[Maxima] use_fast_arrays : true & batch files
willisb at unk.edu
Wed Jul 11 06:54:07 CDT 2012
Maxima appends line number and file name information to the car of an expression when batching a file--stuff like
((MPLUS SIMP (53 "C:/Users/Barton/Desktop/junk/rtest_aref.mac" SRC)) $X ((MTIMES SIMP) -1 $Y))
Since undeclared arrays use CL hash tables with an equal test (not alike1) for equality, batch files can have problems
with undeclared arrays when use_fast_arrays is true. (CL hash tables only support the equality tests eq, eql, equal, and equalp.
There is a source code comment in trans2.lisp that suggests changing the equality test for a hash table to alike--not going to
happen.) Sticking to integer indices for undeclared arrays might be safe.
Maxima isn't careful about preserving extra junk in the car of an expression, by the way.
I suppose this could be fixed by scrubbing the line and file information from the car of an expression before it is stored or accessed
from a CL hash table---ugh. A missing simp flag could cause problems too. When use_fast_arrays is false, I think this problem disappears.
A regression test file that shows the problem (at least it does for me):
(use_fast_arrays : true,0);
(a[%pi] : 42, 0);
(ab[x-y] : s, 0);
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