I don't think using a for loop is "taboo" among Rubyists in general, just for iterating over each element of an array, where Array#each, Array#collect, and Array#inject are preferred. This probably comes from the influence of Lisp and its emphasis on writing code as a series of list operations.
To my mind, anyway, using each/collect/inject expresses intent much more clearly than a for loop. If a clearer approach is available, why not take advantage of it?
I, too, think like that, although Ruby's nomenclature frequently confuses me. Coming from Scheme/Haskell I'm quite at home with 'map', 'filter', and 'fold'.
However, Ruby uses the methods you mention, "collect" and "inject", and these in turn have a few synonyms. And as best I can tell, Ruby's 'filter' variant, 'find' collides with ActiveRecord. What's the general community take on these functions? Which name is commonly used, and how do you do filter in Rails?
> I, too, think like that, although Ruby's nomenclature frequently confuses me.
Most of them come from Smalltalk's Iterable protocol[0]: that's the source for `select:aBlock`, `collect:aBlock`, `inject:thisValue into:binaryBlock` (Smalltalk uses `fold` when there's no starting value, and `inject` as "fold by injecting initial value"), `detect:aBlock` and `reject:aBlock`.
Smalltalk also uses `do:aBlock` where Ruby uses `each`, likely due to `do` being a keyword in Ruby.
Also, `find` is not `filter` (that's `select`, aliased to `find_all`). `find` is also `find` in Haskell[1] (and maps to Smalltalk's `detect`, also useable in Ruby).
> 'find' collides with ActiveRecord
Uh... no, ActiveRecord collides with Enumerable, I'm pretty damn sure Enumerable came first.
> how do you do filter in Rails?
What's wrong with #find? Or #where? Or #find_by_*? Same name, different namespace, different meaning. Kind-of the point.
To my mind, anyway, using each/collect/inject expresses intent much more clearly than a for loop. If a clearer approach is available, why not take advantage of it?