Neil Cerutti <ne...@norwich.edu> writes: > On 2011-07-12, Petter Gustad <newsmailco...@gustad.com> wrote: >> Xah Lee <xah...@gmail.com> writes: >> >>> 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, not in lisps. >> >> In Common Lisp you have: >> >> CL-USER> (union '(a b c) '(b c d)) >> (A B C D) >> CL-USER> (intersection '(a b c) '(b c d)) >> (C B) > > What's the rationale for providing them? Are the definitions > obvious for collections that a not sets?
This seems like a good general question to me, although, I feel like the answer to this question specifically is "yes, obvious enough." A general purpose programming language ought to be general enough to allow expansion, but have enough "obvious" features, that one doesn't have to reinvent the wheel. I recently read somewhere that human languages "differ less in what they allow, and more in what they require" (paraphrase). I have little-to-no computer science expertise, but I sense that in computer languages with Turing equivalency this is exactly true. -- William Clifford -- http://mail.python.org/mailman/listinfo/python-list
