Merge branch 'develop' into wip/jtulach/PolyglotDateSupport_181755990

CHANGELOG.md

@@ -147,8 +147,10 @@
 - [Added `File_Format.Delimited` support to `Table.write` for new files.][3528]
 - [Adjusted `Database.connect` API to new design.][3542]
 - [Added `File_Format.Excel` support to `Table.write` for new files.][3551]
+- [identity,const,flip,curry,uncurry functions][3554]
 - [Added append support for `File_Format.Excel`.][3558]
 - [Added support for custom encodings in `File_Format.Delimited` writing.][3564]
+- [Allow filtering caught error type in `Error.catch`.][3574]
 
 [debug-shortcuts]:
   https://github.com/enso-org/enso/blob/develop/app/gui/docs/product/shortcuts.md#debug
@@ -235,8 +237,10 @@
 [3542]: https://github.com/enso-org/enso/pull/3542
 [3551]: https://github.com/enso-org/enso/pull/3551
 [3552]: https://github.com/enso-org/enso/pull/3552
+[3554]: https://github.com/enso-org/enso/pull/3554
 [3558]: https://github.com/enso-org/enso/pull/3558
 [3564]: https://github.com/enso-org/enso/pull/3564
+[3574]: https://github.com/enso-org/enso/pull/3574
 
 #### Enso Compiler
 

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

@@ -1,5 +1,7 @@
 from Standard.Base import all
 
+from Standard.Base.Error.Common import dataflow_error_handler
+
 # The type that subsumes all types.
 type Any
 
@@ -18,7 +20,7 @@ type Any
        Arguments:
        - handler: The function to call on this if it is an error value.
     catch_primitive : (Error -> Any) -> Any
-    catch_primitive handler = @Builtin_Method "Any.catch"
+    catch_primitive handler = @Builtin_Method "Any.catch_primitive"
 
     ## Generic conversion of an arbitrary Enso value to a corresponding textual
        representation.
@@ -246,23 +248,37 @@ type Any
     if_nothing : Any -> Any
     if_nothing ~_ = self
 
-    ## Executes the provided handler on an error, or returns a non-error value
+    ## Executes the provided handler on an error, or returns the value unchanged.
-       unchanged.
 
        Arguments:
-       - handler: The function to call on this if it is an error value. By default
+       - error_type: The type of error to handle. Defaults to `Any` to handle
-         this is identity.
+         all errors.
+       - handler: The function to call on this if it is an error value of a
+         matching type. By default this is identity.
 
        > Example
-         Catching an erroneous value and getting the length of its message.
+         Catching an `Illegal_Argument_Error` and returning its message.
 
              from Standard.Base import all
 
              example_catch =
-                 error = Error.throw "My message"
+                 error = Error.throw (Illegal_Argument_Error "My message")
-                 error.catch (err -> err.length)
+                 error.catch Illegal_Argument_Error (err -> err.message)
-    catch : (Error -> Any) -> Any
+
-    catch (handler = x->x) = self.catch_primitive handler
+       > Example
+         Catching any dataflow error and turning it into a regular value.
+
+             from Standard.Base import all
+
+             example_catch =
+                 error = Error.throw 42
+                 error.catch == 42
+    catch : Any -> (Error -> Any) -> Any
+    catch (error_type = Any) (handler = x->x) =
+        self.catch_primitive error_value->
+            case error_value.is_a error_type of
+                True -> handler error_value
+                False -> self
 
     ## Transforms an error.
 

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

@@ -38,8 +38,8 @@ from_pairs contents =
          example_parse = Json.parse '{ "a": 1 }'
 parse : Text -> Json ! Parse_Error
 parse json_text =
-    Panic.catch Polyglot_Error (Internal.parse_helper json_text) caught_panic->
+    Panic.catch_java Any (Internal.parse_helper json_text) java_exception->
-        Error.throw (Parse_Error caught_panic.payload.cause.getMessage)
+        Error.throw (Parse_Error java_exception.getMessage)
 
 ## Represents a JSON structure.
 type Json

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

@@ -308,7 +308,7 @@ into_helper fmt json = case fmt of
                     fnames = cons.fields
                     ffmts = m.fields
                     field_values = fnames.zip ffmts n-> inner_fmt->
-                        fjson = json_fields . get n . catch _->
+                        fjson = json_fields . get n . catch Any _->
                             Panic.throw (Missing_Field_Error json fmt n)
                         into_helper inner_fmt fjson
                     cons.new field_values

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

@@ -217,7 +217,7 @@ type Map
              example_get_or_else = Examples.map.get_or_else 2 "zero"
     get_or_else : Any -> Any -> Any
     get_or_else key ~other =
-        self.get key . catch (_ -> other)
+        self.get key . catch No_Value_For_Key_Error (_ -> other)
 
     ## Transforms the map's keys and values to create a new map.
 

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

@@ -56,9 +56,8 @@ now = Time ZonedDateTime.now
          example_new = Time.new 1986 8 5
 new : Integer -> Integer -> Integer -> Integer -> Integer -> Integer -> Integer -> Zone -> Time ! Time_Error
 new year (month = 1) (day = 1) (hour = 0) (minute = 0) (second = 0) (nanosecond = 0) (zone = Zone.system) =
-    Panic.recover Any (Time (ZonedDateTime.of year month day hour minute second nanosecond zone.internal_zone_id)) . catch e-> case e of
+    Panic.catch_java Any (Time (ZonedDateTime.of year month day hour minute second nanosecond zone.internal_zone_id)) java_exception->
-        Polyglot_Error err -> Error.throw (Time_Error err.getMessage)
+        Error.throw (Time_Error java_exception.getMessage)
-        x -> x
 
 ## ALIAS Time from Text
 
@@ -122,8 +121,7 @@ new year (month = 1) (day = 1) (hour = 0) (minute = 0) (second = 0) (nanosecond
 
          import Standard.Base.Data.Time
 
-         example_parse = Time.parse "2020-10-01" . catch e-> case e of
+         example_parse = Time.parse "2020-10-01" . catch Time_Error (_->Time.now)
-             Time.Error _ -> Time.now
 
