Have record implement interface if variant of sum

5 files changed, 77 insertions, 17 deletions

diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/javatypes/JavaTypesGenerator.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/javatypes/JavaTypesGenerator.java
index 6e876f2..43e35b4 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/javatypes/JavaTypesGenerator.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/javatypes/JavaTypesGenerator.java
@@ -18,6 +18,7 @@ import java.io.File;
 import java.io.IOException;
 import java.nio.file.Path;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
 
 public class JavaTypesGenerator implements Generator {
@@ -51,6 +52,21 @@ public class JavaTypesGenerator implements Generator {
     private List<JavaCompilationUnit> generateNamespace(TypedNamespaceNode namespace) {
         var packageParts = namespaceToJavaPackageParts(namespace.namespaceName());
 
+        var javaClassToImplementsType = new HashMap<String, List<JavaTypeRef>>();
+        for (var statement : namespace.body()) {
+            if (statement instanceof TypedSumDefinitionNode sumDefinition) {
+                for (var variant : sumDefinition.variants()) {
+                    var variantTypeName = variant.type().value().name();
+                    javaClassToImplementsType.putIfAbsent(
+                        variantTypeName,
+                        new ArrayList<>()
+                    );
+                    javaClassToImplementsType.get(variantTypeName)
+                        .add(generateTypeRef(sumDefinition.type()));
+                }
+            }
+        }
+
         var javaCompilationUnits = new ArrayList<JavaCompilationUnit>();
 
         for (var statement : namespace.body()) {
@@ -65,7 +81,8 @@ public class JavaTypesGenerator implements Generator {
                                     generateTypeRef(field.type()),
                                     field.name()
                                 ))
-                                .toList()
+                                .toList(),
+                            javaClassToImplementsType.getOrDefault(structDefinition.name(), List.of())
                         )
                     );
 
@@ -73,7 +90,6 @@ public class JavaTypesGenerator implements Generator {
                 }
 
                 case TypedSumDefinitionNode sumDefinition -> {
-                    throw new UnsupportedOperationException("TODO");
                 }
             }
         }
@@ -89,7 +105,10 @@ public class JavaTypesGenerator implements Generator {
 
     private JavaTypeRef generateTypeRef(TypedTypeLevelExpressionNode<Type> typeNode) {
         var type = typeNode.value();
+        return generateTypeRef(type);
+    }
 
+    private JavaTypeRef generateTypeRef(Type type) {
         return switch (type) {
             case StructType structType ->
                 new JavaTypeRef(namespaceToJavaPackageParts(structType.namespaceName()), structType.name());
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/java/JavaWriter.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/java/JavaWriter.java
index 36da8ba..1de6950 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/java/JavaWriter.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/java/JavaWriter.java
@@ -1,8 +1,8 @@
 package org.zwobble.hobgoblin.compiler.output.java;
 
 import org.zwobble.hobgoblin.compiler.output.CodeWriter;
-import org.zwobble.hobgoblin.compiler.output.java.ast.JavaRecordDeclaration;
 import org.zwobble.hobgoblin.compiler.output.java.ast.JavaCompilationUnit;
+import org.zwobble.hobgoblin.compiler.output.java.ast.JavaRecordDeclaration;
 import org.zwobble.hobgoblin.compiler.output.java.ast.JavaTypeDeclaration;
 import org.zwobble.hobgoblin.compiler.output.java.ast.JavaTypeRef;
 
@@ -43,22 +43,29 @@ public class JavaWriter implements AutoCloseable {
         this.writer.write(recordDeclaration.name());
         this.writer.write("(");
 
-        var isFirst = true;
-        for (var component : recordDeclaration.components()) {
-            if (!isFirst) {
-                writer.write(", ");
-            }
-
-            writeTypeRef(component.type());
+        writeWithSeparator(
+            recordDeclaration.components(),
+            component -> {
+                writeTypeRef(component.type());
+                writer.write(" ");
+                writer.write(component.name());
+            },
+            () -> writer.write(", ")
+        );
+
+        writer.write(") ");
+
+        if (!recordDeclaration.implementsTypes().isEmpty()) {
+            this.writer.write("implements ");
+            writeWithSeparator(
+                recordDeclaration.implementsTypes(),
+                this::writeTypeRef,
+                () -> writer.write(", ")
+            );
             writer.write(" ");
-            writer.write(component.name());
-
-            if (isFirst) {
-                isFirst = false;
-            }
         }
 
-        this.writer.write(") {");
+        this.writer.write("{");
         this.writer.newLine();
 
         this.writer.write("}");
@@ -73,4 +80,31 @@ public class JavaWriter implements AutoCloseable {
 
         writer.write(type.name());
     }
+
+    private <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/java/ast/JavaRecordDeclaration.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/java/ast/JavaRecordDeclaration.java
index cbebf74..7398eb9 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/java/ast/JavaRecordDeclaration.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/java/ast/JavaRecordDeclaration.java
@@ -4,6 +4,7 @@ import java.util.List;
 
 public record JavaRecordDeclaration(
     String name,
-    List<JavaRecordComponent> components
+    List<JavaRecordComponent> components,
+    List<JavaTypeRef> implementsTypes
 ) implements JavaTypeDeclaration {
 }
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/types/Type.java b/src/main/java/org/zwobble/hobgoblin/compiler/types/Type.java
index bb3f375..4155d05 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/types/Type.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/types/Type.java
@@ -1,4 +1,5 @@
 package org.zwobble.hobgoblin.compiler.types;
 
 public sealed interface Type extends TypeLevelValue permits ScalarType, StructType, SumType, TypeLevelValueType {
+    String name();
 }
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/types/TypeLevelValueType.java b/src/main/java/org/zwobble/hobgoblin/compiler/types/TypeLevelValueType.java
index b885c25..f2a2e47 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/types/TypeLevelValueType.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/types/TypeLevelValueType.java
@@ -2,6 +2,11 @@ package org.zwobble.hobgoblin.compiler.types;
 
 public record TypeLevelValueType(TypeLevelValue value) implements Type {
     @Override
+    public String name() {
+        return "TypeLevelValue";
+    }
+
+    @Override
     public String describe() {
         return "TypeLevelValue[" + value.describe() + "]";
     }