Support empty inherent impl in Rust AST

6 files changed, 100 insertions, 1 deletions

diff --git a/hobgoblin/src/output/lang/rust/ast.hob b/hobgoblin/src/output/lang/rust/ast.hob
index 8cbe166..929e342 100644
--- a/hobgoblin/src/output/lang/rust/ast.hob
+++ b/hobgoblin/src/output/lang/rust/ast.hob
@@ -11,6 +11,7 @@ struct RustModule {
 
 sum RustItem {
     variant RustEnum;
+    variant RustInherentImpl;
     variant RustStructStruct;
 }
 
@@ -37,6 +38,10 @@ struct RustEnumVariantTuple {
     field fields: List[RustTupleField];
 }
 
+struct RustInherentImpl {
+    field type: RustType;
+}
+
 struct RustStructStruct {
     field name: RustIdentifier;
     field fields: List[RustStructField];
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 59b792c..7ab09c7 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
@@ -62,6 +62,10 @@ public class RustWriter implements AutoCloseable {
                 writeEnum(enum_);
             }
 
+            case RustInherentImpl inherentImpl -> {
+                writeInherentImpl(inherentImpl);
+            }
+
             case RustStructStruct structStruct -> {
                 writeStructStruct(structStruct);
             }
@@ -107,6 +111,14 @@ public class RustWriter implements AutoCloseable {
         this.writer.write("}");
     }
 
+    private void writeInherentImpl(RustInherentImpl inherentImpl) throws IOException {
+        this.writer.write("impl ");
+        this.writeType(inherentImpl.type());
+        this.writer.write(" {");
+        this.writer.newLine();
+        this.writer.write("}");
+    }
+
     private void writeStructStruct(RustStructStruct structStruct) throws IOException {
         this.writeDocComment(structStruct.docComment());
         this.writer.write("pub struct ");
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustInherentImpl.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustInherentImpl.java
new file mode 100644
index 0000000..55447bb
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustInherentImpl.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.RustInherentImpl imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl imports
+
+public record RustInherentImpl(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType type) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl.Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath.arbitrary().build());
+    }
+
+    public record Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType type) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem.Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl(type);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl.Builder withType(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType type) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl.Builder(type);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl.Builder withType(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType.Builder type) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl.Builder(type.build());
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl body
+}
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustItem.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustItem.java
index 4471b49..5da65a1 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustItem.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustItem.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.RustItem imports
 // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem imports
 
-public sealed interface RustItem permits org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustEnum, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct {
+public sealed interface RustItem permits org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustEnum, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct {
     public interface Builder {
         public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem 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 b5583ab..ea04006 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
@@ -128,6 +128,17 @@ public class RustWriterTests {
     }
 
     @Test
+    public void emptyInherentImpl() throws IOException {
+        var rust = RustInherentImpl.arbitrary().withType(RustTypePath.of("Square")).build();
+
+        var string = write(writer -> writer.writeItem(rust));
+
+        assertThat(string, equalTo("""
+            impl Square {
+            }"""));
+    }
+
+    @Test
     public void emptyStruct() throws IOException {
         var rust = RustStructStruct.arbitrary().withName(new RustIdentifier("Rectangle")).build();
 
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustInherentImplMatcher.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustInherentImplMatcher.java
new file mode 100644
index 0000000..23b23a1
--- /dev/null
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustInherentImplMatcher.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.RustInherentImplMatcher imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImplMatcher imports
+
+public class RustInherentImplMatcher implements org.zwobble.precisely.Matcher<java.lang.Object> {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImplMatcher isRustInherentImpl() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImplMatcher(java.util.List.of());
+    }
+
+    private final java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl>> submatchers;
+
+    private RustInherentImplMatcher(java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl>> 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.RustInherentImpl.class, this.submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImplMatcher withType(org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType> type) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("type", org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImpl::type, type));
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImplMatcher(submatchers);
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImplMatcher body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustInherentImplMatcher body
+}