    > Example
      Parse "2020-05-06 04:30:20" as Time

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

@@ -60,7 +60,14 @@ today = now
 
 new : Integer -> Integer -> Integer -> Date ! Time.Time_Error
 new year (month = 1) (day = 1) =
-    Panic.recover Any (LocalDate.of year month day) . catch e-> case e of
+    ## TODO This is left using the old error handling approach, because
+       magically, changing this to the `catch_java` (which is now preferred way
+       of catching Polyglot_Errors) lead to the "should format local date using
+       provided pattern" test failing because it called the `LocalDate.format`
+       instead of Enso format. Hopefully this will be fixed with
+       https://github.com/enso-org/enso/pull/3559
+       Then this should be switched to use `Panic.catch_java`.
+    Panic.recover Any (LocalDate.of year month day) . catch Any e-> case e of
         Polyglot_Error err -> Error.throw (Time.Time_Error err.getMessage)
         x -> x
 
@@ -107,8 +114,8 @@ new year (month = 1) (day = 1) =
          import Standard.Base.Data.Time.Date
          import Standard.Base.Data.Time
 
-         example_parse_err = Date.parse "my birthday" . catch e-> case e of
+         example_parse_err = Date.parse "my birthday" . catch Time.Time_Error _->
-             Time.Time_Error _ -> Date.new 2000 1 1
+             Date.new 2000 1 1
 
    > Example
      Parse "1999-1-1" as Date using a custom format.
@@ -125,8 +132,7 @@ new year (month = 1) (day = 1) =
 
          example_parse_err =
              date = Date.parse "1999-1-1" "yyyy-MM-dd"
-             date.catch e-> case e of
+             date.catch Time.Time_Error (_->Date.new 2000 1 1)
-                 Time.Time_Error _ -> Date.new 2000 1 1
 parse : Text -> (Text | Nothing) -> Date ! Time.Time_Error
 parse text pattern=Nothing =
     result = Panic.recover Any <| case pattern of

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

@@ -48,9 +48,8 @@ now = Time_Of_Day LocalTime.now
          example_epoch = Time_Of_Day.new hour=9 minute=30
 new : Integer -> Integer -> Integer -> Integer -> Time_Of_Day ! Time.Time_Error
 new (hour = 0) (minute = 0) (second = 0) (nanosecond = 0) =
-    Panic.recover Any (Time_Of_Day (LocalTime.of hour minute second nanosecond)) . catch e-> case e of
+    Panic.catch_java Any (Time_Of_Day (LocalTime.of hour minute second nanosecond)) java_exception->
-        Polyglot_Error err -> Error.throw (Time.Time_Error err.getMessage)
+        Error.throw (Time.Time_Error java_exception.getMessage)
-        x -> x
 
 ## Obtains an instance of `Time_Of_Day` from a text such as "10:15".
 
@@ -97,8 +96,8 @@ new (hour = 0) (minute = 0) (second = 0) (nanosecond = 0) =
          import Standard.Base.Data.Time
          import Standard.Base.Data.Time.Time_Of_Day
 
-         example_parse = Time_Of_Day.parse "half twelve" . catch e-> case e of
+         example_parse = Time_Of_Day.parse "half twelve" . catch Time.Time_Error _->
-             Time.Time_Error _ -> Time_Of_Day.new
+             Time_Of_Day.new
 
    > Example
      Parse "04:30:20" as Time_Of_Day.

distribution/lib/Standard/Base/0.0.0-dev/src/Error/Common.enso

@@ -61,24 +61,39 @@ type Error
 
        Returns a human-readable text representing this error.
     to_display_text : Text
-    to_display_text  = "Error: " + (self.catch .to_display_text)
+    to_display_text  = "Error: " + (self.catch Any .to_display_text)
 
-    ## Executes the provided handler on a dataflow error, or returns a non-error
+    ## Executes the provided handler on an error, or returns the value unchanged.
-       value unchanged.
 
        Arguments:
-       - handler: The function to call on this if it is an error value. By default
+       - error_type: The type of error to handle. Defaults to `Any` to handle
-         this is identity.
+         all errors.
+       - handler: The function to call on this if it is an error value of a
+         matching type. By default this is identity.
 
        > Example
-         Catching an erroneous value and getting the length of its message.
+         Catching an `Illegal_Argument_Error` and returning its message.
 
-             import Standard.Examples
+             from Standard.Base import all
 
              example_catch =
-                 Examples.throw_error.catch (err -> err.message.length)
+                 error = Error.throw (Illegal_Argument_Error "My message")
-    catch : (Error -> Any) -> Any
+                 error.catch Illegal_Argument_Error (err -> err.message)
-    catch (handler = x->x) = self.catch_primitive handler
+
+       > Example
+         Catching any dataflow error and turning it into a regular value.
+
+             from Standard.Base import all
+
+             example_catch =
+                 error = Error.throw 42
+                 error.catch == 42
+    catch : Any -> (Error -> Any) -> Any
+    catch (error_type = Any) (handler = x->x) =
+        self.catch_primitive error_value->
+            case error_value.is_a error_type of
+                True -> handler error_value
+                False -> self
 
     ## UNSTABLE
 
@@ -91,7 +106,7 @@ type Error
 
              example_display = Examples.throw_error.to_default_visualization_data
     to_default_visualization_data : Text
-    to_default_visualization_data = self.catch .to_default_visualization_data
+    to_default_visualization_data = self.catch Any .to_default_visualization_data
 
     ## UNSTABLE
 
@@ -106,8 +121,9 @@ type Error
     to_json : Json.Object
     to_json =
         error_type = ["type", "Error"]
-        error_content = ["content", self.catch .to_json]
+        caught = self.catch
-        error_message = ["message", self.catch .to_display_text]
+        error_content = ["content", caught.to_json]
+        error_message = ["message", caught.to_display_text]
         Json.from_pairs [error_type, error_content, error_message]
 
     ## Transforms an error.
@@ -127,7 +143,7 @@ type Error
                  map = Examples.map
                  map.get 10 . map_error (_ -> "The element 10 was not found.")
     map_error : (Error -> Error) -> Any
-    map_error f = self.catch (x -> Error.throw (f x))
+    map_error f = self.catch Any (x -> Error.throw (f x))
 
