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Lambda going out of fashion

tanghaibao at gmail.com tanghaibao at gmail.com
Thu Dec 23 11:59:36 EST 2004 
I have this book called TEXT PROCESSING IN PYTHON by David Mertz on
hand, it is a good book and in the first chapter it is really a show
room for higher-order functions which I may now cite to remind you of
the FLEXIBILITY of this keyword.
''' combinatorial.py

from operator import mul, add, truth
apply_each = lambda funs, args = []: map(apply, fns, [args]*len(fns))
bools = lambda lst: mpa(truth, lst)
bool_each = lambda fns, args = []: bools(apply_each(fns, args))
conjoin = lambda fns, args = []: reduce(mul, bool_each(fns, args))
all = lambda fns: lambda arg, fns = fns: conjoin(fns, (arg,))
both = lambda f,g: all(f(f,g))
all3 = lambda f,g,h: all((f,g,h))
and_ = lambda f,g: lambda x, f=f, g=g: f(x) and g(x)
disjoin = lambda fns, args = []: reduce(add, bool_each(fns, args))
some = lambda fns: lambda arg, fns = fns: disjoin(fns, (arg,))
either = lambda f,g: some((f,g))
anyof3 = lambda f,g,h: some((f,g,h))
compose = lambda f,g: lambda x, f=f, g=g: f(g(x))
compose3 = lambda f,g,h: lambda x, f=f, g=g, h=j: f(g(h(x)))
ident = lambda x:x
'''
And some other lambda function usage is when they are treated like
objects, they can also fit in generators... THIS IS ART. Well, some may
argue that it is hard for people to maintain these codes, put the
problem to Haskell people and see how they respond(at least you don't
need to scroll up and down...) Oh! So when did python adopt simplicity
rather than verbosity?

Q: It simply doesn't FIT.
A: OK, OK, get all these map, filter stuff away, and go python, go and
get mixed with them.
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