Generate Rust types for structs

15 files changed, 616 insertions, 1 deletions

diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/CodeWriter.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/CodeWriter.java
index dba5dbf..fe2c3b9 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/CodeWriter.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/CodeWriter.java
@@ -2,6 +2,7 @@ package org.zwobble.hobgoblin.compiler.output;
 
 import java.io.FileWriter;
 import java.io.IOException;
+import java.io.StringWriter;
 import java.io.Writer;
 import java.nio.file.Files;
 import java.nio.file.NoSuchFileException;
@@ -14,6 +15,33 @@ public class CodeWriter implements AutoCloseable {
         Writer openWriter() throws IOException;
     }
 
+    public static class InMemoryCodeWriterFile implements CodeWriterFile {
+        private final Optional<String> originalContents;
+        private final StringWriter stringWriter;
+
+        public InMemoryCodeWriterFile(
+            Optional<String> originalContents,
+            StringWriter stringWriter
+        ) {
+            this.originalContents = originalContents;
+            this.stringWriter = stringWriter;
+        }
+
+        @Override
+        public String readString() throws IOException {
+            if (originalContents.isPresent()) {
+                return originalContents.get();
+            } else {
+                throw new NoSuchFileException("");
+            }
+        }
+
+        @Override
+        public Writer openWriter() throws IOException {
+            return stringWriter;
+        }
+    }
+
     public record CustomAreas(
         Map<String, List<String>> existing,
         String customAreaStart,
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rust/RustGeneratorConfig.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rust/RustGeneratorConfig.java
new file mode 100644
index 0000000..db0b2fe
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rust/RustGeneratorConfig.java
@@ -0,0 +1,23 @@
+package org.zwobble.hobgoblin.compiler.output.generators.rust;
+
+import org.zwobble.hobgoblin.compiler.builtins.NativeTypes;
+import org.zwobble.hobgoblin.compiler.output.lang.java.ast.*;
+import org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath;
+import org.zwobble.hobgoblin.compiler.types.SimpleNativeType;
+
+import java.util.Map;
+import java.util.Optional;
+
+public class RustGeneratorConfig {
+    private static final Map<SimpleNativeType, RustNativeTypeConfig> DEFAULT_NATIVE_TYPE_CONFIGS = Map.ofEntries(
+        Map.entry(NativeTypes.INT_32, new RustNativeTypeConfig(RustTypePath.primitive("i32"))),
+        Map.entry(NativeTypes.INT_64, new RustNativeTypeConfig(RustTypePath.primitive("i64"))),
+        Map.entry(NativeTypes.STRING, new RustNativeTypeConfig(RustTypePath.of("std", "string", "String"))),
+        Map.entry(NativeTypes.LIST_INNER, new RustNativeTypeConfig(RustTypePath.of("std", "vec", "Vec"))),
+        Map.entry(NativeTypes.OPTION_INNER, new RustNativeTypeConfig(RustTypePath.of("std", "option", "Option")))
+    );
+
+    public Optional<RustNativeTypeConfig> nativeTypeConfig(SimpleNativeType type) {
+        return Optional.ofNullable(DEFAULT_NATIVE_TYPE_CONFIGS.get(type));
+    }
+}
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rust/RustNativeTypeConfig.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rust/RustNativeTypeConfig.java
new file mode 100644
index 0000000..27a6dc8
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rust/RustNativeTypeConfig.java
@@ -0,0 +1,8 @@
+package org.zwobble.hobgoblin.compiler.output.generators.rust;
+
+import org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType;
+
+public record RustNativeTypeConfig(
+    RustType type
+) {
+}
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rusttypes/RustTypesGenerator.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rusttypes/RustTypesGenerator.java
index c93be76..b5cf01c 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rusttypes/RustTypesGenerator.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/rusttypes/RustTypesGenerator.java
@@ -1,14 +1,22 @@
 package org.zwobble.hobgoblin.compiler.output.generators.rusttypes;
 
-import org.zwobble.hobgoblin.compiler.ast.typed.TypedNamespaceNode;
+import org.zwobble.hobgoblin.compiler.ast.typed.*;
 import org.zwobble.hobgoblin.compiler.config.OutputConfig;
 import org.zwobble.hobgoblin.compiler.output.generators.Generator;
+import org.zwobble.hobgoblin.compiler.output.generators.rust.RustGeneratorConfig;
+import org.zwobble.hobgoblin.compiler.output.lang.java.JavaWriter;
+import org.zwobble.hobgoblin.compiler.output.lang.rust.RustWriter;
+import org.zwobble.hobgoblin.compiler.output.lang.rust.ast.*;
 import org.zwobble.hobgoblin.compiler.typechecker.TypesInfo;
+import org.zwobble.hobgoblin.compiler.types.*;
+import org.zwobble.hobgoblin.compiler.util.Casing;
 import org.zwobble.json5.reader.Json5ObjectReader;
 
