Supply condition in function call

[Ian Kelly]

On Wed, Mar 25, 2015 at 1:53 PM, Grant Edwards <invalid at invalid.invalid> wrote:
> On 2015-03-25, Ian Kelly <ian.g.kelly at gmail.com> wrote:
>> On Wed, Mar 25, 2015 at 11:29 AM, Manuel Graune <manuel.graune at koeln.de> wrote:
>>
>>> I'm looking for a way to supply a condition to an if-statement inside a
>>> function body when calling the function. I can sort of get what I want
>>> with using eval [...]
>>
>> Pass the condition as a function.
>>
>> def test1(a, b, condition=lambda i, j: True):
>>     for i,j in zip(a,b):
>>         c=i+j
>>         if condition(i, j):
>>             print("Foo")
>>
>> test1([0,1,2,3],[1,2,3,4], lambda i, j: i+j > 4)
>> # etc.
>
> FWIW, back in the day such a function was referred to as a "thunk"
> (particularly if it was auto-generated by a compiler that used
> pass-by-name instead of pass-by-value or pass-by-reference):
>
>   http://en.wikipedia.org/wiki/Thunk
>
> Dunno if people still use that term or not.

I've heard the term (though not since my college days, I think), but
I've always understood thunks to be parameterless (hence the use as a
form of pass-by-name).