On 02/17/2014 09:21 PM, simendsjo wrote:
On Monday, 17 February 2014 at 20:03:32 UTC, Timon Gehr wrote:
...
It was just to illustrate the issue more clearly. Eg. it means one and
the same iota expression can sometimes iterate in one direction and in
the other direction at other times. That's simply not useful behaviour.
I'm not sure what I find more confusing. Ok if it's a deliberate choice
never to change the step direction, but is it deliberate that it's not
an error to have a greater lower bound than upper bound? Or is this just
the way it happened to be implemented?
That's deliberate. I don't really understand how it is confusing.
To draw an analogy, given (low ∈ ℕ) and (high ∈ ℕ),
{ x ∈ ℕ | low ≤ x ∧ x < high }
is just the empty set if low > high. It is not illegal or unusual.
