initial checkin of SkSL compiler

src/sksl/ir/SkSLBinaryExpression.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_BINARYEXPRESSION
+#define SKSL_BINARYEXPRESSION
+
+#include "SkSLExpression.h"
+#include "../SkSLToken.h"
+
+namespace SkSL {
+
+/**
+ * A binary operation. 
+ */
+struct BinaryExpression : public Expression {
+    BinaryExpression(Position position, std::unique_ptr<Expression> left, Token::Kind op,
+                     std::unique_ptr<Expression> right, std::shared_ptr<Type> type)
+    : INHERITED(position, kBinary_Kind, type)
+    , fLeft(std::move(left))
+    , fOperator(op)
+    , fRight(std::move(right)) {}
+
+    virtual std::string description() const override {
+        return "(" + fLeft->description() + " " + Token::OperatorName(fOperator) + " " +
+               fRight->description() + ")";
+    }
+
+    const std::unique_ptr<Expression> fLeft;
+    const Token::Kind fOperator;
+    const std::unique_ptr<Expression> fRight;
+
+    typedef Expression INHERITED;
+};
+
+} // namespace
+
+#endif