From 0c85c53c643343429bc11b18619c739ca148cc66 Mon Sep 17 00:00:00 2001
From: Dmitry Jemerov <yole@jetbrains.com>
Date: Wed, 6 Jul 2011 15:24:34 +0200
Subject: [PATCH] pattern matching for tuple and expression patterns

---
 .../jet/codegen/ExpressionCodegen.java        | 46 +++++++++++++++++++
 .../jet/codegen/PatternMatchingTest.java      |  8 ++++
 2 files changed, 54 insertions(+)

diff --git a/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java b/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
index 8bfe9bde50e..07d5a41d460 100644
--- a/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
+++ b/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
@@ -1634,6 +1634,17 @@ public class ExpressionCodegen extends JetVisitor {
             StackValue value = StackValue.onStack(Type.BOOLEAN_TYPE);
             return negated ? StackValue.not(value) : value;
         }
+        else if (pattern instanceof JetTuplePattern) {
+            return generateTuplePatternMatch((JetTuplePattern) pattern, negated, expressionToMatch);
+        }
+        else if (pattern instanceof JetExpressionPattern) {
+            final Type subjectType = expressionToMatch.type;
+            expressionToMatch.put(subjectType, v);
+            JetExpression condExpression = ((JetExpressionPattern) pattern).getExpression();
+            gen(condExpression, OBJECT_TYPE);
+            generateEqualsForExpressionsOnStack(JetTokens.EQEQ, subjectType, OBJECT_TYPE);
+            return myStack.pop();
+        }
         else if (pattern instanceof JetWildcardPattern) {
             return StackValue.constant(!negated, Type.BOOLEAN_TYPE);
         }
@@ -1642,6 +1653,41 @@ public class ExpressionCodegen extends JetVisitor {
         }
     }
 
+    private StackValue generateTuplePatternMatch(JetTuplePattern pattern, boolean negated, StackValue expressionToMatch) {
+        final List<JetTuplePatternEntry> entries = pattern.getEntries();
+        Label lblFail = new Label();
+        Label lblDone = new Label();
+        expressionToMatch.put(OBJECT_TYPE, v);
+        v.dup();
+        final String tupleClassName = "jet/Tuple" + entries.size();
+        Type tupleType = Type.getObjectType(tupleClassName);
+        v.instanceOf(tupleType);
+        Label lblCheck = new Label();
+        v.ifne(lblCheck);
+        Label lblPopAndFail = new Label();
+        v.mark(lblPopAndFail);
+        v.pop();
+        v.goTo(lblFail);
+
+        v.mark(lblCheck);
+        for (int i = 0; i < entries.size(); i++) {
+            final boolean isLast = i == entries.size() - 1;
+            if (!isLast) {
+                v.dup();
+            }
+            final StackValue tupleField = StackValue.field(OBJECT_TYPE, tupleClassName, "_" + (i + 1), false);
+            final StackValue stackValue = generatePatternMatch(entries.get(i).getPattern(), false, tupleField);
+            stackValue.condJump(isLast ? lblFail : lblPopAndFail, true, v);
+        }
+
+        v.aconst(!negated);
+        v.goTo(lblDone);
+        v.mark(lblFail);
+        v.aconst(negated);
+        v.mark(lblDone);
+        return StackValue.onStack(Type.BOOLEAN_TYPE);
+    }
+
     private void generateInstanceOf(StackValue expressionToGen, JetType jetType, boolean leaveExpressionOnStack) {
         DeclarationDescriptor descriptor = jetType.getConstructor().getDeclarationDescriptor();
         if (jetType.getArguments().size() > 0 || !(descriptor instanceof ClassDescriptor)) {
diff --git a/idea/tests/org/jetbrains/jet/codegen/PatternMatchingTest.java b/idea/tests/org/jetbrains/jet/codegen/PatternMatchingTest.java
index 87a2980c25e..9c31be0dde8 100644
--- a/idea/tests/org/jetbrains/jet/codegen/PatternMatchingTest.java
+++ b/idea/tests/org/jetbrains/jet/codegen/PatternMatchingTest.java
@@ -1,6 +1,7 @@
 package org.jetbrains.jet.codegen;
 
 import jet.NoPatternMatchedException;
+import jet.Tuple2;
 
 import java.lang.reflect.Method;
 
@@ -61,4 +62,11 @@ public class PatternMatchingTest extends CodegenTestCase {
         Method foo = generateFunction();
         assertEquals("x", foo.invoke(null, ""));
     }
+
+    public void testTuplePattern() throws Exception {
+        loadText("fun foo(x: Tuple2<Any, Any>) = when(x) { is (1,2) => \"one,two\"; else => \"something\" }");
+        Method foo = generateFunction();
+        assertEquals("one,two", foo.invoke(null, new Tuple2<Integer, Integer>(1, 2)));
+        assertEquals("something", foo.invoke(null, new Tuple2<String, String>("not", "tuple")));
+    }
 }