     ## ADVANCED
        UNSTABLE
@@ -297,7 +313,7 @@ type Panic
 
              example_rethrow = Panic.rethrow Examples.throw_error
     rethrow : (Any ! Any) -> Any
-    rethrow value = value.catch Panic.throw
+    rethrow value = value.catch Any Panic.throw
 
     ## Executes the provided action and if a panic matching the provided type was
        thrown, calls the provided callback.
@@ -351,6 +367,36 @@ type Panic
                             False -> Panic.throw caught_panic
                     _ -> Panic.throw caught_panic
 
+    ## Executes the provided action and if a Java exception matching the provided type was
+       thrown, calls the provided callback.
+
+       Normally, Java exceptions are wrapped in a `Polyglot_Error` instance, so
+       using a `Panic.catch` requires unwrapping the error by calling
+       `caught_panic.payload.cause`. This helper function allows the handler to
+       work with the Java exception directly. The downside is that if the Java
+       exception is rethrown, it will be rethrown as a Java exception object
+       wrapped in an Enso panic. So if the handler needs to rethrow the original
+       exception preserving its shape and stacktrace, `Panic.catch` should still
+       be preferred.`
+
+       > Example
+         Convert a string to an integer, catching the Java `NumberFormatException`
+         and converting it to a more Enso-friendly dataflow error.
+
+             polyglot java import java.lang.Long
+             polyglot java import java.lang.NumberFormatException
+             parse str =
+                 Panic.catch_java NumberFormatException (Long.parseLong str) java_exception->
+                     Error.throw (Illegal_Argument_Error "The provided string is not a valid number: "+java_exception.getMessage)
+    catch_java : Any -> Any -> (Throwable -> Any) -> Any
+    catch_java panic_type ~action handler =
+        Panic.catch_primitive action caught_panic-> case caught_panic.payload of
+            Polyglot_Error java_exception ->
+                case (panic_type == Any) || (Java.is_instance java_exception panic_type) of
+                    True -> handler java_exception
+                    False -> Panic.throw caught_panic
+            _ -> Panic.throw caught_panic
+
     ## Executes the provided action and converts a possible panic matching any of
        the provided types into a dataflow Error.
 

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

@@ -1,3 +1,5 @@
+import Standard.Base.Data.Vector
+
 # Function types.
 type Function
 
@@ -7,3 +9,56 @@ type Function
        the this argument.
     @Builtin_Type
     type Function
+
+
+## An identity function which returns the provided argument.
+
+   Arguments:
+   - x: the value to return.
+
+   > Example
+     five = Function.identity 5 # returns number 5
+
+identity : a -> a
+identity x = x
+
+## Flips the first two arguments of a function. Returns function that
+   takes two arguments, but in opposite order.
+
+   Arguments:
+   - f function that takes two arguments
+
+   > Example
+    IO.println <| Function.flip (+) "world" "hello" # Prints 'helloworld'
+
+flip : (a -> b -> c) -> (b -> a -> c)
+flip f = (x -> y -> f y x)
+
+
+## Creates a function which drops its input and returns the provided value instead.
+   The expression const a is the same as \_ -> a.
+
+   Arguments:
+   - x constant value to return
+
+   > Example
+    IO.println <| [1, 2, 3].map (Function.const 7) # Prints '[7, 7, 7]'
+
+const : a -> b -> a
+const x _ = x
+
+## Converts a single-argument function accepting a pair of elements into a multi-argument one.
+
+   Arguments:
+   - f function accepting pair of values
+
+curry : ([a, b] -> c) -> (a -> b -> c)
+curry f = x -> y -> f [x, y]
+
+## Converts a multi-argument function into a single-argument one accepting a pair of elements.
+
+   Arguments:
+   - f function accepting multiple arguments
+
+uncurry : (a -> b -> c) -> ([a, b] -> c)
+uncurry f = (pair -> f pair.head pair.second)

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

@@ -293,7 +293,7 @@ Base.Error.is_a typ = self.is_an typ
    Arguments:
    - typ: The type to check `self` against.
 Base.Error.is_an : Any -> Boolean
-Base.Error.is_an typ = typ == Base.Error
+Base.Error.is_an typ = typ==Any || typ==Base.Error
 
 ## UNSTABLE
    ADVANCED

distribution/lib/Standard/Base/0.0.0-dev/src/Network/Http.enso

@@ -10,7 +10,6 @@ import Standard.Base.Network.Http.Request
 import Standard.Base.Network.Http.Request.Body as Request_Body
 import Standard.Base.Network.Http.Response
 import Standard.Base.Network.Http.Version
-import Standard.Base.Network.Internal
 import Standard.Base.Network.Proxy
 import Standard.Base.Network.Uri
 import Standard.Base.System.File
@@ -597,11 +596,13 @@ type Http
                  http.request req
     request : Request -> Response ! Request_Error
     request req =
-        response = Panic.recover Any <|
+        handle_request_error =
+            Panic.catch_java Any handler=(err-> Error.throw (Request_Error err.getClass.getSimpleName err.getMessage))
+        Panic.recover Any <| handle_request_error <|
             body_publishers = HttpRequest.BodyPublishers
             builder = HttpRequest.newBuilder
             # set uri
-            builder.uri (Internal.panic_on_error req.uri.internal_uri)
+            builder.uri (Panic.rethrow req.uri.internal_uri)
             # prepare headers and body
             req_with_body = case req.body of
                 Request_Body.Empty ->
@@ -651,11 +652,6 @@ type Http
             http_request = builder.build
             body_handler = HttpResponse.BodyHandlers . ofByteArray
             Response.Response (self.internal_http_client.send http_request body_handler)
-        response.catch e-> case e of
-            Polyglot_Error err ->
-                Error.throw (Request_Error err.getClass.getSimpleName err.getMessage)
-            _ ->
-                Error.throw e
 
