Re: [Help-smalltalk] #flatten for seq-collections, #join: for collection classes

[Paolo Bonzini]

> Because of the convenience of {}-syntax, flatten is also useful as a
> more efficient concatenation operator than #','.  In fact, this is what
> I intended it for.

Very cool!  However, what about just calling #join also the 
instance-side #flatten, and omitting the instance-side #flatten: (which 
is simpler to do with a class-side #join:)?

#flatten is more for something like

  #((1 2) 3 (4 5)) => 1 2 3 4 5

This can be done by adding a #flattenInto: method that does "add: self" 
or "self do: [ :each | each flattenInto: dest ]" (the latter for 
collections and streams).

As a nitpick, #inject:into: is slow -- streams might be faster -- and 
#fold: is nicer anyway for the size computation.

And after Lisp, Smalltalk mimics APL too! :-P

Thanks,

Paolo