Match

// System.Text.Match — System.Core (decompiled from Larva HIR)

import System;

into namespace System.Text
{
	/// A match: where it is, its text, and its groups (an unmatched group gives the empty text).
	public final class Match
	{
		u8[] s;
		i32[] starts;
		i32[] ends;

		public:
			bool Success;
			i32 Index;
			i32 Length;
			str Value;

			/// The text between two positions.
			static Slice(u8[] s, i32 from, i32 to) : str
			{
				u8[] bytes = new u8[to - from];
				Array.Copy(s, from, bytes, 0, to - from);
				return new str(bytes);
			}

			new(u8[] text, i32[] groupStarts, i32[] groupEnds, i32 index, i32 end)
			{
				s = text;
				starts = groupStarts;
				ends = groupEnds;
				Success = index >= 0;
				Index = index;
				Length = Success ? end - index : 0;
				Value = Success ? Slice(text, index, end) : "";
			}

			/// Group `i` (1-based; 0 is the whole match).
			Group(i32 i) : str
			{
				if (i == 0)
					return Value;
				if (i < 0 || i >= starts.Length || starts[i] < 0 || ends[i] < 0)
					return "";
				return Slice(s, starts[i], ends[i]);
			}

			i32 GroupCount
			{
				get => starts.Length - 1;
			}
	}
}