Implement Table.order_by for SQLite and the common scaffolding for all backends

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

@@ -92,6 +92,23 @@ type Range
     map function =
         Vector.new this.length (i -> function (this.start + i*this.step))
 
+    ## Returns a vector of all elements of this range which satisfy a predicate.
+
+       Arguments:
+       - predicate: A function that takes a list element and returns a boolean
+         value that says whether that value satisfies the conditions of the
+         function.
+
+       > Example
+         Selecting all elements that are greater than 3.
+
+             (0.up_to 7).filter (> 3)
+    filter : (Any -> Boolean) -> Vector Any
+    filter predicate =
+        builder = this.fold Vector.new_builder builder-> elem->
+            if predicate elem then builder.append elem else builder
+        builder.to_vector
+
     ## Applies a function for each element in the range.
 
        Arguments:

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

@@ -1065,10 +1065,10 @@ Text.repeat count=1 =
    > Examples
      Various different ways to take part of "Hello World!"
 
-         "Hello World!".take First.new == "H"
+         "Hello World!".take First == "H"
          "Hello World!".take (First 5) == "Hello"
          "Hello World!".take (First 0) == ""
-         "Hello World!".take Last.new == "!"
+         "Hello World!".take Last == "!"
          "Hello World!".take (Last 6) == "World!"
          "Hello World!".take (Before " ") == "Hello"
          "Hello World!".take (Before_Last "o") == "Hello W"
@@ -1105,10 +1105,10 @@ Text.take range =
    > Examples
      Various different ways to take part of "Hello World!"
 
-         "Hello World!".drop First.new == "ello World!"
+         "Hello World!".drop First == "ello World!"
          "Hello World!".drop (First 5) == " World!"
          "Hello World!".drop (First 0) == "Hello World!"
-         "Hello World!".drop Last.new == "Hello World"
+         "Hello World!".drop Last == "Hello World"
          "Hello World!".drop (Last 6) == "Hello "
          "Hello World!".drop (Before " ") == " World!"
          "Hello World!".drop (Before_Last "o") == "orld!"

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

@@ -205,48 +205,78 @@ match_criteria_callback matcher objects criteria problem_callback reorder=False
     problem_callback unmatched_criteria
     result.first
 
-## PRIVATE
-internal_match_criteria_implementation matcher objects criteria reorder=False name_mapper=(x->x) = Panic.catch Wrapped_Dataflow_Error (handler = x-> x.payload.unwrap) <|
-    ## TODO [RW] discuss: this line of code also shows an issue we had with ensuring input dataflow-errors are correctly propagated, later on we stopped doing that and testing for that as it was too cumbersome. Maybe it could be helped with an @Accepts_Error annotation similar to the one from the interpreter???
-    [matcher, objects, criteria, reorder, name_mapper] . each v->
-        Panic.rethrow (v.map_error Wrapped_Dataflow_Error)
-
-    # match_matrix . at i . at j specifies whether objects.at i matches criteria.at j
-    match_matrix = objects.map obj->
-        criteria.map criterion->
-            name = name_mapper obj
-            matcher.match_single_criterion name criterion
+type Match_Matrix
+    ## PRIVATE
+       A helper type holding a matrix of matches.
+    type Match_Matrix matrix criteria objects
 
     # Checks if the ith object is matched by any criterion.
     is_object_matched_by_anything : Integer -> Boolean
     is_object_matched_by_anything i =
-        match_matrix.at i . any x->x
+        this.matrix.at i . any x->x
 
