CODEWITHSUNDEEP
erlangbinarylist-comprehension
me2
me2

Reputation: 3119

Erlang list comprehension with two lists in sequence?

Is it possible to use list comprehension on two lists, item by item, in sequence? Given A = [1,2,3], B = [4,5,6], get some C = [f(1, 4), f(2, 5), f(3, 6)]. In other words, a more direct/efficient way to do [f(U, V) || {U, V} = lists:zip(A, B)].

Similar question goes to binaries, if given A = <<1,2,3>> and B = <<4,5,6>>. This would be very useful if you have to xor two binaries, for example.

Upvotes: 5

Views: 1556

Answers (2)

Zed
Zed

Reputation: 57648

It's not currently possible. It has already been proposed in EEP12 and EEP19.

Your best choice is to implement your own recursive function for that.

Upvotes: 8

Christian
Christian

Reputation: 9486

There is already a higher-order-function in the lists module for this and it is called lists:zipwith/3. Your example scenario would be implemented this way:

lists:zipwith(fun f/2, A, B).

Upvotes: 3

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