Improving widgets for take/drop (#6641)

Related to #6410

# Important Notes
- Updated some `Meta` methods (needed for error handling):
- `Meta.Type` now has `name` and `qualified_name`.
- `Meta.Constructor` has `declaring_type` allowing to get the type that this constructor is associated with.

distribution/lib/Standard/Base/0.0.0-dev/src/Data/Array.enso

@@ -241,6 +241,7 @@ type Array
          If an `Index_Sub_Range`, then the selection is interpreted following
          the rules of that type.
          If a `Range`, the selection is specified by two indices, from and to.
+    @range Index_Sub_Range.default_widget
     take : (Index_Sub_Range | Range | Integer) -> Vector Any
     take self range=(Index_Sub_Range.First 1) = Vector.take self range
 
@@ -251,6 +252,7 @@ type Array
          If an `Index_Sub_Range`, then the selection is interpreted following
          the rules of that type.
          If a `Range`, the selection is specified by two indices, from and to.
+    @range Index_Sub_Range.default_widget
     drop : (Index_Sub_Range | Range | Integer) -> Vector Any
     drop self range=(Index_Sub_Range.First 1) = Vector.drop self range
 

distribution/lib/Standard/Base/0.0.0-dev/src/Data/Index_Sub_Range.enso

@@ -5,15 +5,22 @@ import project.Data.Range.Extensions
 import project.Data.Text.Text
 import project.Data.Vector.Vector
 import project.Errors.Common.Index_Out_Of_Bounds
+import project.Errors.Common.Type_Error
 import project.Error.Error
 import project.Errors.Illegal_Argument.Illegal_Argument
+import project.Function.Function
 import project.Math
+import project.Meta
 import project.Panic.Panic
 import project.Random
 import project.Runtime.Ref.Ref
 
 from project.Data.Boolean import Boolean, True, False
 
+from project.Metadata.Widget import Single_Choice
+from project.Metadata.Choice import Option
+import project.Metadata.Display
+
 type Index_Sub_Range
     ## Select the first `count` items.
 
@@ -40,7 +47,7 @@ type Index_Sub_Range
        Only ranges with positive step and positive indices are supported.
        Individual integer indices can be negative which allows for indexing
        from the end of the collection.
-    By_Index (indexes : (Integer | Range | Vector (Integer | Range)) = [0])
+    By_Index (indexes : (Integer | Range | Vector (Integer | Range)))
 
     ## Gets a random sample of entries, without repetitions.
 
@@ -67,6 +74,26 @@ type Index_Sub_Range
         Index_Sub_Range.Sample count _ -> "Sample " + count.to_display_text
         Index_Sub_Range.Every step first -> "Every " + step.to_display_text + (if first == 0 then "" else " from " + first.to_display_text)
 
+    ## PRIVATE
+       It includes all constructors of `Index_Sub_Range` but also `Range`, since
+       the `Index_Sub_Range` type is by default used in sum types containing
+       `Range` too.
+    default_options : Vector Option
+    default_options =
+        o1 = Option "First" "(Index_Sub_Range.First 1)"
+        o2 = Option "Last" "(Index_Sub_Range.Last 1)"
+        o3 = Option "While" "(Index_Sub_Range.While (x-> False))"
+        o4 = Option "By_Index" "(Index_Sub_Range.By_Index [0])"
+        o5 = Option "Sample" "(Index_Sub_Range.Sample 10)"
+        o6 = Option "Every" "(Index_Sub_Range.Every 2)"
+        o7 = Option "Range" "(Range.new 0 100)"
+        [o1, o2, o3, o4, o5, o6, o7]
+
+    ## PRIVATE
+    default_widget : Single_Choice
+    default_widget =
+        Single_Choice display=Display.Always Index_Sub_Range.default_options
+
 ## PRIVATE
    Resolves a vector of ranges or indices into a vector of ranges that fit
    within a sequence.
@@ -169,9 +196,9 @@ sort_and_merge_ranges ranges =
      normalization on its own.
    - range: The `Index_Sub_Range` to take from the collection.
 take_helper : Integer -> (Integer -> Any) -> (Integer -> Integer -> Any) -> (Vector (Integer | Range) -> Vector Any) -> (Index_Sub_Range | Range | Integer) -> Any
-take_helper length at single_slice slice_ranges index_sub_range = case index_sub_range of
+take_helper length at single_slice slice_ranges range = case range of
     count : Integer -> take_helper length at single_slice slice_ranges (Index_Sub_Range.First count)
-    _ : Range -> take_helper length at single_slice slice_ranges (Index_Sub_Range.By_Index index_sub_range)
+    _ : Range -> take_helper length at single_slice slice_ranges (Index_Sub_Range.By_Index range)
     Index_Sub_Range.First count -> single_slice 0 (Math.min length count)
     Index_Sub_Range.Last count -> single_slice length-count length
     Index_Sub_Range.While predicate ->
@@ -193,6 +220,7 @@ take_helper length at single_slice slice_ranges index_sub_range = case index_sub
             if start >= length then single_slice 0 0 else
                 range = start.up_to length . with_step step
                 take_helper length at single_slice slice_ranges (Index_Sub_Range.By_Index range)
+    _ -> handle_unmatched_type [Index_Sub_Range, Range, Integer] range
 
