minix/external/bsd/flex/dist/examples/manual/expr.lex
2012-06-18 10:54:47 +00:00

35 lines
619 B
Text

/*
* expr.lex : Scanner for a simple
* expression parser.
*/
%{
#include "y.tab.h"
%}
%%
[0-9]+ { yylval.val = atol(yytext);
return(NUMBER);
}
[0-9]+\.[0-9]+ {
sscanf(yytext,"%f",&yylval.val);
return(NUMBER);
}
"+" return(PLUS);
"-" return(MINUS);
"*" return(MULT);
"/" return(DIV);
"^" return(EXPON);
"(" return(LB);
")" return(RB);
\n return(EOL);
[\t ]* /* throw away whitespace */
. { yyerror("Illegal character");
return(EOL);
}
%%