Range of n lines from stdin

[Ivan Kazmenko]

Quick question.

(1) I can do
n.iota.map!(_ => readln)
to get the next n lines from stdin.

(2) However, when I do
readln.repeat(n)
it looks clearer but works differently: preserves front and reads 
only one line.

(3) In the particular case of readln, we can substitute it with
stdin.byLine.take(n)
but the question remains for other impure functions.

So, what I ask for is some non-caching repeat for functions with 
side effects.  More idiomatic than (1).  Is there something like 
that in Phobos?  Is it an OK style to have an impure function in 
an UFCS chain?

If repeat could know whether its first argument is pure, it could 
then enable or disable front caching depending on purity... no 
way currently?

Ivan Kazmenko.