Alloc.cs

namespace Lex
{
    /*
     * Class: Alloc
     */
    public class Alloc
    {
        /*
         * Function: NewCDfa
         */
        public static Dfa NewDfa(Spec spec)
        {
            Dfa dfa;

            dfa = new Dfa(spec.dfa_states.Count);
            spec.dfa_states.Add(dfa);

            return dfa;
        }

        /*
         * Function: NewNfaPair
         */
        public static NfaPair NewNfaPair()
        {
            NfaPair pair = new NfaPair();
            return pair;
        }

        /*
         * Function: NewNfa
         */
        public static Nfa NewNfa(Spec spec)
        {
            Nfa p;

            /* UNDONE: Buffer this? */
            p = new Nfa();

            /*p.label = spec.nfa_states.size();*/
            spec.nfa_states.Add(p);
            p.SetEdge(Nfa.EPSILON);

            return p;
        }

        /**
         * NewNLPair
         * return a new NfaPair that matches a new line
         * (\r\n?|\n)
         */
        public static NfaPair NewNLPair(Spec spec)
        {
            NfaPair pair = NewNfaPair();
            pair.end = NewNfa(spec);	// newline accepting state
            pair.start = NewNfa(spec);	// new state with two epsilon edges

            Nfa pstart = pair.start;
            pstart.SetNext(NewNfa(spec));

            Nfa pstartnext = pstart.GetNext();
            pstartnext.SetEdge(Nfa.CCL);
            pstartnext.SetCharSet(new CharSet());
            pstartnext.GetCharSet().add('\n');
            pstartnext.SetNext(pair.end); // accept '\n'

            pstart.SetSib(NewNfa(spec));
            Nfa pstartsib = pstart.GetSib();
            pstartsib.SetEdge('\r');

            pstartsib.SetNext(NewNfa(spec));
            Nfa pstartsibnext = pstartsib.GetNext();
            pstartsibnext.SetNext(null); // do NOT accept just '\r'

            pstartsibnext.SetSib(NewNfa(spec));
            pstartsibnext.GetSib().SetEdge('\n');
            pstartsibnext.GetSib().SetNext(pair.end); // accept '\r\n'

            return pair;
        }
    }
}