12/05/03 14:24:19.11
>>655 を Squeak Smalltalk で書いてみた。バグもそのまま。
perm := [:xs |
xs ifEmpty: [#(())] ifNotEmpty: [
xs gather: [:x | (perm value: (xs copyWithout: x)) collect: [:ys | {x}, ys]]]].
perm value: #(1 2 3) "=> #((1 2 3) (1 3 2) (2 1 3) (2 3 1) (3 1 2) (3 2 1)) "