ocamllex and yyless, putting back chars in lexbuf

ocamllex and yyless, putting back chars in lexbuf

[yoann padioleau]

Hi,

Is there a way in ocamllex to put back certain characters
in the buffer. In flex you can do that

<LOOKING_FOR_XXX>[a-z]+ {
	yy_pop_state();
	yy_push_state(ST_TOP);
	return T_STRING_VARNAME;
}


<LOOKING_FOR_XXX>{ANY_CHAR} {
	yyless(0);
	yy_pop_state();
	yy_push_state(ST_TOP);
}


Should I play with fields like lexbuf_lex_curr_pos ?

Re: [Caml-list] ocamllex and yyless, putting back chars in lexbuf

[Dario Teixeira]

Hi,

> Is there a way in ocamllex to put back certain characters
> in the buffer. In flex you can do that

It is also possible with Ulex, using Ulexing.rollback.

Even if you don't need the UTF8 features, I suggest you take a
look at Ulex anyway; the approach used (it's a syntax extension)
provides greater flexibility.  Moreover, it also handles latin1
streams fine.

Cheers,
Dario Teixeira