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// BEGIN_COPYRIGHT
//
// Copyright (C) 1999 Allen Akin All Rights Reserved.
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the
// Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
// KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
// WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL ALLEN AKIN BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
// AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
// OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
// END_COPYRIGHT
// lex.h: Simple lexical analysis utilities
// Given a string containing C-style tokens, returns information about
// successive tokens. Doesn't support all C tokens; just the few that
// GLEAN needs.
#ifndef __lex_h__
#define __lex_h__
#include <string>
#ifdef __WIN__
// ERROR is already defined in some windows header file
#undef ERROR
#endif
namespace GLEAN {
class Lex {
protected:
// State information:
const char* input;
const char* p;
bool ignoringCase;
public:
// Constructors:
Lex(const char* s, bool ignoreCase = false);
// Creates a lexer which will draw input from the given string.
// Exceptions:
struct Error { }; // Base class for errors.
struct Lexical: public Error { // Lexical error in string.
const char* err;
int position;
Lexical(const char* e, int p) {
err = e;
position = p;
}
};
struct InternalError: public Error { // Shouldn't happen.
};
// Tokens:
typedef enum {
ERROR = 0, // erroneous token; must be zero
END, // end of input
AND, // &
AND_AND, // &&
ASSIGN, // =
BANG, // !
COMMA, // ,
DOT, // .
EQ, // ==
GE, // >=
GT, // >
LE, // <=
LPAREN, // (
LT, // <
MINUS, // -
NE, // !=
OR, // |
OR_OR, // ||
PERCENT, // %
PLUS, // +
RPAREN, // )
SLASH, // /
STAR, // *
ICONST, // signed integer constant
ID // identifier
} Token;
// Utilities:
void next(); // fetch next token
Token token; // current token
std::string id; // most recent identifier
int iValue; // most recent signed integer value
inline int position() { // current position in input string
return p - input;
}
}; // class Lex
} // namespace GLEAN
#endif // __lex_h__
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