punkshell/scriptlib/tests/simplepipe.tcl

proc pipe* args {
    set r [uplevel 1 [lindex $args 0]]
    for {set i 1} {$i < [llength $args]} {incr i} {
        set e [lindex $args $i]
        if {[llength $e] == 1} {
            if {$e eq {>}} {
                incr i
                uplevel 1 [list set [lindex $args $i] $r]
            } else {
                set r [uplevel 1 [list $e $r]]
            }
        } else {
            set cmd {}
            set substdone 0
            foreach arg $e {
                if {$arg eq {*}} {
                    lappend cmd $r
                    set substdone 1
                } else {
                    lappend cmd $arg
                }
            }
            if {$substdone == 0} {
                lappend cmd $r
            }
            set r [uplevel 1 $cmd]
        }
    }
    return $r
}

set s "    supercalifragilisticexpialidocious    "
#set s "    supercalifragilistichespiralitoso    "
pipe*    {string trim $s} {split * {}} {lsort -unique} {join * {}} > s \
        {string length} > l
puts $s
puts $l

#test running of patternmatching pipelines within pipe*
set x [list a b blah etc]
pipe* {set x} {,'a'@0/0= |@0> {puts $data; set data} <| *} {val *}

pipe* {set x} {,'a'@0/0= |@0> {
            puts $data
            set data
        } <| *} {val *}