Generate switch statements in C# backend

5 files changed, 64 insertions, 7 deletions

diff --git a/src/main/java/org/zwobble/couscous/ast/NodeTypes.java b/src/main/java/org/zwobble/couscous/ast/NodeTypes.java
index 86703ff..41ba8af 100644
--- a/src/main/java/org/zwobble/couscous/ast/NodeTypes.java
+++ b/src/main/java/org/zwobble/couscous/ast/NodeTypes.java
@@ -1,6 +1,8 @@
 package org.zwobble.couscous.ast;
 
 import com.google.common.collect.ImmutableMap;
+import org.zwobble.couscous.ast.sugar.SwitchCaseNode;
+import org.zwobble.couscous.ast.sugar.SwitchNode;
 
 import java.util.Map;
 
@@ -69,6 +71,8 @@ public class NodeTypes {
         .put(OperationNode.class, OPERATION)
         .put(ReturnNode.class, RETURN)
         .put(StaticReceiver.class, STATIC_RECEIVER)
+        .put(SwitchNode.class, SWITCH)
+        .put(SwitchCaseNode.class, SWITCH_CASE)
         .put(TernaryConditionalNode.class, TERNARY_CONDITIONAL)
         .put(ThisReferenceNode.class, THIS_REFERENCE)
         .put(ThrowNode.class, THROW)
diff --git a/src/main/java/org/zwobble/couscous/backends/SourceCodeWriter.java b/src/main/java/org/zwobble/couscous/backends/SourceCodeWriter.java
index 57959fd..eb29a4e 100644
--- a/src/main/java/org/zwobble/couscous/backends/SourceCodeWriter.java
+++ b/src/main/java/org/zwobble/couscous/backends/SourceCodeWriter.java
@@ -69,15 +69,23 @@ public class SourceCodeWriter {
 
     public void startBlock() {
         runAction(blockStart);
-        depth++;
+        indent();
         builder.append("\n");
     }
 
     public void endBlock() {
-        depth--;
+        dedent();
         runAction(blockEnd);
     }
 
+    public void indent() {
+        depth++;
+    }
+
+    public void dedent() {
+        depth--;
+    }
+
     public void writeStatement(Action action) {
         startStatement();
         action.run();
diff --git a/src/main/java/org/zwobble/couscous/backends/csharp/CsharpCodeGenerator.java b/src/main/java/org/zwobble/couscous/backends/csharp/CsharpCodeGenerator.java
index 23743d0..537184c 100644
--- a/src/main/java/org/zwobble/couscous/backends/csharp/CsharpCodeGenerator.java
+++ b/src/main/java/org/zwobble/couscous/backends/csharp/CsharpCodeGenerator.java
@@ -7,8 +7,6 @@ import org.zwobble.couscous.ast.Node;
 import org.zwobble.couscous.ast.Receiver;
 import org.zwobble.couscous.ast.visitors.NodeTransformer;
 import org.zwobble.couscous.backends.naming.Naming;
-import org.zwobble.couscous.frontends.java.Scope;
-import org.zwobble.couscous.transforms.DesugarSwitchToIfElse;
 import org.zwobble.couscous.types.*;
 
 import java.util.Map;
@@ -50,9 +48,7 @@ public class CsharpCodeGenerator {
     }
 
     private Node generateCode(Node node) {
-        return node
-            .transform(DesugarSwitchToIfElse.transformer(Scope.create()))
-            .transform(nodeTransformer);
+        return node.transform(nodeTransformer);
     }
 
     private Type transformType(Type type) {
diff --git a/src/main/java/org/zwobble/couscous/backends/csharp/CsharpSerializer.java b/src/main/java/org/zwobble/couscous/backends/csharp/CsharpSerializer.java
index 91a4400..6164d04 100644
--- a/src/main/java/org/zwobble/couscous/backends/csharp/CsharpSerializer.java
+++ b/src/main/java/org/zwobble/couscous/backends/csharp/CsharpSerializer.java
@@ -2,6 +2,8 @@ package org.zwobble.couscous.backends.csharp;
 
 import com.google.common.collect.ImmutableSet;
 import org.zwobble.couscous.ast.*;
+import org.zwobble.couscous.ast.sugar.SwitchCaseNode;
+import org.zwobble.couscous.ast.sugar.SwitchNode;
 import org.zwobble.couscous.ast.visitors.DynamicNodeMapper;
 import org.zwobble.couscous.ast.visitors.DynamicNodeVisitor;
 import org.zwobble.couscous.backends.SourceCodeWriter;
@@ -366,6 +368,36 @@ public class CsharpSerializer {
         }
     }
 
+    public void visit(SwitchNode switchNode) {
+        writer.writeStatement(() -> {
+            writer.writeKeyword("switch");
+            writer.writeSpace();
+            writer.writeSymbol("(");
+            write(switchNode.getValue());
+            writer.writeSymbol(")");
+            writer.startBlock();
+            switchNode.getCases().forEach(this::visit);
+            writer.endBlock();
+        });
+    }
+
+    private void visit(SwitchCaseNode switchCase) {
+        writer.writeStatement(() -> {
+            if (switchCase.getValue().isPresent()) {
+                writer.writeKeyword("case");
+                writer.writeSpace();
+                write(switchCase.getValue().get());
+            } else {
+                writer.writeKeyword("default");
+            }
+            writer.writeSymbol(":");
+        });
+        writer.indent();
+        writeAll(switchCase.getStatements());
+        writer.dedent();
+
+    }
+
     public void visit(WhileNode whileLoop) {
         writer.writeStatement(() -> {
             writer.writeKeyword("while");
diff --git a/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpSerializerTests.java b/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpSerializerTests.java
index 3cb723e..40653af 100644
--- a/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpSerializerTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpSerializerTests.java
@@ -3,6 +3,7 @@ package org.zwobble.couscous.tests.backends.csharp;
 import org.junit.Test;
 import org.zwobble.couscous.ast.*;
 import org.zwobble.couscous.ast.identifiers.Identifiers;
+import org.zwobble.couscous.ast.sugar.SwitchNode;
 import org.zwobble.couscous.backends.csharp.CsharpSerializer;
 import org.zwobble.couscous.tests.TestIds;
 import org.zwobble.couscous.types.ScalarType;
@@ -35,6 +36,7 @@ import static org.zwobble.couscous.ast.TryNode.tryStatement;
 import static org.zwobble.couscous.ast.VariableDeclaration.var;
 import static org.zwobble.couscous.ast.VariableReferenceNode.reference;
 import static org.zwobble.couscous.ast.WhileNode.whileLoop;
+import static org.zwobble.couscous.ast.sugar.SwitchCaseNode.switchCase;
 import static org.zwobble.couscous.types.TypeParameter.typeParameter;
 import static org.zwobble.couscous.util.ExtraLists.list;
 
@@ -308,6 +310,21 @@ public class CsharpSerializerTests {
     }
 
     @Test
+    public void switchStatement() {
+        Node node = new SwitchNode(
+            literal(1),
+            list(
+                switchCase(literal(1), list(returns(literal(10)))),
+                switchCase(list(returns(literal(0))))
+            )
+        );
+
+        String output = serialize(node);
+
+        assertEquals("switch (1) {\n    case 1:\n        return 10;\n    default:\n        return 0;\n}\n", output);
+    }
+
+    @Test
     public void whileLoopPrintsConditionAndBody() {
         String output = serialize(whileLoop(
             literal(true),