Re: Distinguishing LPeg match failure reasons

[Jakub Piotr Cłapa <jpc-ml@...>]

On 30.08.11 04:28, Patrick Donnelly wrote:
> On Mon, Aug 29, 2011 at 10:07 PM, Jakub Piotr Cłapa<jpc-ml@zenburn.net>  wrote:
> [1] may help.
>
> [1] http://lua-users.org/lists/lua-l/2009-10/msg00774.html

Thanks. This is in fact one of the few things I have seen while googling 
for a solution. But IIUC for it to work I would have to alternate each 
character of each rule with an lpeg.Cmt checking i == #s.

I think I need a way to detect that lpeg tried to match beyond the end 
of the string. If it did (and I did not add lpeg.P(-1) at the end of the 
main rule) then I know that it failed because of too little data.

The problem with most "normal" solutions is that I after a match failure 
the capture is immediately unwound and I do not know anything about it. 
If I add an alternative then it will start from the beginning and a 
pattern concatenation will never be reached when something failes before it.

--
regards,
Jakub Piotr Cłapa