interpreter.runtime.error.PanicException;
 
 @BuiltinMethod(type = "Any", name = "to_text", description = "Generic text conversion.")
-public class AnyToTextNode extends Node {
+public abstract class AnyToTextNode extends Node {
+  private static final int DISPATCH_CACHE = 3;
+  private @Child InteropLibrary displays =
+      InteropLibrary.getFactory().createDispatched(DISPATCH_CACHE);
+  private @Child InteropLibrary strings =
+      InteropLibrary.getFactory().createDispatched(DISPATCH_CACHE);
+
+  static AnyToTextNode build() {
+    return AnyToTextNodeGen.create();
+  }
+
+  abstract Text execute(Object _this);
+
+  @Specialization
+  Text doAtom(Atom at) {
+    if (at.getFields().length == 0) {
+      return Text.create(at.getConstructor().getName());
+    } else {
+      return doComplexAtom(at, displays, strings);
+    }
+  }
+
+  @Fallback
+  Text doOther(Object object) {
+    try {
+      return Text.create(strings.asString(displays.toDisplayString(object)));
+    } catch (UnsupportedMessageException e) {
+      return Text.create(object.toString());
+    }
+  }
+
   @CompilerDirectives.TruffleBoundary
-  String execute(Object _this) {
+  private Text doComplexAtom(Atom atom, InteropLibrary displays, InteropLibrary strings) {
-    return _this.toString();
+    Text res = Text.create("(" + atom.getConstructor().getName() + " ");
+    try {
+      res = Text.create(res, strings.asString(displays.toDisplayString(atom.getFields()[0])));
+    } catch (UnsupportedMessageException e) {
+      res = Text.create(res, atom.getFields()[0].toString());
+    }
+    for (int i = 1; i < atom.getFields().length; i++) {
+      res = Text.create(res, " ");
+      try {
+        res = Text.create(res, strings.asString(displays.toDisplayString(atom.getFields()[i])));
+      } catch (UnsupportedMessageException e) {
+        res = Text.create(res, atom.getFields()[i].toString());
+      }
+    }
+    res = Text.create(res, ")");
+    return res;
   }
 }

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/text/ConcatNode.java

@@ -2,10 +2,11 @@ package org.enso.interpreter.node.expression.builtin.text;
 
 import com.oracle.truffle.api.nodes.Node;
 import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.runtime.data.text.Text;
 
 @BuiltinMethod(type = "Text", name = "+", description = "Text concatenation.")
 public class ConcatNode extends Node {
-  String execute(String _this, String that) {
+  Text execute(Text _this, Text that) {
-    return _this + that;
+    return Text.create(_this, that);
   }
 }

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/text/JsonSerializeNode.java

@@ -4,11 +4,12 @@ import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.nodes.Node;
 import org.enso.interpreter.dsl.BuiltinMethod;
 import org.enso.interpreter.runtime.builtin.LanguageEntitySerializer;
+import org.enso.interpreter.runtime.data.text.Text;
 
 @BuiltinMethod(type = "Any", name = "json_serialize", description = "Generic JSON serialization.")
 public class JsonSerializeNode extends Node {
   @CompilerDirectives.TruffleBoundary
-  String execute(Object _this) {
+  Text execute(Object _this) {
-    return LanguageEntitySerializer.serialize(_this);
+    return Text.create(LanguageEntitySerializer.serialize(_this));
   }
 }

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/text/OptimizeNode.java

@@ -0,0 +1,20 @@
+package org.enso.interpreter.node.expression.builtin.text;
+
+import com.oracle.truffle.api.CompilerDirectives;
+import com.oracle.truffle.api.nodes.Node;
+import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.node.expression.builtin.text.util.ToJavaStringNode;
+import org.enso.interpreter.runtime.data.text.Text;
+
+@BuiltinMethod(
+    type = "Prim_Text_Helpers",
+    name = "optimize",
+    description = "Forces flattening of a text value, for testing or purposes.")
+public class OptimizeNode extends Node {
+  private @Child ToJavaStringNode toJavaStringNode = ToJavaStringNode.build();
+
+  Text execute(Object _this, Text text) {
+    toJavaStringNode.execute(text);
+    return text;
+  }
+}

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/text/TextEqualsNode.java

@@ -1,11 +0,0 @@
-package org.enso.interpreter.node.expression.builtin.text;
-
-import com.oracle.truffle.api.nodes.Node;
-import org.enso.interpreter.dsl.BuiltinMethod;
-
-@BuiltinMethod(type = "Text", name = "==", description = "Equality on text.")
-public class TextEqualsNode extends Node {
-  boolean execute(String _this, String that) {
-    return _this.equals(that);
-  }
-}

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/text/util/ToJavaStringNode.java

@@ -0,0 +1,91 @@
+package org.enso.interpreter.node.expression.builtin.text.util;
+
+import com.oracle.truffle.api.CompilerDirectives;
+import com.oracle.truffle.api.nodes.Node;
+import com.oracle.truffle.api.nodes.NodeInfo;
+import org.enso.interpreter.runtime.data.text.ConcatRope;
+import org.enso.interpreter.runtime.data.text.Text;
+
+import java.util.ArrayDeque;
+import java.util.Deque;
+import java.util.concurrent.locks.Lock;
+
+@NodeInfo(description = "Converts Enso Text to a Java String.")
+public class ToJavaStringNode extends Node {
+  private static ToJavaStringNode UNCACHED = new ToJavaStringNode();
+
+  /**
+   * Returns the uncached version of this node.
+   *
+   * @return the uncached version of this node.
+   */
+  public static ToJavaStringNode getUncached() {
+    return UNCACHED;
+  }
+
+  /**
+   * Creates a new instance of this node.
+   *
+   * @return a new instance of this node.
+   */
+  public static ToJavaStringNode build() {
+    return new ToJavaStringNode();
+  }
+
+  /**
+   * Performs the conversion of Enso Text to a Java String.
+   *
+   * @param text the text to convert.
+   * @return the result of conversion.
+   */
+  public String execute(Text text) {
+    if (text.isFlat()) {
+      return (String) text.getContents();
+    } else {
+      return inplaceFlatten(text);
+    }
+  }
+
+  /**
+   * Converts text to a Java String. For use outside of Truffle Nodes.
+   *
+   * @param text the text to convert.
+   * @return the result of conversion.
+   */
+  @CompilerDirectives.TruffleBoundary
+  public static String inplaceFlatten(Text text) {
+    Lock lock = text.getLock();
+    lock.lock();
+    String result;
+    try {
+      if (text.isFlat()) {
+        result = (String) text.getContents();
+      } else {
+        result = doFlatten(text);
+      }
+    } finally {
+      lock.unlock();
+    }
+    return result;
+  }
+
+  private static String doFlatten(Text text) {
+    Deque<Object> workStack = new ArrayDeque<>();
+    StringBuilder bldr = new StringBuilder();
+    workStack.push(text.getContents());
+    while (!workStack.isEmpty()) {
+      Object item = workStack.pop();
+      if (item instanceof String) {
+        bldr.append((String) item);
+      } else {
+        ConcatRope rope = (ConcatRope) item;
+        workStack.push(rope.getRight());
+        workStack.push(rope.getLeft());
+      }
+    }
+    String res = bldr.toString();
+    text.setContents(res);
+    text.setFlat(true);
+    return res;
+  }
+}

engine/runtime/src/main/java/org/enso/interpreter/node/expression/debug/EvalNode.java

@@ -3,6 +3,7 @@ package org.enso.interpreter.node.expression.debug;
 import com.oracle.truffle.api.RootCallTarget;
 import com.oracle.truffle.api.Truffle;
 import com.oracle.truffle.api.dsl.Cached;
+import com.oracle.truffle.api.dsl.ReportPolymorphism;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.nodes.NodeInfo;
 import org.enso.compiler.context.InlineContext;
@@ -12,15 +13,18 @@ import org.enso.interpreter.node.BaseNode;
 import org.enso.interpreter.node.ClosureRootNode;
 import org.enso.interpreter.node.ExpressionNode;
 import org.enso.interpreter.node.callable.thunk.ThunkExecutorNode;
+import org.enso.interpreter.node.expression.builtin.text.util.ToJavaStringNode;
 import org.enso.interpreter.runtime.Context;
 import org.enso.interpreter.runtime.callable.CallerInfo;
 import org.enso.interpreter.runtime.callable.argument.Thunk;
+import org.enso.interpreter.runtime.data.text.Text;
 import org.enso.interpreter.runtime.scope.LocalScope;
 import org.enso.interpreter.runtime.scope.ModuleScope;
 import org.enso.interpreter.runtime.state.Stateful;
 
 /** Node running Enso expressions passed to it as strings. */
 @NodeInfo(shortName = "Eval", description = "Evaluates code passed to it as string")
+@ReportPolymorphism
 public abstract class EvalNode extends BaseNode {
   private final boolean shouldCaptureResultScope;
 
@@ -54,7 +58,7 @@ public abstract class EvalNode extends BaseNode {
    * @param expression the string containing expression to evaluate
    * @return the result of evaluating {@code expression} in the {@code callerInfo} context
    */
-  public abstract Stateful execute(CallerInfo callerInfo, Object state, String expression);
+  public abstract Stateful execute(CallerInfo callerInfo, Object state, Text expression);
 
