Enumerable#collect is just an eager version Python map() in method rather than function form (#map is a avaulable as an alias for #collect); it is a little more concise for when the function you are mapping over is a method on the object being processed (even more than Ruby’s normal advantage with lambdas), but not fundamentally more powerful.

(Enumerable#lazy gives you an object where collect/map is, and other merhods are, lazy rather than eager.)

> I feel like it takes the role that generators have in Python

Ruby has generators, though in either Ruby or Python map/collect (the lazy versions, in Ruby) can be used for some of their uses, since it basically produces a generator from an input collection or generator and a mapping function.

#collect is an alias for #reduce, not #map, making it like Python reduce().

> #collect is an alias for #reduce

It’s not, though. (If it was, we could write about its equivalence with Python’s [from functools in py3, core in Py2] reduce function, though, saying much the same thing as about the actual equivalence with map upthread, except reduce/inject is less often a substitute for generators than map/collect.)

#map is an alias for #collect. [0]

#reduce has the alias #inject. [1]

[0] https://ruby-doc.org/core-3.0.2/Enumerable.html#method-i-col...

[1] https://ruby-doc.org/core-3.0.2/Enumerable.html#method-i-inj...

Then should the example in the above comment, `some_enum.collect(&:+)`, be using reduce instead of collect?

Yes. My bad. :)

I haven't been a professional Rubyist in some years but my habit here was to use inject.

You’re right. My apologies.