/* * Nfa2Dfa * */ function StateCmp(a, b) { if (a.id == b.id) { return true } return false } function NfaStackCmp(x, y) { var ret = true; if (x.length != y.length) { return false } for (var i=0; i < x.length; i++) { ret = ret && StateCmp(x.get(i), y.get(i)); } return ret; } function Nfa2Dfa(nfa) { this.startState = nfa.getStartState(); this.acceptingState = nfa.getAcceptingState(); } Nfa2Dfa.prototype.getStartState = function() { return this.startState } Nfa2Dfa.prototype.getAcceptingState = function() { return this.acceptingState } ttable = new Object(); Nfa2Dfa.prototype.do = function() { var dfaStates = new Stack(); var q = new Stack(); q.push(this.getStartState()); var p = this.epsclosure(q) var q = p.copy(); dfaStates.push(p); document.write('S '+p.str()+'
'); var done = new Array(); //var ttable = new Object(); var ds = null; var j = 0; while (!dfaStates.isEmpty()) { ds = dfaStates.pop(); for (var i = 0; i < ALPHABET.length; i++) { a = ALPHABET.substring(i, i+1); var ds2 = ds.copy(); x = this.epsclosure(this.move(a, ds)); ds = ds2; var adone = false; for (var w=0; w < done.length; w++) { if(NfaStackCmp(done[w], x)) { adone = true; break; } } var q = ds.str().replace(/ /g, '_'); var qq = x.str().replace(/ /g, '_'); if (!ttable[q]) { ttable[q] = new Object(); if(q.split('_').indexOf(''+this.getAcceptingState().id) >= 0) { ttable[q].isFinal = true; } else { ttable[q].isFinal = false; } } ttable[q][a] = qq; if (x.length > 0 && !adone) { for (var h=0; h < j; h++) { document.write("\t"); } document.write(a+' '+x.str()+'
'); dfaStates.push(x); } } done.push(ds); j++; } } Nfa2Dfa.prototype.epsclosure = function(q) { var s = null; var t = null; var p = new Stack(); while(!q.isEmpty()) { s = q.pop(); p.push(s); if(s.symbol == EPSILON) { for (var i = 0; i < 2; i++) { t = s.getFollowUp(i); if (t!=null) { q.push(t); } } } } return p; } Nfa2Dfa.prototype.move = function(str, p) { var s = null; var q = new Stack(); while(!p.isEmpty()) { s = p.pop(); s.mark(false); if (s.symbol == str) { s.getFollowUp(0).mark(true); q.push(s.getFollowUp(0)); } } return q; } /* * DfaStates * */ function DfaState(nfaStates) { this.nfaStates = nfaStates; this.marked = false; } DfaState.prototype.compare = function(b) { } DfaState.prototype.str = function() { res = ''; for (var i=0; i < this.nfaStates.length; i++) { res += this.nfaStates[i].id + ' ' } return res }