   RootCallTarget parseExpression(LocalScope scope, ModuleScope moduleScope, String expression) {
     LocalScope localScope = scope.createChild();
@@ -93,11 +97,13 @@ public abstract class EvalNode extends BaseNode {
   Stateful doCached(
       CallerInfo callerInfo,
       Object state,
-      String expression,
+      Text expression,
-      @Cached("expression") String cachedExpression,
+      @Cached("expression") Text cachedExpression,
+      @Cached("build()") ToJavaStringNode toJavaStringNode,
+      @Cached("toJavaStringNode.execute(expression)") String expressionStr,
       @Cached("callerInfo") CallerInfo cachedCallerInfo,
       @Cached(
-              "parseExpression(callerInfo.getLocalScope(), callerInfo.getModuleScope(), expression)")
+              "parseExpression(callerInfo.getLocalScope(), callerInfo.getModuleScope(), expressionStr)")
           RootCallTarget cachedCallTarget,
       @Cached("build()") ThunkExecutorNode thunkExecutorNode) {
     Thunk thunk = new Thunk(cachedCallTarget, callerInfo.getFrame());
@@ -108,10 +114,14 @@ public abstract class EvalNode extends BaseNode {
   Stateful doUncached(
       CallerInfo callerInfo,
       Object state,
-      String expression,
+      Text expression,
-      @Cached("build()") ThunkExecutorNode thunkExecutorNode) {
+      @Cached("build()") ThunkExecutorNode thunkExecutorNode,
+      @Cached("build()") ToJavaStringNode toJavaStringNode) {
     RootCallTarget callTarget =
-        parseExpression(callerInfo.getLocalScope(), callerInfo.getModuleScope(), expression);
+        parseExpression(
+            callerInfo.getLocalScope(),
+            callerInfo.getModuleScope(),
+            toJavaStringNode.execute(expression));
     Thunk thunk = new Thunk(callTarget, callerInfo.getFrame());
     return thunkExecutorNode.executeThunk(thunk, state, isTail());
   }

engine/runtime/src/main/java/org/enso/interpreter/node/expression/literal/TextLiteralNode.java

@@ -3,14 +3,15 @@ package org.enso.interpreter.node.expression.literal;
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.nodes.NodeInfo;
 import org.enso.interpreter.node.ExpressionNode;
+import org.enso.interpreter.runtime.data.text.Text;
 
 /** Node representing a constant String value. */
 @NodeInfo(shortName = "StringLiteral", description = "Constant string literal expression")
 public class TextLiteralNode extends ExpressionNode {
-  private final String value;
+  private final Text value;
 
   private TextLiteralNode(String value) {
-    this.value = value;
+    this.value = Text.create(value);
   }
 
   /**
@@ -30,7 +31,7 @@ public class TextLiteralNode extends ExpressionNode {
    * @return the string value this node was created with
    */
   @Override
-  public Object executeGeneric(VirtualFrame frame) {
+  public Text executeGeneric(VirtualFrame frame) {
     return value;
   }
 }

engine/runtime/src/main/java/org/enso/interpreter/runtime/Module.java

@@ -25,6 +25,7 @@ import org.enso.interpreter.runtime.callable.CallerInfo;
 import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
 import org.enso.interpreter.runtime.callable.function.Function;
 import org.enso.interpreter.runtime.data.Array;
+import org.enso.interpreter.runtime.data.text.Text;
 import org.enso.interpreter.runtime.scope.LocalScope;
 import org.enso.interpreter.runtime.scope.ModuleScope;
 import org.enso.interpreter.runtime.type.Types;
@@ -205,10 +206,7 @@ public class Module implements TruffleObject {
     return scope;
   }
 
-  /**
+  /** Create scope if it does not exist. */
-   * Create scope if it does not exist.
-   *
-   */
   public void ensureScopeExists() {
     if (scope == null) {
       scope = new ModuleScope(this);
@@ -387,7 +385,7 @@ public class Module implements TruffleObject {
       CallerInfo callerInfo = new CallerInfo(null, LocalScope.root(), scope);
       Object state = context.getBuiltins().unit().newInstance();
       return callOptimiserNode
-          .executeDispatch(eval, callerInfo, state, new Object[] {debug, expr})
+          .executeDispatch(eval, callerInfo, state, new Object[] {debug, Text.create(expr)})
           .getValue();
     }
 

engine/runtime/src/main/java/org/enso/interpreter/runtime/builtin/Builtins.java

@@ -5,18 +5,27 @@ import com.oracle.truffle.api.Truffle;
 import org.enso.interpreter.Language;
 import org.enso.interpreter.node.expression.builtin.debug.DebugBreakpointMethodGen;
 import org.enso.interpreter.node.expression.builtin.debug.DebugEvalMethodGen;
-import org.enso.interpreter.node.expression.builtin.error.*;
+import org.enso.interpreter.node.expression.builtin.error.CatchErrorMethodGen;
+import org.enso.interpreter.node.expression.builtin.error.CatchPanicMethodGen;
+import org.enso.interpreter.node.expression.builtin.error.ThrowErrorMethodGen;
+import org.enso.interpreter.node.expression.builtin.error.ThrowPanicMethodGen;
 import org.enso.interpreter.node.expression.builtin.function.ApplicationOperatorMethodGen;
 import org.enso.interpreter.node.expression.builtin.function.ExplicitCallFunctionMethodGen;
 import org.enso.interpreter.node.expression.builtin.interop.generic.*;
-import org.enso.interpreter.node.expression.builtin.interop.syntax.MethodDispatchNode;
+import org.enso.interpreter.node.expression.builtin.interop.java.AddToClassPathMethodGen;
+import org.enso.interpreter.node.expression.builtin.interop.java.LookupClassMethodGen;
 import org.enso.interpreter.node.expression.builtin.interop.syntax.ConstructorDispatchNode;
-import org.enso.interpreter.node.expression.builtin.io.*;
+import org.enso.interpreter.node.expression.builtin.interop.syntax.MethodDispatchNode;
+import org.enso.interpreter.node.expression.builtin.io.PrintErrMethodGen;
+import org.enso.interpreter.node.expression.builtin.io.PrintlnMethodGen;
+import org.enso.interpreter.node.expression.builtin.io.ReadlnMethodGen;
 import org.enso.interpreter.node.expression.builtin.runtime.GCMethodGen;
 import org.enso.interpreter.node.expression.builtin.runtime.NoInlineMethodGen;
-import org.enso.interpreter.node.expression.builtin.state.*;
+import org.enso.interpreter.node.expression.builtin.state.GetStateMethodGen;
-import org.enso.interpreter.node.expression.builtin.interop.java.*;
+import org.enso.interpreter.node.expression.builtin.state.PutStateMethodGen;
-import org.enso.interpreter.node.expression.builtin.text.*;
+import org.enso.interpreter.node.expression.builtin.state.RunStateMethodGen;
+import org.enso.interpreter.node.expression.builtin.text.AnyToTextMethodGen;
+import org.enso.interpreter.node.expression.builtin.text.JsonSerializeMethodGen;
 import org.enso.interpreter.node.expression.builtin.thread.WithInterruptHandlerMethodGen;
 import org.enso.interpreter.node.expression.builtin.unsafe.SetAtomFieldMethodGen;
 import org.enso.interpreter.runtime.Context;
@@ -47,16 +56,13 @@ public class Builtins {
   private final AtomConstructor any;
   private final Number number;
   private final AtomConstructor function;
-  private final AtomConstructor text;
   private final AtomConstructor debug;
+  private final Text text;
   private final Error error;
   private final Bool bool;
   private final System system;
   private final Array array;
-
+  private final Polyglot polyglot;
-  private final RootCallTarget interopDispatchRoot;
-  private final FunctionSchema interopDispatchSchema;
-  private final Function newInstanceFunction;
 
   /**
    * Creates an instance with builtin methods installed.
@@ -74,10 +80,11 @@ public class Builtins {
     error = new Error(language, scope);
     array = new Array(language, scope);
     function = new AtomConstructor("Function", scope).initializeFields();
-    text = new AtomConstructor("Text", scope).initializeFields();
+    text = new Text(language, scope);
     debug = new AtomConstructor("Debug", scope).initializeFields();
     system = new System(language, scope);
     number = new Number(language, scope);
+    polyglot = new Polyglot(language, scope);
 
     AtomConstructor nil = new AtomConstructor("Nil", scope).initializeFields();
     AtomConstructor cons =
@@ -98,7 +105,6 @@ public class Builtins {
     scope.registerConstructor(unit);
     scope.registerConstructor(any);
     scope.registerConstructor(function);
-    scope.registerConstructor(text);
 
     scope.registerConstructor(cons);
     scope.registerConstructor(nil);
@@ -114,8 +120,6 @@ public class Builtins {
 
     scope.registerConstructor(unsafe);
 
-    createPolyglot(language);
-
     scope.registerMethod(io, "println", PrintlnMethodGen.makeFunction(language));
     scope.registerMethod(io, "print_err", PrintErrMethodGen.makeFunction(language));
     scope.registerMethod(io, "readln", ReadlnMethodGen.makeFunction(language));
@@ -138,8 +142,6 @@ public class Builtins {
     scope.registerMethod(function, "call", ExplicitCallFunctionMethodGen.makeFunction(language));
     scope.registerMethod(function, "<|", ApplicationOperatorMethodGen.makeFunction(language));
 
-    scope.registerMethod(text, "+", ConcatMethodGen.makeFunction(language));
-    scope.registerMethod(text, "==", TextEqualsMethodGen.makeFunction(language));
     scope.registerMethod(any, "to_text", AnyToTextMethodGen.makeFunction(language));
     scope.registerMethod(any, "json_serialize", JsonSerializeMethodGen.makeFunction(language));
 