 ## PRIVATE
    A helper that implements dropping from an arbitrary collection using a set of
@@ -219,9 +247,9 @@ take_helper length at single_slice slice_ranges index_sub_range = case index_sub
      normalized.
    - range: The `Index_Sub_Range` to drop from the collection.
 drop_helper : Integer -> (Integer -> Any) -> (Integer -> Integer -> Any) -> (Vector (Integer | Range) -> Vector Any) -> (Index_Sub_Range | Range | Integer) -> Any
-drop_helper length at single_slice slice_ranges index_sub_range = case index_sub_range of
-    _ : Integer -> single_slice index_sub_range length
-    _ : Range -> drop_helper length at single_slice slice_ranges (Index_Sub_Range.By_Index index_sub_range)
+drop_helper length at single_slice slice_ranges range = case range of
+    _ : Integer -> single_slice range length
+    _ : Range -> drop_helper length at single_slice slice_ranges (Index_Sub_Range.By_Index range)
     Index_Sub_Range.First count -> single_slice count length
     Index_Sub_Range.Last count -> single_slice 0 length-count
     Index_Sub_Range.While predicate ->
@@ -245,3 +273,21 @@ drop_helper length at single_slice slice_ranges index_sub_range = case index_sub
             if start >= length then single_slice 0 length else
                 range = start.up_to length . with_step step
                 drop_helper length at single_slice slice_ranges (Index_Sub_Range.By_Index range)
+    _ -> handle_unmatched_type [Index_Sub_Range, Range, Integer] range
+
+## PRIVATE
+handle_unmatched_type expected_types actual_value =
+    m = Meta.meta actual_value
+    return_type_error =
+        expected_types_str = expected_types . map .to_text . join " | "
+        Error.throw (Type_Error.Error expected_types_str actual_value "range")
+    case m of
+        _ : Meta.Constructor ->
+            declaring_type = m.declaring_type
+            is_expected_constructor = expected_types.map Meta.meta . contains declaring_type
+            if is_expected_constructor.not then return_type_error else
+                msg = "The constructor " + m.name + " is missing some arguments."
+                Error.throw (Illegal_Argument.Error msg)
+        _ -> case actual_value.is_a Function of
+            True  -> Error.throw (Illegal_Argument.Error "Got a Function instead of a range, is a constructor argument missing?")
+            False -> return_type_error