     ## PRIVATE
 

distribution/lib/Standard/Base/0.0.0-dev/src/Network/Http/Request.enso

@@ -4,7 +4,6 @@ import Standard.Base.Network.Http.Form
 import Standard.Base.Network.Http.Header
 import Standard.Base.Network.Http.Method
 import Standard.Base.Network.Http.Request.Body as Request_Body
-import Standard.Base.Network.Internal
 import Standard.Base.Network.Uri
 import Standard.Base.System.File
 
@@ -26,7 +25,7 @@ import Standard.Base.System.File
          example_new = Request.new Method.Post (Uri.parse "http://example.com")
 new : Method -> (Text | Uri) -> Vector.Vector -> Request_Body -> Request
 new method addr (headers = []) (body = Request_Body.Empty) =
-    Panic.recover Any (Request method (Internal.panic_on_error (addr.to_uri)) headers body) . catch Internal.recover_panic
+    Panic.recover Any (Request method (Panic.rethrow (addr.to_uri)) headers body)
 
 ## Create an Options request.
 

distribution/lib/Standard/Base/0.0.0-dev/src/Network/Internal.enso

@@ -1,17 +0,0 @@
-from Standard.Base import all
-
-## PRIVATE
-   
-   Panics on encountering an error.
-
-   Arguments:
-   - action: The action to perform that may recurn an error.
-panic_on_error : Any -> Any
-panic_on_error ~action =
-    action . catch Panic.throw
-
-## PRIVATE
-
-   Recovers from a panic.
-recover_panic : Any -> Error
-recover_panic error = Error.throw error

distribution/lib/Standard/Base/0.0.0-dev/src/Network/Uri.enso

@@ -22,9 +22,8 @@ polyglot java import java.util.Optional
          example_parse = Uri.parse "http://example.com"
 parse : Text -> Uri ! Syntax_Error
 parse text =
-    Panic.recover Any (Uri (Java_URI.create text)) . catch e-> case e of
+    Panic.catch_java Any (Uri (Java_URI.create text)) java_exception->
-        Polyglot_Error ex -> Error.throw (Syntax_Error ex.getMessage)
+        Error.throw (Syntax_Error java_exception.getMessage)
-        other -> Panic.throw other
 
 ## Convert Text to a Uri.
 

distribution/lib/Standard/Base/0.0.0-dev/src/System/File/Existing_File_Behavior.enso

@@ -57,7 +57,7 @@ type Existing_File_Behavior
                    temporary file and creates a backup.
                 handle_file_already_exists <| handle_internal_dataflow <|
                     Panic.rethrow <| file.with_output_stream [Option.Write, Option.Create_New] output_stream->
-                        action output_stream . catch dataflow_error->
+                        action output_stream . catch Any dataflow_error->
                             Panic.throw (Internal_Write_Operation_Errored dataflow_error)
 
 ## PRIVATE
@@ -87,7 +87,7 @@ write_file_backing_up_old_one file action = Panic.recover [Io_Error, File_Not_Fo
                 new_file.with_output_stream [Option.Write, Option.Create_New] output_stream->
                     result = Panic.catch Any (action output_stream) caught_panic->
                         Panic.throw (Internal_Write_Operation_Panicked caught_panic)
-                    result.catch dataflow_error->
+                    result.catch Any dataflow_error->
                         Panic.throw (Internal_Write_Operation_Errored dataflow_error)
             ## We ignore the file not found error, because it means that there
                is no file to back-up. This may also be caused by someone

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

@@ -156,7 +156,7 @@ map_attached_warnings mapper value =
 map_warnings_and_errors : (Any -> Maybe Any) -> Any -> Any
 map_warnings_and_errors mapper value =
     mapped_warnings_or_error = map_attached_warnings_helper mapper value 1
-    mapped_warnings_or_error.catch error->
+    mapped_warnings_or_error.catch Any error->
         case mapper error of
             Maybe.Some new_error -> Error.throw new_error
             ## If the mapper did not want to affect the error, we return the

distribution/lib/Standard/Image/0.0.0-dev/src/Codecs.enso

@@ -38,10 +38,8 @@ read location flags=[] =
             if flags.is_empty then Java_Codecs.READ_FLAG_EMPTY else
                 flags.map .to_integer . reduce (_.bit_or _)
         _ -> flags.to_integer
-    Panic.recover Any (Image.Image (Java_Codecs.read path read_flags)) . catch e->
+    Panic.catch_java Any (Image.Image (Java_Codecs.read path read_flags)) java_exception->
-        case e of
+        Error.throw (File.Io_Error (File.new path) 'Failed to read the file')
-            Polyglot_Error _ -> Error.throw (File.Io_Error (File.new path) 'Failed to read the file')
-            err -> Error.throw err
 
 ## UNSTABLE
 
@@ -71,10 +69,8 @@ Image.Image.write location flags=[] =
         Vector.Vector _ -> flags
         _ -> [flags]
     int_flags = Internal.mat_of_int (write_flags.flat_map x-> [x.to_integer, x.value])
-    Panic.recover Any (Java_Codecs.write path self.opencv_mat int_flags) . catch e->
+    Panic.catch_java Any (Java_Codecs.write path self.opencv_mat int_flags) java_exception->
-        case e of
+        Error.throw (File.Io_Error (File.new path) 'Failed to write to the file')
-            Polyglot_Error _ -> Error.throw (File.Io_Error (File.new path) 'Failed to write to the file')
-            err -> Error.throw err
 
 ## UNSTABLE
 type Read_Flag

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

@@ -153,7 +153,7 @@ type Image
                  image = Examples.image
                  image + (Matrix.zeros rows=image.rows columns=image.columns channels=image.channels)
     + : (Number | Vector | Matrix) -> Image ! Matrix.Dimensions_Not_Equal
-    + value = Panic.recover Any (Internal.core_op self.opencv_mat value (Java_Image.add _ _ _)) . catch Internal.core_op_handler
+    + value = Panic.recover Any (Internal.core_op self.opencv_mat value (Java_Image.add _ _ _)) . catch Any Internal.core_op_handler
 