@@ -151,36 +153,9 @@ public class Builtins {
 
     scope.registerMethod(unsafe, "set_atom_field", SetAtomFieldMethodGen.makeFunction(language));
 
-    interopDispatchRoot = Truffle.getRuntime().createCallTarget(MethodDispatchNode.build(language));
-    interopDispatchSchema =
-        new FunctionSchema(
-            FunctionSchema.CallStrategy.ALWAYS_DIRECT,
-            FunctionSchema.CallerFrameAccess.NONE,
-            new ArgumentDefinition[] {
-              new ArgumentDefinition(1, "this", ArgumentDefinition.ExecutionMode.EXECUTE),
-              new ArgumentDefinition(2, "method_name", ArgumentDefinition.ExecutionMode.EXECUTE),
-              new ArgumentDefinition(3, "arguments", ArgumentDefinition.ExecutionMode.EXECUTE)
-            },
-            new boolean[] {false, true, false},
-            new CallArgumentInfo[0]);
-    newInstanceFunction = ConstructorDispatchNode.makeFunction(language);
-
     module.unsafeBuildIrStub();
   }
 
-  private void createPolyglot(Language language) {
-    AtomConstructor polyglot = new AtomConstructor("Polyglot", scope).initializeFields();
-    scope.registerConstructor(polyglot);
-    scope.registerMethod(polyglot, "execute", ExecuteMethodGen.makeFunction(language));
-    scope.registerMethod(polyglot, "invoke", InvokeMethodGen.makeFunction(language));
-    scope.registerMethod(polyglot, "new", InstantiateMethodGen.makeFunction(language));
-    scope.registerMethod(polyglot, "get_member", GetMemberMethodGen.makeFunction(language));
-    scope.registerMethod(polyglot, "get_members", GetMembersMethodGen.makeFunction(language));
-    scope.registerMethod(polyglot, "get_array_size", GetArraySizeMethodGen.makeFunction(language));
-    scope.registerMethod(
-        polyglot, "get_array_element", GetArrayElementMethodGen.makeFunction(language));
-  }
-
   /**
    * Returns the {@code Unit} atom constructor.
    *
@@ -191,11 +166,11 @@ public class Builtins {
   }
 
   /**
-   * Returns the {@code Text} atom constructor.
+   * Returns the {@code Text} part of builtins.
    *
-   * @return the {@code Text} atom constructor
+   * @return the {@code Text} part of builtins.
    */
-  public AtomConstructor text() {
+  public Text text() {
     return text;
   }
 
@@ -255,6 +230,11 @@ public class Builtins {
     return array;
   }
 
+  /** @return the container for polyglot-related builtins. */
+  public Polyglot polyglot() {
+    return polyglot;
+  }
+
   /**
    * Returns the builtin module scope.
    *
@@ -267,20 +247,4 @@ public class Builtins {
   public Module getModule() {
     return module;
   }
-
-  /**
-   * Builds a function dispatching to a polyglot method call.
-   *
-   * @param method the name and scope of the method this function will dispatch to.
-   * @return a function calling {@code method} with given arguments.
-   */
-  public Function buildPolyglotMethodDispatch(UnresolvedSymbol method) {
-    Object[] preAppliedArr = new Object[] {null, method, null};
-    return new Function(interopDispatchRoot, null, interopDispatchSchema, preAppliedArr, null);
-  }
-
-  /** @return a function executing a constructor with given arguments. */
-  public Function getConstructorDispatch() {
-    return newInstanceFunction;
-  }
 }

engine/runtime/src/main/java/org/enso/interpreter/runtime/builtin/Polyglot.java

@@ -0,0 +1,107 @@
+package org.enso.interpreter.runtime.builtin;
+
+import com.oracle.truffle.api.RootCallTarget;
+import com.oracle.truffle.api.Truffle;
+import org.enso.interpreter.Language;
+import org.enso.interpreter.node.expression.builtin.interop.generic.*;
+import org.enso.interpreter.node.expression.builtin.interop.syntax.*;
+import org.enso.interpreter.node.expression.builtin.interop.syntax.GetArrayElementMethodGen;
+import org.enso.interpreter.runtime.callable.UnresolvedSymbol;
+import org.enso.interpreter.runtime.callable.argument.ArgumentDefinition;
+import org.enso.interpreter.runtime.callable.argument.CallArgumentInfo;
+import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
+import org.enso.interpreter.runtime.callable.function.Function;
+import org.enso.interpreter.runtime.callable.function.FunctionSchema;
+import org.enso.interpreter.runtime.scope.ModuleScope;
+
+/** A container class for all Polyglot-related stdlib builtins. */
+public class Polyglot {
+
+  private final RootCallTarget interopDispatchRoot;
+  private final FunctionSchema interopDispatchSchema;
+  private final Function newInstanceFunction;
+  private final Function polyglotArrayLengthFunction;
+  private final Function polyglotArrayAtFunction;
+  private final Function polyglotToTextFunction;
+
+  /**
+   * Creates and registers all polyglot-related functions and types.
+   *
+   * @param language the current language instance.
+   * @param scope the builtin scope.
+   */
+  public Polyglot(Language language, ModuleScope scope) {
+
+    // Note [Syntactic Functions]
+    interopDispatchRoot = Truffle.getRuntime().createCallTarget(MethodDispatchNode.build(language));
+    interopDispatchSchema =
+        new FunctionSchema(
+            FunctionSchema.CallStrategy.ALWAYS_DIRECT,
+            FunctionSchema.CallerFrameAccess.NONE,
+            new ArgumentDefinition[] {
+              new ArgumentDefinition(1, "this", ArgumentDefinition.ExecutionMode.EXECUTE),
+              new ArgumentDefinition(2, "method_name", ArgumentDefinition.ExecutionMode.EXECUTE),
+              new ArgumentDefinition(3, "arguments", ArgumentDefinition.ExecutionMode.EXECUTE)
+            },
+            new boolean[] {false, true, false},
+            new CallArgumentInfo[0]);
+    newInstanceFunction = ConstructorDispatchNode.makeFunction(language);
+    polyglotArrayAtFunction = GetArrayElementMethodGen.makeFunction(language);
+    polyglotArrayLengthFunction = ArrayLengthMethodGen.makeFunction(language);
+    polyglotToTextFunction = PolyglotToTextMethodGen.makeFunction(language);
+
+    createPolyglot(language, scope);
+  }
+
+  /* Note [Syntactic Functions]
+   * ~~~~~~~~~~~~~~~~~~~~~~~~~~
+   * Certain functions in this module (ones that are not being directly registered in the scope)
+   * are not parts of the standard library. Instead, they are used by the method dispatch system
+   * to call into functionality of polyglot objects. As such, they are represented as Enso-level
+   * functions, but they are not directly accessible through the standard library.
+   */
+
+  private void createPolyglot(Language language, ModuleScope scope) {
+    AtomConstructor polyglot = new AtomConstructor("Polyglot", scope).initializeFields();
+    scope.registerConstructor(polyglot);
+    scope.registerMethod(polyglot, "execute", ExecuteMethodGen.makeFunction(language));
+    scope.registerMethod(polyglot, "invoke", InvokeMethodGen.makeFunction(language));
+    scope.registerMethod(polyglot, "new", InstantiateMethodGen.makeFunction(language));
+    scope.registerMethod(polyglot, "get_member", GetMemberMethodGen.makeFunction(language));
+    scope.registerMethod(polyglot, "get_members", GetMembersMethodGen.makeFunction(language));
+  }
+
+  /*
+   * Builds a function dispatching to a polyglot method call.
+   *
+   * @param method the name and scope of the method this function will dispatch to.
+   * @return a function calling {@code method} with given arguments.
+   */
+  public Function buildPolyglotMethodDispatch(UnresolvedSymbol method) {
+    Object[] preAppliedArr = new Object[] {null, method, null};
+    return new Function(interopDispatchRoot, null, interopDispatchSchema, preAppliedArr, null);
+  }
+
+  /** @return a function taking a polyglot array and returning its length. */
+  public Function getPolyglotArrayLengthFunction() {
+    return polyglotArrayLengthFunction;
+  }
+
+  /**
+   * @return a function taking a polyglot array and an index and accessing the item at the given
+   *     index.
+   */
+  public Function getPolyglotArrayAtFunction() {
+    return polyglotArrayAtFunction;
+  }
+
+  /** @return a function taking a polyglot object and displaying it as a human-readable string. */
+  public Function getPolyglotToTextFunction() {
+    return polyglotToTextFunction;
+  }
+
+  /** @return a function executing a constructor with given arguments. */
+  public Function getConstructorDispatch() {
+    return newInstanceFunction;
+  }
+}

engine/runtime/src/main/java/org/enso/interpreter/runtime/builtin/Text.java

@@ -0,0 +1,34 @@
+package org.enso.interpreter.runtime.builtin;
+
+import org.enso.interpreter.Language;
+import org.enso.interpreter.node.expression.builtin.text.ConcatMethodGen;
+import org.enso.interpreter.node.expression.builtin.text.OptimizeMethodGen;
+import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
+import org.enso.interpreter.runtime.scope.ModuleScope;
+
+/** A container class for all Text-related stdlib builtins. */
+public class Text {
+  private final AtomConstructor text;
+
+  /**
+   * Creates and registers all the text constructors and methods.
+   *
+   * @param language the current language instance.
+   * @param scope the scope to register constructors and methods in.
+   */
+  public Text(Language language, ModuleScope scope) {
+    text = new AtomConstructor("Text", scope).initializeFields();
+    scope.registerConstructor(text);
+    AtomConstructor primTextHelpers =
+        new AtomConstructor("Prim_Text_Helper", scope).initializeFields();
+    scope.registerConstructor(primTextHelpers);
+
+    scope.registerMethod(text, "+", ConcatMethodGen.makeFunction(language));
+    scope.registerMethod(primTextHelpers, "optimize", OptimizeMethodGen.makeFunction(language));
+  }
+
+  /** @return the Text atom constructor. */
+  public AtomConstructor getText() {
+    return text;
+  }
+}

engine/runtime/src/main/java/org/enso/interpreter/runtime/callable/UnresolvedSymbol.java

