WIP

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

@@ -0,0 +1,12 @@
+private
+
+import project.Column.Column
+import project.Table.Table
+import project.Refined_Types.Numeric_Column.Numeric_Column
+
+from project.Internal.Type_Refinements.Single_Column_Table_Conversions import all
+from project.Internal.Type_Refinements.Typed_Column_Conversions import all
+
+## This conversion is internal and should never be exported.
+Numeric_Column.from (that : Table) =
+    Numeric_Column.from (Column.from that)

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

@@ -8,6 +8,7 @@ import project.Refined_Types.Numeric_Column.Numeric_Column
 import project.Table.Table
 import project.Value_Type.Value_Type
 from project.Internal.Type_Refinements.Single_Column_Table_Conversions import all
+from project.Internal.Type_Refinements.Single_Column_Typed_Table_Conversions import all
 from project.Internal.Type_Refinements.Column_Refinements import is_single_value
 
 refine_table (table : Table) =

test/Table_Tests/src/Common_Table_Operations/Numeric_Column_Spec.enso

@@ -53,5 +53,9 @@ add_numeric_columns_specs suite_builder setup =
             signum_column.to_vector . should_equal [-1, 0, 0, 1, 1]
 
         group_builder.specify "a single value column can also be Numeric_Column" <|
-            column = table_builder [["X", [1]]] . at "X"
+            table = table_builder [["X", [1]]]
+            column = table . at "X"
             column:Numeric_Column
+
+            # But a single column table can also be converted
+            table:Numeric_Column