gist.nim

GateKind = enum
  gateNot
  gateAnd
  gateOr
  gateNand
  gateNor
  gateXor

proc raiseValue[T](e: ref Exception): T =
  raise e
  # leave result set to the zero value for T

let kind =
  case kindStr
  of "NOT":  gateNot
  of "AND":  gateAnd
  of "OR":   gateOr
  of "NAND": gateNand
  of "NOR":  gateNor
  of "XOR":  gateXor
  else:
    raiseValue[GateKind] newException(ParseError, "bad kindStr")