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 # define YY_USER_ACTION  yylloc->columns (yyleng);
  15 %}
  16 %%
  17 %{
  18   yylloc->step ();
  19 %}
  20 {blank}+   yylloc->step ();
  21 [\n]+      yylloc->lines (yyleng); yylloc->step ();
  22
  23 [-+*/]     return yytext[0];
  24 ":="       return TOKEN_ASSIGN;
  25 {int}      yylval->ival = atoi (yytext); return TOKEN_NUMBER;
  26 {id}       yylval->sval = new std::string (yytext); return TOKEN_IDENTIFIER;
  27 .          driver.error (*yylloc, "invalid character");
  28 %%
  29
  30 void
  31 calcxx_driver::scan_begin ()
  32 {
  33   yy_flex_debug = trace_scanning;
  34   if (!(yyin = fopen (file.c_str (), "r")))
  35     error (std::string ("cannot open ") + file);
  36 }
  37
  38 void
  39 calcxx_driver::scan_end ()
  40 {
  41   fclose (yyin);
  42 }