CharSet.cs

namespace Lex
{
    /*
     * Class: CharSet
     */
    using System;
    using System.Collections;
    using BitSet;

    public class CharSet
    {
        /*
         * Member Variables
         */
        private BitSet set;
        private bool compflag;

        /*
         * Function: CharSet
         */
        public CharSet()
        {
            set = new BitSet();
            compflag = false;
        }

        /*
         * Function: complement
         */
        public void complement()
        {
            compflag = true;
        }

        /*
         * Function: add
         */
        public void add(int i)
        {
            if (i == 0)
                Console.WriteLine("i = 0");
            set.Set(i, true);
        }

        /*
         * Function: addncase
         * Description: add, ignoring case.
         */
        public void addncase(char c)
        {
            /* Do this in a Unicode-friendly way. */
            /* (note that duplicate adds have no effect) */
            add(c);
            add(Char.ToLower(c));
            add(Char.ToUpper(c));
        }

        /*
         * Function: contains
         */
        public bool contains(int i)
        {
            bool result;

            result = set.Get(i);
            if (compflag)
                return (false == result);
            return result;
        }

        /*
         * Function: mimic
         */
        public void mimic(CharSet s)
        {
            compflag = s.compflag;
            set = new BitSet(s.set);
        }

        public IEnumerator GetEnumerator() { return set.GetEnumerator(); }

        /*
         * Map set using character classes
         */
        public void map(CharSet old, int[] mapping)
        {
            compflag = old.compflag;
            set = new BitSet();

            foreach (int index in old)
            {
                if (index < mapping.Length) // skip unmapped chars
                {
                    int pos = mapping[index];
                    set.Set(pos, true);
                }
            }
        }

    }
}