Re: [Caml-list] How to write an efficient interpreter

[Xavier Leroy <Xavier.Leroy@inria.fr>]

On 10/24/2011 11:10 AM, Diego Olivier Fernandez Pons wrote:

> I have to write an interpreter for a datatype rich purely applicative
> language. I have already written a naive interpreter (like in programming
> languages class) and was wondering what where the options for writing
> something that would perform better while keeping it maintainable by a single
> person < 5% dedicated and preferably only in core-ML (no C code or fancy ML
> extensions).

Gabriel and Gerd gave very good advice already, but here are my two
cents:

- Beware of premature optimizations.  It could very well be that your
  naive interpreter is already fast enough for your applications.
  Test and profile to find hot spots.

- Pay special attention to your data structures, e.g. environments should
  be maps, not A-lists.  A good trick is to hash-cons identifiers
  into unique integers: not only comparisons are much faster,
  but you can use Patricia trees for your environments.

- Compiling to bytecode is probably overkill.

Hope this helps.

- Xavier Leroy