@@ -9,6 +9,7 @@ import com.oracle.truffle.api.library.ExportLibrary;
 import com.oracle.truffle.api.library.ExportMessage;
 import org.enso.interpreter.Constants;
 import org.enso.interpreter.node.callable.MethodResolverNode;
+import org.enso.interpreter.node.expression.builtin.interop.syntax.HostValueToEnsoNode;
 import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
 import org.enso.interpreter.runtime.callable.function.Function;
 import org.enso.interpreter.runtime.scope.ModuleScope;
@@ -99,11 +100,16 @@ public class UnresolvedSymbol implements TruffleObject {
         UnresolvedSymbol symbol,
         Object[] arguments,
         @Cached MethodResolverNode methodResolverNode,
+        @Cached HostValueToEnsoNode hostValueToEnsoNode,
         @CachedLibrary(limit = "BUILTIN_INTEROP_DISPATCH") InteropLibrary library)
         throws ArityException, UnsupportedTypeException, UnsupportedMessageException {
+      Object[] args = new Object[arguments.length];
+      for (int i = 0; i < arguments.length; i++) {
+        args[i] = hostValueToEnsoNode.execute(arguments[i]);
+      }
       if (arguments.length == 0) throw ArityException.create(1, 0);
-      Function function = methodResolverNode.execute(symbol, arguments[0]);
+      Function function = methodResolverNode.execute(symbol, args[0]);
-      return library.execute(function, arguments);
+      return library.execute(function, args);
     }
   }
 }

engine/runtime/src/main/java/org/enso/interpreter/runtime/callable/atom/Atom.java

@@ -2,12 +2,23 @@ package org.enso.interpreter.runtime.callable.atom;
 
 import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
-import com.oracle.truffle.api.interop.InteropLibrary;
+import com.oracle.truffle.api.dsl.Cached;
-import com.oracle.truffle.api.interop.TruffleObject;
+import com.oracle.truffle.api.dsl.Specialization;
+import com.oracle.truffle.api.interop.*;
+import com.oracle.truffle.api.library.CachedLibrary;
 import com.oracle.truffle.api.library.ExportLibrary;
 import com.oracle.truffle.api.library.ExportMessage;
+import com.oracle.truffle.api.nodes.UnexpectedResultException;
+import org.enso.interpreter.node.expression.builtin.text.util.ToJavaStringNode;
+import org.enso.interpreter.runtime.callable.UnresolvedSymbol;
+import org.enso.interpreter.runtime.callable.function.Function;
+import org.enso.interpreter.runtime.data.Array;
+import org.enso.interpreter.runtime.data.text.Text;
+import org.enso.interpreter.runtime.type.TypesGen;
+
 import java.util.Arrays;
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 /** A runtime representation of an Atom in Enso. */
@@ -84,14 +95,65 @@ public class Atom implements TruffleObject {
     return toString(false);
   }
 
-  /**
-   * Displays a human-readable string representation of this atom.
-   *
-   * @param allowSideEffects whether or not to allow side effects in displaying the string
-   * @return a string representation of this atom
-   */
   @ExportMessage
-  public Object toDisplayString(boolean allowSideEffects) {
+  public boolean hasMembers() {
-    return this.toString();
+    return true;
+  }
+
+  @ExportMessage
+  @CompilerDirectives.TruffleBoundary
+  public Array getMembers(boolean includeInternal) {
+    Map<String, Function> members = constructor.getDefinitionScope().getMethods().get(constructor);
+    if (members == null) {
+      return new Array(0);
+    }
+    Object[] mems = members.keySet().toArray();
+    return new Array(mems);
+  }
+
+  @ExportMessage
+  @CompilerDirectives.TruffleBoundary
+  public boolean isMemberInvocable(String member) {
+    Map<String, ?> members = constructor.getDefinitionScope().getMethods().get(constructor);
+    return members != null && members.containsKey(member);
+  }
+
+  @ExportMessage
+  static class InvokeMember {
+    static UnresolvedSymbol buildSym(AtomConstructor cons, String name) {
+      return UnresolvedSymbol.build(name, cons.getDefinitionScope());
+    }
+
+    @Specialization(
+        guards = {"receiver.getConstructor() == cachedConstructor", "member.equals(cachedMember)"})
+    static Object doCached(
+        Atom receiver,
+        String member,
+        Object[] arguments,
+        @Cached(value = "receiver.getConstructor()", allowUncached = true)
+            AtomConstructor cachedConstructor,
+        @Cached(value = "member", allowUncached = true) String cachedMember,
+        @Cached(value = "buildSym(cachedConstructor, cachedMember)", allowUncached = true)
+            UnresolvedSymbol cachedSym,
+        @CachedLibrary("cachedSym") InteropLibrary symbols)
+        throws UnsupportedMessageException, ArityException, UnsupportedTypeException {
+      Object[] args = new Object[arguments.length + 1];
+      args[0] = receiver;
+      System.arraycopy(arguments, 0, args, 1, arguments.length);
+      return symbols.execute(cachedSym, args);
+    }
+  }
+
+  @ExportMessage
+  Text toDisplayString(boolean allowSideEffects, @CachedLibrary("this") InteropLibrary atoms) {
+    try {
+      return TypesGen.expectText(atoms.invokeMember(this, "to_text"));
+    } catch (UnsupportedMessageException
+        | ArityException
+        | UnknownIdentifierException
+        | UnsupportedTypeException
+        | UnexpectedResultException e) {
+      return Text.create(this.toString());
+    }
   }
 }

engine/runtime/src/main/java/org/enso/interpreter/runtime/data/text/ConcatRope.java

@@ -0,0 +1,28 @@
+package org.enso.interpreter.runtime.data.text;
+
+/** Represents a concatenation of two text values. */
+public class ConcatRope {
+  private final Object left;
+  private final Object right;
+
+  /**
+   * Creates a new rope concatenating the arguments.
+   *
+   * @param left the left operand
+   * @param right the right operand
+   */
+  public ConcatRope(Object left, Object right) {
+    this.left = left;
+    this.right = right;
+  }
+
+  /** @return the left operand of this concatenation. */
+  public Object getLeft() {
+    return left;
+  }
+
+  /** @return the right operand of this concatenation. */
+  public Object getRight() {
+    return right;
+  }
+}

engine/runtime/src/main/java/org/enso/interpreter/runtime/data/text/Text.java

@@ -0,0 +1,128 @@
+package org.enso.interpreter.runtime.data.text;
+
+import com.oracle.truffle.api.dsl.Cached;
+import com.oracle.truffle.api.interop.InteropLibrary;
+import com.oracle.truffle.api.interop.TruffleObject;
+import com.oracle.truffle.api.library.ExportLibrary;
+import com.oracle.truffle.api.library.ExportMessage;
+import org.enso.interpreter.node.expression.builtin.text.util.ToJavaStringNode;
+
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+
+/** The main runtime type for Enso's Text. */
+@ExportLibrary(InteropLibrary.class)
+public class Text implements TruffleObject {
+  private volatile Object contents;
+  private volatile boolean isFlat;
+  private final Lock lock = new ReentrantLock();
+
+  private Text(String string) {
+    this.contents = string;
+    this.isFlat = true;
+  }
+
+  private Text(ConcatRope contents) {
+    this.contents = contents;
+    this.isFlat = false;
+  }
+
+  /**
+   * Wraps a string in an instance of Text.
+   *
+   * @param string the string to wrap.
+   * @return a Text corresponding to the original string.
+   */
+  public static Text create(String string) {
+    return new Text(string);
+  }
+
+  /**
+   * Creates a new Text by concatenating two other texts.
+   *
+   * @param t1 the left operand.
+   * @param t2 the right operand.
+   * @return a Text representing concatenation of t1 and t2.
+   */
+  public static Text create(Text t1, Text t2) {
+    return new Text(new ConcatRope(t1.contents, t2.contents));
+  }
+
+  /**
+   * Creates a new Text by concatenating a text and a string.
+   *
+   * @param t1 the left operand.
+   * @param t2 the right operand.
+   * @return a Text representing concatenation of t1 and t2.
+   */
+  public static Text create(Text t1, String t2) {
+    return new Text(new ConcatRope(t1.contents, t2));
+  }
+
+  @ExportMessage
+  boolean isString() {
+    return true;
+  }
+
+  @ExportMessage
+  String asString(@Cached("build()") @Cached.Shared("strings") ToJavaStringNode toJavaStringNode) {
+    return toJavaStringNode.execute(this);
+  }
+
+  @ExportMessage
+  String toDisplayString(
+      boolean allowSideEffects,
+      @Cached("build()") @Cached.Shared("strings") ToJavaStringNode toJavaStringNode) {
+    String str = toJavaStringNode.execute(this);
+    // TODO This should be more extensible
+    String replaced =
+        str.replace("'", "\\'")
+            .replace("\n", "\\n")
+            .replace("\t", "\\t")
+            .replace("\u0007", "\\a")
+            .replace("\u0008", "\\b")
+            .replace("\u000c", "\\f")
+            .replace("\r", "\\r")
+            .replace("\u000B", "\\v")
+            .replace("\u001B", "\\e");
+    return "'" + replaced + "'";
+  }
+
+  /** @return true if this text wraps a string literal and does not require any optimization. */
+  public boolean isFlat() {
+    return isFlat;
+  }
+
+  /** @param flat the new value of the isFlat flag. */
+  public void setFlat(boolean flat) {
+    isFlat = flat;
+  }
+
+  /** @return the contents of this text. */
+  public Object getContents() {
+    return contents;
+  }
+
+  /**
+   * Sets the contents of this text.
+   *
+   * @param contents the new contents.
+   */
+  public void setContents(Object contents) {
+    this.contents = contents;
+  }
+
+  /** @return the lock required for modification of this text. */
+  public Lock getLock() {
+    return lock;
+  }
+
+  @Override
+  public String toString() {
+    if (isFlat) {
+      return (String) this.contents;
+    } else {
+      return ToJavaStringNode.inplaceFlatten(this);
+    }
+  }
+}

