Re: yet another pattern-matching library for Lua

[Brian Hagerty <Brian.Hagerty@...>]

One thing to keep in mind about LPEG, it's not just "another 
pattern-matching library" on par with regular expression parsers 
and string manipulation libraries.

LPEG is (or is on its way to be) a full /Parsing Expression 
Grammar/ library, fully capable of expressing and implementing 
Grammars, as well as Regular Expressions.  RegExps are very 
limited kinds of pattern languages (typically limited to 
recognizing lexical tokens).

RegExps cannot express the much more complex syntax of Context 
Free Grammars (CFGs), Context Sensitive Grammars (CSGs), and 
Parsing Grammars (PGs, aka PEG: Parsing Expression Grammars).

PEGS are a kind of context-sensitive grammar, which are a proper 
superset of CFGs, which in turn are a superset of RegExps.

...

If any of you haven't already done so, and you have an interest 
in or need for the broader applications of Grammars over 
RegExps, check out Roberto's LPEG pages and Bryan Ford's PEG pages:

http://www.inf.puc-rio.br/~roberto/lpeg.html
http://pdos.csail.mit.edu/~baford/packrat/

// Brian

Philippe Lhoste wrote:
> Funnily, I recently thought it would be nice to have a real 
> pattern-matching language, that would be more flexible and more 
> readable, with a gentler learning curve than regular expressions.
> I am not too sure about the readability of LPeg... But it is close of 
> what I had in mind.
>
> I didn't knew this PEG technology, it looks very promising.
> Now that I master regular expressions, I have to learn a new syntax and 
> even more new concepts/way of thinking...