ginsh/ginsh_lexer.lpp

   1 /** @file ginsh_lexer.lpp
   2  *
   3  *  Lexical analyzer definition for ginsh.
   4  *  This file must be processed with flex. */
   5
   6 /*
   7  *  GiNaC Copyright (C) 1999-2016 Johannes Gutenberg University Mainz, Germany
   8  *
   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.
  13  *
  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.
  18  *
  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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  22  */
  23
  24
  25 /*
  26  *  Definitions
  27  */
  28
  29 %option nounput
  30
  31 %pointer
  32
  33 %{
  34 #ifdef HAVE_CONFIG_H
  35 #include "config.h"
  36 #endif
  37
  38 #include "ginsh.h"
  39 #include "ginsh_parser.hpp"
  40
  41 #define YY_INPUT(buf, result, max_size) (result = ginsh_input(buf, max_size))
  42
  43 // Table of all used symbols
  44 sym_tab syms;
  45
  46 // Type of symbols to generate (real or complex)
  47 unsigned symboltype = domain::complex;
  48
  49 // lex input function
  50 static int ginsh_input(char *buf, int max_size);
  51 %}
  52
  53         /* Abbreviations */
  54 D       [0-9]
  55 E       [elEL][-+]?{D}+
  56 A       [a-zA-Z_]
  57 AN      [0-9a-zA-Z_]
  58
  59
  60 /*
  61  *  Lexical rules
  62  */
  63
  64 %%
  65 [ \t\n]+                /* skip whitespace */
  66 \\$                     /* skip line continuations */
  67 "//".*                  /* skip comments starting with "//" */
  68 ^"#".*                  /* skip lines starting with "#" */
  69 ^"!".*                  system(yytext + 1);     /* execute shell command */
  70
  71                         /* special values */
  72 Pi                      yylval = Pi; return T_LITERAL;
  73 Euler                   yylval = Euler; return T_LITERAL;
  74 Catalan                 yylval = Catalan; return T_LITERAL;
  75 FAIL                    yylval = *new fail(); return T_LITERAL;
  76 I                       yylval = I; return T_NUMBER;
  77 Digits                  yylval = (long)Digits; return T_DIGITS;
  78
  79                         /* keywords */
  80 quit|exit               return T_QUIT;
  81 warranty                return T_WARRANTY;
  82 print                   return T_PRINT;
  83 iprint                  return T_IPRINT;
  84 print_latex             return T_PRINTLATEX;
  85 print_csrc              return T_PRINTCSRC;
  86 time                    return T_TIME;
  87 xyzzy                   return T_XYZZY;
  88 inventory               return T_INVENTORY;
  89 look                    return T_LOOK;
  90 score                   return T_SCORE;
  91 complex_symbols return T_COMPLEX_SYMBOLS;
  92 real_symbols    return T_REAL_SYMBOLS;
  93
  94                         /* comparison */
  95 "=="                    return T_EQUAL;
  96 "!="                    return T_NOTEQ;
  97 "<="                    return T_LESSEQ;
  98 ">="                    return T_GREATEREQ;
  99
 100                         /* last 1..3 expressions */
 101 \%                      return T_QUOTE;
 102 \%\%                    return T_QUOTE2;
 103 \%\%\%                  return T_QUOTE3;
 104
 105                         /* numbers */
 106 {D}+                    |
 107 "#"{D}+"R"{AN}+         |
 108 "#b"([01])+             |
 109 "#o"[0-7]+              |
 110 "#x"[0-9a-fA-F]+        |
 111 {D}+"."{D}*({E})?       |
 112 {D}*"."{D}+({E})?       |
 113 {D}+{E}                 yylval = numeric(yytext); return T_NUMBER;
 114
 115                         /* symbols */
 116 {A}{AN}*                {
 117                                 sym_tab::const_iterator i = syms.find(yytext);
 118                                 if (i == syms.end()) {
 119                                         if (symboltype == domain::complex) {
 120                                                 symbol tmp(yytext);
 121                                                 syms[yytext] = tmp;
 122                                                 yylval = tmp;
 123                                         } else {
 124                                                 realsymbol tmp(yytext);
 125                                                 syms[yytext] = tmp;
 126                                                 yylval = tmp;
 127                                         }
 128                                 } else
 129                                         yylval = i->second;
 130                                 return T_SYMBOL;
 131                         }
 132
 133                         /* wildcards */
 134 \${D}+                  yylval = wild(atoi(yytext + 1)); return T_LITERAL;
 135
 136                         /* everything else */
 137 .                       return *yytext;
 138
 139 %%
 140
 141
 142 /*
 143  *  Routines
 144  */
 145
 146 static int line_length = 0;
 147 static char *line_read = nullptr;
 148 static char *line_ptr;
 149
 150 // Input function that uses libreadline for interactive input
 151 static int ginsh_input(char *buf, int max_size)
 152 {
 153         int result;
 154 #if defined(YY_CURRENT_BUFFER)
 155         if (YY_CURRENT_BUFFER->yy_is_interactive) {
 156 #else
 157         if (yy_current_buffer->yy_is_interactive) {
 158 #endif
 159 #ifdef HAVE_LIBREADLINE
 160                 // Do we need to read a new line?
 161                 int actual;
 162                 if (line_length == 0) {
 163
 164                         // Free old line
 165                         if (line_read)
 166                                 free(line_read);
 167
 168                         // Read new line, prompt "> "
 169                         line_read = line_ptr = readline("> ");
 170
 171                         // EOF?
 172                         if (!line_read) {
 173                                 line_length = 0;
 174                                 return YY_NULL;
 175                         }
 176
 177                         // Add non-empty lines to history
 178                         line_length = strlen(line_read) + 1;
 179                         if (line_length > 1)
 180                                 add_history(line_read);
 181
 182                         // Reappend trailing '\n' which is stripped by readline()
 183                         line_read[line_length - 1] = '\n';
 184                 }
 185
 186                 // Copy data to lex buffer
 187                 actual = line_length > max_size ? max_size : line_length;
 188                 memcpy(buf, line_ptr, actual);
 189                 line_length -= actual;
 190                 line_ptr += actual;
 191                 result = actual;
 192 #else
 193                 printf("> "); fflush(stdout);
 194                 int c = '*', n;
 195                 for (n = 0; n < max_size && (c = getc(yyin)) != EOF && c != '\n'; ++n)
 196                         buf[n] = (char)c;
 197                 if (c == '\n')
 198                         buf[n++] = (char)c;
 199                 if (c == EOF && ferror(yyin))
 200                         YY_FATAL_ERROR("input in flex scanner failed");
 201                 result = n;
 202 #endif
 203         } else if (((result = fread(buf, 1, max_size, yyin)) == 0) && ferror(yyin))
 204                 YY_FATAL_ERROR("input in flex scanner failed");
 205
 206         return result;
 207 }
 208
 209 // List of input files to be processed
 210 int num_files = 0;
 211 char **file_list = nullptr;
 212
 213 // EOF encountered, connect to next file. If this was the last file,
 214 // connect to stdin. If this was stdin, terminate the scanner.
 215 int yywrap()
 216 {
 217         if (yyin == stdin)
 218                 return 1;
 219
 220         fclose(yyin);
 221         if (num_files) {
 222                 yyin = fopen(*file_list, "r");
 223                 if (yyin == nullptr) {
 224                         cerr << "Can't open " << *file_list << endl;
 225                         return 1;
 226                 }
 227                 num_files--;
 228                 file_list++;
 229         } else
 230                 yyin = stdin;
 231         return 0;
 232 }