std.algorithm.map with side-effects

[bearophile via Digitalmars-d-learn]

Joseph Rushton Wakeling:

> Can anyone advise why,

map is lazy, like most other ranges.


> and whether there's a nice range iteration option to ensure 
> that this function gets called using each element of the 
> filteredRange?

Lazy higher order functions like map/filter should be used only 
with pure functions. There are bugs/troubles in using them on 
impure code.

There was a proposal for a "each" function to terminate a range 
chain with something effectful, but I think it has gone nowhere. 
This means you have to use a foreach on a range.

Bye,
bearophile