Парсер FEN на Си

[codedot]

А не распарсить ли мне FEN на Сях, раз такая пьянка? Распаршу:

#include <assert.h>
#include <ctype.h>
#include <stdio.h>

#define RANK "%8[12345678PNBRQKpnbrqk]"
#define ENPASS "%2[abcdefgh12345678-]"
#define FEN \
	RANK "/" RANK "/" RANK "/" RANK "/" \
	RANK "/" RANK "/" RANK "/" RANK " " \
	"%1[wb] %4[KQkq-] " ENPASS " %*2d %*d\n"
#define RANKS(board) \
	(board)[7], (board)[6], (board)[5], (board)[4], \
	(board)[3], (board)[2], (board)[1], (board)[0]

static fen()
{
	struct {
		char board[8][9];
		int enpassi, enpassj;
		enum {
			WHITE, BLACK
		} act;
		struct {
			int cshort, clong;
		} white, black;
	} pos;
	char buf[8][9], act[2], cast[5], enpass[3];
	int n, i, j;

	n = scanf(FEN, RANKS(buf), act, cast, enpass);

	assert(11 == n);
	pos.act = ('w' == act[0]) ? WHITE : BLACK;
	pos.enpassi = enpass[1] - '1';
	pos.enpassj = enpass[0] - 'a';
	pos.white.cshort = ('K' == cast[0]);
	pos.white.clong = ('Q' == cast[1]);
	pos.black.cshort = ('k' == cast[2]);
	pos.black.clong = ('q' == cast[3]);

	for (i = 0; i < 8; i++) {
		const char *src = buf[i];
		char *dst = pos.board[i];
		int sq = 0;

		for (j = 0; j < 8; j++) {
			char piece = src[j];

			if (!piece) {
				assert(8 == sq);
				break;
			} else if (isdigit(piece)) {
				int skip = piece - '0';

				while (skip) {
					assert(sq < 8);
					dst[sq] = '.';
					++sq;
					--skip;
				}
			} else {
				assert(sq < 8);
				dst[sq] = src[j];
				++sq;
			}
		}
	}

	for (i = 7; i > -1; i--)
		printf("%.8s\n", pos.board[i]);
	printf("%s's move\n", pos.act ? "Black" : "White");

	return 0;
}

main()
{
	while (!feof(stdin))
		fen();

	return 0;
}