Partial support for reading type parameters for methods

6 files changed, 67 insertions, 23 deletions

diff --git a/src/main/java/org/zwobble/couscous/ast/MethodNode.java b/src/main/java/org/zwobble/couscous/ast/MethodNode.java
index 8863619..1e682fb 100644
--- a/src/main/java/org/zwobble/couscous/ast/MethodNode.java
+++ b/src/main/java/org/zwobble/couscous/ast/MethodNode.java
@@ -11,6 +11,7 @@ import java.util.Optional;
 import java.util.function.Function;
 
 import static org.zwobble.couscous.util.ExtraLists.eagerMap;
+import static org.zwobble.couscous.util.ExtraLists.list;
 
 public class MethodNode implements Node {
     public static Builder staticMethod(String name) {
@@ -83,6 +84,7 @@ public class MethodNode implements Node {
                 annotations.build(),
                 isStatic,
                 name,
+                list(),
                 arguments.build(),
                 returnType,
                 isAbstract ? Optional.empty() : Optional.of(body.build()),
@@ -94,17 +96,19 @@ public class MethodNode implements Node {
         List<AnnotationNode> annotations,
         boolean isStatic,
         String name,
+        List<FormalTypeParameterNode> typeParameters,
         List<FormalArgumentNode> arguments,
         Type returnType,
         Optional<List<StatementNode>> body,
         List<MethodSignature> overrides)
     {
-        return new MethodNode(annotations, isStatic, name, arguments, returnType, body, overrides);
+        return new MethodNode(annotations, isStatic, name, typeParameters, arguments, returnType, body, overrides);
     }
     
     private final List<AnnotationNode> annotations;
     private final boolean isStatic;
     private final String name;
+    private final List<FormalTypeParameterNode> typeParameters;
     private final List<FormalArgumentNode> arguments;
     private final Type returnType;
     private final Optional<List<StatementNode>> body;
@@ -114,6 +118,7 @@ public class MethodNode implements Node {
         List<AnnotationNode> annotations,
         boolean isStatic,
         String name,
+        List<FormalTypeParameterNode> typeParameters,
         List<FormalArgumentNode> arguments,
         Type returnType,
         Optional<List<StatementNode>> body,
@@ -122,6 +127,7 @@ public class MethodNode implements Node {
         this.annotations = annotations;
         this.isStatic = isStatic;
         this.name = name;
+        this.typeParameters = typeParameters;
         this.arguments = arguments;
         this.returnType = returnType;
         this.body = body;
@@ -139,7 +145,11 @@ public class MethodNode implements Node {
     public String getName() {
         return name;
     }
-    
+
+    public List<FormalTypeParameterNode> getTypeParameters() {
+        return typeParameters;
+    }
+
     public List<FormalArgumentNode> getArguments() {
         return arguments;
     }
@@ -168,7 +178,7 @@ public class MethodNode implements Node {
     }
 
     public MethodNode mapBody(Function<List<StatementNode>, List<StatementNode>> function) {
-        return new MethodNode(annotations, isStatic, name, arguments, returnType, body.map(function), overrides);
+        return new MethodNode(annotations, isStatic, name, typeParameters, arguments, returnType, body.map(function), overrides);
     }
 
     @Override
@@ -181,6 +191,7 @@ public class MethodNode implements Node {
             transformer.transformAnnotations(annotations),
             isStatic,
             transformer.transformMethodName(signature()),
+            transformer.transformFormalTypeParameters(typeParameters),
             transformer.transformFormalArguments(arguments),
             transformer.transform(returnType),
             body.map(transformer::transformStatements),
@@ -188,6 +199,20 @@ public class MethodNode implements Node {
     }
 
