use baserune routines

Reference: /n/sources/patch/applied/rune7-dict
Date: Thu Apr 25 01:01:51 CES 2013
Signed-off-by: geoff@plan9.bell-labs.com

--- /sys/src/cmd/dict/utils.c	Thu Apr 25 01:01:42 2013
+++ /sys/src/cmd/dict/utils.c	Thu Apr 25 01:01:42 2013
@@ -230,34 +230,6 @@
 [MES-MULTI]	L"  ",
 };
 
-#define	risupper(r)	(L'A' <= (r) && (r) <= L'Z')
-#define	rislatin1(r)	(0xC0 <= (r) && (r) <= 0xFF)
-#define	rtolower(r)	((r)-'A'+'a')
-
-static Rune latin_fold_tab[] =
-{
-/*	Table to fold latin 1 characters to ASCII equivalents
-			based at Rune value 0xc0
-
-	 À    Á    Â    Ã    Ä    Å    Æ    Ç
-	 È    É    Ê    Ë    Ì    Í    Î    Ï
-	 Ð    Ñ    Ò    Ó    Ô    Õ    Ö    ×
-	 Ø    Ù    Ú    Û    Ü    Ý    Þ    ß
-	 à    á    â    ã    ä    å    æ    ç
-	 è    é    ê    ë    ì    í    î    ï
-	 ð    ñ    ò    ó    ô    õ    ö    ÷
-	 ø    ù    ú    û    ü    ý    þ    ÿ
-*/
-	'a', 'a', 'a', 'a', 'a', 'a', 'a', 'c',
-	'e', 'e', 'e', 'e', 'i', 'i', 'i', 'i',
-	'd', 'n', 'o', 'o', 'o', 'o', 'o',  0 ,
-	'o', 'u', 'u', 'u', 'u', 'y',  0 ,  0 ,
-	'a', 'a', 'a', 'a', 'a', 'a', 'a', 'c',
-	'e', 'e', 'e', 'e', 'i', 'i', 'i', 'i',
-	'd', 'n', 'o', 'o', 'o', 'o', 'o',  0 ,
-	'o', 'u', 'u', 'u', 'u', 'y',  0 , 'y',
-};
-
 static Rune 	*ttabstack[20];
 static int	ntt;
 
@@ -426,7 +398,7 @@
 /*
  * Fold the runes in null-terminated rp.
  * Use the sort(1) definition of folding (uppercase to lowercase,
- * latin1-accented characters to corresponding unaccented chars)
+ * accented characters to corresponding unaccented chars)
  */
 void
 fold(Rune *rp)
@@ -434,10 +406,9 @@
 	Rune r;
 
 	while((r = *rp) != 0) {
-		if (rislatin1(r) && latin_fold_tab[r-0xc0])
-				r = latin_fold_tab[r-0xc0];
-		if(risupper(r))
-			r = rtolower(r);
+		r = tobaserune(r);
+		if(isupperrune(r))
+			r = tolowerrune(r);
 		*rp++ = r;
 	}
 }
@@ -455,10 +426,9 @@
 
 	while(*old) {
 		old += chartorune(&r, old);
-		if (rislatin1(r) && latin_fold_tab[r-0xc0])
-				r = latin_fold_tab[r-0xc0];
-		if(risupper(r))
-			r = rtolower(r);
+		r = tobaserune(r);
+		if(isupperrune(r))
+			r = tolowerrune(r);
 		new += runetochar(new, &r);
 	}
 	*new = 0;