On Sunday, 8 July 2012 at 09:14:32 UTC, Dmitry Olshansky wrote:
On 08-Jul-12 13:05, Tobias Pankrath wrote:
Yup, LL(*) is my favorite so far.
That's Terence Parr's discovery, right? I've always liked
ANTLR, so if
PEGs turn out to have issues LL(*) sounds like a promising
alternative.
We should also consider using GLR if LL(*) doesn't work.
GLR ... are you serious? It still does parsing in n^3 if I'm
not mistaken.
Since GLR can parse any CFG the upper bound is in O(n^3), but the
actual performance seems to depend on the grammar.
From Elkhound [1]
It should be competitive with Bison for LALR (fragements of)
grammars, and degrade gracefully from there. On the scale of
grammar nondeterminism, from none
(LALR) to some to lots, "some" is the niche Elkhound is going
after.
These goals are driven by Elkhound's primary application, the
Elsa C++ Parser. In essence, Elkhound came about because I
wanted to apply automatic parsing technology to parsing C++,
but found exiting systems inadequate.
So it seems to me that it is not worse than PEG if you have a
grammar with
reasonable many ambiguities.
Performance is one thing, but you should be able to express your
language in the underlying formalism without too many hurdles.
