Richard Suchenwirth 2002-11-27 - A visitor in the Tcl chatroom asked for a modified foreach to cover all combinations of the input lists. In database technical terms, this is called a "nested list join", at least one functional programming tutorial tells me so.
Well, and reason enough to do some Tcl'ing - from the input, build up a nested command of foreaches, insert the specified body in the middle, and presto:
proc foreach2 args {
set body [lindex $args end]
set cmd ""
foreach {vars list} [lrange $args 0 end-1] {
append cmd "[list foreach $vars $list] \{\n"
append body "\}"
}
uplevel 1 $cmd$body
}#------------------------- Testing:
% foreach2 x {a b} y {c d} {puts x:$x,y:$y}
x:a,y:c
x:a,y:d
x:b,y:c
x:b,y:dNo error-checking yet - the length of args must be odd and >2. Caveat user.