Support trait object types in Rust AST

6 files changed, 97 insertions, 1 deletions

diff --git a/hobgoblin/src/output/lang/rust/ast.hob b/hobgoblin/src/output/lang/rust/ast.hob
index 18b5978..a592f4e 100644
--- a/hobgoblin/src/output/lang/rust/ast.hob
+++ b/hobgoblin/src/output/lang/rust/ast.hob
@@ -290,6 +290,7 @@ sum RustType {
     variant RustMutableReferenceType;
     variant RustPath;
     variant RustSharedReferenceType;
+    variant RustTraitObjectType;
     variant RustTupleType;
 }
 
@@ -305,6 +306,10 @@ struct RustSharedReferenceType {
     field referencedType: RustType;
 }
 
+struct RustTraitObjectType {
+    field bound: RustPath;
+}
+
 struct RustTupleType {
     field elementTypes: List[RustType];
 }
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 d894253..aa8d6cb 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
@@ -761,6 +761,10 @@ public class RustWriter implements AutoCloseable {
                 writeSharedReferenceType(sharedReferenceType);
             }
 
+            case RustTraitObjectType traitObjectType -> {
+                writeTraitObjectType(traitObjectType);
+            }
+
             case RustTupleType tupleType -> {
                 writeTupleType(tupleType);
             }
@@ -782,6 +786,11 @@ public class RustWriter implements AutoCloseable {
         this.writeType(sharedReferenceType.referencedType());
     }
 
+    private void writeTraitObjectType(RustTraitObjectType traitObjectType) throws IOException {
+        this.writer.write("dyn ");
+        this.writeType(traitObjectType.bound());
+    }
+
     private void writeTupleType(RustTupleType tupleType) throws IOException {
         this.writer.write("(");
         if (tupleType.elementTypes().size() == 1) {
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustTraitObjectType.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustTraitObjectType.java
new file mode 100644
index 0000000..406a8bd
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustTraitObjectType.java
@@ -0,0 +1,32 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType imports
+
+public record RustTraitObjectType(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPath bound) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType.Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPath.arbitrary().build());
+    }
+
+    public record Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPath bound) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType.Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType(bound);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType.Builder withBound(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPath bound) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType.Builder(bound);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType.Builder withBound(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPath.Builder bound) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType.Builder(bound.build());
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType 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 6e13102..92757e7 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.RustTupleType {
+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 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 481d99e..fe1f9b4 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
@@ -1035,6 +1035,17 @@ public class RustWriterTests {
     }
 
     @Test
+    public void traitObjectTypeWithSingleTraitBound() throws IOException {
+        var rust = RustTraitObjectType.arbitrary()
+            .withBound(RustPath.of("Any"))
+            .build();
+
+        var string = write(writer -> writer.writeType(rust));
+
+        assertThat(string, equalTo("dyn Any"));
+    }
+
+    @Test
     public void tupleTypeSingleton() throws IOException {
         var rust = RustTupleType.arbitrary()
             .addElementType(RustPath.of("A"))
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustTraitObjectTypeMatcher.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustTraitObjectTypeMatcher.java
new file mode 100644
index 0000000..8d79f6d
--- /dev/null
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustTraitObjectTypeMatcher.java
@@ -0,0 +1,39 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectTypeMatcher imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectTypeMatcher imports
+
+public class RustTraitObjectTypeMatcher implements org.zwobble.precisely.Matcher<java.lang.Object> {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectTypeMatcher isRustTraitObjectType() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectTypeMatcher(java.util.List.of());
+    }
+
+    private final java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType>> submatchers;
+
+    private RustTraitObjectTypeMatcher(java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType>> 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.RustTraitObjectType.class, this.submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectTypeMatcher withBound(org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPath> bound) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("bound", org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectType::bound, bound));
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectTypeMatcher(submatchers);
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectTypeMatcher body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTraitObjectTypeMatcher body
+}