distribution/lib/Standard/Base/0.0.0-dev/src/Data/Text/Extensions.enso

@@ -939,6 +939,7 @@ Text.repeat self count=1 =
          "Hello World!".take (By_Index [1, 0, 0, 6, 0]) == "eHHWH"
          "Hello World!".take (By_Index [Range 0 3, 6, Range 6 12 2]) == "HelWWrd"
          "Hello World!".take (Sample 3 seed=42) == "l d"
+@range Text_Sub_Range.default_widget
 Text.take : (Text_Sub_Range | Index_Sub_Range | Range | Integer) -> Text ! Index_Out_Of_Bounds
 Text.take self range=(Index_Sub_Range.First 1) =
     ranges = Codepoint_Ranges.resolve self range
@@ -985,6 +986,7 @@ Text.take self range=(Index_Sub_Range.First 1) =
          "Hello World!".drop (By_Index [1, 0, 0, 6, 0]) == "llo orld!"
          "Hello World!".drop (By_Index [Range 0 3, 6, Range 6 12 2]) == "lo ol!"
          "Hello World!".drop (Sample 3 seed=42) == "HeloWorl!"
+@range Text_Sub_Range.default_widget
 Text.drop : (Text_Sub_Range | Index_Sub_Range | Range) -> Text ! Index_Out_Of_Bounds
 Text.drop self range=(Index_Sub_Range.First 1) =
     ranges = Codepoint_Ranges.resolve self range

distribution/lib/Standard/Base/0.0.0-dev/src/Data/Text/Text_Sub_Range.enso

@@ -6,6 +6,7 @@ import project.Data.Range.Range
 import project.Data.Text.Text
 import project.Data.Vector.Vector
 import project.Errors.Common.Index_Out_Of_Bounds
+import project.Errors.Common.Type_Error
 import project.Error.Error
 import project.Errors.Illegal_Argument.Illegal_Argument
 import project.Nothing.Nothing
@@ -16,6 +17,11 @@ from project.Data.Boolean import Boolean, True, False
 
 import project.Data.Index_Sub_Range as Index_Sub_Range_Module
 import project.Data.Text.Span as Span_Module
+from project.Data.Index_Sub_Range import handle_unmatched_type
+
+from project.Metadata.Widget import Single_Choice
+from project.Metadata.Choice import Option
+import project.Metadata.Display
 
 polyglot java import com.ibm.icu.text.BreakIterator
 polyglot java import org.enso.base.Text_Utils
@@ -41,13 +47,31 @@ type Text_Sub_Range
     After_Last (delimiter : Text)
 
     ## PRIVATE
-       Convert to a display representation of this Index_Sub_Range.
+       Convert to a display representation of this `Text_Sub_Range`.
     to_display_text : Text
     to_display_text self = case self of
-        Text_Sub_Range.Before delimiter -> "Before " + delimiter.to_display_text
-        Text_Sub_Range.Before_Last delimiter -> "Before Last " + delimiter.to_display_text
-        Text_Sub_Range.After delimiter -> "After " + delimiter.to_display_text
-        Text_Sub_Range.After_Last delimiter -> "After Last " + delimiter.to_display_text
+        Text_Sub_Range.Before delimiter -> "Before " + delimiter.pretty
+        Text_Sub_Range.Before_Last delimiter -> "Before Last " + delimiter.pretty
+        Text_Sub_Range.After delimiter -> "After " + delimiter.pretty
+        Text_Sub_Range.After_Last delimiter -> "After Last " + delimiter.pretty
+
+    ## PRIVATE
+    default_options : Vector Option
+    default_options =
+        o1 = Option "Before" "(Text_Sub_Range.Before ' ')"
+        o2 = Option "Before_Last" "(Text_Sub_Range.Before_Last ' ')"
+        o3 = Option "After" "(Text_Sub_Range.After ' ')"
+        o4 = Option "After_Last" "(Text_Sub_Range.After_Last ' ')"
+        [o1, o2, o3, o4]
+
+    ## PRIVATE
+       The widget for `Text_Sub_Range` also displays options for
+       `Index_Sub_Range` since the former is supposed to 'expand' the latter and
+       is always used together with it.
+    default_widget : Single_Choice
+    default_widget =
+        options = Index_Sub_Range.default_options + Text_Sub_Range.default_options
+        Single_Choice display=Display.Always options
 
 type Codepoint_Ranges
     ## PRIVATE
@@ -64,7 +88,7 @@ type Codepoint_Ranges
        Returns a new sorted list of ranges where intersecting ranges have been
        merged.
 