     ## UNSTABLE
 
@@ -204,7 +204,7 @@ type Image
                  image = Examples.image
                  image - (Matrix.zeros rows=image.rows columns=image.columns channels=image.channels)
     - : (Number | Vector | Matrix) -> Image ! Matrix.Dimensions_Not_Equal
-    - value = Panic.recover Any (Internal.core_op self.opencv_mat value (Java_Image.subtract _ _ _)) . catch Internal.core_op_handler
+    - value = Panic.recover Any (Internal.core_op self.opencv_mat value (Java_Image.subtract _ _ _)) . catch Any Internal.core_op_handler
 
     ## UNSTABLE
 
@@ -255,7 +255,7 @@ type Image
                  image = Examples.image
                  image * (Matrix.ones rows=image.rows columns=image.columns channels=image.channels)
     * : (Number | Vector | Matrix) -> Image ! Matrix.Dimensions_Not_Equal
-    * value = Panic.recover Any (Internal.core_op self.opencv_mat value (Java_Image.multiply _ _ _)) . catch Internal.core_op_handler
+    * value = Panic.recover Any (Internal.core_op self.opencv_mat value (Java_Image.multiply _ _ _)) . catch Any Internal.core_op_handler
 
     ## UNSTABLE
 
@@ -306,7 +306,7 @@ type Image
                  image = Examples.image
                  image / (Matrix.ones rows=image.rows columns=image.columns channels=image.channels)
     / : (Number | Vector | Matrix) -> Image ! Matrix.Dimensions_Not_Equal
-    / value = Panic.recover Any (Internal.core_op self.opencv_mat value (Java_Image.divide _ _ _)) . catch Internal.core_op_handler
+    / value = Panic.recover Any (Internal.core_op self.opencv_mat value (Java_Image.divide _ _ _)) . catch Any Internal.core_op_handler
 
     ## UNSTABLE
 

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

@@ -1061,7 +1061,7 @@ type Column
 
              example_first = Examples.integer_column.first
     first : Any ! Empty_Error
-    first = self.at 0 . catch (_ -> Error.throw Empty_Error)
+    first = self.at 0 . catch Index_Out_Of_Bounds_Error (_ -> Error.throw Empty_Error)
 
     ## UNSTABLE
 
@@ -1093,7 +1093,7 @@ type Column
 
              example_last = Examples.integer_column.last
     last : Any ! Empty_Error
-    last = self.at (self.length - 1) . catch (_ -> Error.throw Empty_Error)
+    last = self.at (self.length - 1) . catch Index_Out_Of_Bounds_Error (_ -> Error.throw Empty_Error)
 
     ## UNSTABLE
 

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

@@ -198,7 +198,7 @@ type Table
              example_to_json = Examples.inventory_table.to_json
     to_json : Json
     to_json =
-        index_prep = case self.index.catch (_->Nothing) of
+        index_prep = case self.index.catch No_Index_Set_Error (_->Nothing) of
             Nothing -> []
             index -> [index]
         cols = index_prep + self.columns

distribution/lib/Standard/Table/0.0.0-dev/src/Internal/Aggregate_Column_Helper.enso

@@ -167,9 +167,7 @@ resolve_aggregate table problem_builder aggregate_column =
 
     ## Downgrade the `Internal_Missing_Column_Error` error into a `Nothing`
        value, keeping any other dataflow errors intact.
-    result.catch err-> case err of
+    result.catch Internal_Missing_Column_Error (_->Nothing)
-        Internal_Missing_Column_Error -> Nothing
-        _ -> result
 
 ## PRIVATE
    A marker for missing columns during resolution.

distribution/lib/Standard/Table/0.0.0-dev/src/Internal/Delimited_Reader.enso

@@ -68,8 +68,8 @@ read_text text format on_problems =
      or `Nothing`. It is used for more detailed error reporting.
 read_stream : Delimited -> Input_Stream -> Problem_Behavior -> Integer -> File | Nothing -> Any
 read_stream format stream on_problems max_columns=4096 related_file=Nothing =
-    handle_io_exception ~action = Panic.catch IOException action caught_panic->
+    handle_io_exception ~action = Panic.catch_java IOException action java_exception->
-        Error.throw (File.wrap_io_exception related_file caught_panic.payload.cause)
+        Error.throw (File.wrap_io_exception related_file java_exception)
 
     handle_io_exception <|
         stream.with_stream_decoder format.encoding on_problems reporting_stream_decoder->

distribution/lib/Standard/Table/0.0.0-dev/src/Internal/Parse_Values_Helper.enso

@@ -11,6 +11,6 @@ translate_parsing_problem expected_datatype problem =
 
     translations = [invalid_format, leading_zeros]
     found = translations.find t-> Java.is_instance problem t.first
-    translation = found.catch _->
+    translation = found.catch Any _->
         Error.throw (Illegal_State_Error "Reported an unknown problem type: "+problem.to_text)
     translation.second problem

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

@@ -56,7 +56,7 @@ Json.Array.to_table fields = case self of
         rows = items.map item-> case item of
             Json.Object fs ->
                 row = if item.get_type == Geo_Json.Feature.to_text then item.get_feature_row else fs
-                fields.map n-> row.get n . unwrap . catch (_ -> Nothing)
+                fields.map n-> row.get n . unwrap . catch Any (_ -> Nothing)
             _ -> Vector.fill fields.length Nothing
         cols = fields.map_with_index i-> n->
             [n, rows.map (_.at i)]
@@ -107,7 +107,7 @@ Json.Object.to_table fields=Nothing =
                         column_names_row.keys
                     _ -> fields
                 rows = feature_rows.map row->
-                    column_names.map n-> row.get n . unwrap . catch (_ -> Nothing)
+                    column_names.map n-> row.get n . unwrap . catch Any (_ -> Nothing)
                 cols = column_names.map_with_index i-> n->
                     [n, rows.map (_.at i)]
                 Table.new cols

distribution/lib/Standard/Test/0.0.0-dev/src/Main.enso

@@ -234,7 +234,7 @@ Any.should_fail_with matcher frames_to_skip=0 =
             Examples.throw_error . should_fail_with Examples.My_Error
 Error.should_fail_with : Any -> Integer -> Assertion
 Error.should_fail_with matcher frames_to_skip=0 =
-    caught = self.catch x->x
+    caught = self.catch
     if caught.is_a matcher then Nothing else
         loc = Meta.get_source_location 2+frames_to_skip
         fail ("Expected error "+matcher.to_text+", but error " + caught.to_text + " has been returned (at " + loc + ").")
@@ -261,7 +261,7 @@ expect_panic_with ~action matcher =
             loc = Meta.get_source_location 2
             return_suffix = if res.is_nothing then "" else "and returned ["+res.to_text+"]"
             fail ("Expected a " + matcher.to_text + " to be thrown, but the action succeeded " + return_suffix + " (at "+loc+").")
-    err = res.catch x->x
+    err = res.catch
     if err.is_a matcher then Nothing else
         fail ("Expected a " + matcher.to_text + ", but " + err.to_text + " was thrown instead.")
 
