On Mon, Feb 2, 2015 at 11:53 AM, Chris Angelico <rosuav@gmail.com> wrote:
On Mon, Feb 2, 2015 at 9:26 PM, Todd <toddrjen@gmail.com> wrote:
> First, it wouldn't be a replacement.  The existing range syntax would still
> exist.
> But the reason it is beneficial is the same reason we have [a, b, c] for
> list, {a:1, b:2, c:3} for dicts, {a, b, c} for sets, and (a, b, c) for
> tuples.  It is more compact way to create a commonly-used data structure.
> And I wouldn't consider it any more cryptic than any other literal we have.

Considering the single most common use of ranges, let's see how a for
loop would look:

for i in 1:10:

Is that nastily cryptic, or beautifully clean? I'm inclined toward the
former, but could be persuaded.

It would be

for i in (1:10):

Anyone who uses sequences should be familiar with this sort of notation:

for i in spam[1:10]:

So should have at least some understanding that 1:10 can mean "1 to 10, not including 10".

I don't see it being any more cryptic than {'a': 1, 'b': 2} meaning dict(a=1, b=2).  On the contrary, I think the dict literal syntax is even more cryptic, since it has no similarity to any other syntax.  The syntax I propose here is at least similar (although not identical) to slicing.