+import java.io.File;
 import java.io.IOException;
 import java.nio.file.Path;
 import java.util.List;
+import java.util.stream.Collectors;
 
 public class RustTypesGenerator implements Generator {
     public static final String NAME = "rust-types";
@@ -23,6 +31,7 @@ public class RustTypesGenerator implements Generator {
     }
 
     private final Path outputPath;
+    private final RustGeneratorConfig config = new RustGeneratorConfig();
 
     private RustTypesGenerator(Path outputPath) {
         this.outputPath = outputPath;
@@ -30,6 +39,112 @@ public class RustTypesGenerator implements Generator {
 
     @Override
     public void generate(List<TypedNamespaceNode> namespaces, TypesInfo typesInfo) throws IOException {
+        for (var namespace : namespaces) {
+            var rustModule = generateNamespace(namespace);
 
+            write(rustModule);
+        }
+    }
+
+    private void write(RustModule rustModule) throws IOException {
+        var path = this.outputPath.resolve(
+            rustModule.name().stream()
+                .map(name -> name.value())
+                .collect(Collectors.joining(File.separator)) + ".rs"
+        );
+        try (var writer = RustWriter.file(path)) {
+            writer.writeModule(rustModule);
+        }
+    }
+
+    private RustModule generateNamespace(TypedNamespaceNode namespace) {
+        var rustModuleName = generateNamespaceName(namespace.namespaceName());
+        
+        var rustItems = namespace.body().stream()
+            .flatMap(statement -> generateNamespaceStatement(statement).stream())
+            .toList();
+
+        return new RustModule(rustModuleName, rustItems);
+    }
+
+    private List<RustIdentifier> generateNamespaceName(NamespaceName namespaceName) {
+        return namespaceName.parts().stream()
+            .map(part -> generateModuleName(part))
+            .toList();
+    }
+
+    private List<RustItem> generateNamespaceStatement(TypedNamespaceStatementNode statement) {
+        return switch (statement) {
+            case TypedEnumDefinitionNode enumDefinition -> {
+                yield List.of();
+            }
+
+            case TypedNativeTypeDefinitionNode nativeTypeDefinition -> {
+                yield List.of();
+            }
+
+            case TypedStructDefinitionNode structDefinition -> {
+                var rustStructName = generateTypeName(structDefinition.name());
+
+                var rustFields = structDefinition.fields().stream()
+                    .map(field -> new RustStructField(generateFieldName(field.name()), generateRustTypeExpression(field.type())))
+                    .toList();
+
+                var rustStruct = new RustStructStruct(rustStructName, rustFields);
+
+                yield List.of(rustStruct);
+            }
+
+            case TypedSumDefinitionNode sumDefinition -> {
+                yield List.of();
+            }
+        };
+    }
+
+    private RustType generateRustTypeExpression(TypedTypeLevelExpressionNode<Type> type) {
+        return switch (type.value()) {
+            case ConstructedNativeType constructedNativeType -> {
+                throw new UnsupportedOperationException("TODO");
+            }
+
+            case EnumType enumType -> {
+                throw new UnsupportedOperationException("TODO");
+            }
+
+            case SimpleNativeType simpleNativeType -> {
+                yield this.config.nativeTypeConfig(simpleNativeType)
+                    .orElseThrow(() -> new UnsupportedOperationException("TODO"))
+                    .type();
+            }
+
+            case StructType structType -> {
+                // TODO: qualify name
+                yield RustTypePath.of(generateTypeName(structType.name()));
+            }
+
+            case SumType sumType -> {
+                throw new UnsupportedOperationException("TODO");
+            }
+
+            case TypeLevelValueType typeLevelValueType -> {
+                throw new UnsupportedOperationException("TODO");
+            }
+
+            case TypeParam typeParam -> {
+                throw new UnsupportedOperationException("TODO");
+            }
+        };
+    }
+
+    private RustIdentifier generateFieldName(String fieldName) {
+        return new RustIdentifier(Casing.lowerCamelCaseToSnakeCase(fieldName));
+    }
+
+    private RustIdentifier generateTypeName(String typeName) {
+        return new RustIdentifier(typeName);
+    }
+
+    private RustIdentifier generateModuleName(String part) {
+        return new RustIdentifier(Casing.lowerCamelCaseToSnakeCase(part));
     }
 }
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
new file mode 100644
index 0000000..16384a4
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriter.java
@@ -0,0 +1,138 @@
+package org.zwobble.hobgoblin.compiler.output.lang.rust;
+
+import org.zwobble.hobgoblin.compiler.output.CodeWriter;
+import org.zwobble.hobgoblin.compiler.output.lang.java.JavaWriter;
+import org.zwobble.hobgoblin.compiler.output.lang.rust.ast.*;
+
+import java.io.IOException;
+import java.nio.file.Path;
+
+public class RustWriter implements AutoCloseable {
+    private static final String LINE_COMMENT_START = "//";
+
+    public static RustWriter file(CodeWriter.CodeWriterFile file) throws IOException {
+        return new RustWriter(CodeWriter.file(
+            file,
+            LINE_COMMENT_START
+        ));
+    }
+
+    public static RustWriter file(Path path) throws IOException {
+        return new RustWriter(CodeWriter.file(
+            path,
+            LINE_COMMENT_START
+        ));
+    }
+
+    private final CodeWriter writer;
+
+    public RustWriter(CodeWriter writer) {
+        this.writer = writer;
+    }
+
+    @Override
+    public void close() throws IOException {
+        this.writer.close();
+    }
+
+    public void writeModule(RustModule module) throws IOException {
+        writeWithSeparator(
+            module.items(),
+            this::writeItem,
+            () -> {
+                this.writer.newLine();
+                this.writer.newLine();
+            }
+        );
+
+        this.writer.newLine();
+    }
+
+    void writeIdentifier(RustIdentifier identifier) throws IOException {
+        // TODO: handle keywords
+        this.writer.write(identifier.value());
+    }
+
+    void writeItem(RustItem item) throws IOException {
+        switch (item) {
+            case RustStructStruct structStruct -> {
+                writeStructStruct(structStruct);
+            }
+        }
+    }
+
+    private void writeStructStruct(RustStructStruct structStruct) throws IOException {
+        this.writer.write("pub struct ");
+        this.writeIdentifier(structStruct.name());
+        this.writer.write(" {");
+
+        if (!structStruct.fields().isEmpty()) {
+            this.writer.indent();
+
+            for (var field : structStruct.fields()) {
+                this.writer.newLine();
+                this.writeIdentifier(field.name());
+                this.writer.write(": ");
+                this.writeType(field.type());
+                this.writer.write(",");
+            }
+
+            this.writer.dedent();
+        }
+
+        this.writer.newLine();
