basic do.. loop

[rafalsk]

why isn't it supported?

[awarm]

do...loop implementation. tnx for https://github.com/ruv

: do postpone begin postpone 2>r ; immediate 
: loop postpone 2r> postpone 1+ postpone 2dup postpone = postpone until postpone 2drop ; immediate
: unloop postpone rdrop postpone rdrop ; immediate
: i postpone r@ ; immediate
: j postpone 2r> postpone i postpone rot postpone rot postpone 2>r ; immediate