unified: Emit function and initializer parameter types

Emit a parameter's declared type on the mapped `parameter` node. The
tree-sitter path dropped it — its untyped-parameter rule was ordered
before the typed one and shadowed it — and the mapping matched that for
corpus parity; swift-syntax models the type as a required
`functionParameter.type`, so emitting it is a correctness improvement.

The existing function-parameter corpus cases (and the initializer cases
from the previous commit) witness the restored types.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

unified/extractor/src/languages/swift/swift.rs

@@ -560,17 +560,13 @@ fn translation_rules() -> Vec<Rule<SwiftContext>> {
         ),
         // A function parameter. With two names (`firstName`+`secondName`) the
         // first is the external argument label and the second the internal name;
-        // with one name it is just the internal name. The default value is
-        // optional.
-        //
-        // PARITY: the declared type is intentionally dropped. In the tree-sitter
-        // path the untyped-parameter rule was ordered before the typed one and
-        // shadowed it (first match wins), so the baseline emits no parameter
-        // type; emitting one here would diverge from it.
+        // with one name it is just the internal name. The declared type is
+        // emitted; the default value is optional.
         rule!(
             (functionParameter
                 firstName: @@first
                 secondName: _? @@second
+                type: @ty
                 defaultValue: (initializerClause value: @val)?)
             =>
             parameter {
@@ -581,6 +577,7 @@ fn translation_rules() -> Vec<Rule<SwiftContext>> {
                 tree!((parameter
                     external_name: {external}
                     pattern: (name_pattern identifier: (identifier #{name}))
+                    type: {ty}
                     default: {val}))
             }
         ),

unified/extractor/tests/corpus/swift/functions/function-with-default-parameter-value.output

@@ -69,6 +69,9 @@ top_level
           name: identifier "greet"
           parameter:
             parameter
+              type:
+                named_type_expr
+                  name: identifier "String"
               pattern:
                 name_pattern
                   identifier: identifier "name"

unified/extractor/tests/corpus/swift/functions/function-with-named-parameters.output

@@ -61,6 +61,9 @@ top_level
           parameter:
             parameter
               external_name: identifier "person"
+              type:
+                named_type_expr
+                  name: identifier "String"
               pattern:
                 name_pattern
                   identifier: identifier "name"

unified/extractor/tests/corpus/swift/functions/function-with-parameters-and-return-type.output

@@ -78,11 +78,17 @@ top_level
           parameter:
             parameter
               external_name: identifier "_"
+              type:
+                named_type_expr
+                  name: identifier "Int"
               pattern:
                 name_pattern
                   identifier: identifier "a"
             parameter
               external_name: identifier "_"
+              type:
+                named_type_expr
+                  name: identifier "Int"
               pattern:
                 name_pattern
                   identifier: identifier "b"

unified/extractor/tests/corpus/swift/functions/generic-function.output

@@ -68,6 +68,9 @@ top_level
           parameter:
             parameter
               external_name: identifier "_"
+              type:
+                named_type_expr
+                  name: identifier "T"
               pattern:
                 name_pattern
                   identifier: identifier "x"

unified/extractor/tests/corpus/swift/functions/variadic-function.output

@@ -82,6 +82,9 @@ top_level
           parameter:
             parameter
               external_name: identifier "_"
+              type:
+                named_type_expr
+                  name: identifier "Int"
               pattern:
                 name_pattern
                   identifier: identifier "values"

unified/extractor/tests/corpus/swift/types/class-with-initializer.output

@@ -105,6 +105,9 @@ top_level
             constructor_declaration
               parameter:
                 parameter
+                  type:
+                    named_type_expr
+                      name: identifier "Int"
                   pattern:
                     name_pattern
                       identifier: identifier "x"

unified/extractor/tests/corpus/swift/types/constructor-with-parameters.output

@@ -71,11 +71,17 @@ top_level
               parameter:
                 parameter
                   external_name: identifier "width"
+                  type:
+                    named_type_expr
+                      name: identifier "Int"
                   pattern:
                     name_pattern
                       identifier: identifier "w"
                 parameter
                   external_name: identifier "height"
+                  type:
+                    named_type_expr
+                      name: identifier "Int"
                   pattern:
                     name_pattern
                       identifier: identifier "h"