-    # Checks if the ith criterion matches any columns.
+    # Checks if the ith criterion matches any objects.
     does_criterion_match_anything : Integer -> Boolean
     does_criterion_match_anything i =
-        match_matrix.map (col -> col.at i) . any x->x
+        this.matrix.map (col -> col.at i) . any x->x
+
+    ## PRIVATE
+       Extracts the list of criteria that did not have any matches.
+    unmatched_criteria =
+        checked_criteria = this.criteria.map_with_index j-> criterion->
+            has_matches = this.does_criterion_match_anything j
+            Pair has_matches criterion
+        checked_criteria.filter (p -> p.first.not) . map .second
+
+    ## PRIVATE
+       Returns the list of criteria that match the ith object.
+    criteria_matching_object : Integer -> Vector
+    criteria_matching_object i =
+        this.criteria.filter_with_index j-> _->
+            this.matrix . at i . at j
+
+    ## PRIVATE
+       Returns the list of criteria indices that match the ith object.
+    criteria_indices_matching_object : Integer -> Vector
+    criteria_indices_matching_object i =
+        (0.up_to this.criteria.length).filter j->
+            this.matrix . at i . at j
+
+## PRIVATE
+   Generates a matrix specifying which criteria match which object.
+
+   The returned `match_matrix` satisfies the following condition:
+   `match_matrix . at i . at j` is `True` if and only if `objects.at i` matches
+   `criteria.at j`.
+make_match_matrix matcher objects criteria object_name_mapper=(x->x) criterion_mapper=(x->x) =
+    matrix = objects.map obj->
+        criteria.map criterion->
+            matcher.match_single_criterion (object_name_mapper obj) (criterion_mapper criterion)
+    Match_Matrix matrix criteria objects
+
+## PRIVATE
+internal_match_criteria_implementation matcher objects criteria reorder=False name_mapper=(x->x) = Panic.catch Wrapped_Dataflow_Error (handler = x-> x.payload.unwrap) <|
+    ## TODO [RW] discuss: this line of code also shows an issue we had with ensuring input dataflow-errors are correctly propagated, later on we stopped doing that and testing for that as it was too cumbersome. Maybe it could be helped with an @Accepts_Error annotation similar to the one from the interpreter???
+    [matcher, objects, criteria, reorder, name_mapper] . each v->
+        Panic.rethrow (v.map_error Wrapped_Dataflow_Error)
+
+    match_matrix = here.make_match_matrix matcher objects criteria name_mapper
+    unmatched_criteria = match_matrix.unmatched_criteria
 
     # Selects object indices which satisfy the provided predicate.
     select_matching_indices : (Integer -> Boolean) -> Vector Text
     select_matching_indices matcher =
         0.up_to objects.length . to_vector . filter matcher
 
-    # Check consistency
-    checked_criteria = criteria.map_with_index j-> criterion->
-        has_matches = does_criterion_match_anything j
-        Pair has_matches criterion
-    unmatched_criteria = checked_criteria.filter (p -> p.first.not) . map .second
-
     selected_indices = case reorder of
         True ->
             nested_indices = 0.up_to criteria.length . map j->
                 is_object_matched_by_this_criterion i =
-                    match_matrix.at i . at j
+                    match_matrix.matrix.at i . at j
                 select_matching_indices is_object_matched_by_this_criterion
             nested_indices.flat_map x->x . distinct
         False ->
-            select_matching_indices is_object_matched_by_anything
+            select_matching_indices match_matrix.is_object_matched_by_anything
 
     result = selected_indices.map objects.at
     Pair result unmatched_criteria

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

@@ -6,4 +6,4 @@ from Standard.Base import all
    - sort_digits_as_numbers: Sort digits in the text as numbers. Setting this to
      `True` results in a "Natural" ordering.
    - case_sensitive: Specifies if the ordering should be case case sensitive.
-type Text_Ordering (sort_digits_as_numbers:Bool=False) (case_sensitive:(True|Case_Insensitive)=True)
+type Text_Ordering (sort_digits_as_numbers:Boolean=False) (case_sensitive:(True|Case_Insensitive)=True)