@@ -572,7 +572,7 @@ type Suite_Config
     should_run_group name =
         regexp = self.only_group_regexp
         case regexp of
-            Text -> name.matches regexp . catch (_->True)
+            Text -> name.matches regexp . catch Any (_->True)
             _ -> True
 
     should_output_junit =
@@ -678,11 +678,12 @@ run_spec : Any -> Assertion
 run_spec ~behavior =
     recovery = Panic.recover Any <|
         result = behavior
-        result.catch err-> Panic.throw (Finished_With_Error err result.get_stack_trace_text)
+        result.catch Any err->
+            Panic.throw (Finished_With_Error err result.get_stack_trace_text)
         Nothing
     maybeExc = case recovery of
         _ -> Success
-    result = maybeExc.catch ex->
+    result = maybeExc.catch Any ex->
         case ex of
             Failure _ -> ex
             Finished_With_Error err stack_trace_text ->

distribution/lib/Standard/Visualization/0.0.0-dev/src/Helpers.enso

@@ -73,7 +73,7 @@ Error.map_valid _ = self
    Arguments:
    - val: a value that will be evaluated and returned if `self` is an error.
 Any.catch_ : Any -> Any
-Any.catch_ ~val = self.catch (_-> val)
+Any.catch_ ~val = self.catch Any (_-> val)
 
 ## PRIVATE
 
@@ -84,13 +84,13 @@ Any.catch_ ~val = self.catch (_-> val)
    Arguments:
    - val: a value that will be evaluated and returned if `self` is an error.
 Error.catch_ : Any -> Any
-Error.catch_ ~val = self.catch (_-> val)
+Error.catch_ ~val = self.catch Any (_-> val)
 
 ## PRIVATE
 recover_errors : Any -> Any
 recover_errors ~body =
     result = Panic.recover Any body
-    result.catch err->
+    result.catch Any err->
         Json.from_pairs [["error", err.to_display_text]] . to_text
 
 ## PRIVATE

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

@@ -24,7 +24,7 @@ prepare_visualization x max_rows = Helpers.recover_errors <| case x of
         dataframe = x.take_start max_rows
         all_rows_count = x.row_count
         included_rows = dataframe.row_count
-        index = dataframe.index.catch _->
+        index = dataframe.index.catch Any _->
             Dataframe_Column.from_vector "" (Vector.new included_rows i->i)
         make_json dataframe [index] all_rows_count
 

engine/runtime-with-instruments/src/test/scala/org/enso/interpreter/test/instrument/RuntimeServerTest.scala

@@ -2970,7 +2970,7 @@ class RuntimeServerTest
         |main =
         |    x = Panic.catch_primitive @ .convert_to_dataflow_error
         |    IO.println x
-        |    IO.println (x.catch .to_text)
+        |    IO.println (x.catch Any .to_text)
         |""".stripMargin.linesIterator.mkString("\n")
     val contents = metadata.appendToCode(code)
     val mainFile = context.writeMain(contents)
@@ -3032,10 +3032,11 @@ class RuntimeServerTest
     val code =
       """import Standard.Base.IO
         |from Standard.Base.Error.Common import all
+        |from Standard.Base.Data.Any import all
         |
         |main =
         |    x = Panic.catch_primitive () .convert_to_dataflow_error
-        |    IO.println (x.catch .to_text)
+        |    IO.println (x.catch Any .to_text)
         |
         |""".stripMargin.linesIterator.mkString("\n")
     val contents = metadata.appendToCode(code)
@@ -3076,7 +3077,7 @@ class RuntimeServerTest
             Api.ExecutionResult.Diagnostic.error(
               "Parentheses can't be empty.",
               Some(mainFile),
-              Some(model.Range(model.Position(4, 30), model.Position(4, 32)))
+              Some(model.Range(model.Position(5, 30), model.Position(5, 32)))
             )
           )
         )

engine/runtime/src/main/scala/org/enso/compiler/context/SuggestionBuilder.scala

@@ -403,6 +403,8 @@ final class SuggestionBuilder[A: IndexedSource](val source: A) {
           val tdef = resolveTypeName(bindings, typeName)
             .getOrElse(TypeArg.Value(QualifiedName.simpleName(typeName)))
           args :+ tdef
+        case seq: IR.Application.Literal.Sequence =>
+          seq.items.foldLeft(args)((a, t) => go(t, a))
         case _ =>
           args
       }

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

@@ -196,7 +196,7 @@ class DataflowErrorsTest extends InterpreterTest {
           |main =
           |    x = Panic.catch_primitive @ .convert_to_dataflow_error
           |    IO.println x
-          |    IO.println (x.catch .to_text)
+          |    IO.println (x.catch Any .to_text)
           |""".stripMargin
       eval(code)
       consumeOut shouldEqual List(

