std.range: Lockstep vs. Zip

[Seb via Digitalmars-d-learn]

On Thursday, 3 March 2016 at 15:00:10 UTC, Alex Parrill wrote:
> On Wednesday, 2 March 2016 at 08:51:07 UTC, Manuel Maier wrote:
>> Hi there,
>>
>> I was wondering why I should ever prefer std.range.lockstep 
>> over std.range.zip. In my (very limited) tests std.range.zip 
>> offered the same functionality as std.range.lockstep, i.e. I 
>> was able to iterate using `foreach(key, value; 
>> std.range.zip(...)) {}` which, according to the docs, is what 
>> std.range.lockstep was supposed to be designed for. On top of 
>> that, std.range.zip is capable of producing a 
>> RandomAccessRange, but std.range.lockstep only produces 
>> something with opApply.
>>
>> Cheers
> zip uses the InputRange protocol, and bundles up all the values 
> in a Tuple.
>
> lockstep uses the opApply protocol, and doesn't bundle the 
> values.
>
> Lockstep is useful for foreach loops since you don't need to 
> unpack a tuple, but zip is compatible with all of the std.range 
> and std.algorithm functions that take ranges.

That helps a lot - it is funny that the documentation shows an 
example with foreach an `zip`. Your insights also helped me and I 
thought it should also help other people, so I made a PR ;-)

https://github.com/D-Programming-Language/phobos/pull/4054