engine/runtime/src/main/java/org/enso/interpreter/runtime/error/RuntimeError.java

@@ -1,8 +1,14 @@
 package org.enso.interpreter.runtime.error;
 
 import com.oracle.truffle.api.interop.TruffleObject;
+import com.oracle.truffle.api.interop.UnsupportedMessageException;
+import com.oracle.truffle.api.library.CachedLibrary;
+import com.oracle.truffle.api.library.ExportLibrary;
+import com.oracle.truffle.api.library.ExportMessage;
+import com.oracle.truffle.api.interop.InteropLibrary;
 
 /** A runtime object representing an arbitrary, user-created error. */
+@ExportLibrary(InteropLibrary.class)
 public class RuntimeError implements TruffleObject {
   private final Object payload;
 
@@ -33,4 +39,16 @@ public class RuntimeError implements TruffleObject {
   public String toString() {
     return "Error:" + getPayload().toString();
   }
+
+  @ExportMessage
+  public String toDisplayString(
+      boolean allowSideEffects,
+      @CachedLibrary(limit = "3") InteropLibrary displays,
+      @CachedLibrary(limit = "3") InteropLibrary strings) {
+    try {
+      return "(Error: " + strings.asString(displays.toDisplayString(payload)) + ")";
+    } catch (UnsupportedMessageException e) {
+      return "Error";
+    }
+  }
 }

engine/runtime/src/main/java/org/enso/interpreter/runtime/type/Types.java

@@ -11,6 +11,7 @@ import org.enso.interpreter.runtime.callable.atom.Atom;
 import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
 import org.enso.interpreter.runtime.callable.function.Function;
 import org.enso.interpreter.runtime.data.Array;
+import org.enso.interpreter.runtime.data.text.Text;
 import org.enso.interpreter.runtime.error.RuntimeError;
 import org.enso.interpreter.runtime.number.EnsoBigInteger;
 
@@ -28,7 +29,7 @@ import org.enso.interpreter.runtime.number.EnsoBigInteger;
   long.class,
   boolean.class,
   double.class,
-  String.class,
+  Text.class,
   Function.class,
   Atom.class,
   AtomConstructor.class,
@@ -109,7 +110,7 @@ public class Types {
       return "Number";
     } else if (TypesGen.isBoolean(value)) {
       return "Boolean";
-    } else if (TypesGen.isString(value)) {
+    } else if (TypesGen.isText(value)) {
       return "Text";
     } else if (TypesGen.isFunction(value)) {
       return "Function";

engine/runtime/src/main/scala/org/enso/compiler/codegen/AstToIr.scala

@@ -1,5 +1,7 @@
 package org.enso.compiler.codegen
 
+import java.nio.ByteBuffer
+
 import cats.Foldable
 import cats.implicits._
 import org.enso.compiler.core.IR
@@ -7,8 +9,17 @@ import org.enso.compiler.core.IR.Name.MethodReference
 import org.enso.compiler.core.IR._
 import org.enso.compiler.exception.UnhandledEntity
 import org.enso.syntax.text.AST
+import org.enso.syntax.text.Shape.{
+  SegmentEscape,
+  SegmentExpr,
+  SegmentPlain,
+  SegmentRawEscape
+}
+import org.enso.syntax.text.ast.text.Escape
+import org.enso.syntax.text.ast.text.Escape.Unicode
 
 import scala.annotation.tailrec
+import scala.util.control.Breaks.{break, breakable}
 
 /**
   * This file contains the functionality that translates from the parser's
@@ -480,16 +491,22 @@ object AstToIr {
               .mkString("\n")
 
             Literal.Text(fullString, getIdentifiedLocation(literal))
-          case AST.Literal.Text.Block.Fmt(_, _, _) =>
+          case AST.Literal.Text.Block.Fmt(lines, _, _) =>
-            Error.Syntax(
+            val ls  = lines.map(l => parseFmtSegments(literal, l.text))
-              literal,
+            val err = ls.collectFirst { case Left(e) => e }
-              Error.Syntax.UnsupportedSyntax("format strings")
+            err match {
-            )
+              case Some(err) => err
-          case AST.Literal.Text.Line.Fmt(_) =>
+              case None =>
-            Error.Syntax(
+                val str = ls.collect { case Right(str) => str }.mkString("\n")
-              literal,
+                IR.Literal.Text(str, getIdentifiedLocation(literal))
-              Error.Syntax.UnsupportedSyntax("format strings")
+            }
-            )
+          case AST.Literal.Text.Line.Fmt(segments) =>
+            parseFmtSegments(literal, segments) match {
+              case Left(err) => err
+              case Right(str) =>
+                IR.Literal.Text(str, getIdentifiedLocation(literal))
+            }
+
           case _ =>
             throw new UnhandledEntity(literal.shape, "translateLiteral")
         }
@@ -497,6 +514,70 @@ object AstToIr {
     }
   }
 
+  private def parseFmtSegments(
+    literal: AST,
+    segments: Seq[AST.Literal.Text.Segment[AST]]
+  ): Either[IR.Error, String] = {
+    val bldr                  = new StringBuilder
+    var err: Option[IR.Error] = None
+    breakable {
+      segments.foreach {
+        case SegmentEscape(code) =>
+          code match {
+            case Escape.Number(_) =>
+              err = Some(
+                Error.Syntax(
+                  literal,
+                  Error.Syntax.UnsupportedSyntax("escaped numbers")
+                )
+              )
+              break()
+            case unicode: Escape.Unicode =>
+              unicode match {
+                case Unicode.InvalidUnicode(unicode) =>
+                  err = Some(
+                    Error.Syntax(
+                      literal,
+                      Error.Syntax.InvalidEscapeSequence(unicode.repr)
+                    )
+                  )
+                  break()
+                case Unicode._U16(digits) =>
+                  val buffer = ByteBuffer.allocate(2)
+                  buffer.putChar(
+                    Integer.parseInt(digits, 16).asInstanceOf[Char]
+                  )
+                  val str = new String(buffer.array(), "UTF-16")
+                  bldr.addAll(str)
+                case Unicode._U32(digits) =>
+                  val buffer = ByteBuffer.allocate(4)
+                  buffer.putInt(Integer.parseInt(digits, 16))
+                  val str = new String(buffer.array(), "UTF-32")
+                  bldr.addAll(str)
+                case Unicode._U21(digits) =>
+                  val buffer = ByteBuffer.allocate(4)
+                  buffer.putInt(Integer.parseInt(digits, 16))
+                  val str = new String(buffer.array(), "UTF-32")
+                  bldr.addAll(str)
+              }
+            case e: Escape.Character => bldr.addOne(e.code)
+            case e: Escape.Control   => bldr.addAll(e.repr)
+          }
+        case SegmentPlain(text) => bldr.addAll(text)
+        case SegmentExpr(_) =>
+          err = Some(
+            Error.Syntax(
+              literal,
+              Error.Syntax.UnsupportedSyntax("interpolated expressions")
+            )
+          )
+          break()
+        case SegmentRawEscape(e) => bldr.addAll(e.repr)
+      }
+    }
+    err.map(Left(_)).getOrElse(Right(bldr.toString))
+  }
+
   /**
     * Translates a sequence literal into its [[IR]] counterpart.
     * @param literal the literal to translate

engine/runtime/src/main/scala/org/enso/compiler/codegen/IrToTruffle.scala

@@ -65,6 +65,7 @@ import org.enso.interpreter.runtime.callable.function.{
   FunctionSchema,
   Function => RuntimeFunction
 }
+import org.enso.interpreter.runtime.data.text.Text
 import org.enso.interpreter.runtime.error.DuplicateArgumentNameException
 import org.enso.interpreter.runtime.scope.{LocalScope, ModuleScope}
 import org.enso.interpreter.{Constants, Language}
@@ -533,7 +534,9 @@ class IrToTruffle(
             .error()
             .syntaxError()
             .newInstance(
-              "Type operators are not currently supported at runtime."
+              Text.create(
+                "Type operators are not currently supported at runtime."
+              )
             )
         ),
         value.location
@@ -573,7 +576,7 @@ class IrToTruffle(
             val error = context.getBuiltins
               .error()
               .compileError()
-              .newInstance(message)
+              .newInstance(Text.create(message))
 
