PEP 276 Simple Iterator for ints

[Skip Montanaro]

    Magnus> I'd love to drop range() or xrange() from my for loops... (I
    Magnus> would like some pseudocode-like literal like 0..n myself, but I
    Magnus> see the [0:n] PEP has been rejected, so... :|)

The proposed integer iterator would replace the most common range/xrange
usage directly, but wouldn't supplant them completely without some help.  Of
course you could twiddle the index at the beginning of the loop to acheive
the desired effect:

    for i in 10:
      i = -i            # for i in range(0, -10, -1)

    for i in 10:
      i = 2*i           # for i in range(0, 10, 2)

    for i in 10:
      i = i+1           # for i in range(1, 11)

    for i in 10:
      i = 3*i+1         # for i in range(1, 11, 3)

    etc.

Taking that one gruesome step farther, one could envision a further
extension to for loops:

    for i=-i in 10:
      ...

    for i=2*i in 10:
      ...

    for i=i+1 in 10:
      ...

    for i=3*i+1 in 10:
      ...

but I won't even suggest it as more than an idle thought... ;-)

-- 
Skip Montanaro (skip at pobox.com)
http://www.mojam.com/
http://www.musi-cal.com/