On Tuesday, 24 May 2016 at 02:40:24 UTC, Observer wrote:
As for utility, if you're a PostScript programmer, where keeping
track of data is done via a stack-oriented model, this
capability
gets used all the time, to bring relevant arguments to the top
of the stack to be operated upon, or to shove arguments deeper
into the stack for later use.
Forth also has "swap" and "rot". The former moves 2nd value to
the top of the stack (i.e. a, b becomes b, a). The latter moves
3rd value to the top (i.e. a, b, c becomes b, c, a).