+        this.writer.write("}");
+    }
+
+    void writeType(RustType type) throws IOException {
+        switch (type) {
+            case RustTypePath typePath -> {
+                this.writeWithSeparator(
+                    typePath.segments(),
+                    this::writeTypePathSegment,
+                    () -> this.writer.write("::")
+                );
+            }
+        }
+    }
+
+    private void writeTypePathSegment(RustTypePathSegment segment) throws IOException {
+        writePathIdentSegment(segment.pathIdentSegment());
+    }
+
+    private void writePathIdentSegment(RustPathIdentSegment pathIdentSegment) throws IOException {
+        switch (pathIdentSegment) {
+            case RustPathIdentSegmentIdentifier pathIdentSegmentIdentifier -> {
+                this.writeIdentifier(pathIdentSegmentIdentifier.name());
+            }
+        }
+    }
+
+    // TODO: de-dupe with Java writer
+    private static <T> void writeWithSeparator(
+        Iterable<T> iterable,
+        WriteElement<T> writeElement,
+        WriteSeparator writeSeparator
+    ) throws IOException {
+        var isFirst = true;
+        for (var element : iterable) {
+            if (!isFirst) {
+                writeSeparator.write();
+            }
+
+            writeElement.write(element);
+
+            if (isFirst) {
+                isFirst = false;
+            }
+        }
+    }
+
+    interface WriteElement<T> {
+        void write(T element) throws IOException;
+    }
+
+    interface WriteSeparator {
+        void write() throws IOException;
+    }
+}
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIdentifier.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIdentifier.java
new file mode 100644
index 0000000..34e0ff7
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustIdentifier.java
@@ -0,0 +1,28 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier imports
+
+public record RustIdentifier(String value) {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.Builder("");
+    }
+
+    public record Builder(String value) {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier(value);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.Builder withValue(String value) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.Builder(value);
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier 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
new file mode 100644
index 0000000..d1fa342
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustItem.java
@@ -0,0 +1,18 @@
+// Generated by hobgoblin.
+
+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.RustStructStruct {
+    public interface Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem build();
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem body
+}
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustModule.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustModule.java
new file mode 100644
index 0000000..e40895e
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustModule.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.RustModule imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustModule imports
+
+public record RustModule(java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier> name, java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem> items) {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustModule.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustModule.Builder(java.util.List.of(), java.util.List.of());
+    }
+
+    public record Builder(java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier> name, java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem> items) {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustModule build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustModule(name, items);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustModule.Builder withName(java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier> name) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustModule.Builder(name, items);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustModule.Builder withItems(java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem> items) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustModule.Builder(name, items);
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustModule.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustModule.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustModule body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustModule body
+}
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustPathIdentSegment.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustPathIdentSegment.java
new file mode 100644
index 0000000..325a4a4
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustPathIdentSegment.java
@@ -0,0 +1,18 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegment imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegment imports
+
+public sealed interface RustPathIdentSegment permits org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier {
+    public interface Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegment build();
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegment.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegment.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegment body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegment body
+}
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustPathIdentSegmentIdentifier.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustPathIdentSegmentIdentifier.java
new file mode 100644
index 0000000..72e6cb0
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustPathIdentSegmentIdentifier.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.RustPathIdentSegmentIdentifier imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier imports
+
+public record RustPathIdentSegmentIdentifier(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier name) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegment {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier.Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.arbitrary().build());
+    }
+
+    public record Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier name) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegment.Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier(name);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier.Builder withName(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier name) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier.Builder(name);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier.Builder withName(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.Builder name) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier.Builder(name.build());
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier body
+}
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustStructField.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustStructField.java
new file mode 100644
index 0000000..dc1ddf0
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustStructField.java
@@ -0,0 +1,40 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField imports