test/Tests/src/Data/Function_Spec.enso

@@ -0,0 +1,43 @@
+from Standard.Base import all
+import Standard.Base.Data.Numbers
+
+import Standard.Test
+from Standard.Base.Data.Ordering import Equal, Less, Greater
+
+spec =
+    Test.group "identity" <|
+        Test.specify "identity on number" <|
+            (identity 5) . should_equal 5
+
+        Test.specify "identity on text" <|
+            (identity '5') . should_equal '5'
+
+        Test.specify "identity on boolean" <|
+            (identity False) . should_equal False
+
+    Test.group "flip" <|
+        Test.specify "flip on number" <|
+            (flip (-) 2 5) . should_equal 3
+
+        Test.specify "flip on text" <|
+            (flip (+) "world" "hello") . should_equal "helloworld"
+
+    Test.group "const" <|
+        Test.specify "const on number" <|
+            two = const 2
+            two 5 . should_equal 2
+
+    Test.group "curry" <|
+        Test.specify "curry on number list" <|
+            sum = x -> x.fold 0 (+)
+            sum [1, 2, 3, 4] . should_equal 10
+            plus = curry sum
+            plus 6 3 . should_equal 9
+
+    Test.group "uncurry" <|
+        Test.specify "uncurry on number list" <|
+            times = uncurry (*)
+            times [6, 7] . should_equal 42
+
+
+main = Test.Suite.run_main spec

test/Tests/src/Data/Json_Spec.enso

@@ -8,7 +8,7 @@ type Book title author
 Text.should_fail_parsing_with expected =
     as_fail = case Json.parse self of
         _ -> Test.Failure "Expected a parse error, but no error reported."
-    result = as_fail.catch e-> case e of
+    result = as_fail.catch Any e-> case e of
         Json.Parse_Error msg ->
             if msg.contains expected then Test.Success else
                 fail_msg = "The reported message " + msg.to_text + " did not contain " + expected.to_text + "."

test/Tests/src/Data/Time/Date_Spec.enso

@@ -25,7 +25,7 @@ specWith name createNewDate parseDate =
             date . day . should_equal 1
 
         Test.specify "should handle errors when creating local date" <|
-            case createNewDate 2020 30 30 . catch (x -> x) of
+            case createNewDate 2020 30 30 . catch of
                 Time.Time_Error msg ->
                     msg . should_equal "Invalid value for MonthOfYear (valid values 1 - 12): 30"
                 result ->
@@ -47,7 +47,7 @@ specWith name createNewDate parseDate =
             date . day . should_equal 21
 
         Test.specify "should throw error when parsing invalid date" <|
-            case parseDate "birthday" . catch (x -> x) of
+            case parseDate "birthday" . catch of
                 Time.Time_Error msg ->
                     msg . should_equal "Text 'birthday' could not be parsed at index 0"
                 result ->
@@ -67,7 +67,7 @@ specWith name createNewDate parseDate =
 
         Test.specify "should throw error when parsing custom format" <|
             date = parseDate "1999-01-01" "yyyy M d"
-            case date.catch (x -> x) of
+            case date.catch of
                 Time.Time_Error msg ->
                     msg . should_equal "Text '1999-01-01' could not be parsed at index 4"
                 result ->
@@ -108,14 +108,14 @@ specWith name createNewDate parseDate =
             date . day . should_equal 1
 
         Test.specify "should throw error when adding time-based interval" <|
-            case (createNewDate 1970 + 1.hour) . catch (x -> x) of
+            case (createNewDate 1970 + 1.hour) . catch of
                 Time.Time_Error message ->
                     message . should_equal "Date does not support time intervals"
                 result ->
                     Test.fail ("Unexpected result: " + result.to_text)
 
         Test.specify "should throw error when subtracting time-based interval" <|
-            case (createNewDate 1970 - (1.day - 1.minute)) . catch (x -> x) of
+            case (createNewDate 1970 - (1.day - 1.minute)) . catch of
                 Time.Time_Error message ->
                     message . should_equal "Date does not support time intervals"
                 result ->

test/Tests/src/Data/Time/Time_Of_Day_Spec.enso

@@ -18,7 +18,7 @@ spec =
             time . to_seconds . should_equal 3600
 
         Test.specify "should handle errors when creating a time" <|
-            case Time_Of_Day.new 24 0 0 . catch (x -> x) of
+            case Time_Of_Day.new 24 0 0 . catch of
                 Time.Time_Error msg ->
                     msg . should_equal "Invalid value for HourOfDay (valid values 0 - 23): 24"
                 result ->
@@ -48,7 +48,7 @@ spec =
             time.to_seconds . should_equal 36000
 
         Test.specify "should throw error when parsing invalid time" <|
-            case Time_Of_Day.parse "1200" . catch (x -> x) of
+            case Time_Of_Day.parse "1200" . catch of
                 Time.Time_Error msg ->
                     msg . should_equal "Text '1200' could not be parsed at index 2"
                 result ->
@@ -60,7 +60,7 @@ spec =
 
         Test.specify "should throw error when parsing custom format" <|
             time = Time_Of_Day.parse "12:30" "HH:mm:ss"
-            case time.catch (x -> x) of
+            case time.catch of
                 Time.Time_Error msg ->
                     msg . should_equal "Text '12:30' could not be parsed at index 5"
                 result ->
@@ -90,14 +90,14 @@ spec =
             time . to_seconds . should_equal 3599
 
         Test.specify "should throw error when adding date-based interval" <|
-            case (Time_Of_Day.new + 1.day) . catch (x -> x) of
+            case (Time_Of_Day.new + 1.day) . catch of
                 Time.Time_Error message ->
                     message . should_equal "Time_Of_Day does not support date intervals"
                 result ->
                     Test.fail ("Unexpected result: " + result.to_text)
 
         Test.specify "should throw error when subtracting date-based interval" <|
-            case (Time_Of_Day.new - (1.day - 1.minute)) . catch (x -> x) of
+            case (Time_Of_Day.new - (1.day - 1.minute)) . catch of
                 Time.Time_Error message ->
                     message . should_equal "Time_Of_Day does not support date intervals"
                 result ->

test/Tests/src/Data/Time/Time_Spec.enso

@@ -20,7 +20,7 @@ spec =
             time . zone . zone_id . should_equal Zone.utc.zone_id
 
         Test.specify "should handle errors when creating time" <|
-            case Time.new 1970 0 0 . catch (x -> x) of
+            case Time.new 1970 0 0 . catch of
                 Time.Time_Error msg ->
                     msg . should_equal "Invalid value for MonthOfYear (valid values 1 - 12): 0"
                 result ->
@@ -108,7 +108,7 @@ spec =
             time . zone . zone_id . should_equal "Europe/Paris"
 