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

@@ -102,25 +102,3 @@ type Text_Sub_Range
                     predicate (Text_Utils.substring text start end) . not
                 if indices.first == -1 then (Range 0 indices.second) else
                     Range 0 indices.first
-
-## UNSTABLE
-   A temporary workaround to allow the `First` constructor to work with default
-   arguments.
-
-   It is needed, because there are issues with relying on default arguments of
-   Atom constructors, as described in the following issue:
-   https://github.com/enso-org/enso/issues/1600
-   Once that issue is fixed, it can be removed.
-First.new : Integer -> First
-First.new (count = 1) = First count
-
-## UNSTABLE
-   A temporary workaround to allow the `Last` constructor to work with default
-   arguments.
-
-   It is needed, because there are issues with relying on default arguments of
-   Atom constructors, as described in the following issue:
-   https://github.com/enso-org/enso/issues/1600
-   Once that issue is fixed, it can be removed.
-Last.new : Integer -> Last
-Last.new (count = 1) = Last count

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

@@ -3,6 +3,7 @@ from Standard.Base import all
 import Standard.Base.Error.Common as Errors
 import Standard.Table.Data.Aggregate_Column
 import Standard.Database.Data.Sql
+import Standard.Database.Data.Internal.IR
 import Standard.Database.Data.Dialect.Postgres
 import Standard.Database.Data.Dialect.Redshift
 import Standard.Database.Data.Dialect.Sqlite as Sqlite_Module
@@ -39,6 +40,14 @@ type Dialect
     resolve_target_sql_type : Aggregate_Column -> Sql_Type
     resolve_target_sql_type = Errors.unimplemented "This is an interface only."
 
+    ## PRIVATE
+       Prepares an ordering descriptor.
+
+       One of the purposes of this method is to verify if the expected ordering
+       settings are supported by the given database backend.
+    prepare_order_descriptor : Connection -> IR.Internal_Column -> Sort_Direction -> Text_Ordering -> IR.Order_Descriptor
+    prepare_order_descriptor = Errors.unimplemented "This is an interface only."
+
 ## PRIVATE
 
    A vector of SQL dialects supported by the Database library.

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

@@ -1,5 +1,6 @@
 from Standard.Base import all
 
+import Standard.Base.Error.Common as Errors
 from Standard.Table.Data.Aggregate_Column import all
 from Standard.Database.Data.Sql import Sql_Type
 import Standard.Database.Data.Dialect
@@ -43,6 +44,16 @@ type Postgresql_Dialect
     resolve_target_sql_type : Aggregate_Column -> Sql_Type
     resolve_target_sql_type aggregate = here.resolve_target_sql_type aggregate
 
+    ## PRIVATE
+       Prepares an ordering descriptor.
+
+       One of the purposes of this method is to verify if the expected ordering
+       settings are supported by the given database backend.
+    prepare_order_descriptor : Connection -> IR.Internal_Column -> Sort_Direction -> Text_Ordering -> IR.Order_Descriptor
+    prepare_order_descriptor connection internal_column sort_direction text_ordering =
+        _ = [connection, internal_column, sort_direction, text_ordering]
+        Errors.unimplemented "TODO"
+
 ## PRIVATE
 make_internal_generator_dialect =
     text = [here.starts_with, here.contains, here.ends_with, here.agg_shortest, here.agg_longest]+here.concat_ops

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

@@ -1,5 +1,6 @@
 from Standard.Base import all
 
+import Standard.Base.Error.Common as Errors
 import Standard.Table.Data.Aggregate_Column
 import Standard.Database.Data.Sql
 import Standard.Database.Data.Dialect
@@ -42,3 +43,13 @@ type Redshift_Dialect
     resolve_target_sql_type : Aggregate_Column -> Sql_Type
     resolve_target_sql_type aggregate =
         Postgres.resolve_target_sql_type aggregate
+
+    ## PRIVATE
+       Prepares an ordering descriptor.
+
+       One of the purposes of this method is to verify if the expected ordering
+       settings are supported by the given database backend.
+    prepare_order_descriptor : Connection -> IR.Internal_Column -> Sort_Direction -> Text_Ordering -> IR.Order_Descriptor
+    prepare_order_descriptor connection internal_column sort_direction text_ordering =
+        _ = [connection, internal_column, sort_direction, text_ordering]
+        Errors.unimplemented "TODO"