             setLocation(ErrorNode.build(error), caseExpr.location)
           }
@@ -884,19 +887,40 @@ class IrToTruffle(
         case Error.InvalidIR(_, _, _) =>
           throw new CompilerError("Unexpected Invalid IR during codegen.")
         case err: Error.Syntax =>
-          context.getBuiltins.error().syntaxError().newInstance(err.message)
+          context.getBuiltins
+            .error()
+            .syntaxError()
+            .newInstance(Text.create(err.message))
         case err: Error.Redefined.Binding =>
-          context.getBuiltins.error().compileError().newInstance(err.message)
+          context.getBuiltins
+            .error()
+            .compileError()
+            .newInstance(Text.create(err.message))
         case err: Error.Redefined.Method =>
-          context.getBuiltins.error().compileError().newInstance(err.message)
+          context.getBuiltins
+            .error()
+            .compileError()
+            .newInstance(Text.create(err.message))
         case err: Error.Redefined.Atom =>
-          context.getBuiltins.error().compileError().newInstance(err.message)
+          context.getBuiltins
+            .error()
+            .compileError()
+            .newInstance(Text.create(err.message))
         case err: Error.Redefined.ThisArg =>
-          context.getBuiltins.error().compileError().newInstance(err.message)
+          context.getBuiltins
+            .error()
+            .compileError()
+            .newInstance(Text.create(err.message))
         case err: Error.Unexpected.TypeSignature =>
-          context.getBuiltins.error().compileError().newInstance(err.message)
+          context.getBuiltins
+            .error()
+            .compileError()
+            .newInstance(Text.create(err.message))
         case err: Error.Resolution =>
-          context.getBuiltins.error().compileError().newInstance(err.message)
+          context.getBuiltins
+            .error()
+            .compileError()
+            .newInstance(Text.create(err.message))
         case _: Error.Pattern =>
           throw new CompilerError(
             "Impossible here, should be handled in the pattern match."
@@ -1064,7 +1088,9 @@ class IrToTruffle(
                 .error()
                 .syntaxError()
                 .newInstance(
-                  "Typeset literals are not yet supported at runtime."
+                  Text.create(
+                    "Typeset literals are not yet supported at runtime."
+                  )
                 )
             ),
             application.location

engine/runtime/src/main/scala/org/enso/compiler/core/IR.scala

@@ -5570,6 +5570,10 @@ object IR {
         def explanation: String
       }
 
+      case class InvalidEscapeSequence(lit: String) extends Reason {
+        override def explanation: String = s"Invalid escape sequence $lit."
+      }
+
       case object InvalidBaseInDecimalLiteral extends Reason {
         override def explanation: String =
           "Cannot change base of the fractional part of a number literal."

engine/runtime/src/main/scala/org/enso/compiler/pass/resolve/VectorLiterals.scala

@@ -99,7 +99,7 @@ case object VectorLiterals extends IRPass {
       case seq: IR.Application.Literal.Sequence =>
         val trans = seq.mapExpressions(doExpression(_, vec))
         IR.Application.Prefix(
-          vec,
+          vec.duplicate(),
           List(IR.CallArgument.Specified(None, trans, None, None)),
           false,
           None

engine/runtime/src/main/scala/org/enso/interpreter/instrument/job/ProgramExecutionSupport.scala

@@ -24,6 +24,7 @@ import org.enso.interpreter.instrument.{
   Visualisation
 }
 import org.enso.interpreter.node.callable.FunctionCallInstrumentationNode.FunctionCall
+import org.enso.interpreter.runtime.data.text.Text
 import org.enso.interpreter.service.error.ServiceException
 import org.enso.polyglot.runtime.Runtime.Api
 import org.enso.polyglot.runtime.Runtime.Api.ContextId
@@ -301,6 +302,7 @@ trait ProgramExecutionSupport {
         .leftMap(_.getMessage)
         .flatMap {
           case text: String       => Right(text.getBytes("UTF-8"))
+          case text: Text         => Right(text.toString.getBytes("UTF-8"))
           case bytes: Array[Byte] => Right(bytes)
           case other =>
             Left(s"Cannot encode ${other.getClass} to byte array")

engine/runtime/src/main/scala/org/enso/interpreter/runtime/builtin/LanguageEntitySerializer.scala

@@ -1,5 +1,6 @@
 package org.enso.interpreter.runtime.builtin
 
+import com.oracle.truffle.api.interop.InteropLibrary
 import io.circe.Json
 import org.enso.interpreter.runtime.callable.atom.{Atom, AtomConstructor}
 
@@ -7,6 +8,7 @@ import org.enso.interpreter.runtime.callable.atom.{Atom, AtomConstructor}
   * Helper for JSON-serializing runtime entities of the language.
   */
 object LanguageEntitySerializer {
+  private val interopLibrary: InteropLibrary = InteropLibrary.getUncached()
 
   /**
     * Serializes a language entity into a JSON string. Returns null JSON for
@@ -20,7 +22,6 @@ object LanguageEntitySerializer {
 
   private def toJson(obj: Any): Json = obj match {
     case l: Long   => Json.fromLong(l)
-    case s: String => Json.fromString(s)
     case cons: AtomConstructor =>
       Json.obj("type" -> Json.fromString(cons.getName), "fields" -> Json.arr())
     case atom: Atom =>
@@ -28,6 +29,11 @@ object LanguageEntitySerializer {
         "type"   -> Json.fromString(atom.getConstructor.getName),
         "fields" -> Json.arr(atom.getFields.map(toJson).toIndexedSeq: _*)
       )
-    case _ => Json.Null
+    case _ =>
+      if (interopLibrary.isString(obj)) {
+        Json.fromString(interopLibrary.asString(obj))
+      } else {
+        Json.Null
+      }
   }
 }

engine/runtime/src/test/scala/org/enso/interpreter/test/semantic/CompileDiagnosticsTest.scala

@@ -29,7 +29,7 @@ class CompileDiagnosticsTest extends InterpreterTest {
           |    x = Panic.recover @
           |    x.catch to_text
           |""".stripMargin
-      eval(code) shouldEqual "Syntax_Error Unrecognized token."
+      eval(code) shouldEqual "(Syntax_Error 'Unrecognized token.')"
     }
 
     "surface redefinition errors in the language" in {
@@ -42,7 +42,7 @@ class CompileDiagnosticsTest extends InterpreterTest {
           |
           |main = Panic.recover here.foo . catch to_text
           |""".stripMargin
-      eval(code) shouldEqual "Compile_Error Variable x is being redefined."
+      eval(code) shouldEqual "(Compile_Error 'Variable x is being redefined.')"
     }
   }
 }

engine/runtime/src/test/scala/org/enso/interpreter/test/semantic/ErrorsTest.scala

@@ -46,7 +46,7 @@ class ErrorsTest extends InterpreterTest {
           |""".stripMargin
 
       noException shouldBe thrownBy(eval(code))
-      consumeOut shouldEqual List("Error:MyError")
+      consumeOut shouldEqual List("(Error: MyError)")
     }
 
     "propagate through pattern matches" in {
@@ -64,7 +64,7 @@ class ErrorsTest extends InterpreterTest {
           |    IO.println matched
           |""".stripMargin
       noException shouldBe thrownBy(eval(code))
-      consumeOut shouldEqual List("Error:MyError")
+      consumeOut shouldEqual List("(Error: MyError)")
     }
 
     "propagate through specialized pattern matches" in {
@@ -83,7 +83,7 @@ class ErrorsTest extends InterpreterTest {
           |    IO.println (f brokenVal)
           |""".stripMargin
       noException shouldBe thrownBy(eval(code))
-      consumeOut shouldEqual List("1", "Error:MyError")
+      consumeOut shouldEqual List("1", "(Error: MyError)")
     }
 
     "be catchable by a user-provided special handling function" in {
@@ -108,7 +108,7 @@ class ErrorsTest extends InterpreterTest {
           |    IO.println (unitErr.catch MyCons)
           |""".stripMargin
       eval(code)
-      consumeOut shouldEqual List("MyCons Unit")
+      consumeOut shouldEqual List("(MyCons Unit)")
     }
 
     "accept a method handle in catch function" in {
@@ -126,7 +126,7 @@ class ErrorsTest extends InterpreterTest {
           |    IO.println(myErr.catch recover)
           |""".stripMargin
       eval(code)
-      consumeOut shouldEqual List("MyRecovered 20")
+      consumeOut shouldEqual List("(MyRecovered 20)")
     }
 
     "make the catch method an identity for non-error values" in {

engine/runtime/src/test/scala/org/enso/interpreter/test/semantic/EvalTest.scala

@@ -46,7 +46,7 @@ class EvalTest extends InterpreterTest {
            |        IO.println (MyType x)
            |""".stripMargin
       eval(code)
-      consumeOut shouldEqual List("MyType 10")
+      consumeOut shouldEqual List("(MyType 10)")
     }
 
     "return a value usable in the caller scope" in {

engine/runtime/src/test/scala/org/enso/interpreter/test/semantic/InteropTest.scala

