if 0 {[Richard Suchenwirth] 2004-01-13 - In [RPN in Tcl] I've played a bit with emulating [Forth] in Tcl. Here is a much shorter take that defines a single ''rpn'' proc, which takes a body in Reverse Polish Notation, and the rest of the arguments as the initial stack. The words in the body are executed from left to right, either as Forth-like stack operations, or as a Tcl command which has to have one argument (popped from stack) and whose result is pushed on the stack.} proc rpn {body args} { foreach word $body { switch -- $word { drop {pop args} dup {push args [lindex $args end]} swap {set 1 [pop args] set 2 [pop args] push args $1 $2 } default {push args [$word [pop args]]} } } set args } # Simple stack routines: interp alias {} push {} lappend proc pop stackName { upvar 1 $stackName stack K [lindex $stack end] [set stack [lrange $stack 0 end-1]] } # ..and the indispensable [K] combinator: proc K {a b} {set a} # This test will display the source file on stdout: puts [rpn {open dup read swap close drop} rpn.tcl] ''Wow, Richard, what a delightful wizzlet! -[jcw]'' ---- [Arts and crafts of Tcl-Tk programming]