Concepts

LISP and Haskell inspired functional programming concepts for Python

Originally this was called fmap and was only an implementation of the fmap function for Python3. Now that I've been tinkering around some more I thought it'd be nice to collect a few things together. (For about a day it was then called PythFun but then I saw the error of my ways...)

• fmap: apply a function to all elements of a collection style object.
• pattern_match: A hybrid of Haskell's pattern matching and Clojure's destructuring.
• dispatch: single and multiple dispatch for your Python functions.
• prelude: a collection of functional programming functions.

Any suggestions for improvements are welcome and if you'd like to hack away and submit a pull request for a feature then raise an issue and let me know!

I hope you enjoy!

Some examples...

def fibgen():
    '''Because EVERYONE needs a list of Fibonacci numbers...'''
    yield 1
    yield from iscanl(fibgen(), add, 2)

>>> take(20, fibgen())
[1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765, 10946]


@tcall
def fact(n, acc=1):
    '''And compute some factorials...'''
    if n == 0:
        return acc
    else:
        return fact, (n-1, acc*n)

>>> fact(99)
9332621544394415268169923885626670049071596826438162146859296389521759999322991560894146397
61565182862536979208272237582511852109168640000000000000000000000

>>> import sys

>>> sys.getrecursionlimit()
2000

>>> fact(9999)
284625968091705451890641321211986889014805140170279923079417999427...
# This one is 35656 digits long...


# From prelude.py
def cmap(func, col):
    '''
    Concat-Map: map a function that takes a value and returns a list over an
    iterable and concatenate the results
    '''
    return foldl(map(func, col))


def flatten(col):
    '''
    Flatten an arbitrarily nested list of lists into a single list.
    '''
    if not iscollection(col):
        return [col]
    else:
        return cmap(flatten, col)


>>> l = [1,2,[3,4,[5,6,7],[8,9]],[10,11,12],13]

>>> flatten(l)
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]