Beispiel #1
0
        public FA ToFA(int match)
        {
            Ast ast = this;

            if (ast.IsLazy)
            {
                throw new NotSupportedException("The AST node cannot be lazy");
            }
            switch (ast.Kind)
            {
            case Ast.Alt:
                return(FA.Or(_ToFAs(ast.Exprs, match), match));

            case Ast.Cat:
                if (1 == ast.Exprs.Length)
                {
                    return(ast.Exprs[0].ToFA(match));
                }
                return(FA.Concat(_ToFAs(ast.Exprs, match), match));

            case Ast.Dot:
                return(FA.Set(new int[] { 0, 0xd7ff, 0xe000, 0x10ffff }, match));

            case Ast.Lit:
                return(FA.Literal(new int[] { ast.Value }, match));

            case Ast.NSet:
                var pairs = RangeUtility.ToPairs(ast.Ranges);
                RangeUtility.NormalizeRangeList(pairs);
                var pairl = new List <KeyValuePair <int, int> >(RangeUtility.NotRanges(pairs));
                return(FA.Set(RangeUtility.FromPairs(pairl), match));

            case Ast.NUCode:
                pairs = RangeUtility.ToPairs(CharacterClasses.UnicodeCategories[ast.Value]);
                RangeUtility.NormalizeRangeList(pairs);
                pairl = new List <KeyValuePair <int, int> >(RangeUtility.NotRanges(pairs));
                return(FA.Set(RangeUtility.FromPairs(pairl), match));

            case Ast.Opt:
                return(FA.Optional(ast.Exprs[0].ToFA(match), match));

            case Ast.Plus:
                return(FA.Repeat(ast.Exprs[0].ToFA(match), 1, 0, match));

            case Ast.Rep:
                return(FA.Repeat(ast.Exprs[0].ToFA(match), ast.Min, ast.Max, match));

            case Ast.Set:
                return(FA.Set(ast.Ranges, match));

            case Ast.Star:
                return(FA.Repeat(ast.Exprs[0].ToFA(match), 0, 0, match));

            case Ast.UCode:
                return(FA.Set(CharacterClasses.UnicodeCategories[ast.Value], match));

            default:
                throw new NotImplementedException();
            }
        }
Beispiel #2
0
        static int[] _GetFirsts(int[][] part, int index)
        {
            if (part.Length <= index)
            {
                return(new int[0]);
            }
            int        idx;
            List <int> resl;

            int[] result;
            var   pc = part[index];

            switch (pc[0])
            {
            case Char:
                return(new int[] { pc[1], pc[1] });

            case Set:
                result = new int[pc.Length - 1];
                Array.Copy(pc, 1, result, 0, result.Length);
                return(result);

            case NSet:
                result = new int[pc.Length - 1];
                Array.Copy(pc, 1, result, 0, result.Length);
                return(RangeUtility.FromPairs(new List <KeyValuePair <int, int> >(RangeUtility.NotRanges(RangeUtility.ToPairs(result)))));

            case Any:
                return(new int[] { 0, 0x10ffff });

            case UCode:
                result = CharacterClasses.UnicodeCategories[pc[1]];
                return(result);

            case NUCode:
                result = CharacterClasses.UnicodeCategories[pc[1]];
                Array.Copy(pc, 1, result, 0, result.Length);
                return(RangeUtility.FromPairs(new List <KeyValuePair <int, int> >(RangeUtility.NotRanges(RangeUtility.ToPairs(result)))));

            case Switch:
                resl = new List <int>();
                idx  = 1;
                while (pc.Length > idx && -2 != pc[idx])
                {
                    if (-1 == pc[idx])
                    {
                        idx += 2;
                        continue;
                    }
                    resl.Add(pc[idx]);
                }
                if (pc.Length > idx && -2 == pc[idx])
                {
                    ++idx;
                    while (pc.Length > idx)
                    {
                        resl.AddRange(_GetFirsts(part, pc[idx]));
                        ++idx;
                    }
                }
                return(resl.ToArray());

            case Jmp:
                resl = new List <int>();
                idx  = 1;
                while (pc.Length > idx)
                {
                    resl.AddRange(_GetFirsts(part, pc[idx]));
                    ++idx;
                }
                return(resl.ToArray());

            case Match:
                return(new int[0]);

            case Save:
                return(_GetFirsts(part, index + 1));
            }
            // should never get here
            throw new NotImplementedException();
        }