         Test.specify "should throw error when parsing invalid time" <|
-            case Time.parse "2008-1-1" . catch (x -> x) of
+            case Time.parse "2008-1-1" . catch of
                 Time.Time_Error msg ->
                     msg . should_equal "Text '2008-1-1' could not be parsed at index 5"
                 result ->
@@ -137,7 +137,7 @@ spec =
 
         Test.specify "should throw error when parsing custom format" <|
             time = Time.parse "2008-01-01" "yyyy-MM-dd'T'HH:mm:ss'['z']'"
-            case time.catch (x -> x) of
+            case time.catch of
                 Time.Time_Error msg ->
                     msg . should_equal "Text '2008-01-01' could not be parsed at index 10"
                 result ->

test/Tests/src/Data/Vector_Spec.enso

@@ -297,7 +297,7 @@ spec = Test.group "Vectors" <|
 
     Test.specify "should be able to map over errors" <|
         fail a = Error.throw <| My_Error a
-        [fail 1].map (x -> x.catch (x -> x.a)) . should_equal [1]
+        [fail 1].map (x -> x.catch Any (x -> x.a)) . should_equal [1]
         [1].map fail . map .catch . should_equal [My_Error 1]
 
     Test.specify "should be able to be efficiently converted to a visualisation" <|

test/Tests/src/Main.enso

@@ -20,6 +20,7 @@ import project.Semantic.R_Interop_Spec
 
 import project.Data.Array_Spec
 import project.Data.Bool_Spec
+import project.Data.Function_Spec
 import project.Data.Interval_Spec
 import project.Data.Json_Spec
 import project.Data.List_Spec
@@ -66,6 +67,7 @@ main = Test.Suite.run_main <|
     Any_Spec.spec
     Array_Spec.spec
     Bool_Spec.spec
+    Function_Spec.spec
     Case_Spec.spec
     Conversion_Spec.spec
     Deep_Export_Spec.spec

test/Tests/src/Semantic/Conversion_Spec.enso

@@ -71,9 +71,9 @@ spec =
             Text.from Methods.get_bar . should_equal "'bar'"
 
         Test.specify "should fail graciously when there is no conversion" <|
-            Panic.recover Any (Foo.from (Quux 10)) . catch .to_display_text . should_equal "Could not find a conversion from `Quux` to `Foo`"
+            Panic.recover Any (Foo.from (Quux 10)) . catch Any .to_display_text . should_equal "Could not find a conversion from `Quux` to `Foo`"
         Test.specify "should fail graciously when the conversion target is invalid" <|
-            Panic.recover Any (123.from (Quux 10)) . catch .to_display_text . should_equal "123 is not a valid conversion target. Expected a type."
+            Panic.recover Any (123.from (Quux 10)) . catch Any .to_display_text . should_equal "123 is not a valid conversion target. Expected a type."
 
         Test.specify "should be callable with by-name arguments" <|
             .from that=4 self=Foo . should_equal (Foo [4, 0, 0, 0])

test/Tests/src/Semantic/Error_Spec.enso

@@ -18,9 +18,9 @@ do_a_parse str = Long.parseLong str
 spec =
     Test.group "No Method Errors" <|
         Test.specify "should be recoverable" <|
-            err_1 = Panic.recover Any (123 . foobar "baz") . catch e->e
+            err_1 = Panic.recover Any (123 . foobar "baz") . catch
-            err_2 = Panic.recover Any ("foo" . baz 123) . catch e->e
+            err_2 = Panic.recover Any ("foo" . baz 123) . catch
-            err_3 = Panic.recover Any (My_Type False . nope) . catch e->e
+            err_3 = Panic.recover Any (My_Type False . nope) . catch
 
             err_1.target.should_equal 123
             err_1.method_name.should_equal "foobar"
@@ -32,6 +32,17 @@ spec =
             err_3.method_name.should_equal "nope"
 
     Test.group "Dataflow Errors" <|
+        Test.specify "should be recoverable" <|
+            err = Error.throw 42
+            err.catch . should_equal 42
+            err.should_fail_with Integer
+
+        Test.specify "should allow recovery of only a specific error-type" <|
+            recover_illegal_argument ~action =
+                action . catch Illegal_Argument_Error err->
+                    "recovered error: "+err.message
+            (recover_illegal_argument (Error.throw (Illegal_Argument_Error "foo"))) . should_equal "recovered error: foo"
+            (recover_illegal_argument (Error.throw (Illegal_State_Error "bar"))) . should_fail_with Illegal_State_Error
 
         Test.specify "should be able to be shown in the default visualization" <|
             json = (Error.throw <| My_Type "aaa").to_default_visualization_data
@@ -153,7 +164,7 @@ spec =
             Test.expect_panic_with (parse 0.0) Unsupported_Argument_Types
 
         Test.specify "should allow to throw raw Java exceptions" <|
-            exception = Panic.catch NumberFormatException (throw_raw_java "foo") (p -> p.payload.cause)
+            exception = Panic.catch_java NumberFormatException (throw_raw_java "foo") (p -> p)
             exception.getMessage . should_equal "foo"
             Panic.get_attached_stack_trace exception . second . name . should_equal "Error_Spec.throw_raw_java"
 

test/micro-distribution/lib/Standard/Base/0.0.0-dev/src/Error/Common.enso

@@ -1,3 +1,5 @@
+from project.Data.Any import Any
+
 type Panic
     @Builtin_Type
     type Panic
@@ -24,4 +26,6 @@ type Error
     type Error
     throw payload = @Builtin_Method "Error.throw"
     catch_primitive handler = @Builtin_Method "Error.catch_primitive"
-    catch (handler = x->x) = self.catch_primitive handler
+    catch (error_type = Any) (handler = x->x) =
+        _ = error_type
+        self.catch_primitive handler

test/micro-distribution/lib/Standard/Base/0.0.0-dev/src/Main.enso

@@ -1,6 +1,9 @@
 import project.IO
 export project.IO
 
+import project.Data.Any
+from project.Data.Any export Any
+
 import project.Data.List
 from project.Data.List export Nil, Cons, List