From 57d7f43d0944db2edd140e2380f5114229ae334d Mon Sep 17 00:00:00 2001
From: Michael Williamson <mike@zwobble.org>
Date: Sun, 9 Aug 2026 14:12:44 +0100
Subject: Add function pointer types to Rust AST

---
 .../compiler/output/lang/rust/RustWriterTests.java | 13 ++++++
 .../rust/ast/RustFunctionPointerTypeMatcher.java   | 47 ++++++++++++++++++++++
 2 files changed, 60 insertions(+)
 create mode 100644 src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustFunctionPointerTypeMatcher.java

(limited to 'src/test')

diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriterTests.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriterTests.java
index 7272eea..0bf96e4 100644
--- a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriterTests.java
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriterTests.java
@@ -1069,6 +1069,19 @@ public class RustWriterTests {
 
     // == Types ==
 
+    @Test
+    public void functionPointerType() throws IOException {
+        var rust = RustFunctionPointerType.arbitrary()
+            .addParam(RustPath.of("A"))
+            .addParam(RustPath.of("B"))
+            .withReturnType(RustPath.of("C"))
+            .build();
+
+        var string = write(writer -> writer.writeType(rust));
+
+        assertThat(string, equalTo("fn(A, B) -> C"));
+    }
+
     @Test
     public void implTraitType() throws IOException {
         var rust = RustImplTraitType.arbitrary()
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustFunctionPointerTypeMatcher.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustFunctionPointerTypeMatcher.java
new file mode 100644
index 0000000..72ff1ab
--- /dev/null
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustFunctionPointerTypeMatcher.java
@@ -0,0 +1,47 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerTypeMatcher imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerTypeMatcher imports
+
+public final class RustFunctionPointerTypeMatcher implements org.zwobble.precisely.Matcher<java.lang.Object> {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerTypeMatcher isRustFunctionPointerType() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerTypeMatcher(java.util.List.of());
+    }
+
+    private final java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType>> submatchers;
+
+    private RustFunctionPointerTypeMatcher(
+        java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType>> submatchers
+    ) {
+        this.submatchers = submatchers;
+    }
+
+    public org.zwobble.precisely.MatchResult match(java.lang.Object actual) {
+        return this.toMatcher().match(actual);
+    }
+
+    public org.zwobble.precisely.TextTree describe() {
+        return this.toMatcher().describe();
+    }
+
+    private org.zwobble.precisely.Matcher<java.lang.Object> toMatcher() {
+        return org.zwobble.precisely.Matchers.instanceOf(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.class, this.submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerTypeMatcher withParams(org.zwobble.precisely.Matcher<? super java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType>> params) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("params", org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType::params, params));
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerTypeMatcher(submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerTypeMatcher withReturnType(org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType> returnType) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("returnType", org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType::returnType, returnType));
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerTypeMatcher(submatchers);
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerTypeMatcher body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerTypeMatcher body
+}
-- 
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