On 5/2/16 6:55 AM, ag0aep6g wrote:
On 02.05.2016 09:45, Jacob Carlborg wrote:
Does it matter? I thought the idea was to get the same behavior not
explicitly a range.
default0 said that D's ranges would be more awkward than a for loop. I
think D's iota is fine.
D's special syntax is even nicer, but it's a language thing. And
apparently Swift is cutting down on syntax, not adding. Something like
iota is probably doable in a library. I don't know Swift, though.
Swift has both builtin syntax and library mechanism similar to iota:
for i in 0..<5 // [0 to 5)
for i in 0...5 // [0 to 5]
for i in 0.stride(to: 5, by: 1) // [0 to 5)
for i in 0.stride(through: 5, by: 1) // [0 to 5]
You can also hack with where expressions the builtin range syntax to
skip values like iota, but I'm almost positive this doesn't perform
well, or at least won't in complex situations:
for i in 0..<10 where i % 2 == 0 // even numbers less than 10
I think for-in (swift) and foreach (D) are both fantastic for iterating
a straight range or pre-determined sequence. I would never use for loops
for a straightforward index progression (and ideally, I would ignore the
index if at all possible).
However, there are cases where I pull out the for loop because the
ending condition is complex, or strangely related to the index variable,
or the increments aren't regular. For loops have so much power in such a
succinct syntax, I can't understand why anyone would shun them as taboo
or error prone. Seems like it's more a philosophical decision than
practical or helpful.
And anyone who says "bleh, you can just use a while loop if you need
that" I want to beat with a semi-colon over the head.
-Steve
