chess-puzzles

commit d30b443f23a15ffab12f6a00931d979b9cfab061
parent 07c37ef3931e33b55aebe2561ed92d37735cabe8
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Sun,  9 Mar 2025 10:46:12 +0100

do not use ctype functions

These can be locale-specific on some platforms.

Diffstat:
M
fen.c
 | 
23
++++++++++++++---------

1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/fen.c b/fen.c
@@ -1,4 +1,3 @@
-#include <ctype.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -11,6 +10,12 @@
 
 #define LEN(s)    (sizeof(s)/sizeof(*s))
 
+/* ctype-like macros, but always compatible with ASCII / UTF-8 */
+#define ISDIGIT(c) (((unsigned)c) - '0' < 10)
+#define ISXDIGIT(c) ((((unsigned)c) - '0' < 10) || ((unsigned)c | 32) - 'a' < 6)
+#define TOLOWER(c) ((((unsigned)c) - 'A' < 26) ? ((c) | 32) : (c))
+#define TOUPPER(c) ((((unsigned)c) - 'a' < 26) ? ((c) & 0x5f) : (c))
+
 /* macro for truecolor RGB output to tty */
 #define SETFGCOLOR(r,g,b)    printf("\x1b[38;2;%d;%d;%dm", r, g, b)
 #define SETBGCOLOR(r,g,b)    printf("\x1b[48;2;%d;%d;%dm", r, g, b)
@@ -238,7 +243,7 @@ speak(const char *fmt, ...)
 int
 pgnpiece(int piece)
 {
-	piece = toupper(piece);
+	piece = TOUPPER(piece);
 
 	/* no mapping */
 	if (!pgn_piecemapping[0])
@@ -554,7 +559,7 @@ output_tty(struct board *b)
 					fputs("\x1b[30m", stdout); /* black */
 				/* workaround: use black unicode chess symbol, because
 				   the color is filled and better visible */
-				showpiece_tty(tolower(piece));
+				showpiece_tty(TOLOWER(piece));
 			} else {
 				fputs(" ", stdout);
 			}
@@ -1027,7 +1032,7 @@ board_setup_fen(struct board *b, const char *fen)
 			if (l >= 0 && l < 32767) {
 				b->halfmove = l;
 
-				for (; *s && isdigit((unsigned char)*s); s++)
+				for (; *s && ISDIGIT((unsigned char)*s); s++)
 					;
 			}
 			break;
@@ -1038,7 +1043,7 @@ board_setup_fen(struct board *b, const char *fen)
 			l = strtol(s, NULL, 10);
 			if (l >= 0 && l < 32767) {
 				b->movenumber = (int)l;
-				for (; *s && isdigit((unsigned char)*s); s++)
+				for (; *s && ISDIGIT((unsigned char)*s); s++)
 					;
 			}
 			break;
@@ -1162,9 +1167,9 @@ board_playmoves(struct board *b, const char *moves)
 		/* is a valid piece? should be queen, rook, bishop, knight (not validated exactly) */
 		if (isvalidpiece(*s)) {
 			if (side == 'w')
-				promote = toupper(*s);
+				promote = TOUPPER(*s);
 			else
-				promote = tolower(*s);
+				promote = TOLOWER(*s);
 			s++;
 		}
 
@@ -1450,8 +1455,8 @@ decodeparam(char *buf, size_t bufsiz, const char *s)
 		case '%':
 			if (i + 3 >= bufsiz)
 				return -1;
-			if (!isxdigit((unsigned char)*(s+1)) ||
-			    !isxdigit((unsigned char)*(s+2)))
+			if (!ISXDIGIT((unsigned char)*(s+1)) ||
+			    !ISXDIGIT((unsigned char)*(s+2)))
 				return -1;
 			buf[i++] = hexdigit(*(s+1)) * 16 + hexdigit(*(s+2));
 			s += 2;