+
+public record RustStructField(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier name, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType type) {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField.Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.arbitrary().build(), org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath.arbitrary().build());
+    }
+
+    public record Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier name, org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType type) {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField(name, type);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField.Builder withName(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier name) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField.Builder(name, type);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField.Builder withName(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.Builder name) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField.Builder(name.build(), type);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField.Builder withType(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType type) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField.Builder(name, type);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField.Builder withType(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType.Builder type) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField.Builder(name, type.build());
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField body
+}
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustStructStruct.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustStructStruct.java
new file mode 100644
index 0000000..3e9c3ad
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustStructStruct.java
@@ -0,0 +1,36 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct imports
+
+public record RustStructStruct(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier name, java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField> fields) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct.Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.arbitrary().build(), java.util.List.of());
+    }
+
+    public record Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier name, java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField> fields) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustItem.Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct(name, fields);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct.Builder withName(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier name) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct.Builder(name, fields);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct.Builder withName(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustIdentifier.Builder name) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct.Builder(name.build(), fields);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct.Builder withFields(java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructField> fields) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct.Builder(name, fields);
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustStructStruct 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
new file mode 100644
index 0000000..e9d2283
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustType.java
@@ -0,0 +1,18 @@
+// Generated by hobgoblin.
+
+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.RustTypePath {
+    public interface Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType build();
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType body
+}
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustTypePath.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustTypePath.java
new file mode 100644
index 0000000..c55b53d
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustTypePath.java
@@ -0,0 +1,49 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath imports
+import java.util.Arrays;
+import java.util.List;
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath imports
+
+public record RustTypePath(java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment> segments) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath.Builder(java.util.List.of());
+    }
+
+    public record Builder(java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment> segments) implements org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustType.Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath(segments);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath.Builder withSegments(java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment> segments) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath.Builder(segments);
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath body
+    public static RustTypePath primitive(String name) {
+        return new RustTypePath(List.of(
+            new RustTypePathSegment(new RustPathIdentSegmentIdentifier(new RustIdentifier(name)))
+        ));
+    }
+
+    public static RustType of(String... names) {
+        var segments = Arrays.stream(names)
+            .map(name -> new RustTypePathSegment(new RustPathIdentSegmentIdentifier(new RustIdentifier(name))))
+            .toList();
+        return new RustTypePath(segments);
+    }
+
+    public static RustType of(RustIdentifier... names) {
+        var segments = Arrays.stream(names)
+            .map(name -> new RustTypePathSegment(new RustPathIdentSegmentIdentifier(name)))
+            .toList();
+        return new RustTypePath(segments);
+    }
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePath body
+}
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustTypePathSegment.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustTypePathSegment.java
new file mode 100644
index 0000000..cbd1c69
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustTypePathSegment.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.RustTypePathSegment imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment imports
+
+public record RustTypePathSegment(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegment pathIdentSegment) {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment.Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegmentIdentifier.arbitrary().build());
+    }
+
+    public record Builder(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegment pathIdentSegment) {
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment(pathIdentSegment);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment.Builder withPathIdentSegment(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegment pathIdentSegment) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment.Builder(pathIdentSegment);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment.Builder withPathIdentSegment(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPathIdentSegment.Builder pathIdentSegment) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment.Builder(pathIdentSegment.build());
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustTypePathSegment body
+}