klex/src/NFAState.i3


 Copyright (c) 2000 California Institute of Technology 
 All rights reserved. See the file COPYRIGHT for a full description. 
 $Id: NFAState.i3.html,v 1.3 2010-04-29 17:18:49 wagner Exp $ 

INTERFACE NFAState;
IMPORT NFA;
IMPORT Word;
CONST
  Brand = "NFAState";
TYPE
  T <: REFANY;
An NFAState.T represents a collection of NFANode.T's which are the nodes occupied after an input sequence
 Targets = REF ARRAY CHAR OF T; 

Don't forget to call NFA.AssignIDs(a) before calling New

PROCEDURE New(a: NFA.T): T;           (* the start state *)

PROCEDURE Step(s: T; key: CHAR; VAR keyEnd: CHAR): T;
  (* copy and advance to the next state.
     same results will apply up to key=keyEnd. *)
PROCEDURE Steps(s: T): Targets; (* low-performance version of Step. Some elements in the returned array can be NIL, signifying Dead
*)

PROCEDURE Dead(s: T): BOOLEAN; (* Are there no more transitions to be made? *)
PROCEDURE Output(s: T): INTEGER;  (* lowest output from last step, or
                                  0 if none *)

PROCEDURE Equal(s, t: T): BOOLEAN;
PROCEDURE Hash(s: T): Word.T;

PROCEDURE Test(a: NFA.T);
PROCEDURE Format(s: T): TEXT;

END NFAState.