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Again, I didn't really think you were being judgmental. It's just that in Ruby, the for loop definitely doesn't have pride of place at all. You're may be right that most programmers learn languages where for is more common, but I wonder about people who start with Ruby. That is, do they think for is weirdly primitive when they start doing Javascript?

Anyhow, no offense taken at all. But I would be shocked if any Rubyist did use for.

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Even in languages like C# the standard for-loop seems to be heading in the direction of being considered harmful. Its status hasn't gone nearly as far along the path as for Ruby, but the tide's turning that way.

As far as creating a new array (or several new arrays) goes, there are some new considerations such as composability that are starting to be valued more highly than efficiency. And pure functions are more composable than ones that mutate the existing data.

Granted, the n < 0 case could still be handled in a way that's more efficient but still pure by allocating an array and filling it backward rather than using two reverses and an iterator.

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