Re: [Caml-list] Array.make exception and parser

[Francois Pottier <Francois.Pottier@inria.fr>]

Hello all,

On Tue, Jan 04, 2011 at 04:38:56PM +0100, bluestorm wrote:
> You may be interested in trying to use menhir [1] as a Parser generator
> instead of ocamlyacc. Menhir is mostly compatible with ocamlyacc, but
> doesn't use the Parsing module. While I don't think it as done anything
> specific to support larger input files, the issue may go away (or don't
> appear on the input sizes you need) using the different menhir
> implementation.
> 
>  [1] http://gallium.inria.fr/~fpottier/menhir/

Interesting suggestion, indeed. Menhir does not use an ocaml array to
implement the parser's stack; instead, it uses a heap-allocated linked
list. It might scale up better than the ocamlyacc-generated parser
(although of course it might just fill up the heap; the linked list
approach probably consumes more space than the array-based approach
by a constant factor).

I would be curious to hear whether this works.

Earlier, Daniel Bünzli wrote:
> I don't really understand why people insist on using
> yacc like parser generators where a recursive descent parser
> with some combinators ...

For what it's worth, here is my answer: an LR parser generator (like Menhir)
accepts a larger class of grammars without refactoring (no need to eliminate
left recursion, identify common left factors, etc.) and is also able to
*explain* why the grammar is ambiguous (or rather, why it lies outside the LR
class), which a combinator-based approach cannot do.

-- 
François Pottier
Francois.Pottier@inria.fr
http://gallium.inria.fr/~fpottier/