[metapost] MetaPost - terminally ill or just playing dead? Also New Version

Taco Hoekwater taco at elvenkind.com
Fri Mar 24 10:45:51 CET 2006

Karl Berry wrote:
>     ! MetaPost capacity exceeded, sorry [main memory size=2199001].
> Did you increase it?  The default I see (the main_memory setting in
> teTeX/TL texmf.cnf) is 1 500 000.  Does mp use something else these days?
> Perhaps we should double that, or more.  I'm not sure.

The current executable can go up to 8,000,000 (in web2c-based systems).
My own system uses 6,000,000 currently, and I hardly ever get 'capacity
exceeded' anymore (for main_memory, that is).

> I don't know what else we can do, though, since I doubt Taco plans to
> rewrite all the memory handling code :), so that it can be truly be
> dynamically allocated.

I hope I get around that that, eventually. But I want to attempt with
tex first, because I am more familiar with TeX's internals. The main
problem is that what TeX/MF/MP call 'mem' is conceptually not an array,
but two allocatable memory areas. The bottom area grows up, and the
top area grows down. The data in the bottom area is structurally
different from the data in the top area, and this difference in type
is indicated (solely) by the value of its index in the mem array.
Attempts to untangle this optimization are challenging and prone to

Cheers, Taco

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