I don't know why you'd need to make a copy inside the block but this works: | m p | m := #(1 2 3). p := Bag new. m permutationsDo: [:each | Transcript show: each ; cr. p add: each copy. Transcript show: p ; cr. ]. Transcript show: '------'; cr. p do: [:each| Transcript show: each; cr] The Transcript shows: #(1 2 3) a Bag(#(1 2 3)) #(1 3 2) a Bag(#(1 2 3) #(1 3 2)) #(2 1 3) a Bag(#(1 2 3) #(1 3 2) #(2 1 3)) #(2 3 1) a Bag(#(2 3 1) #(1 2 3) #(1 3 2) #(2 1 3)) #(3 2 1) a Bag(#(2 3 1) #(1 2 3) #(1 3 2) #(2 1 3) #(3 2 1)) #(3 1 2) a Bag(#(2 3 1) #(1 2 3) #(1 3 2) #(2 1 3) #(3 2 1) #(3 1 2)) ------ #(2 3 1) #(1 2 3) #(1 3 2) #(2 1 3) #(3 2 1) #(3 1 2) On 10/01/2012 10:14 AM, Ginny Hendry wrote:

I would like to get a collection of permutations of another collection but I can't make it work.

This ends up incorrectly with the same element many times in Bag p:

| m p | m := #(1 2 3). p := Bag new. m permutationsDo: [:each | Transcript show: each ; cr. p add: each. Transcript show: p ; cr. ]. Transcript show: '------'; cr. p do: [:each| Transcript show: each; cr]

But this very similar code ends up correctly with different elements in Bag p:

| m p | m := #(1 2 3). p := Bag new. m do: [:each | Transcript show: each ; cr. p add: each. Transcript show: p ; cr. ]. Transcript show: '------'; cr. p do: [:each| Transcript show: each; cr]

Any ideas about what am I doing wrong? How can I get a collection of permutations?

Working in Pharo 1.4 one-click for Mac OSX.

Thanks.

-Ginny