@@ -74,7 +74,7 @@ class InteropTest extends InterpreterTest {
       val code   = "main = to_text"
       val symbol = eval(code)
       symbol.call(1) shouldEqual "1"
-      symbol.execute("Foo") shouldEqual "Foo"
+      symbol.execute("Foo") shouldEqual "'Foo'"
     }
   }
 }

engine/runtime/src/test/scala/org/enso/interpreter/test/semantic/NamedArgumentsTest.scala

@@ -238,7 +238,7 @@ class NamedArgumentsTest extends InterpreterTest {
           |main = Cons2 5
           |""".stripMargin
 
-      eval(code).toString shouldEqual "Cons2 5 Nil2"
+      eval(code).toString shouldEqual "(Cons2 5 Nil2)"
     }
 
     "work with constructors" in {

engine/runtime/src/test/scala/org/enso/interpreter/test/semantic/PolyglotTest.scala

@@ -42,10 +42,10 @@ class PolyglotTest extends InterpreterTest {
           |    class = Java.lookup_class "org.enso.example.TestClass"
           |    instance = Polyglot.new class Array.empty
           |    members = Polyglot.get_members instance
-          |    IO.println (Polyglot.get_array_size members)
+          |    IO.println members.length
-          |    IO.println (Polyglot.get_array_element members 0)
+          |    IO.println (members.at 0)
-          |    IO.println (Polyglot.get_array_element members 1)
+          |    IO.println (members.at 1)
-          |    IO.println (Polyglot.get_array_element members 2)
+          |    IO.println (members.at 2)
           |""".stripMargin
       eval(code)
       val count :: methods = consumeOut

engine/runtime/src/test/scala/org/enso/interpreter/test/semantic/TextTest.scala

@@ -1,12 +1,12 @@
 package org.enso.interpreter.test.semantic
 
-import org.enso.interpreter.test.{InterpreterTest, InterpreterContext}
+import org.enso.interpreter.test.{InterpreterContext, InterpreterTest}
 
 class TextTest extends InterpreterTest {
   override def subject = "Text Library"
 
-  override def specify(
+  override def specify(implicit
-    implicit interpreterContext: InterpreterContext
+    interpreterContext: InterpreterContext
   ): Unit = {
 
     "support text creation with single-line literals" in {
@@ -40,12 +40,12 @@ class TextTest extends InterpreterTest {
           |type My_Type a
           |
           |main =
-          |    IO.println 5.to_text
+          |    IO.println 5
-          |    IO.println (My_Type (My_Type 10)).to_text
+          |    IO.println (My_Type (My_Type 10))
-          |    IO.println "123".to_text
+          |    IO.println "123"
           |""".stripMargin
       eval(code)
-      consumeOut shouldEqual List("5", "My_Type (My_Type 10)", "123")
+      consumeOut shouldEqual List("5", "(My_Type (My_Type 10))", "123")
     }
 
     "support text creation with raw block literals" in {
@@ -77,17 +77,14 @@ class TextTest extends InterpreterTest {
     }
 
     "support printing to standard error" in {
-      val errString = "\"My error string\""
-      val resultStr = errString.drop(1).dropRight(1)
-
       val code =
         s"""from Builtins import all
            |
-           |main = IO.print_err $errString
+           |main = IO.print_err "My error string"
            |""".stripMargin
 
       eval(code)
-      consumeErr shouldEqual List(resultStr)
+      consumeErr shouldEqual List("My error string")
     }
 
     "support reading from standard input" in {

lib/scala/syntax/definition/src/main/scala/org/enso/syntax/text/ast/text/Escape.scala

@@ -128,47 +128,49 @@ object Escape {
   }
 
   // Reference: https://en.wikipedia.org/wiki/String_literal
-  sealed trait Character extends Escape
+  sealed trait Character extends Escape {
+    def code: Char
+  }
   object Character {
     case object a extends Character {
-      val code: Int     = '\u0007'
+      override val code: Char = '\u0007'
-      def name: String  = toString
+      def name: String        = toString
-      override val repr = name
+      override val repr       = name
     }
     case object b extends Character {
-      val code: Int     = '\u0008'
+      override val code: Char = '\u0008'
-      def name: String  = toString
+      def name: String        = toString
-      override val repr = name
+      override val repr       = name
     }
     case object f extends Character {
-      val code: Int     = '\u000C'
+      override val code: Char = '\u000C'
-      def name: String  = toString
+      def name: String        = toString
-      override val repr = name
+      override val repr       = name
     }
     case object n extends Character {
-      val code: Int     = '\n'
+      override val code: Char = '\n'
-      def name: String  = toString
+      def name: String        = toString
-      override val repr = name
+      override val repr       = name
     }
     case object r extends Character {
-      val code: Int     = '\r'
+      override val code: Char = '\r'
-      def name: String  = toString
+      def name: String        = toString
-      override val repr = name
+      override val repr       = name
     }
     case object t extends Character {
-      val code: Int     = '\u0009'
+      override val code: Char = '\u0009'
-      def name: String  = toString
+      def name: String        = toString
-      override val repr = name
+      override val repr       = name
     }
     case object v extends Character {
-      val code: Int     = '\u000B'
+      override val code: Char = '\u000B'
-      def name: String  = toString
+      def name: String        = toString
-      override val repr = name
+      override val repr       = name
     }
     case object e extends Character {
-      val code: Int     = '\u001B'
+      override val code: Char = '\u001B'
-      def name: String  = toString
+      def name: String        = toString
-      override val repr = name
+      override val repr       = name
     }
     val codes = ADT.constructors[Character]
   }
@@ -229,32 +231,32 @@ object Escape {
       override val repr = name
     }
     case object LF extends Control {
-      val code: Int     = 0x0A
+      val code: Int     = 0x0a
       def name: String  = toString
       override val repr = name
     }
     case object VT extends Control {
-      val code: Int     = 0x0B
+      val code: Int     = 0x0b
       def name: String  = toString
       override val repr = name
     }
     case object FF extends Control {
-      val code: Int     = 0x0C
+      val code: Int     = 0x0c
       def name: String  = toString
       override val repr = name
     }
     case object CR extends Control {
-      val code: Int     = 0x0D
+      val code: Int     = 0x0d
       def name: String  = toString
       override val repr = name
     }
     case object SO extends Control {
-      val code: Int     = 0x0E
+      val code: Int     = 0x0e
       def name: String  = toString
       override val repr = name
     }
     case object SI extends Control {
-      val code: Int     = 0x0F
+      val code: Int     = 0x0f
       def name: String  = toString
       override val repr = name
     }
@@ -309,37 +311,37 @@ object Escape {
       override val repr = name
     }
     case object SUB extends Control {
-      val code: Int     = 0x1A
+      val code: Int     = 0x1a
       def name: String  = toString
       override val repr = name
     }
     case object ESC extends Control {
-      val code: Int     = 0x1B
+      val code: Int     = 0x1b
       def name: String  = toString
       override val repr = name
     }
     case object FS extends Control {
-      val code: Int     = 0x1C
+      val code: Int     = 0x1c
       def name: String  = toString
       override val repr = name
     }
     case object GS extends Control {
-      val code: Int     = 0x1D
+      val code: Int     = 0x1d
       def name: String  = toString
       override val repr = name
     }
     case object RS extends Control {
-      val code: Int     = 0x1E
+      val code: Int     = 0x1e
       def name: String  = toString
       override val repr = name
     }
     case object US extends Control {
-      val code: Int     = 0x1F
+      val code: Int     = 0x1f
       def name: String  = toString
       override val repr = name
     }
     case object DEL extends Control {
-      val code: Int     = 0x7F
+      val code: Int     = 0x7f
       def name: String  = toString
       override val repr = name
     }

std-bits/pom.xml

@@ -0,0 +1,106 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>org.enso</groupId>
+    <artifactId>base</artifactId>
+    <version>1.0</version>
+    <packaging>jar</packaging>
+
+    <name>base</name>
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+    <dependencies>
+        <dependency>
+            <groupId>com.ibm.icu</groupId>
+            <artifactId>icu4j</artifactId>
+            <version>67.1</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.8.0</version>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <version>2.3.1</version>
+                <configuration>
+                    <outputDirectory>
+                        ${project.build.directory}/../../distribution/std-lib/Base/polyglot/java
+                    </outputDirectory>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>license-maven-plugin</artifactId>
+                <version>2.0.0</version>
+                <executions>
+                    <execution>
+                        <id>add-third-party-licenses</id>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>download-licenses</goal>
+                        </goals>
+                        <configuration>
+                            <licensesOutputDirectory>
+                                ${project.build.directory}/../../distribution/std-lib/Base/third-party-licenses
+                            </licensesOutputDirectory>
+                        </configuration>
+                    </execution>
+                    <execution>
+                        <id>add-third-party-licenses-list</id>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>add-third-party</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>
+                                ${project.build.directory}/../../distribution/std-lib/Base/third-party-licenses
+                            </outputDirectory>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <version>2.10</version>
+                <executions>
+                    <execution>
+                        <id>copy</id>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>copy</goal>
+                        </goals>
+                        <configuration>
+                            <artifactItems>
+                                <artifactItem>
+                                    <groupId>com.ibm.icu</groupId>
+                                    <artifactId>icu4j</artifactId>
+                                    <version>67.1</version>
+                                    <type>jar</type>
+                                    <overWrite>true</overWrite>
+                                    <destFileName>icu4j.jar</destFileName>
+                                </artifactItem>
+                            </artifactItems>
+                            <outputDirectory>
+                                ${project.build.directory}/../../distribution/std-lib/Base/polyglot/java
+                            </outputDirectory>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+</project>

