Something
public text v1 · immutableon *:INPUT:*:{
if ($left($1,1) != /) && ($ctrlenter != $true) {
if ($left($1,1) == $eval($,0)) || ($left($1,1) == $eval(%,0)) {
haltdef
msg $active [Eval] ( $+ $1- $+ ) ==> $iif([ [ $1- ] ] == $null,$ $+ null,$iif([ [ $1- ] ] == $false,$ $+ false,$iif([ [ $1- ] ] == $true,$ $+ true,[ [ $1- ] ])))
}
}
}