initial checkin of SkSL compiler

src/sksl/ast/SkSLASTFunction.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_ASTFUNCTION
+#define SKSL_ASTFUNCTION
+
+#include "SkSLASTBlock.h"
+#include "SkSLASTDeclaration.h"
+#include "SkSLASTParameter.h"
+#include "SkSLASTType.h"
+
+namespace SkSL {
+
+/**
+ * A function declaration or definition. The fBody field will be null for declarations. 
+ */
+struct ASTFunction : public ASTDeclaration {
+    ASTFunction(Position position, std::unique_ptr<ASTType> returnType, std::string name,
+                std::vector<std::unique_ptr<ASTParameter>> parameters, 
+                std::unique_ptr<ASTBlock> body)
+    : INHERITED(position, kFunction_Kind)
+    , fReturnType(std::move(returnType))
+    , fName(std::move(name))
+    , fParameters(std::move(parameters))
+    , fBody(std::move(body)) {}
+
+    std::string description() const override {
+        std::string result = fReturnType->description() + " " + fName + "(";
+        for (size_t i = 0; i < fParameters.size(); i++) {
+            if (i > 0) {
+                result += ", ";
+            }
+            result += fParameters[i]->description();
+        }
+        if (fBody) {
+            result += ") " + fBody->description();
+        } else {
+            result += ");";
+        }
+        return result;        
+    }
+
+    const std::unique_ptr<ASTType> fReturnType;
+    const std::string fName;
+    const std::vector<std::unique_ptr<ASTParameter>> fParameters;
+    const std::unique_ptr<ASTBlock> fBody;
+
+    typedef ASTDeclaration INHERITED;
+};
+
+} // namespace
+
+#endif