/* scanner for a toy JavaScript-like language */
%{
#define YY_NO_UNISTD_H
%}
DIGIT [0-9]
ID [a-z_$][a-z0-9_$]*
STRQ '([^\']|(\\\'))*'
STRDQ "([^\"]|(\\\"))*"
%%
{DIGIT}+ {
printf("%s", yytext);
}
{DIGIT}+"."{DIGIT}* {
printf("%s", yytext);
}
if|else|for|while|do|break|switch|case|function|return|new|delete|try|throw|catch|class|public|private {
printf("%s", yytext);
}
{ID} printf("%s", yytext);
{STRQ}|{STRDQ} printf("%s", yytext);
"."|"+"|"-"|"*"|"/"|"="|"!"|">"|"<"|"!=="|"==="|">="|"<="|"++"|"--"|"=>" printf("%s", yytext);
[;(){}:? \t\n]+ printf("%s", yytext); /* echo the rest */
. printf( "Unrecognized character: %s\n", yytext );
%%
int yywrap()
{
return 1;
}
int main(int argc, const char* argv[])
{
++argv, --argc; /* skip over program name */
if ( argc > 0 )
yyin = fopen( argv[0], "r" );
else
yyin = stdin;
puts(
""
""
""
" hello.js"
" "
""
""
" "
);
yylex();
puts("");
return 0;
}