| 1 | fun cp [] =[] |
| 2 | | cp (x::xs)= x :: cp xs |
| 3 | |
| 4 | (* exormorphic merge *) |
| 5 | fun merge(xs, []):int list = cp xs |
| 6 | | merge([], ys) = cp ys |
| 7 | | merge(l1 as x::xs, l2 as y::ys) = |
| 8 | if x<y then x :: merge(xs, l2) |
| 9 | else y :: merge(l1, ys) |
| 10 | |
| 11 | (* splitting a list *) |
| 12 | fun split(x::y::zs, l, r) = split(zs, x::l, y::r) |
| 13 | | split([x], l, r) = (x::l, r) |
| 14 | | split([], l, r) = (l, r) |
| 15 | |
| 16 | (* exomorphic merge sort *) |
| 17 | fun msort [] = [] |
| 18 | | msort [x] = [x] |
| 19 | | msort xs = let val (l, r) = split(xs, [], []) |
| 20 | in merge(msort l, msort r) |
| 21 | end; |