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      1 %{ /* -*- C++ -*- */
      2 # include <cstdlib>
      3 # include <cerrno>
      4 # include <climits>
      5 # include <string>
      6 # include "calc++-driver.hh"
      7 # include "calc++-parser.hh"
      8 
      9 /* Work around an incompatibility in flex (at least versions
     10    2.5.31 through 2.5.33): it generates code that does
     11    not conform to C89.  See Debian bug 333231
     12    <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=333231>.  */
     13 # undef yywrap
     14 # define yywrap() 1
     15 
     16 /* By default yylex returns int, we use token_type.
     17    Unfortunately yyterminate by default returns 0, which is
     18    not of token_type.  */
     19 #define yyterminate() return token::END
     20 %}
     21 
     22 %option noyywrap nounput batch debug
     23 
     24 id    [a-zA-Z][a-zA-Z_0-9]*
     25 int   [0-9]+
     26 blank [ \t]
     27 
     28 
     29 %{
     30 # define YY_USER_ACTION  yylloc->columns (yyleng);
     31 %}
     32 
     33 %%
     34 %{
     35   yylloc->step ();
     36 %}
     37 {blank}+   yylloc->step ();
     38 [\n]+      yylloc->lines (yyleng); yylloc->step ();
     39 
     40 %{
     41   typedef yy::calcxx_parser::token token;
     42 %}
     43          /* Convert ints to the actual type of tokens.  */
     44 [-+*/]   return yy::calcxx_parser::token_type (yytext[0]);
     45 
     46 ":="     return token::ASSIGN;
     47 
     48 
     49 {int}    {
     50            errno = 0;
     51            long n = strtol (yytext, NULL, 10);
     52            if (! (INT_MIN <= n && n <= INT_MAX && errno != ERANGE))
     53              driver.error (*yylloc, "integer is out of range");
     54            yylval->ival = n;
     55            return token::NUMBER;
     56          }
     57 
     58 
     59 
     60 {id}     {
     61            yylval->sval = new std::string (yytext);
     62            return token::IDENTIFIER;
     63          }
     64 
     65 
     66 .        driver.error (*yylloc, "invalid character");
     67 %%
     68 
     69 
     70 void
     71 calcxx_driver::scan_begin ()
     72 {
     73   yy_flex_debug = trace_scanning;
     74   if (file.empty () || file == "-")
     75     yyin = stdin;
     76   else if (!(yyin = fopen (file.c_str (), "r")))
     77     {
     78       error ("cannot open " + file + ": " + strerror(errno));
     79       exit (EXIT_FAILURE);
     80     }
     81 }
     82 
     83 
     84 
     85 void
     86 calcxx_driver::scan_end ()
     87 {
     88   fclose (yyin);
     89 }
     90 
     91