In TCL, zip functionality is built into the foreach loop. foreach x $list1 y $list2 { lappend result [Myfunc $x $y] } To directly return a

In TCL, zip functionality is built into the foreach loop. foreach x $list1 y $list2 { lappend result [Myfunc $x $y] } To directly return a list of outputs without having to append to a list, TCL also provides lmap which works the same way: lmap x $list1 y $list2 {Myfunc $x $y} But wait there's more! Foreach and lmap also support taking more than one element from the list each time: lmap {x y} $list1 {Myfunc $x $y}