(side-)effects and ...

Terry Reedy tjreedy at udel.edu
Mon Jul 6 01:12:40 CEST 2015

On 7/5/2015 4:29 PM, Stefan Ram wrote:

>    And this is the intention of my post: Maybe there is such
>    a term, and I just missed to learn it so far? So,
>    do you know a term for the phenomenon that can be found
>    in Python but not in mathematics and consists in the state
>    of the world influencing the value of an expressions?


In mathematics, 'pure' functions defined in terms of named functions, 
such as

def f(x): return exp(sin(2*pi*x) + cos(2*pi*x))

are actually namespace dependent, but this is not counted as the local 
namespace (which here must contain exp, pi, sin, and cos) is considered 
to be write-once, read-forever.

Terry Jan Reedy

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