Passing a symbol table to the parser

Passing a symbol table to the parser

[Joel Reymont]

Folks,

How would I pass a symbol table to a Menhir parser so that it's  
available in my rules?

	Thanks, Joel

--
http://wagerlabs.com/

Re: [Menhir-list] Passing a symbol table to the parser

[Francois Pottier]

Hello,

On Thu, Apr 26, 2007 at 09:48:35AM +0100, Joel Reymont wrote:
> How would I pass a symbol table to a Menhir parser so that it's  
> available in my rules?

The most basic solution is to make the symbol table mutable (e.g.  make it a
hash table, or a mutable reference to a persistent data structure) and place
it in a global variable in some earlier module.

If, in addition, you need reentrancy and don't want your parser to depend on a
global variable, then you can move this global variable to a functor parameter,
using a %parameter declaration, like this:

  %parameter <T : sig
    type symbol
    type info
     val get: symbol -> info
     val set: symbol -> info -> unit
  end>

Then, your semantic actions can refer to T.get and T.set, and Menhir produces
a parser that is parameterized over T.

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