initial checkin of SkSL compiler

src/sksl/ir/SkSLConstructor.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_CONSTRUCTOR
+#define SKSL_CONSTRUCTOR
+
+#include "SkSLExpression.h"
+
+namespace SkSL {
+
+/**
+ * Represents the construction of a compound type, such as "vec2(x, y)".
+ */
+struct Constructor : public Expression {
+    Constructor(Position position, std::shared_ptr<Type> type, 
+                std::vector<std::unique_ptr<Expression>> arguments)
+    : INHERITED(position, kConstructor_Kind, std::move(type))
+    , fArguments(std::move(arguments)) {}
+
+    std::string description() const override {
+        std::string result = fType->description() + "(";
+        std::string separator = "";
+        for (size_t i = 0; i < fArguments.size(); i++) {
+            result += separator;
+            result += fArguments[i]->description();
+            separator = ", ";
+        }
+        result += ")";
+        return result;
+    }
+
+    bool isConstant() const override {
+        for (size_t i = 0; i < fArguments.size(); i++) {
+            if (!fArguments[i]->isConstant()) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    const std::vector<std::unique_ptr<Expression>> fArguments;
+
+    typedef Expression INHERITED;
+};
+
+} // namespace
+
+#endif