Sure, I also did a function like this in the emacs help group

But I was asking about designing a generic iterator solution, opening a variety of applications and augmenting readablity

already a reduce_list {BLOCK} LIST variant of reduce could be sufficient in this case

 reduce_list { $a ne $b } qw(a a a a b c c a a d e e e e undef undef f g g)

another application would be Haskells group iterator which partitions into successive groups: 

group [1, 1, 1, 1, 2, 3, 3, 1, 1, 4, 5, 5, 5, 5]
==>  [[1,1,1,1], [2], [3,3], [1,1], [4], [5,5,5,5]]

[download]

Simpling allowing access to the previous iteration easily would help implementing this with part from List::MoreUtils

 part { $a eq $b } LIST

or

 part { $^PRE eq $_ } LIST

Without the need to invent and name a whole new group of iterators.

Cheers Rolf

In reply to Re^2: reduce like iterators by LanX
in thread reduce like iterators by LanX

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