Nim equivilent of Python's slicing with step list[start: end: step]

[hugogranstrom]

I'm trying to get a slice of a seq but I only want every second element. I 
could write a loop that does this but I'm wondering if there is a more elegant 
way of doing it? In Python you can do: 
    
    
    a = [0, 1, 2, 3, 4, 5]
    print(a[::2])
    # Outputs: [0, 2, 4]
    
    
    Run

I know that Arraymancer has this syntax: a[0.._|2] but is there any equivilent 
for normal seqs?