Add function pointer types to Rust AST

5 files changed, 130 insertions, 1 deletions

diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriter.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriter.java
index ec8d70b..a101528 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriter.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriter.java
@@ -796,6 +796,10 @@ public class RustWriter implements AutoCloseable {
 
     void writeType(RustType type) throws IOException {
         switch (type) {
+            case RustFunctionPointerType functionPointerType -> {
+                writeFunctionPointerType(functionPointerType);
+            }
+
             case RustImplTraitType implTraitType -> {
                 writeImplTraitType(implTraitType);
             }
@@ -822,6 +826,17 @@ public class RustWriter implements AutoCloseable {
         }
     }
 
+    private void writeFunctionPointerType(RustFunctionPointerType functionPointerType) throws IOException {
+        this.writer.write("fn(");
+        writeWithSeparator(
+            functionPointerType.params(),
+            this::writeType,
+            () -> this.writer.write(", ")
+        );
+        this.writer.write(") -> ");
+        this.writeType(functionPointerType.returnType());
+    }
+
     private void writeImplTraitType(RustImplTraitType implTraitType) throws IOException {
         this.writer.write("impl ");
         this.writePath(implTraitType.trait());
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustFunctionPointerType.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustFunctionPointerType.java
new file mode 100644
index 0000000..6f2e13b
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustFunctionPointerType.java
@@ -0,0 +1,54 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType imports
+
+public record RustFunctionPointerType(
+    java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType> params,
+    org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType returnType
+) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder(java.util.List.of(), org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustImplTraitType.arbitrary().build());
+    }
+
+    public record Builder(
+        java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType> params,
+        org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType returnType
+    ) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType.Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType(params, returnType);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder withParams(java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType> params) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder(params, returnType);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder addParam(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType param) {
+            var params = new java.util.ArrayList<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType>(this.params);
+            params.add(param);
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder(params, returnType);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder addParam(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType.Builder param) {
+            var params = new java.util.ArrayList<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType>(this.params);
+            params.add(param.build());
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder(params, returnType);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder withReturnType(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType returnType) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder(params, returnType);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder withReturnType(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType.Builder returnType) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder(params, returnType.build());
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType body
+}
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustType.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustType.java
index 92757e7..818f88f 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustType.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustType.java
@@ -5,7 +5,7 @@ package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
 // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType imports
 // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType imports
 
-public sealed interface RustType permits org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustImplTraitType, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustMutableReferenceType, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPath, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustSharedReferenceType, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTupleType {
+public sealed interface RustType permits org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustFunctionPointerType, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustImplTraitType, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustMutableReferenceType, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPath, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustSharedReferenceType, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTupleType {
     public interface Builder {
         public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType build();
 
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
@@ -1070,6 +1070,19 @@ 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()
             .withTrait(RustPath.of("std", "io", "Read"))
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
+}