initial checkin of SkSL compiler

src/sksl/ast/SkSLASTIfStatement.h

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+ 
+#ifndef SKSL_ASTIFSTATEMENT
+#define SKSL_ASTIFSTATEMENT
+
+#include "SkSLASTStatement.h"
+
+namespace SkSL {
+
+/**
+ * An 'if' statement. 
+ */
+struct ASTIfStatement : public ASTStatement {
+    ASTIfStatement(Position position, std::unique_ptr<ASTExpression> test, 
+                   std::unique_ptr<ASTStatement> ifTrue, std::unique_ptr<ASTStatement> ifFalse)
+    : INHERITED(position, kIf_Kind)
+    , fTest(std::move(test))
+    , fIfTrue(std::move(ifTrue))
+    , fIfFalse(std::move(ifFalse)) {}
+
+    std::string description() const override {
+        std::string result("if (");
+        result += fTest->description();
+        result += ") ";
+        result += fIfTrue->description();
+        if (fIfFalse) {
+            result += " else ";
+            result += fIfFalse->description();
+        }
+        return result;        
+    }
+
+    const std::unique_ptr<ASTExpression> fTest;
+    const std::unique_ptr<ASTStatement> fIfTrue;
+    const std::unique_ptr<ASTStatement> fIfFalse;
+
+    typedef ASTStatement INHERITED;
+};
+
+} // namespace
+
+#endif