-       Empty subranges are not discarded.
+       Empty ranges are not discarded.
     sorted_and_distinct_ranges : Vector Range
     sorted_and_distinct_ranges self = if self.is_sorted_and_distinct then self.ranges else
         Index_Sub_Range_Module.sort_and_merge_ranges self.ranges
@@ -80,8 +104,8 @@ type Codepoint_Ranges
        in such a way that the ranges returned by this method always have a step
        equal to 1.
     resolve : Text -> (Text_Sub_Range | Index_Sub_Range | Range | Integer) -> (Range | Codepoint_Ranges)
-    resolve text subrange =
-        case subrange of
+    resolve text range =
+        case range of
             Text_Sub_Range.Before delimiter ->
                 if delimiter.is_empty then (0.up_to 0) else
                     span = Text_Utils.span_of text delimiter
@@ -134,12 +158,14 @@ type Codepoint_Ranges
                 if step <= 0 then Error.throw (Illegal_Argument.Error "Step within Every must be positive.") else
                     len = text.length
                     if start >= len then 0.up_to 0 else
-                        range = start.up_to text.length . with_step step
-                        Codepoint_Ranges.resolve text (Index_Sub_Range.By_Index range)
+                        simple_range = start.up_to text.length . with_step step
+                        Codepoint_Ranges.resolve text (Index_Sub_Range.By_Index simple_range)
             _ : Range ->
-                Codepoint_Ranges.resolve text (Index_Sub_Range.By_Index subrange)
+                Codepoint_Ranges.resolve text (Index_Sub_Range.By_Index range)
             _ : Integer ->
-                Codepoint_Ranges.resolve text (Index_Sub_Range.First subrange)
+                Codepoint_Ranges.resolve text (Index_Sub_Range.First range)
+            _ -> handle_unmatched_type [Text_Sub_Range, Index_Sub_Range, Range, Integer] range
+
 
 ## PRIVATE
    Utility function to find char indices for Text_Sub_Range.

distribution/lib/Standard/Base/0.0.0-dev/src/Data/Vector.enso

@@ -758,6 +758,7 @@ type Vector a
          If an `Index_Sub_Range`, then the selection is interpreted following
          the rules of that type.
          If a `Range`, the selection is specified by two indices, from and to.
+    @range Index_Sub_Range.default_widget
     take : (Index_Sub_Range | Range | Integer) -> Vector Any
     take self range=(Index_Sub_Range.First 1) = case range of
         ## We are using a specialized implementation for `take Sample`, because
@@ -777,6 +778,7 @@ type Vector a
          If an `Index_Sub_Range`, then the selection is interpreted following
          the rules of that type.
          If a `Range`, the selection is specified by two indices, from and to.
+    @range Index_Sub_Range.default_widget
     drop : (Index_Sub_Range | Range | Integer) -> Vector Any
     drop self range=(Index_Sub_Range.First 1) =
         drop_helper self.length (self.at _) self.slice (slice_ranges self) range

distribution/lib/Standard/Base/0.0.0-dev/src/Meta.enso

@@ -44,10 +44,18 @@ type Type
     ## ADVANCED
 
        Returns the fully qualified name of the type.
+    qualified_name : Text
+    qualified_name self =
+        c = self.value
+        get_qualified_type_name c
+
+    ## ADVANCED
+
+       Returns the short name of the type.
     name : Text
     name self =
-        c = self.value ...
-        get_constructor_name c
+        c = self.value
+        get_short_type_name c
 
 type Atom
     ## PRIVATE
@@ -111,6 +119,13 @@ type Constructor
         ctor = self.value ...
         new_atom ctor fields.to_array
 
