progs/display/thompson2.scala
changeset 489 e28d7a327870
parent 488 598741d39d21
equal deleted inserted replaced
488:598741d39d21 489:e28d7a327870
    22        enfa2.fins)
    22        enfa2.fins)
    23 }
    23 }
    24 
    24 
    25 // alternative of two NFAs
    25 // alternative of two NFAs
    26 def NFA_ALT(enfa1: NFAt, enfa2: NFAt) : NFAt = {
    26 def NFA_ALT(enfa1: NFAt, enfa2: NFAt) : NFAt = {
    27   val Q = TState()
    27   val new_delta : NFAtrans = { 
    28   val new_delta : eNFAtrans = 
    28     case (q, c) => applyOrElse(enfa1.delta, (q, c)) | 
    29     { case (Q, None) => enfa1.starts | enfa2.starts }
    29                    applyOrElse(enfa2.delta, (q, c)) }
    30   val new_fins = (q: TState) => enfa1.fins(q) || enfa2.fins(q)
    30   val new_fins = (q: TState) => enfa1.fins(q) || enfa2.fins(q)
    31 
    31 
    32   eNFA(Set(Q), new_delta +++ enfa1.delta +++ enfa2.delta, 
    32   NFA(enfa1.starts | enfa2.starts, new_delta, new_fins)
    33        new_fins)
       
    34 }
    33 }
    35 
    34 
    36 // star of a NFA
    35 // star of a NFA
    37 def NFA_STAR(enfa: NFAt) : NFAt = {
    36 def NFA_STAR(enfa: NFAt) : NFAt = {
    38   val Q = TState()
    37   val Q = TState()