std-bits/src/main/java/org/enso/base/Text_Utils.java

@@ -0,0 +1,87 @@
+package org.enso.base;
+
+import com.ibm.icu.text.Normalizer2;
+
+import java.nio.charset.StandardCharsets;
+import java.util.regex.Pattern;
+
+/** Utils for standard library operations on Text. */
+public class Text_Utils {
+  /**
+   * Creates a substring of the given string, indexing using the Java standard (UTF-16) indexing
+   * mechanism.
+   *
+   * @param string the string to substring
+   * @param from starting index
+   * @param to index one past the end of the desired substring
+   * @return a suitable substring
+   */
+  public static String substring(String string, int from, int to) {
+    return string.substring(from, to);
+  }
+
+  /**
+   * Converts a string into an array of UTF-8 bytes.
+   *
+   * @param str the string to convert
+   * @return the UTF-8 representation of the string.
+   */
+  public static byte[] get_bytes(String str) {
+    return str.getBytes(StandardCharsets.UTF_8);
+  }
+
+  /**
+   * Converts a string into an array of Unicode codepoints.
+   *
+   * @param str the string to convert
+   * @return the codepoints of the original string.
+   */
+  public static int[] get_codepoints(String str) {
+    return str.codePoints().toArray();
+  }
+
+  /**
+   * Splits the string on each occurrence of {@code sep}, returning the resulting substrings in an
+   * array.
+   *
+   * @param str the string to split
+   * @param sep the separator string
+   * @return array of substrings of {@code str} contained between occurences of {@code sep}
+   */
+  public static String[] split_at(String str, String sep) {
+    return str.split(Pattern.quote(sep));
+  }
+
+  /**
+   * Checks whether two strings are equal up to Unicode canonicalization.
+   *
+   * @param str1 the first string
+   * @param str2 the second string
+   * @return the result of comparison
+   */
+  public static boolean equals(String str1, String str2) {
+    return Normalizer2.getNFDInstance()
+        .normalize(str1)
+        .equals(Normalizer2.getNFDInstance().normalize(str2));
+  }
+
+  /**
+   * Converts an array of codepoints into a string.
+   *
+   * @param codepoints the codepoints to convert
+   * @return the resulting string
+   */
+  public static String from_codepoints(int[] codepoints) {
+    return new String(codepoints, 0, codepoints.length);
+  }
+
+  /**
+   * Converts an array of UTF-8 bytes into a string.
+   *
+   * @param bytes the bytes to convert
+   * @return the resulting string
+   */
+  public static String from_utf_8(byte[] bytes) {
+    return new String(bytes, StandardCharsets.UTF_8);
+  }
+}

test/Benchmarks/src/Main.enso

@@ -19,6 +19,12 @@ sum_tco_decimal = sum_to ->
     res = summator 0.0 0.0
     res
 
+sum_tco_eval = sumTo ->
+    summator = acc -> current ->
+        if current == 0 then acc else Debug.eval "summator (acc + current) (current - 1)"
+
+    res = summator 0 sumTo
+    res
 
 sum_tco_java = sum_to ->
     summator = acc -> current ->
@@ -49,11 +55,13 @@ sum_state = sum_to ->
 main =
     hundred_mil = 100000000
     IO.println "Measuring Sum TCO Decimal"
-    Bench_Utils.measure (here.sum_tco_decimal hundred_mil) "sum_tco" 100 10
+    Bench_Utils.measure (here.sum_tco_decimal hundred_mil) "sum_tco_float" 100 10
     IO.println "Measuring SumTCO"
     Bench_Utils.measure (here.sum_tco hundred_mil) "sum_tco" 100 10
     IO.println "Measuring SumTCO Java"
-    Bench_Utils.measure (here.sum_tco_java hundred_mil) "sum_tco" 100 10
+    Bench_Utils.measure (here.sum_tco_java hundred_mil) "sum_tco_java" 100 10
+    IO.println "Measuring SumTCO Eval"
+    Bench_Utils.measure (here.sum_tco_eval hundred_mil) "sum_tco_eval" 100 10
     IO.println "Measuring State"
     Bench_Utils.measure (here.sum_state hundred_mil) "sum_state" 100 10
     IO.println "Measuring Co-State"

test/Benchmarks/src/Text.enso

@@ -0,0 +1,21 @@
+from Base import all
+from Builtins import Prim_Text_Helper
+import Base.Bench_Utils
+
+polyglot java import java.lang.StringBuilder
+
+build_long n =
+    res = 1.upto n . fold "" acc-> n-> acc + n.to_text
+    Prim_Text_Helper.optimize res
+    res
+
+build_long_bldr n =
+    bldr = new StringBuilder [].to_array
+    1.upto n . each n-> bldr.append [n]
+    res = bldr.toString []
+    res
+
+main =
+    Bench_Utils.measure (here.build_long_bldr 1000000) "string append bldr" 100 10
+    Bench_Utils.measure (here.build_long 1000000) "string append" 100 10
+    IO.println "Bye"

test/Test/src/Java_Interop/Spec.enso

@@ -4,11 +4,22 @@ import Base.Test
 polyglot java import java.lang.Long
 polyglot java import java.lang.Integer
 polyglot java import java.lang.Float
+polyglot java import java.lang.String
+polyglot java import java.util.ArrayList
 
 spec = describe "Java FFI" <|
     it "should call methods imported from Java" <|
         Long.sum [1, 2] . should_equal 3
+
+    ## TODO
+       https://github.com/enso-org/enso/issues/1163
+    it "should call constructors imported from Java" pending=True <|
+        list = ArrayList.new []
+        list.add 432
+        list.get [0] . should_equal 432
     it "should auto-convert numeric types across the polyglot boundary" <|
         (Float.valueOf ["123.3"] + 5).should_equal 128.3 epsilon=0.0001
         (Integer.sum [1, 2] + 3) . should_equal 6
+    it "should auto-convert strings across the polyglot boundary" <|
+        (String.format ["%s bar %s", "baz", "quux"] + " foo").should_equal "baz bar quux foo"
 

test/Test/src/Main.enso

@@ -8,6 +8,7 @@ import Test.Process_Spec
 import Test.Java_Interop.Spec as Java_Spec
 import Test.Vector.Spec as Vector_Spec
 import Test.Numbers.Spec as Numbers_Spec
+import Test.Text.Spec as Text_Spec
 
 main = Test.Suite.runMain <|
     List_Spec.spec
@@ -19,3 +20,4 @@ main = Test.Suite.runMain <|
     Java_Spec.spec
     Vector_Spec.spec
     Numbers_Spec.spec
+    Text_Spec.spec

test/Test/src/Text/Spec.enso

@@ -0,0 +1,42 @@
+from Base import all
+import Base.Test
+
+type Auto a
+
+type Manual b
+
+Manual.to_text = "[[[MyREP " + this.b.to_text + "]]]"
+
+spec = describe "Text" <|
+    kshi = '\u0915\u094D\u0937\u093F'
+    kshi_utf_8 = [-32, -92, -107, -32, -91, -115, -32, -92, -73, -32, -92, -65]
+    facepalm = '\u{1F926}\u{1F3FC}\u200D\u2642\uFE0F'
+    facepalm_codes = [129318, 127996, 8205, 9794, 65039]
+    accent_1 = '\u00E9'
+    accent_2 = '\u0065\u{301}'
+    it "should compare strings using utf normalization" <|
+        "abc".equals "def" . should_be_false
+        accent_1 . should_equal accent_2
+    it "should split the text into grapheme clusters" <|
+        str = kshi + facepalm + accent_1 + accent_2
+        str.characters . should_equal [kshi, facepalm, accent_1, accent_2]
+    it "should split the text on arbitrary sequence" <|
+        "foo, bar, baz" . split_at ", " . should_equal ["foo", "bar", "baz"]
+    it "should dump utf-8 bytes to a vector" <|
+        kshi.utf_8.should_equal kshi_utf_8
+    it "should convert an array of bytes to text" <|
+        Text.from_utf_8 kshi_utf_8 . should_equal kshi
+    it "should dump utf codepoints to a vector" <|
+        facepalm.codepoints.should_equal facepalm_codes
+    it "should convert an array of codepoints to text" <|
+        Text.from_codepoints facepalm_codes . should_equal facepalm
+    it "should convert any type to text automatically and using provided methods" <|
+        t = Auto (Manual 123) . to_text
+        t.should_equal "(Auto [[[MyREP 123]]])"
+    it "should escape special characters when debug-printing text" <|
+        text_1 = '''
+            foo
+            bar\r\tbaz
+        text_1.to_text.should_equal "'foo\\nbar\\r\\tbaz'"
+        text_2 = '\n\t\a\b\f\r\v\e\''
+        text_2.to_text.should_equal "'\\n\\t\\a\\b\\f\\r\\v\\e\\''"

test/Test/src/Vector/Spec.enso

@@ -19,4 +19,8 @@ spec = describe "Vectors" <|
         mapped = vec.map x-> x * x
         vec.to_text.should_equal "[1, 2, 3, 4]"
         mapped.to_text.should_equal "[1, 4, 9, 16]"
+    it "should define equality" <|
+        [1,2,3].equals [1,2] . should_be_false
+        [1,2,3].equals [1,2,3] . should_be_true
+        [1,2,3].equals [3,4,5] . should_be_false