Lisp refactoring puzzle
tjreedy at udel.edu
Tue Jul 12 17:03:08 CEST 2011
On 7/11/2011 11:37 PM, Xah Lee wrote:
> it's funny, in all these supposedly modern high-level langs, they
> don't provide even simple list manipulation functions such as union,
> intersection, and the like. Not in perl, not in python,
Union and intersection are set operations, not list operations. Python
has had a set type with a full set of set operations for several years.
It has list concatenation, which is the list equivalent of union. It has
lots of other useful list operations.
> Mathematica has Union, Intersection, and a host of others
> some 20 years ago, and today it has a complete set of combinatorics
> functions as *builtin* functions
Python has the basic combinatoric function in the itertools module,
though they are not used much. If Mathematica has Catalan sequences
builtin, I wonder how much they are used. Since Python is free, in both
meanings, it does not have paid people sitting around writing things to
pad numbers to justify a $2k price tag. On the other hand, lots of
people have added and made available lots of good add-ons. Mathematica
should probably be most fairly compared with Python+numpy+scipy and
maybe a few other things.
Terry Jan Reedy
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