[CM] TeXmacs & S7

[bil at ccrma.Stanford.EDU]

It's not the size of the environment that matters;
look at libgsl.scm (or the timing test tools/tgsl.scm) --
it creates the *libgsl* environment that has about 2600
entries, but lookup_from takes up maybe 2% of the total
time).  Or tools/tlet.scm which creates an environment
with 1000000 entries, then sums them all and so on.
It essentially never has to do a linear search.
If I can find the time, I'll try to see what is
happening in texmacs.  annotate_callgrind output
from a sample run might help. (Run texmacs
under valgrind --tool=callgrind, then run the output
of that through annotate_callgrind  --auto=yes --show-percs=no
  --threshold=100 callgrind.out.<xxxx> > output) where
<xxxx> is the number at the end of the callgrind output
file name.)