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

@@ -5,6 +5,7 @@ from Standard.Database.Data.Sql import Sql_Type
 import Standard.Database.Data.Dialect
 import Standard.Database.Data.Dialect.Helpers
 import Standard.Database.Data.Internal.Base_Generator
+import Standard.Database.Data.Internal.IR
 from Standard.Database.Error as Database_Errors import Unsupported_Database_Operation_Error
 
 ## PRIVATE
@@ -43,6 +44,20 @@ type Sqlite_Dialect
     resolve_target_sql_type : Aggregate_Column -> Sql_Type
     resolve_target_sql_type aggregate = here.resolve_target_sql_type aggregate
 
+    ## PRIVATE
+       Prepares an ordering descriptor.
+
+       One of the purposes of this method is to verify if the expected ordering
+       settings are supported by the given database backend.
+    prepare_order_descriptor : Connection -> IR.Internal_Column -> Sort_Direction -> Text_Ordering -> IR.Order_Descriptor
+    prepare_order_descriptor _ internal_column sort_direction text_ordering = case internal_column.sql_type.is_likely_text of
+        True ->
+            if text_ordering.sort_digits_as_numbers then Error.throw (Unsupported_Database_Operation_Error "Natural ordering is not supported by the SQLite backend. You may need to materialize the Table to perform this operation.") else
+                if text_ordering.case_sensitive != True then Error.throw (Unsupported_Database_Operation_Error "Case insensitive ordering is not supported by the SQLite backend. You may need to materialize the Table to perform this operation.") else
+                    IR.Order_Descriptor internal_column.expression sort_direction collation=Nothing
+        False ->
+            IR.Order_Descriptor internal_column.expression sort_direction collation=Nothing
+
 ## PRIVATE
 make_internal_generator_dialect =
     text = [here.starts_with, here.contains, here.ends_with]+here.concat_ops

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

@@ -235,18 +235,22 @@ generate_from_part dialect from_spec = case from_spec of
 
    Arguments:
    - dialect: The SQL dialect for which the code is generated.
-   - order_description: A description of the ORDER clause.
-
-   # generate_order : Internal_Dialect -> [Expression, IR.Order_Direction, IR.Nulls_Order] -> Sql.Builder
-generate_order : Internal_Dialect -> Vector Any -> Sql.Builder
-generate_order dialect order_description =
-    order_suffix = case order_description.second of
-        IR.Ascending -> Sql.code " ASC"
-        IR.Descending -> Sql.code " DESC"
-    nulls_suffix = case order_description.at 2 of
+   - order_descriptor: A description of the ORDER clause.
+generate_order : Internal_Dialect -> Order_Descriptor -> Sql.Builder
+generate_order dialect order_descriptor =
+    order_suffix = case order_descriptor.direction of
+        Sort_Direction.Ascending -> Sql.code " ASC"
+        Sort_Direction.Descending -> Sql.code " DESC"
+    nulls_suffix = case order_descriptor.nulls_order of
+        Nothing -> Sql.empty
         IR.Nulls_First -> Sql.code " NULLS FIRST"
         IR.Nulls_Last -> Sql.code " NULLS LAST"
-    (here.generate_expression dialect (order_description.first)) ++ order_suffix ++ nulls_suffix
+    collation = case order_descriptor.collation of
+        Nothing -> Sql.empty
+        collation_name -> Sql.code ' COLLATE "'+collation_name+'"'
+    base_expression = here.generate_expression dialect order_descriptor.expression
+    base_expression ++ collation ++ order_suffix ++ nulls_suffix
+
 
 ## PRIVATE