     @Override
+    public String toString() {
+        return "MethodNode(" +
+            "annotations=" + annotations +
+            ", isStatic=" + isStatic +
+            ", name=" + name +
+            ", typeParameters=" + typeParameters +
+            ", arguments=" + arguments +
+            ", returnType=" + returnType +
+            ", body=" + body +
+            ", overrides=" + overrides +
+            ')';
+    }
+
+    @Override
     public boolean equals(Object o) {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
@@ -197,6 +222,7 @@ public class MethodNode implements Node {
         if (isStatic != that.isStatic) return false;
         if (!annotations.equals(that.annotations)) return false;
         if (!name.equals(that.name)) return false;
+        if (!typeParameters.equals(that.typeParameters)) return false;
         if (!arguments.equals(that.arguments)) return false;
         if (!returnType.equals(that.returnType)) return false;
         if (!body.equals(that.body)) return false;
@@ -209,24 +235,11 @@ public class MethodNode implements Node {
         int result = annotations.hashCode();
         result = 31 * result + (isStatic ? 1 : 0);
         result = 31 * result + name.hashCode();
+        result = 31 * result + typeParameters.hashCode();
         result = 31 * result + arguments.hashCode();
         result = 31 * result + returnType.hashCode();
         result = 31 * result + body.hashCode();
         result = 31 * result + overrides.hashCode();
         return result;
     }
-
-    @Override
-    public String toString() {
-        return "MethodNode(" +
-            "annotations=" + annotations +
-            ", isStatic=" + isStatic +
-            ", name=" + name +
-            ", arguments=" + arguments +
-            ", returnType=" + returnType +
-            ", body=" + body +
-            ", overrides=" + overrides +
-            ')';
-    }
-
 }
diff --git a/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java b/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
index 73e6ced..4036a85 100644
--- a/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
+++ b/src/main/java/org/zwobble/couscous/backends/python/PythonCodeGenerator.java
@@ -208,6 +208,8 @@ public class PythonCodeGenerator {
                     methodNode.getAnnotations(),
                     methodNode.isStatic(),
                     methodNode.getName(),
+                    // TODO: should get type parameters from signature
+                    list(),
                     arguments,
                     override.getReturnType(),
                     Optional.of(list(body)),
diff --git a/src/main/java/org/zwobble/couscous/frontends/java/JavaReader.java b/src/main/java/org/zwobble/couscous/frontends/java/JavaReader.java
index d4366c2..063ffc6 100644
--- a/src/main/java/org/zwobble/couscous/frontends/java/JavaReader.java
+++ b/src/main/java/org/zwobble/couscous/frontends/java/JavaReader.java
@@ -117,8 +117,12 @@ public class JavaReader {
     }
 
     private List<FormalTypeParameterNode> readTypeParameters(TypeDeclaration typeDeclaration) {
+        return readTypeParameters(typeDeclaration.resolveBinding().getTypeParameters());
+    }
+
+    private List<FormalTypeParameterNode> readTypeParameters(ITypeBinding[] typeParameters) {
         return eagerMap(
-            asList(typeDeclaration.resolveBinding().getTypeParameters()),
+            asList(typeParameters),
             parameter -> formalTypeParameter(parameter.getName()));
     }
 
