C# backend: Implement for-each loops

3 files changed, 36 insertions, 1 deletions

diff --git a/src/main/java/org/zwobble/couscous/backends/csharp/CsharpBackend.java b/src/main/java/org/zwobble/couscous/backends/csharp/CsharpBackend.java
index 3cd778b..6e648e6 100644
--- a/src/main/java/org/zwobble/couscous/backends/csharp/CsharpBackend.java
+++ b/src/main/java/org/zwobble/couscous/backends/csharp/CsharpBackend.java
@@ -18,7 +18,11 @@ public class CsharpBackend implements Backend {
     private static final List<String> RUNTIME_FILES = ImmutableList.of(
         "java/lang/Integer.cs",
         "java/lang/Object.cs",
-        "java/lang/String.cs");
+        "java/lang/String.cs",
+        "java/util/Arrays.cs",
+        // TODO: implement Iterable/Iterator in Java
+        "java/lang/Iterable.cs",
+        "java/lang/Iterator.cs");
 
     private final Path directoryPath;
     private final String namespace;
diff --git a/src/main/java/org/zwobble/couscous/frontends/java/JavaStatementReader.java b/src/main/java/org/zwobble/couscous/frontends/java/JavaStatementReader.java
index 4185f88..83c10f4 100644
--- a/src/main/java/org/zwobble/couscous/frontends/java/JavaStatementReader.java
+++ b/src/main/java/org/zwobble/couscous/frontends/java/JavaStatementReader.java
@@ -61,6 +61,9 @@ class JavaStatementReader {
             case ASTNode.FOR_STATEMENT:
                 return readForStatement((ForStatement)statement);
 
+            case ASTNode.ENHANCED_FOR_STATEMENT:
+                return readEnhancedForStatement((EnhancedForStatement)statement);
+
             case ASTNode.VARIABLE_DECLARATION_STATEMENT:
                 return readVariableDeclarationStatement((VariableDeclarationStatement)statement);
 
@@ -180,6 +183,24 @@ class JavaStatementReader {
                     eagerMap(updaters, updater -> expressionStatement(readExpressionWithoutBoxing(updater))))));
     }
 
+    private List<StatementNode> readEnhancedForStatement(EnhancedForStatement statement) {
+        SingleVariableDeclaration parameter = statement.getParameter();
+        Type elementType = typeOf(parameter.getType());
+
+        ExpressionNode iterableValue = readExpression(JavaTypes.iterable(elementType), statement.getExpression());
+        ExpressionNode iteratorValue = methodCall(iterableValue, "iterator", list(), JavaTypes.iterator(elementType));
+        LocalVariableDeclarationNode iterator = scope.temporaryVariable(iteratorValue);
+
+        ExpressionNode hasNext = methodCall(reference(iterator), "hasNext", list(), Types.BOOLEAN);
+        ExpressionNode next = methodCall(reference(iterator), "next", list(), elementType);
+        IVariableBinding parameterBinding = parameter.resolveBinding();
+        WhileNode loop = whileLoop(hasNext, cons(
+            scope.localVariable(parameterBinding.getKey(), parameterBinding.getName(), elementType, next),
+            readStatement(statement.getBody())));
+
+        return list(iterator, loop);
+    }
+
     private List<StatementNode> readVariableDeclarationStatement(VariableDeclarationStatement statement) {
         @SuppressWarnings("unchecked")
         List<VariableDeclarationFragment> fragments = statement.fragments();
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 0148b9b..d63ec89 100644
--- a/src/main/java/org/zwobble/couscous/frontends/java/JavaTypes.java
+++ b/src/main/java/org/zwobble/couscous/frontends/java/JavaTypes.java
@@ -14,9 +14,11 @@ import java.util.Set;
 
 import static com.google.common.collect.Iterables.transform;
 import static java.util.Arrays.asList;
+import static org.zwobble.couscous.types.ParameterizedType.parameterizedType;
 import static org.zwobble.couscous.types.Types.erasure;
 import static org.zwobble.couscous.util.Casts.tryCast;
 import static org.zwobble.couscous.util.ExtraLists.eagerMap;
+import static org.zwobble.couscous.util.ExtraLists.list;
 
 public class JavaTypes {
     static Type typeOf(Expression expression) {
@@ -119,4 +121,12 @@ public class JavaTypes {
             return Optional.empty();
         }
     }
+
+    public static Type iterable(Type elementType) {
+        return parameterizedType(ScalarType.of("java.lang.Iterable"), list(elementType));
+    }
+
+    public static Type iterator(Type elementType) {
+        return parameterizedType(ScalarType.of("java.lang.Iterator"), list(elementType));
+    }
 }