+    ## ADVANCED
+       Returns the type that this constructor is a part of.
+    declaring_type : Type
+    declaring_type self =
+        c = self.value ...
+        Type.Value (get_constructor_declaring_type c)
+
 type Primitive
     ## PRIVATE
        ADVANCED
@@ -504,3 +519,19 @@ get_simple_type_name value = @Builtin_Method "Meta.get_simple_type_name"
    - value: the value to get the type of.
 get_qualified_type_name : Any -> Text
 get_qualified_type_name value = @Builtin_Method "Meta.get_qualified_type_name"
+
+## PRIVATE
+   Returns a short name of a type (the last part of its qualified name).
+
+   Arguments:
+   - typ: the type to get the short name of.
+get_short_type_name : Any -> Text
+get_short_type_name typ = @Builtin_Method "Meta.get_short_type_name"
+
+## PRIVATE
+   Returns the type that this constructor is a part of.
+
+   Arguments:
+   - constructor: the constructor to get the declaring type of.
+get_constructor_declaring_type : Any -> Any
+get_constructor_declaring_type constructor = @Builtin_Method "Meta.get_constructor_declaring_type"

distribution/lib/Standard/Database/0.0.0-dev/src/Data/Column.enso

@@ -749,6 +749,7 @@ type Column
 
        Arguments:
        - range: The selection of rows from the table to return.
+    @range Index_Sub_Range.default_widget
     take : (Index_Sub_Range | Range | Integer) -> Column
     take self range=(First 1) =
         _ = range
@@ -761,6 +762,7 @@ type Column
 
        Arguments:
        - range: The selection of rows from the table to remove.
+    @range Index_Sub_Range.default_widget
     drop : (Index_Sub_Range | Range | Integer) -> Column
     drop self range=(First 1) =
         _ = range

distribution/lib/Standard/Database/0.0.0-dev/src/Data/Table.enso

@@ -522,6 +522,7 @@ type Table
 
        Arguments:
        - range: The selection of rows from the table to return.
+    @range Index_Sub_Range.default_widget
     take : (Index_Sub_Range | Range | Integer) -> Table
     take self range=(First 1) =
         _ = range
@@ -535,6 +536,7 @@ type Table
 
        Arguments:
        - range: The selection of rows from the table to remove.
+    @range Index_Sub_Range.default_widget
     drop : (Index_Sub_Range | Range | Integer) -> Table
     drop self range=(First 1) =
         _ = range

distribution/lib/Standard/Table/0.0.0-dev/src/Data/Column.enso

@@ -1547,6 +1547,7 @@ type Column
 
        Arguments:
        - range: The selection of rows from the table to return.
+    @range Index_Sub_Range.default_widget
     take : (Index_Sub_Range | Range | Integer) -> Column
     take self range=(First 1) =
         Index_Sub_Range_Module.take_helper self.length self.at self.slice (slice_ranges self) range
@@ -1556,6 +1557,7 @@ type Column
 
        Arguments:
        - range: The selection of rows from the table to remove.
+    @range Index_Sub_Range.default_widget
     drop : (Index_Sub_Range | Range | Integer) -> Column
     drop self range=(First 1) =
         Index_Sub_Range_Module.drop_helper self.length self.at self.slice (slice_ranges self) range

distribution/lib/Standard/Table/0.0.0-dev/src/Data/Table.enso

@@ -1148,6 +1148,7 @@ type Table
          Take rows from the top of the table as long as their values sum to 10.
 
              table.take (While row-> row.to_vector.compute Statistic.Sum == 10)
+    @range Index_Sub_Range.default_widget
     take : (Index_Sub_Range | Range | Integer) -> Table
     take self range=(First 1) =
         Index_Sub_Range_Module.take_helper self.row_count self.rows.at self.slice (slice_ranges self) range
@@ -1170,6 +1171,7 @@ type Table
          Drop rows from the top of the table as long as their values sum to 10.
 
              table.drop (While row-> row.to_vector.compute Statistic.Sum == 10)
+    @range Index_Sub_Range.default_widget
     drop : (Index_Sub_Range | Range | Integer) -> Table
     drop self range=(First 1) =
         Index_Sub_Range_Module.drop_helper self.row_count self.rows.at self.slice (slice_ranges self) range

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/GetConstructorDeclaringTypeNode.java

