examples/calc++/calc++-scanner.ll

   1 %{                                            /* -*- C++ -*- */
   2 # include <string>
   3 # include "calc++-driver.hh"
   4 # include "calc++-parser.hh"
   5 %}
   6
   7 %option noyywrap nounput batch debug
   8
   9 id    [a-zA-Z][a-zA-Z_0-9]*
  10 int   [0-9]+
  11 blank [ \t]
  12
  13 %%
  14 %{
  15   yylloc->step ();
  16 # define YY_USER_ACTION  yylloc->columns (yyleng);
  17 %}
  18 {blank}+   yylloc->step ();
  19 [\n]+      yylloc->lines (yyleng); yylloc->step ();
  20
  21 [-+*/]     return yytext[0];
  22 ":="       return TOKEN_ASSIGN;
  23 {int}      yylval->ival = atoi (yytext); return TOKEN_NUMBER;
  24 {id}       yylval->sval = new std::string (yytext); return TOKEN_IDENTIFIER;
  25 .          driver.error (*yylloc, "invalid character");
  26 %%
  27
  28 void
  29 calcxx_driver::scan_begin ()
  30 {
  31   yy_flex_debug = trace_scanning;
  32   if (!(yyin = fopen (file.c_str (), "r")))
  33     error (std::string ("cannot open ") + file);
  34 }
  35
  36 void
  37 calcxx_driver::scan_end ()
  38 {
  39   fclose (yyin);
  40 }