tests/glean/lex.h

   1 // BEGIN_COPYRIGHT
   2 //
   3 // Copyright (C) 1999  Allen Akin   All Rights Reserved.
   4 //
   5 // Permission is hereby granted, free of charge, to any person
   6 // obtaining a copy of this software and associated documentation
   7 // files (the "Software"), to deal in the Software without
   8 // restriction, including without limitation the rights to use,
   9 // copy, modify, merge, publish, distribute, sublicense, and/or
  10 // sell copies of the Software, and to permit persons to whom the
  11 // Software is furnished to do so, subject to the following
  12 // conditions:
  13 //
  14 // The above copyright notice and this permission notice shall be
  15 // included in all copies or substantial portions of the
  16 // Software.
  17 //
  18 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
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  25 // DEALINGS IN THE SOFTWARE.
  26 //
  27 // END_COPYRIGHT
  28
  29
  30
  31
  32 // lex.h:  Simple lexical analysis utilities
  33
  34 // Given a string containing C-style tokens, returns information about
  35 // successive tokens.  Doesn't support all C tokens; just the few that
  36 // GLEAN needs.
  37
  38
  39 #ifndef __lex_h__
  40 #define __lex_h__
  41
  42 #include <string>
  43
  44 #ifdef __WIN__
  45 // ERROR is already defined in some windows header file
  46 #undef ERROR
  47 #endif
  48
  49 namespace GLEAN {
  50
  51 class Lex {
  52     protected:
  53
  54         // State information:
  55         const char* input;
  56         const char* p;
  57         bool ignoringCase;
  58
  59     public:
  60
  61         // Constructors:
  62
  63         Lex(const char* s, bool ignoreCase = false);
  64                 // Creates a lexer which will draw input from the given string.
  65
  66         // Exceptions:
  67
  68         struct Error { };                       // Base class for errors.
  69         struct Lexical: public Error {          // Lexical error in string.
  70                 const char* err;
  71                 int position;
  72                 Lexical(const char* e, int p) {
  73                         err = e;
  74                         position = p;
  75                 }
  76         };
  77         struct InternalError: public Error {    // Shouldn't happen.
  78         };
  79
  80         // Tokens:
  81
  82         typedef enum {
  83                 ERROR = 0,      // erroneous token; must be zero
  84                 END,            // end of input
  85
  86                 AND,            // &
  87                 AND_AND,        // &&
  88                 ASSIGN,         // =
  89                 BANG,           // !
  90                 COMMA,          // ,
  91                 DOT,            // .
  92                 EQ,             // ==
  93                 GE,             // >=
  94                 GT,             // >
  95                 LE,             // <=
  96                 LPAREN,         // (
  97                 LT,             // <
  98                 MINUS,          // -
  99                 NE,             // !=
 100                 OR,             // |
 101                 OR_OR,          // ||
 102                 PERCENT,        // %
 103                 PLUS,           // +
 104                 RPAREN,         // )
 105                 SLASH,          // /
 106                 STAR,           // *
 107
 108                 ICONST,         // signed integer constant
 109
 110                 ID              // identifier
 111         } Token;
 112
 113         // Utilities:
 114
 115         void next();            // fetch next token
 116
 117         Token token;            // current token
 118         std::string id;         // most recent identifier
 119         int iValue;             // most recent signed integer value
 120
 121         inline int position() { // current position in input string
 122                 return p - input;
 123         }
 124 }; // class Lex
 125
 126 } // namespace GLEAN
 127
 128 #endif // __lex_h__