1 /** @file input_lexer.ll
3 * Lexical analyzer definition for reading expressions.
4 * This file must be processed with flex. */
7 * GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
35 #include "input_lexer.h"
43 using namespace GiNaC;
46 #include "input_parser.h"
50 // Table of all used symbols
52 sym_def() : predefined(false) {}
53 sym_def(const ex &s, bool predef) : sym(s), predefined(predef) {}
56 sym_def(const sym_def &other) {sym = other.sym; predefined = other.predefined;}
57 const sym_def &operator=(const sym_def &other)
61 predefined = other.predefined;
67 bool predefined; // true = user supplied symbol, false = lexer generated symbol
69 typedef std::map<std::string, sym_def> sym_tab;
73 static int lexer_input(char *buf, int max_size);
74 #define YY_INPUT(buf, result, max_size) (result = lexer_input(buf, max_size))
89 [ \t]+ /* skip whitespace */
92 Pi ginac_yylval = Pi; return T_LITERAL;
93 Euler ginac_yylval = Euler; return T_LITERAL;
94 Catalan ginac_yylval = Catalan; return T_LITERAL;
95 FAIL ginac_yylval = *new fail(); return T_LITERAL;
96 I ginac_yylval = I; return T_NUMBER;
97 Digits ginac_yylval = (long)Digits; return T_DIGITS;
102 "<=" return T_LESSEQ;
103 ">=" return T_GREATEREQ;
113 {D}+{E} ginac_yylval = numeric(yytext); return T_NUMBER;
117 sym_tab::const_iterator i = syms.find(yytext);
118 if (i == syms.end()) {
119 syms[yytext] = sym_def(ginac_yylval = *(new symbol(yytext)), false);
121 ginac_yylval = (*i).second.sym;
125 /* everything else */
135 // The string from which we will read
136 static std::string lexer_string;
138 // The current position within the string
139 static int curr_pos = 0;
141 // Input function that reads from string
142 static int lexer_input(char *buf, int max_size)
144 int actual = lexer_string.length() - curr_pos;
145 if (actual > max_size)
149 lexer_string.copy(buf, actual, curr_pos);
154 // EOF encountered, terminate the scanner
162 // Set the input string
163 void set_lexer_string(const std::string &s)
169 // Set the list of predefined symbols
170 void set_lexer_symbols(ex l)
173 if (!is_exactly_a<lst>(l))
175 for (unsigned i=0; i<l.nops(); i++) {
176 if (is_exactly_a<symbol>(l.op(i)))
177 syms[ex_to<symbol>(l.op(i)).get_name()] = sym_def(l.op(i), true);
181 // Check whether symbol was predefined
182 bool is_lexer_symbol_predefined(const ex &s)
184 sym_tab::const_iterator i = syms.find(ex_to<symbol>(s).get_name());
188 return (*i).second.predefined;