Re^4: map in void context

I don't consider assignment to have a "side effect". Assignment is the effect.

So,

map {$sum += $_} @array;
[download]

is side-effect free?

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Re^5: map in void context by JadeNB (Chaplain) on Dec 18, 2008 at 01:47 UTC
I don't consider assignment to have a "side effect". Assignment is the effect. So, `map {$sum += $_} @array;` [download] is side-effect free? This seems disingenuous. While I agree that arguing that assignment is “side-effect free” seems a little strange, your example isn't just assigning, it's mutating. Even in the purest of functional languages, `x = 5` is OK (I think!); but `x += 1` isn't.	[reply] [d/l] [select]
Re^6: map in void context by JavaFan (Canon) on Dec 18, 2008 at 10:14 UTC
In a pure functional language, there is no assignment (there are no variables either - there are identifiers, but their values don't vary over time). `x = 5` isn't an assignment. It just means that x is 5. Unlike an assignment which says that x becomes 5 (meaning that it could be something else before, and may become something else later).	[reply] [d/l]