chess-puzzles

commit 2f8f9b16e1834cdd577d590efc51be17f3013585
parent 752c96801f72527cf5bc3faab7ad7d1d7889ddbf
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Thu, 21 Dec 2023 18:27:41 +0100

fen.c: code cleanup: separate parsing FEN and moves in 2 functions

Diffstat:
M
TODO
 | 
5
++---
M
fen.c
 | 
148
++++++++++++++++++++++++++++++++++++++++++++-----------------------------------

2 files changed, 85 insertions(+), 68 deletions(-)
diff --git a/TODO b/TODO
@@ -1,6 +1,5 @@
-- code cleanup:
-  - separate parsefen() function.
-  - separate parsemoves() function.
+- stream_lichess.sh: lichess API: read FEN of start position, for chess 960
+chess variant.
 
 - option for output for annotating moves in a human-like way (for screenreaders/espeak).
 https://en.wikipedia.org/wiki/Portable_Game_Notation
diff --git a/fen.c b/fen.c
@@ -444,63 +444,14 @@ showboard_ascii(void)
 }
 
 void
-usage(char *argv0)
-{
-	fprintf(stderr, "usage: %s [-cCfF] [-o ascii|fen|svg|tty] [FEN] [moves]\n", argv0);
-	exit(1);
-}
-
-int
-main(int argc, char *argv[])
+parsefen(const char *fen)
 {
-	const char *fen, *moves, *s, *output = "svg";
-	int x, y, x2, y2, field, piece, takepiece;
-	int i, j;
 	char square[3];
+	const char *s;
 	long l;
+	int x, y, field;
 
-#ifdef __OpenBSD__
-	if (pledge("stdio", NULL) == -1)
-		err(1, "pledge");
-#endif
-
-	fen = "startpos";
-	moves = "";
-
-	for (i = 1; i < argc; i++) {
-		if (argv[i][0] != '-')
-			break;
-
-		for (j = 1; argv[i][j]; j++) {
-			switch (argv[i][j]) {
-			case 'c': showcoords = 1; break;
-			case 'C': showcoords = 0; break;
-			case 'f': flipboard = 1; break;
-			case 'F': flipboard = 0; break;
-			case 'o':
-				if (i + 1 >= argc)
-					usage(argv[0]);
-				output = argv[++i];
-				goto next;
-			default:
-				usage(argv[0]);
-				break;
-			}
-		}
-next:
-	;
-	}
-	if (i < argc) {
-		fen = argv[i];
-		i++;
-	}
-	if (i < argc) {
-		moves = argv[i];
-		i++;
-	}
-
-	if (!strcmp(fen, "startpos"))
-		fen = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
+	square[2] = '\0';
 
 	/* initial board state, FEN format */
 	x = y = field = 0;
@@ -547,7 +498,6 @@ next:
 				*(s + 1) >= '1' && *(s + 1) <= '6') {
 				square[0] = *s;
 				square[1] = *(s + 1);
-				square[2] = '\0';
 				squaretoxy(square, &x, &y);
 
 				enpassantsquare[0] = x;
@@ -589,6 +539,14 @@ next:
 			continue;
 		}
 	}
+}
+
+void
+parsemoves(const char *moves)
+{
+	char square[3];
+	const char *s;
+	int i, x, y, x2, y2, piece, takepiece;
 
 	/* process moves */
 	square[2] = '\0';
@@ -634,10 +592,10 @@ next:
 					place(0, x2, y2); /* clear rook square */
 				} else if (x2 <= x - 2) { /* moved more than 1 square */
 					/* white: queenside castling: "e1c1" */
-					for (j = x2 - 1; j > 0; j--) {
-						if (getpiece(j, y2) == 'R') {
+					for (i = x2 - 1; i > 0; i--) {
+						if (getpiece(i, y2) == 'R') {
 							place('R', x2 + 1, y2); /* next to king */
-							place(0, j, y2); /* clear rook square */
+							place(0, i, y2); /* clear rook square */
 							break;
 						}
 					}
@@ -664,21 +622,21 @@ next:
 			} else if (piece == 'k') {
 				black_can_castle[0] = black_can_castle[1] = 0;
 			} else if (piece == 'R' && y == 7) {
-				for (j = 0; j < 7; j++) {
-					if (getpiece(j, y) == 'K') {
-						if (j < x)
+				for (i = 0; i < 7; i++) {
+					if (getpiece(i, y) == 'K') {
+						if (i < x)
 							white_can_castle[0] = 0;
-						else if (j > x)
+						else if (i > x)
 							white_can_castle[1] = 0;
 						break;
 					}
 				}
 			} else if (piece == 'r' && y == 0) {
-				for (j = 0; j < 7; j++) {
-					if (getpiece(j, y) == 'k') {
-						if (j > x)
+				for (i = 0; i < 7; i++) {
+					if (getpiece(i, y) == 'k') {
+						if (i > x)
 							black_can_castle[1] = 0;
-						else if (j < x)
+						else if (i < x)
 							black_can_castle[0] = 0;
 						break;
 					}
@@ -728,6 +686,66 @@ next:
 
 	/* highlight last move */
 	highlightmove(x, y, x2, y2);
+}
+
+void
+usage(char *argv0)
+{
+	fprintf(stderr, "usage: %s [-cCfF] [-o ascii|fen|svg|tty] [FEN] [moves]\n", argv0);
+	exit(1);
+}
+
+int
+main(int argc, char *argv[])
+{
+	const char *fen, *moves, *output = "svg";
+	int i, j;
+
+#ifdef __OpenBSD__
+	if (pledge("stdio", NULL) == -1)
+		err(1, "pledge");
+#endif
+
+	fen = "startpos";
+	moves = "";
+
+	for (i = 1; i < argc; i++) {
+		if (argv[i][0] != '-')
+			break;
+
+		for (j = 1; argv[i][j]; j++) {
+			switch (argv[i][j]) {
+			case 'c': showcoords = 1; break;
+			case 'C': showcoords = 0; break;
+			case 'f': flipboard = 1; break;
+			case 'F': flipboard = 0; break;
+			case 'o':
+				if (i + 1 >= argc)
+					usage(argv[0]);
+				output = argv[++i];
+				goto next;
+			default:
+				usage(argv[0]);
+				break;
+			}
+		}
+next:
+	;
+	}
+	if (i < argc) {
+		fen = argv[i];
+		i++;
+	}
+	if (i < argc) {
+		moves = argv[i];
+		i++;
+	}
+
+	if (!strcmp(fen, "startpos"))
+		fen = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
+
+	parsefen(fen);
+	parsemoves(moves);
 
 	if (!strcmp(output, "ascii"))
 		showboard_ascii();