A-M baby

Task/First-class-functions/Python/first-class-functions.py

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+>>> # Some built in functions and their inverses
+>>> from math import sin, cos, acos, asin
+>>> # Add a user defined function and its inverse
+>>> cube = lambda x: x * x * x
+>>> croot = lambda x: x ** (1/3.0)
+>>> # First class functions allow run-time creation of functions from functions
+>>> # return function compose(f,g)(x) == f(g(x))
+>>> compose = lambda f1, f2: ( lambda x: f1(f2(x)) )
+>>> # first class functions should be able to be members of collection types
+>>> funclist = [sin, cos, cube]
+>>> funclisti = [asin, acos, croot]
+>>> # Apply functions from lists as easily as integers
+>>> [compose(inversef, f)(.5) for f, inversef in zip(funclist, funclisti)]
+[0.5, 0.4999999999999999, 0.5]
+>>>