@@ -0,0 +1,17 @@
+package org.enso.interpreter.node.expression.builtin.meta;
+
+import com.oracle.truffle.api.nodes.Node;
+import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
+import org.enso.interpreter.runtime.data.Type;
+
+@BuiltinMethod(
+    type = "Meta",
+    name = "get_constructor_declaring_type",
+    description = "Gets the type that declared this constructor.",
+    autoRegister = false)
+public class GetConstructorDeclaringTypeNode extends Node {
+  Type execute(AtomConstructor cons) {
+    return cons.getType();
+  }
+}

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/GetConstructorNameNode.java

@@ -12,20 +12,8 @@ import org.enso.interpreter.runtime.data.text.Text;
     name = "get_constructor_name",
     description = "Gets the name of a constructor.",
     autoRegister = false)
-public abstract class GetConstructorNameNode extends Node {
-  static GetConstructorNameNode build() {
-    return GetConstructorNameNodeGen.create();
-  }
-
-  abstract Text execute(Object atom_constructor);
-
-  @Specialization
-  Text doConstructor(AtomConstructor cons) {
+public class GetConstructorNameNode extends Node {
+  Text execute(AtomConstructor cons) {
     return Text.create(cons.getName());
   }
-
-  @Specialization
-  Text doType(Type type) {
-    return Text.create(type.getQualifiedName().toString());
-  }
 }

engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/GetShortTypeNameNode.java

@@ -0,0 +1,19 @@
+package org.enso.interpreter.node.expression.builtin.meta;
+
+import com.oracle.truffle.api.dsl.Specialization;
+import com.oracle.truffle.api.nodes.Node;
+import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
+import org.enso.interpreter.runtime.data.Type;
+import org.enso.interpreter.runtime.data.text.Text;
+
+@BuiltinMethod(
+    type = "Meta",
+    name = "get_short_type_name",
+    description = "Gets the short name of a Type.",
+    autoRegister = false)
+public class GetShortTypeNameNode extends Node {
+  Text execute(Type type) {
+    return Text.create(type.getName());
+  }
+}

test/Table_Tests/src/Common_Table_Operations/Take_Drop_Spec.enso

@@ -1,6 +1,7 @@
 from Standard.Base import all
 from Standard.Base.Data.Index_Sub_Range.Index_Sub_Range import While, Sample, Every
 import Standard.Base.Errors.Common.Index_Out_Of_Bounds
+import Standard.Base.Errors.Common.Type_Error
 import Standard.Base.Errors.Illegal_Argument.Illegal_Argument
 
 from Standard.Table.Errors import all
@@ -151,8 +152,30 @@ spec setup =
             rnd.at "alpha" . to_vector . should_equal alpha_sample
             rnd.at "beta" . to_vector . should_equal beta_sample
 
-        Test.specify "should allow selecting rows as long as they satisfy a predicate" pending="While is not implemented for Table until the Row type is implemented." <|
-            Nothing
+        Test.specify "should allow selecting rows as long as they satisfy a predicate" <|
+            t = table_builder [["a", [1, 2, 3, 4]], ["b", [5, 6, 7, 8]]]
+
+            t2 = t.take (While (row -> row.at "a" < 3))
+            t2.row_count . should_equal 2
+            t2.at "a" . to_vector . should_equal [1, 2]
+            t2.at "b" . to_vector . should_equal [5, 6]
+
+        Test.specify "should gracefully handle missing constructor arguments" <|
+            t = table_builder [["X", [1, 2, 3]]]
+            t.take "FOO" . should_fail_with Type_Error
+            t.drop "FOO" . should_fail_with Type_Error
+
+            r1 = t.take (Index_Sub_Range.While)
+            r1.should_fail_with Illegal_Argument
+            r1.catch.to_display_text . should_contain "The constructor While is missing some arguments"
+
+            r2 = t.drop (Index_Sub_Range.Every ...)
+            r2.should_fail_with Illegal_Argument
+            r2.catch.to_display_text . should_contain "The constructor Every is missing some arguments"
+
+            r3 = t.take (Index_Sub_Range.First _)
+            r3.should_fail_with Illegal_Argument
+            r3.catch.to_display_text . should_contain "Got a Function instead of a range, is a constructor argument missing?"
 
