Translate anonymous Swift parameters as ignore patterns

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 49ef7786-959a-40d6-861f-3dcd71a73665

Author: paldepind

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

@@ -111,6 +111,17 @@ fn make_or_pattern(
     }
 }
 
+fn parameter_pattern(
+    ctx: &mut yeast::build::BuildCtx<'_, SwiftContext>,
+    name: yeast::Id,
+) -> yeast::OutputId {
+    if ctx.source_text(name) == "_" {
+        tree!((ignore_pattern #{name}))
+    } else {
+        tree!((identifier #{name}))
+    }
+}
+
 /// Translate a multi-part identifier (for example `Foo.Bar.Baz`) into a
 /// `member_access_expr` chain rooted at a `name_node` for the first
 /// part. Panics on an empty input because the grammar's `_+` quantifier
@@ -669,7 +680,7 @@ fn translation_rules() -> Vec<Rule<SwiftContext>> {
             =>
             (parameter
                 external_name_node: (identifier #{first})
-                pattern: (identifier #{second})
+                pattern: {parameter_pattern(&mut ctx, second)}
                 type: {ty}
                 default: {val})
         ),
@@ -681,7 +692,7 @@ fn translation_rules() -> Vec<Rule<SwiftContext>> {
             =>
             (parameter
                 external_name_node: (identifier #{first}) // duplicate the parameter name
-                pattern: (identifier #{first})
+                pattern: {parameter_pattern(&mut ctx, first)}
                 type: {ty}
                 default: {val})
         ),
@@ -867,14 +878,14 @@ fn translation_rules() -> Vec<Rule<SwiftContext>> {
         rule!(
             (closureParameter firstName: @@name type: _? @ty)
             =>
-            (parameter pattern: (identifier #{name}) type: {ty})
+            (parameter pattern: {parameter_pattern(&mut ctx, name)} type: {ty})
         ),
         // A shorthand closure parameter (`x` in `{ x, y in … }`): a bare name
         // with no parentheses and no type.
         rule!(
             (closureShorthandParameter name: @@name)
             =>
-            (parameter pattern: (identifier #{name}))
+            (parameter pattern: {parameter_pattern(&mut ctx, name)})
         ),
         // ---- Control flow ----
         // An `if`/`else` expression. Conditions are joined via `and_chain`; the

unified/extractor/tests/corpus/swift/expressions/array-type-constructor.output

@@ -181,7 +181,7 @@ top_level source="⟨body⟩"
                     function_expr source="{ ⟨parameter⟩, ⟨parameter⟩ in\n\t⟨body⟩\n}"
                       parameter:
                         parameter source="⟨pattern⟩"
-                          pattern: identifier "_" source="_"
+                          pattern: ignore_pattern "_" source="_"
                         parameter source="⟨pattern⟩"
                           pattern: identifier "count" source="count"
                       body:

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

@@ -199,23 +199,23 @@ top_level source="⟨body⟩"
             parameter source="⟨external_name_node⟩⟨pattern⟩: ⟨type⟩"
               external_name_node: identifier "_" source="_"
               type: identifier "Int" source="Int"
-              pattern: identifier "_" source="_"
+              pattern: ignore_pattern "_" source="_"
             parameter source="⟨external_name_node⟩⟨pattern⟩: ⟨type⟩"
               external_name_node: identifier "_" source="_"
               type: identifier "String" source="String"
-              pattern: identifier "_" source="_"
+              pattern: ignore_pattern "_" source="_"
           body: block "{\n}" source="{\n}"
         function_declaration source="func ⟨name_node⟩(⟨parameter⟩, ⟨parameter⟩) ⟨body⟩"
           name_node: identifier "ignore" source="ignore"
           parameter:
             parameter source="⟨external_name_node⟩ ⟨pattern⟩: ⟨type⟩"
               external_name_node: identifier "first" source="first"
               type: identifier "Int" source="Int"
-              pattern: identifier "_" source="_"
+              pattern: ignore_pattern "_" source="_"
             parameter source="⟨external_name_node⟩ ⟨pattern⟩: ⟨type⟩"
               external_name_node: identifier "second" source="second"
               type: identifier "String" source="String"
-              pattern: identifier "_" source="_"
+              pattern: ignore_pattern "_" source="_"
           body: block "{\n}" source="{\n}"
         variable_declaration source="⟨modifier⟩ ⟨pattern⟩: ⟨type⟩ = ⟨value⟩"
           modifier: modifier "let" source="let"
@@ -232,9 +232,9 @@ top_level source="⟨body⟩"
             function_expr source="{ ⟨parameter⟩, ⟨parameter⟩ in\n}"
               parameter:
                 parameter source="⟨pattern⟩"
-                  pattern: identifier "_" source="_"
+                  pattern: ignore_pattern "_" source="_"
                 parameter source="⟨pattern⟩"
-                  pattern: identifier "_" source="_"
+                  pattern: ignore_pattern "_" source="_"
               body: block source=""
         variable_declaration source="⟨modifier⟩ ⟨pattern⟩ = ⟨value⟩"
           modifier: modifier "let" source="let"
@@ -244,8 +244,8 @@ top_level source="⟨body⟩"
               parameter:
                 parameter source="⟨pattern⟩: ⟨type⟩"
                   type: identifier "Int" source="Int"
-                  pattern: identifier "_" source="_"
+                  pattern: ignore_pattern "_" source="_"
                 parameter source="⟨pattern⟩: ⟨type⟩"
                   type: identifier "String" source="String"
-                  pattern: identifier "_" source="_"
+                  pattern: ignore_pattern "_" source="_"
               body: block source=""

unified/extractor/tests/corpus/swift/types/function-type-with-inout-parameter.output

@@ -79,5 +79,5 @@ top_level source="⟨body⟩"
             function_expr source="{ ⟨parameter⟩ in }"
               parameter:
                 parameter source="⟨pattern⟩"
-                  pattern: identifier "_" source="_"
+                  pattern: ignore_pattern "_" source="_"
               body: block source=""