$ieif ($iif with elseif)

; Untested
; Returns the value (V) following the FIRST true conditional (C).
; If no conditionals are true, returns final parameter (E) if $0 is odd, else $null
; Syntax: $ieif(C1,V1[,C2,V2,C3,...][,E])
/*
Examples: {

  $ieif(3 == 1,x,3 == 2,y,3 == 3,z) = z

  $ieif(3 == 3,x,2 == 2,y) = x

  $ieif(3 == 1,x,3 == 2,y,z) = z

  $ieif(3 == 1,x,3 == 2,y) = $null

}
*/
alias ieif {
  var %c 1, %v 2
  while (%v <= $0) {
    if ( [ $ [ $+ %c ] ] ) return [ $ [ $+ %v ] ]
    inc %c 2
    inc %v 2
  }
  elseif ($0 \\ 2) return [ $ [ $+ $0 ] ]
  else return
}