B.xs: rationalise all methods aliased to next()

[perl5.git] / utfebcdic.h

diff --git a/utfebcdic.h b/utfebcdic.h
index 1662103..4a662f6 100644 (file)
--- a/utfebcdic.h
+++ b/utfebcdic.h
@@ -562,8 +562,8 @@ END_EXTERN_C
                      (uv) < 0x400000       ? 5 : \
                      (uv) < 0x4000000      ? 6 : 7 )
 
-
 #define UNI_IS_INVARIANT(c)            ((c) <  0xA0)
+
 /* UTF-EBCDIC semantic macros - transform back into I8 and then compare */
 
 #define UTF8_IS_START(c)               (NATIVE_TO_UTF(c) >= 0xC5 && NATIVE_TO_UTF(c) != 0xE0)
@@ -578,6 +578,19 @@ END_EXTERN_C
 #define UTF_CONTINUATION_MASK          ((U8)0x1f)
 #define UTF_ACCUMULATION_SHIFT         5
 
+/* How wide can a single UTF-8 encoded character become in bytes. */
+/* NOTE: Strictly speaking Perl's UTF-8 should not be called UTF-8 since UTF-8
+ * is an encoding of Unicode, and Unicode's upper limit, 0x10FFFF, can be
+ * expressed with 5 bytes.  However, Perl thinks of UTF-8 as a way to encode
+ * non-negative integers in a binary format, even those above Unicode */
+#define UTF8_MAXBYTES 7
+
+/* The maximum number of UTF-8 bytes a single Unicode character can
+ * uppercase/lowercase/fold into.  Unicode guarantees that the maximum
+ * expansion is 3 characters.  On EBCDIC platforms, the highest Unicode
+ * character occupies 5 bytes, therefore this number is 15 */
+#define UTF8_MAXBYTES_CASE     15
+
 /*
  * Local variables:
  * c-indentation-style: bsd