Memoization [was: `undefine']

[Greg Harvey <Greg.Harvey@thezone.net>]

"Marisha Ray & Neil Jerram" <mpriz@dircon.co.uk> writes:

> 
> >A space finds a symbol's binding either by looking up the symbol in a
> >hash table (as for a local space), or by delegating the search to other
> >spaces.  This means that the full symbol lookup process is too
> >expensive to perform on each variable reference.  Thus, Guile uses
> >memoization and caching to avoid repeating the search for a given
> >variable's binding, unless the space's configuration has changed.
> 
> I know I should really go and read the code, but I don't understand the
> benefit of memoization.  Why is looking up a value in a GLOC so much quicker
> than looking it up in a value cell?

The GLOC is inserted in place of the original symbol, so the next time
through there's no need to do any environment lookups at all.

-- 
Greg