Re: LPeg - new version

[Dave Dodge <dododge@...>]

On Fri, Mar 23, 2007 at 01:20:43PM +0100, Mike Pall wrote:
> Philippe Lhoste wrote:
> > So I went ahead and created my own opcodes, reusing most of Roberto's 
> > ideas and creating new codes to make some common expressions optimal.
> 
> Since a PEG implementation leads naturally to a bytecode
> interpreter,

Aside: if you're willing to accept some limitations it's of course not
necessary.  I too recently implemented a PEG library (in plain C,
unrelated to Lua), but I took the easier road of direct recursive
evaluation.

Granted, this means I have to keep evaluation depth in mind when
creating the expressions, but the nice thing was that it let me get
something usable in a day or two.  That way I could start working
sooner on some other things I needed, such as a yacc-style parser
generator (that reads a textual description of a grammar and emits
compilable C code to implement that grammar using the PEG library).
If at some point I decide that recursive evaluation is not sufficient
for the project, my PEG API should allow me to transparently replace
the evaluator with an iterative/bytecode design.

                                                  -Dave Dodge