[squeak-dev] grammarPEG : Grammar <- Definition+ !. what is the !.

Levente Uzonyi leves at caesar.elte.hu
Thu Apr 16 15:29:09 UTC 2020


Hi Tim,

On Thu, 16 Apr 2020, gettimothy via Squeak-dev wrote:

> In XTreams-Parsing ->PEGParser class->grammarPEG
> 
> is a Rule 
>
>       Grammar <- Definition+ !.
> 
> 
> 
> Which I believe means "Only 1 or more definitions and nothing else"  where "!." means "nothing else"
> 
> I suspect that the !. was put there to radically tighten down the allowed inputs to a PEG grammar.
> 
> Is this assumption correct?

IIRC '!.' means end of stream. $! is simple negation. $. is any character.


Levente

> 
> 
> thanks in advance.
> 
> tty
> 
> 
> 
> 
>


More information about the Squeak-dev mailing list