Performance of Comprehensions versus For Loops

[Tamas_Papp]

I am aware of it, but many extra ingredients are needed to replicate what eg map or collect does. Eg recursively calling on widening:

Functional implementation of collect

I am working on something that is in a sense a generalization of collect (except it would pick named tuples apart into vectors, apply some simple RLE compression, etc), and I wanted to understand the type widening part better. For my problem, I do not know the element type or the size ex ante, so the following type is defined to make results comparable (all the code is available in a gist for quick copy&paste): # define an iterator with unknown type and length struct MyItr N::Int end Base.Itera…

using size hints for preallocating, etc. It is all feasible (since it is done in Base ), but you essentially end up reimplementing Base functionality, which is very involved.