[Thanks for steering me to hugs-bugs. Where can I find out about
haskell-cafe?]
On Sun, 24 Sep 2000, Mark P Jones wrote:
> [Let's take any further correspondence on this over into Hugs-bugs,
> or at least into haskell-cafe ... thanks!]
>
> | When I try to load the parser generated by Happy for a modest-sized
> | language into Hugs I get:
> |
> | Too many variables (16000) in type checker
> |
> | I'm running Hugs 98 on a Power Macintosh. I increased the constraint
> | cutoff limit to no avail (which didn't surprise me).
>
> Right, the constraint cutoff limit isn't a factor here.
>
> | I am unable to increase the heap size (much) above its
> | default 250000 cells. It sounds from the error message,
> | though, that 16000 is simply a limit set in the
> | Hugs interpreter.
>
> No, it's not an intrinsic limit in Hugs. The message appears
> when a call to malloc (i.e., the memory allocation function
> provided by the underlying C implementation) fails.
>
> Perhaps there is a limit in the Mac version of Hugs on the
> amount of memory that can be allocated to a program? Perhaps
> the folks that have worked on Mac Hugs can answer this. Or
> perhaps there is a way for you to change memory limits for
> Hugs within the MacOS.
Yes, I increased the memory allocated to Hugs and the problem went away.
Thanks!
> | Any ideas on how to make this combination of Happy-generated
> | parser and Hugs work together?
>
> Parser generators are good tools for stressing an implementation;
> they tend to generate code that no human would ever write, often
> with huge groups of mutually recursive functions. In these days
> of multimegabyte machines, the kind of problem you describe doesn't
> happen too often any more. But even on bigger machines, you'll
> often see a noticeable pause when Hugs loads the source for a
> generated parser.
And also lexer generators, apparently. After extending my lexer modestly
(I think), I now get:
INTERNAL ERROR: Application parameter stack overflow
from Hugs when trying to run Alex to generate a lexer. I haven't been
able to find any mention of internal errors in all the Hugs documentation
I've seen. Any ideas?
>
> All the best,
> Mark
Thanks again. By the way, I'm new to Hugs but finding it a very pleasant
development environment on the whole.
Dean