     Test.group prefix+"Column.take/drop" pending=take_drop_by_pending <|
         table =
@@ -310,3 +333,20 @@ spec setup =
 
             three.drop (While (_ > 10)) . should_equal three
             three.drop (While (_ < 10)) . should_equal empty
+
+        Test.specify "should gracefully handle missing constructor arguments" <|
+            c = table_builder [["X", [1, 2, 3]]] . at "X"
+            c.take "FOO" . should_fail_with Type_Error
+            c.drop "FOO" . should_fail_with Type_Error
+
+            r1 = c.take (Index_Sub_Range.While)
+            r1.should_fail_with Illegal_Argument
+            r1.catch.to_display_text . should_contain "The constructor While is missing some arguments"
+
+            r2 = c.drop (Index_Sub_Range.Every ...)
+            r2.should_fail_with Illegal_Argument
+            r2.catch.to_display_text . should_contain "The constructor Every is missing some arguments"
+
+            r3 = c.take (Index_Sub_Range.First _)
+            r3.should_fail_with Illegal_Argument
+            r3.catch.to_display_text . should_contain "Got a Function instead of a range, is a constructor argument missing?"

test/Tests/src/Data/Text_Spec.enso

@@ -736,6 +736,25 @@ spec =
             "".drop (Sample 0) . should_equal ""
             "".drop (Sample 100) . should_equal ""
 
+        Test.specify "take and drop should gracefully handle missing constructor arguments" <|
+            "".take "FOO" . should_fail_with Type_Error
+            "".drop "FOO" . should_fail_with Type_Error
+
+            r1 = "".take (Index_Sub_Range.While)
+            r1.should_fail_with Illegal_Argument
+            r1.catch.to_display_text . should_contain "The constructor While is missing some arguments"
+
+            r2 = "".drop (Text_Sub_Range.Before ...)
+            r2.should_fail_with Illegal_Argument
+            r2.catch.to_display_text . should_contain "The constructor Before is missing some arguments"
+
+            r3 = "".take (Index_Sub_Range.First _)
+            r3.should_fail_with Illegal_Argument
+            r3.catch.to_display_text . should_contain "Got a Function instead of a range, is a constructor argument missing?"
+
+            # Double-check that constructors of _unexpected_ types are still yielding a type error.
+            "".take (Case_Sensitivity.Insensitive ...) . should_fail_with Type_Error
+
         Test.specify "should correctly convert character case" <|
             "FooBar Baz".to_case Case.Lower . should_equal "foobar baz"
             "FooBar Baz".to_case Case.Upper . should_equal "FOOBAR BAZ"

test/Tests/src/Data/Vector_Spec.enso

@@ -413,7 +413,7 @@ type_spec name alter = Test.group name <|
         vec.slice 1 1 . should_equal []
         vec.slice 0 100 . should_equal [1, 2, 3, 4, 5, 6]
         Meta.is_same_object vec (vec.slice 0 100) . should_be_true
-        Meta.meta Vector . name . should_equal (Meta.get_qualified_type_name (vec.slice 1 1))
+        Meta.get_qualified_type_name (vec.slice 1 1) . should_equal (Meta.meta Vector . qualified_name)
 
     Test.specify "should define take and drop family of operations" <|
         vec = alter [1, 2, 3, 4, 5, 6]
@@ -536,6 +536,22 @@ type_spec name alter = Test.group name <|
         alter ["a", "a", "a"] . drop (Sample 1) . should_equal ["a", "a"]
         alter ["a", "a", "a"] . drop (Sample 100) . should_equal []
 
