#2444 use_fast_arrays & undeclared arrays

open
nobody
Lisp Core (472)
4
2012-11-18
2012-07-12
Barton Willis
No

When use_fast_arrays is true, Maxima uses CL hashtables to store undeclared arrays. These
hashtables use CL equal to test equality of keys. This has some undesired consequences;
for example:

(%i1) use_fast_arrays : true$
(%i2) a[factor(2*z)] : 1$
(%i3) a[2*z] : 2$
(%i4) [a[2*z], a[factor(2*z)]];
(%o4) [2,1]

See also

http://www.math.utexas.edu/pipermail/maxima/2012/029525.html
http://www.math.utexas.edu/pipermail/maxima/2012/029527.html
http://www.math.utexas.edu/pipermail/maxima/2012/029528.html

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