1 // Copyright 2015 Google Inc. All rights reserved 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #ifndef EXPR_H_ 16 #define EXPR_H_ 17 18 #include <string> 19 #include <vector> 20 21 #include "string_piece.h" 22 23 using namespace std; 24 25 class Evaluator; 26 struct Loc; 27 28 class Evaluable { 29 public: 30 virtual void Eval(Evaluator* ev, string* s) const = 0; 31 string Eval(Evaluator*) const; 32 33 protected: 34 Evaluable(); 35 virtual ~Evaluable(); 36 }; 37 38 class Value : public Evaluable { 39 public: 40 virtual ~Value(); 41 42 virtual Value* Compact() { return this; } 43 44 virtual bool IsLiteral() const { return false; } 45 // Only safe after IsLiteral() returns true. 46 virtual StringPiece GetLiteralValueUnsafe() const { return ""; } 47 48 string DebugString() const; 49 50 protected: 51 Value(); 52 virtual string DebugString_() const = 0; 53 }; 54 55 enum struct ParseExprOpt { 56 NORMAL = 0, 57 DEFINE, 58 COMMAND, 59 FUNC, 60 }; 61 62 Value* ParseExprImpl(const Loc& loc, StringPiece s, const char* terms, 63 ParseExprOpt opt, 64 size_t* index_out, bool trim_right_space = false); 65 Value* ParseExpr(const Loc& loc, StringPiece s, 66 ParseExprOpt opt = ParseExprOpt::NORMAL); 67 68 string JoinValues(const vector<Value*>& vals, const char* sep); 69 70 Value* NewExpr2(Value* v1, Value* v2); 71 Value* NewExpr3(Value* v1, Value* v2, Value* v3); 72 73 Value* NewLiteral(StringPiece s); 74 75 #endif // EXPR_H_ 76
