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// Copyright 2015 Google Inc. All rights reserved
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef VAR_H_
#define VAR_H_
#include <memory>
#include <string>
#include <unordered_map>
#include "string_piece.h"
#include "value.h"
using namespace std;
class Evaluator;
class Value;
class Var : public Evaluable {
public:
virtual ~Var();
virtual const char* Flavor() const = 0;
virtual const char* Origin() const = 0;
virtual bool IsDefined() const { return true; }
virtual void AppendVar(Evaluator* ev, Value* v);
virtual StringPiece String() const = 0;
virtual string DebugString() const = 0;
protected:
Var();
};
class SimpleVar : public Var {
public:
SimpleVar(shared_ptr<string> v, const char* origin);
virtual const char* Flavor() const {
return "simple";
}
virtual const char* Origin() const {
return origin_;
}
virtual shared_ptr<string> Eval(Evaluator*) const override {
return v_;
}
virtual void Eval(Evaluator* ev, string* s) const override;
virtual void AppendVar(Evaluator* ev, Value* v);
virtual StringPiece String() const override;
virtual string DebugString() const override;
private:
shared_ptr<string> v_;
const char* origin_;
};
class RecursiveVar : public Var {
public:
RecursiveVar(Value* v, const char* origin, StringPiece orig);
virtual const char* Flavor() const {
return "recursive";
}
virtual const char* Origin() const {
return origin_;
}
virtual void Eval(Evaluator* ev, string* s) const override;
virtual void AppendVar(Evaluator* ev, Value* v);
virtual StringPiece String() const override;
virtual string DebugString() const override;
private:
Value* v_;
const char* origin_;
StringPiece orig_;
};
class UndefinedVar : public Var {
public:
UndefinedVar();
virtual const char* Flavor() const {
return "undefined";
}
virtual const char* Origin() const {
return "undefined";
}
virtual bool IsDefined() const { return false; }
virtual void Eval(Evaluator* ev, string* s) const override;
virtual StringPiece String() const override;
virtual string DebugString() const override;
};
extern UndefinedVar* kUndefined;
class Vars : public unordered_map<StringPiece, Var*> {
public:
~Vars();
Var* Lookup(StringPiece name) const;
void Assign(StringPiece name, Var* v);
};
class ScopedVar {
public:
// Does not take ownerships of arguments.
ScopedVar(Vars* vars, StringPiece name, Var* var);
~ScopedVar();
private:
Vars* vars_;
Var* orig_;
Vars::iterator iter_;
};
#endif // VAR_H_
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