bug, array swaping values

[kostya]

./bin/crystal -e 'a = [1,2]; a[0], a[1] = a[1], a[0]; p a'
Syntax error in -:1: Impossible

./bin/crystal -e 'a = [1,2]; t = a[1]; a[1] = a[0]; a[0] = t; p a'
[2, 1]

[asterite]

I also added Array#swap(index0, index1) that should be faster if you care about performance (if that's your bottleneck). This only does two bounds check. The other way:

a[0], a[1] = a[1], a[0]

gets translated to:

temp1 = a[1]
temp2 = a[0]
a[0] = temp1
a[1] = temp2

so that's four bounds check.

[kostya]

thanks, maybe better to call it swap! because it changes array state.

[asterite]

I don't think it makes sense to clone the array and swap the elements. There's also no "pop!" in Ruby and "pop" modifies self, so...