+    Test.specify "take/drop should gracefully handle missing constructor arguments" <|
+        [].take "FOO" . should_fail_with Type_Error
+        [].drop "FOO" . should_fail_with Type_Error
+
+        r1 = [].take (Index_Sub_Range.While)
+        r1.should_fail_with Illegal_Argument
+        r1.catch.to_display_text . should_contain "The constructor While is missing some arguments"
+
+        r2 = [].drop (Index_Sub_Range.Every ...)
+        r2.should_fail_with Illegal_Argument
+        r2.catch.to_display_text . should_contain "The constructor Every is missing some arguments"
+
+        r3 = [].take (Index_Sub_Range.First _)
+        r3.should_fail_with Illegal_Argument
+        r3.catch.to_display_text . should_contain "Got a Function instead of a range, is a constructor argument missing?"
+
     Test.specify "should allow getting the last element of the vector" <|
         non_empty_vec = alter [1, 2, 3, 4, 5]
         singleton_vec = alter [1]
@@ -763,5 +779,10 @@ spec =
         arr
     type_spec "Use Array_Proxy as vectors" v->
         Array_Proxy.new v.length (ix -> v.at ix)
+    type_spec "Use a slice of an array as vectors" v->
+        v2 = v+[Nothing]
+        sliced_vector = v2.slice 0 v.length
+        sliced_array = sliced_vector.to_array
+        sliced_array
 
 main = Test_Suite.run_main spec

test/Tests/src/Semantic/Meta_Spec.enso

@@ -207,6 +207,7 @@ spec =
             Meta.is_atom typ . should_be_false
             meta_typ = Meta.meta typ
             meta_typ . should_be_a Meta.Type
+            meta_typ.name . should_equal "Boolean"
             cons = case meta_typ of
                 Meta.Type.Value _ -> meta_typ.constructors
                 _ -> Test.fail "Should be a Meta.Type.Value: " + meta_typ.to_text
@@ -222,6 +223,7 @@ spec =
             Meta.is_atom typ . should_be_false
             meta_typ = Meta.meta typ
             meta_typ . should_be_a Meta.Type
+            meta_typ.name . should_equal "My_Type"
             cons = case meta_typ of
                 Meta.Type.Value _ -> meta_typ.constructors
                 _ -> Test.fail "Should be a Meta.Type.Value: " + meta_typ.to_text
@@ -229,6 +231,8 @@ spec =
             cons.length . should_equal 1
             cons.at 0 . should_be_a Meta.Constructor
             cons . map (x -> x.name) . sort . should_equal [ "Value" ]
+            cons.each ctor->
+                ctor.declaring_type . should_equal meta_typ
 
         Test.specify "methods of MyType" <|
             typ = My_Type

test/Visualization_Tests/src/Widgets/Text_Widgets_Spec.enso

@@ -0,0 +1,35 @@
+from Standard.Base import all
+import Standard.Base.Runtime.State
+
+import Standard.Base.Metadata.Choice
+import Standard.Base.Metadata.Widget
+import Standard.Base.Metadata.Display
+
+import Standard.Visualization.Widgets
+
+from Standard.Test import Test, Test_Suite
+import Standard.Test.Extensions
+
+spec =
+    Test.group "Widgets for the Text type" <|
+        Test.specify "works for `take` and `drop`" <|
+            mock_text = "abc def"
+            default_widget = Text_Sub_Range.default_widget
+            expect = [["range", default_widget]] . to_json
+            json = Widgets.get_widget_json mock_text "take" ["range"]
+            json . should_equal expect
+            Widgets.get_widget_json mock_text "drop" ["range"] . should_equal expect
+            obj = json.parse_json
+            widget = obj.first.second
+            options = widget . at "values"
+            options.each o-> Test.with_clue o.to_text+": " <|
+                o.should_be_a JS_Object
+            labels = options.map o->
+                o.at "label"
+            labels.should_be_a Vector
+            labels.should_contain "First"
+            labels.should_contain "While"
+            labels.should_contain "After"
+            labels.should_contain "Before_Last"
+
+main = Test_Suite.run_main spec

test/Visualization_Tests/src/Widgets_Spec.enso

@@ -4,9 +4,11 @@ from Standard.Test import Test_Suite
 
 import project.Widgets.Database_Widgets_Spec
 import project.Widgets.Table_Widgets_Spec
+import project.Widgets.Text_Widgets_Spec
 
 spec =
     Table_Widgets_Spec.spec
     Database_Widgets_Spec.spec
+    Text_Widgets_Spec.spec
 
 main = Test_Suite.run_main spec