D parsing

[Timothee Cour]

for lexing there's already dscanner we could use (while we wait for perhaps
a autogenerated lexer);
so I think priority is on the autogenerated parser (dscanner has one but
hand designed), where it's still unknown what will work well.


On Mon, Nov 4, 2013 at 2:43 AM, Dmitry Olshansky <dmitry.olsh at gmail.com>wrote:

> 04-Nov-2013 12:28, Robert Schadek пишет:
>
>> On 11/04/2013 06:48 AM, Philippe Sigaud wrote:
>>
>>> On Sun, Nov 3, 2013 at 7:08 PM, Timothee Cour
>>> <thelastmammoth at gmail.com <mailto:thelastmammoth at gmail.com>> wrote:
>>>
>>>
>>>     On Sun, Nov 3, 2013 at 1:13 AM, Philippe Sigaud
>>>     <philippe.sigaud at gmail.com <mailto:philippe.sigaud at gmail.com>>wrote:
>>>
>>>
>>>
>>>         My current plan is to write different engines, and letting
>>>         either the user select them at compile-time, or to have the
>>>         parser decide which one to use, depending on the grammar. I'm
>>>         pretty sure the 'Type 3' parts of a grammar (regular
>>>         expressions) could be bone by using std.regex, for example.
>>>
>>>
>>>     even lexing can't be done with regex, eg nesting comments : /+ ... +/
>>>     Also, although it may seem cleaner at first to combine lexing and
>>>     parsing in 1 big grammar (as done in pegged), it usually is faster
>>>     do feed a (separate) lexer output into parser.
>>>
>>>
>>> Lexing, yes. I was imprecise: even in a context-free grammar, some
>>> rules are regular and could use std.regex (the ct part) as the
>>> underlying engine, just for that rule.
>>>
>> Lexing can not be done with regex. Think myArray[1. ] ! What is next a
>> dot or a number.
>>
>
> You could use lookahead extension ;)
>
> In general I would not recommend ATM to use std.regex for
> performance-critical lexer if only because it wasn't tuned for such a use
> case yet.
>
> I have plans for extending std.regex capabilities in many directions,
> lexing being one important use case.
>
> --
> Dmitry Olshansky
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.puremagic.com/pipermail/digitalmars-d/attachments/20131104/99523cb7/attachment-0001.html>