if_nothing

Remove Group_By_Key

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

@@ -236,6 +236,15 @@ type Any
     is_nothing : Boolean
     is_nothing = False
 
+    ## If this is Nothing then returns `function`.
+
+       > Example
+         If the value "Hello" is nothing return "".
+
+             "Hello".if_nothing ""
+    if_nothing : Any
+    if_nothing ~_ = this
+
     ## Executes the provided handler on an error, or returns a non-error value
        unchanged.
 

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

@@ -249,8 +249,8 @@ us = here.from_language_tag "en-US"
          example_new = Locale.new "en" "GB" "UTF-8"
 new : Text -> Text | Nothing -> Text | Nothing -> Locale
 new language country=Nothing variant=Nothing =
-    country_text = if country.is_nothing then "" else country
-    variant_text = if variant.is_nothing then "" else variant
+    country_text = country.if_nothing ""
+    variant_text = variant.if_nothing ""
     java_locale = JavaLocale.new language country_text variant_text
     here.from_java java_locale
 

distribution/lib/Standard/Base/0.0.0-dev/src/Nothing.enso

@@ -1,7 +1,8 @@
 from Standard.Base import Boolean, True
 
 type Nothing
-    ## The type that has only a singleton value.
+    ## The type that has only a singleton value. Nothing in Enso is used as an
+       universal value to indicate the lack of presence of a value.
 
        It is often used alongside a value of type a to provide a Maybe or
        Option abstraction. The type a | Nothing is semantically equivalent to
@@ -11,12 +12,18 @@ type Nothing
 
     ## Checks if the type is an instance of `Nothing`.
 
-       Nothing in Enso is used as a universal value to indicate the lack of presence
-       of a value. This function is primarily useful in the IDE.
-
        > Example
          Checking if the value 1 is nothing.
 
              1.is_nothing
     is_nothing : Boolean
-    is_nothing = True
+    is_nothing = True
+
+    ## If this is Nothing then returns `function`.
+
+       > Example
+         If the value "Hello" is nothing return "".
+
+             "Hello".if_nothing ""
+    if_nothing : Any
+    if_nothing ~function = function

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

@@ -114,7 +114,7 @@ type Column
        defaults to the current type if not provided.
     make_binary_op : Text -> Text -> (Column | Any) -> (Sql_Type | Nothing) -> (Sql_Type | Nothing) -> Column
     make_binary_op op_kind operand new_type=Nothing operand_type=Nothing =
-        actual_new_type = if new_type.is_nothing then this.sql_type else new_type
+        actual_new_type = new_type.if_nothing this.sql_type
         case operand of
             Column _ _ _ other_expr _ ->
                 case Helpers.check_integrity this operand of
@@ -124,7 +124,7 @@ type Column
                         new_expr = IR.Operation op_kind [this.expression, other_expr]
                         Column this.name this.connection actual_new_type new_expr this.context
             _ ->
-                actual_operand_type = if operand_type.is_nothing then this.sql_type else operand_type
+                actual_operand_type = operand_type.if_nothing this.sql_type
                 other = IR.make_constant actual_operand_type operand
                 new_expr = IR.Operation op_kind [this.expression, other]
                 Column this.name this.connection actual_new_type new_expr this.context
@@ -139,7 +139,7 @@ type Column
          operator.
     make_unary_op : Text -> Text -> (Sql_Type | Nothing) -> Column
     make_unary_op op_kind new_type=Nothing =
-        actual_new_type = if new_type.is_nothing then this.sql_type else new_type
+        actual_new_type = new_type.if_nothing this.sql_type
         new_expr = IR.Operation op_kind [this.expression]
         Column this.name this.connection actual_new_type new_expr this.context
 
@@ -605,7 +605,7 @@ type Aggregate_Column_Builder
    - new_type: The SQL type of the result column.
 make_aggregate : Column -> Text -> Text -> Sql_Type -> Column
 make_aggregate column operation name_suffix="_agg" new_type=Nothing =
-    actual_new_type = if new_type.is_nothing then column.sql_type else new_type
+    actual_new_type = new_type.if_nothing column.sql_type
     expr = IR.Operation operation [column.expression]
     case Helpers.ensure_name_is_sane name_suffix of
         True ->

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

@@ -507,8 +507,8 @@ type Table
             Text -> wrap_elem elem
             Column _ _ _ _ _ -> wrap_elem elem
             Order_Rule elem Nothing my_order my_nulls ->
-                chosen_order = if my_order.is_nothing then order else my_order
-                chosen_nulls = if my_nulls.is_nothing then missing_last else my_nulls
+                chosen_order = my_order.if_nothing order
+                chosen_nulls = my_nulls.if_nothing missing_last
                 [this.resolve elem . expression, order_to_ir chosen_order, missing_to_ir chosen_nulls]
             Order_Rule _ _ _ _ ->
                 Error.throw <| Unsupported_Database_Operation_Error "Custom comparators are not supported in Database"

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

@@ -17,7 +17,6 @@ from Standard.Base.Error.Problem_Behavior as Problem_Behavior_Module import Prob
 import Standard.Table.Data.Column_Mapping
 import Standard.Table.Data.Position
 
-import Standard.Table.Data.Group_By_Key
 import Standard.Table.Data.Aggregate_Column
 
 polyglot java import org.enso.table.data.table.Table as Java_Table

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

@@ -67,7 +67,7 @@ prepare_aggregate_columns aggregates table =
     pass_1 = valid_resolved_aggregate_columns.map c->(if c.new_name.is_nothing then Nothing else unique.make_unique c.new_name)
     renamed_columns = pass_1.map_with_index i->name->
         agg = valid_resolved_aggregate_columns.at i
-        new_name = (if name.is_nothing then unique.make_unique (here.default_aggregate_column_name agg) else name)
+        new_name = name.if_nothing (unique.make_unique (here.default_aggregate_column_name agg))
         Pair new_name agg
 
     # Build Problems Output
@@ -116,7 +116,7 @@ resolve_aggregate table problem_builder aggregate_column =
     resolve : (Integer|Text|Column) -> Column ! Internal_Missing_Column_Error
     resolve c =
         res = Table_Helpers.resolve_column_helper table_columns c problem_builder
-        if res.is_nothing then Error.throw Internal_Missing_Column_Error else res
+        res.if_nothing (Error.throw Internal_Missing_Column_Error)
 
     resolve_selector_to_vector : Column_Selector -> [Column] ! Internal_Missing_Column_Error
     resolve_selector_to_vector selector =

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

@@ -164,7 +164,7 @@ rename_columns internal_columns mapping on_problems =
 
             new_names = 0.up_to col_count . map i->
                 target = index_map.get_or_else i Nothing
-                if target.is_nothing then target else unique.make_unique target
+                if target.is_nothing then Nothing else unique.make_unique target
 
             new_names
         Column_Mapping.By_Position vec ->
@@ -179,7 +179,7 @@ rename_columns internal_columns mapping on_problems =
             new_names
 
     processed = mapped.map_with_index i->n->
-        if n.is_nothing then (unique.make_unique (internal_columns.at i).name) else n
+        n.if_nothing (unique.make_unique (internal_columns.at i).name)
 
     if unique.invalid_names.not_empty then
         problem_builder.report_other_warning (Invalid_Output_Column_Names unique.invalid_names.to_vector)