Re: LPeg indent/whitespace based grammar

[Matthias Dörfelt <lists@...>]

Thank you so much! re module looks very nice, will give it a shot I think after I got it to work with pure LPeg!

Best
Matthias

> On Jul 7, 2017, at 14:21, Duncan Cross <duncan.cross@gmail.com> wrote:
> 
> On Fri, Jul 7, 2017 at 9:09 PM, Matthias Dörfelt <lists@mokafolio.de> wrote:
>> Awesome, thanks that is super helpful!
>> Haven’t looked at the “re” portion of lpeg, yet. I was initially gonna stick with pure LPeg, but let’s see!
>> 
>> Is it pretty straight forward to express your re code in pure lua & LPeg?
>> 
>> Thanks!
> 
> Sure, I think this should be the equivalent:
> 
> 
> --
> local hierarchy = lpeg.P {
> 
>  'hierarchy';
> 
>  hierarchy = initial_indent
>    *
>    lpeg.Ct(
>      lpeg.Cg(
>        lpeg.Ct(
>          (
>            lpeg.V('first_root')
>            *
>            lpeg.V('next_root')^0
>          )^-1
>        ),
>        'children'
>      )
>    )
>    *
>    lpeg.P(-1);
> 
>  first_root = lpeg.V('entry');
> 
>  next_root = '\n' * lpeg.V('entry');
> 
>  entry = lpeg.Ct(
>    lpeg.Cg(lpeg.V('name'), 'name')
>    *
>    lpeg.Cg(
>      lpeg.Ct(
>        (
>          lpeg.V('first_child')
>          *
>          lpeg.V('next_child')^0
>        )^-1
>      ),
>      'children'
>    )
>  );
> 
>  first_child = '\n' * capture_deeper_indent * lpeg.V('entry');
>  next_child = '\n' * match_same_indent * lpeg.V('entry');
> 
>  name = (1 - lpeg.P('\n'))^0;
> 
> }
> --
> 
> 
> -Duncan
> 
>