All looping is done via foreach statements, which have two forms. One is:
foreach var in exp do block end
Where exp has type t list, block is executed for each of exp's elements, binding var to each of them in order from first to last.
There is also a shortcut integer iteration form:
for var in fromExp .. toExp do block end
fromExp and toExp must have type int. block is evaluated with var bound in sequence to each integer in the range defined by fromExp and toExp.