initial checkin of SkSL compiler

src/sksl/ast/SkSLASTBinaryExpression.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_ASTBINARYEXPRESSION
+#define SKSL_ASTBINARYEXPRESSION
+
+#include "SkSLASTExpression.h"
+#include "../SkSLToken.h"
+#include <sstream>
+
+namespace SkSL {
+
+/**
+ * Represents a binary operation, with the operator represented by the token's type. 
+ */
+struct ASTBinaryExpression : public ASTExpression {
+    ASTBinaryExpression(std::unique_ptr<ASTExpression> left, Token op,
+                        std::unique_ptr<ASTExpression> right)
+    : INHERITED(op.fPosition, kBinary_Kind)
+    , fLeft(std::move(left))
+    , fOperator(op.fKind)
+    , fRight(std::move(right)) {}
+
+    std::string description() const override {
+        return "(" + fLeft->description() + " " + Token::OperatorName(fOperator) + " " +
+               fRight->description() + ")";
+    }
+
+    const std::unique_ptr<ASTExpression> fLeft;
+    const Token::Kind fOperator;
+    const std::unique_ptr<ASTExpression> fRight;
+
+    typedef ASTExpression INHERITED;
+};
+
+} // namespace
+
+#endif