#package require Thread
#
#set tid [thread::create]
#
#lassign [chan pipe] pr pw
#thread::transfer $tid $pr
#thread::send  $tid [list set pr $pr] 
#thread::send -async $tid {
#        while 1 {
#                puts [list nuts [read $pr]]
#                puts ganga
#                flush stdout
#        }
#}
#chan configure $pw -blocking 0
#puts $pw hello
#flush $pw
#puts [list gunka]
#
#
#
#vwait ::forever
#


proc valid value {
    expr {[llength [regexp -all -inline {\[} $value]] == [
        llength [regexp -all -inline {\]} $value]]}
}

puts [list hey [valid "{()}"]]