@@ -156,6 +160,8 @@ public class JavaReader {
             emptyList(),
             false,
             functionalInterfaceMethod.getName(),
+            // TODO: should get formal type parameters from the lambda
+            list(),
             lambda.getFormalArguments(),
             typeOf(functionalInterfaceMethod.getReturnType()),
             Optional.of(lambda.getBody()),
@@ -414,6 +420,7 @@ public class JavaReader {
                 annotations,
                 isStatic,
                 methodName,
+                readTypeParameters(method.resolveBinding().getTypeParameters()),
                 formalArguments,
                 returnType.get(),
                 body,
diff --git a/src/main/java/org/zwobble/couscous/frontends/java/JavaTypes.java b/src/main/java/org/zwobble/couscous/frontends/java/JavaTypes.java
index d63ec89..3b7a472 100644
--- a/src/main/java/org/zwobble/couscous/frontends/java/JavaTypes.java
+++ b/src/main/java/org/zwobble/couscous/frontends/java/JavaTypes.java
@@ -41,8 +41,11 @@ public class JavaTypes {
             return Types.array(typeOf(typeBinding.getElementType()));
         }
         ITypeBinding outerClass = typeBinding.getDeclaringClass();
-        // TODO: handle type variables for methods
-        if (typeBinding.isTypeVariable() && outerClass != null) {
+        if (typeBinding.isTypeVariable()) {
+            if (outerClass == null) {
+                // TODO: handle type variables for methods properly
+                outerClass = typeBinding.getDeclaringMethod().getDeclaringClass();
+            }
             return new TypeParameter(erasure(typeOf(outerClass)), typeBinding.getName());
         }
         ScalarType rawType = outerClass == null
diff --git a/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaReaderTests.java b/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaReaderTests.java
index 5bcb044..4a05385 100644
--- a/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaReaderTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaReaderTests.java
@@ -29,7 +29,9 @@ import static org.zwobble.couscous.ast.TypeCoercionNode.typeCoercion;
 import static org.zwobble.couscous.ast.VariableReferenceNode.reference;
 import static org.zwobble.couscous.ast.WhileNode.whileLoop;
 import static org.zwobble.couscous.tests.frontends.java.JavaReading.*;
-import static org.zwobble.couscous.tests.frontends.java.NodeMatchers.isArgument;
+import static org.zwobble.couscous.tests.frontends.java.NodeMatchers.isFormalArgument;
+import static org.zwobble.couscous.tests.frontends.java.NodeMatchers.isFormalTypeParameter;
+import static org.zwobble.couscous.types.TypeParameter.typeParameter;
 import static org.zwobble.couscous.util.ExtraLists.list;
 import static org.zwobble.couscous.util.ExtraSets.set;
 
@@ -75,11 +77,24 @@ public class JavaReaderTests {
             "}");
         
         MethodNode method = classNode.getMethods().get(0);
-        assertThat(method.getArguments(), contains(isArgument("value", ScalarType.of("int"))));
+        assertThat(method.getArguments(), contains(isFormalArgument("value", ScalarType.of("int"))));
         
         ReturnNode returnNode = (ReturnNode)method.getBody().get().get(0);
         assertEquals(reference(method.getArguments().get(0)), returnNode.getValue());
     }
+
+    @Test
+    public void canReadTypeParametersForMethod() {
+        ClassNode classNode = readClass(
+            "public <T> T identity(T value) {" +
+            "    return value;" +
+            "}");
+
+        MethodNode method = classNode.getMethods().get(0);
+        assertThat(method.getTypeParameters(), contains(isFormalTypeParameter("T")));
+        // TODO: typeParameter should be declared on method, not class
+        assertThat(method.getArguments(), contains(isFormalArgument("value", typeParameter(classNode.getName(), "T"))));
+    }
     
     @Test
     public void canReadExpressionStatements() {
diff --git a/src/test/java/org/zwobble/couscous/tests/frontends/java/NodeMatchers.java b/src/test/java/org/zwobble/couscous/tests/frontends/java/NodeMatchers.java
index efd4eb4..104cf8b 100644
--- a/src/test/java/org/zwobble/couscous/tests/frontends/java/NodeMatchers.java
+++ b/src/test/java/org/zwobble/couscous/tests/frontends/java/NodeMatchers.java
@@ -14,7 +14,11 @@ public class NodeMatchers {
         return hasFeature("initial value", node -> node.getInitialValue(), matcher);
     }
 
-    public static Matcher<FormalArgumentNode> isArgument(String name, Type type) {
+    public static Matcher<FormalTypeParameterNode> isFormalTypeParameter(String name) {
+        return hasFeature("name", node -> node.getName(), equalTo(name));
+    }
+
+    public static Matcher<FormalArgumentNode> isFormalArgument(String name, Type type) {
         return allOf(
             hasFeature("name", node -> node.getName(), equalTo(name)),
             hasFeature("type", node -> node.getType(), equalTo(type)));