utf8.h, utfebcdic.h: Use mnemonic constant

The magic number 13 is used in various places on ASCII platforms, and
7 correspondingly on EBCDIC.  This moves the #defines for what these
represent to early in their files, and uses the symbolic name
thereafter.

2 files changed, 24 insertions, 23 deletions

diff --git a/utf8.h b/utf8.h
index ef11af9330..bc6e0025ab 100644
--- a/utf8.h
+++ b/utf8.h
@@ -97,6 +97,13 @@ than just the ASCII characters, so C<is_invariant_string> is preferred.
 #else	/* ! EBCDIC */
 START_EXTERN_C
 
+/* 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 4 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 13
+
 #ifdef DOINIT
 EXTCONST unsigned char PL_utf8skip[] = {
 /* 0x00 */ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* ascii */
@@ -119,7 +126,7 @@ EXTCONST unsigned char PL_utf8skip[] = {
            /* Perl extended (never was official UTF-8).  Up to 36 bit */
 /* 0xFE */                             7,
            /* More extended, Up to 72 bits (64-bit + reserved) */
-/* 0xFF */                               13
+/* 0xFF */                               UTF8_MAXBYTES
 };
 #else
 EXTCONST unsigned char PL_utf8skip[];
@@ -264,7 +271,7 @@ Perl's extended UTF-8 means we can have start bytes up to FF.
 		      (uv) < 0x200000       ? 4 : \
 		      (uv) < 0x4000000      ? 5 : \
 		      (uv) < 0x80000000     ? 6 : \
-                      (uv) < UTF8_QUAD_MAX ? 7 : 13 )
+                      (uv) < UTF8_QUAD_MAX ? 7 : UTF8_MAXBYTES )
 #else
 /* No, I'm not even going to *TRY* putting #ifdef inside a #define */
 #define OFFUNISKIP(uv) ( (uv) < 0x80        ? 1 : \
@@ -275,13 +282,6 @@ Perl's extended UTF-8 means we can have start bytes up to FF.
 		      (uv) < 0x80000000     ? 6 : 7 )
 #endif
 
-/* 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 4 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 13
-
 /* 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 ASCIIish platforms, the highest Unicode
diff --git a/utfebcdic.h b/utfebcdic.h
index 5912b3a142..1e4dc7c26a 100644
--- a/utfebcdic.h
+++ b/utfebcdic.h
@@ -145,6 +145,13 @@ END_EXTERN_C
 #define NATIVE_TO_UNI(ch)    (FITS_IN_8_BITS(ch) ? NATIVE_TO_LATIN1(ch) : (ch))
 #define UNI_TO_NATIVE(ch)    (FITS_IN_8_BITS(ch) ? LATIN1_TO_NATIVE(ch) : (ch))
 
+/* 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 following table is adapted from tr16, it shows I8 encoding of Unicode code points.
 
@@ -164,12 +171,13 @@ END_EXTERN_C
  */
 
 /* Input is a true Unicode (not-native) code point */
-#define OFFUNISKIP(uv) ( (uv) < 0xA0        ? 1 : \
-		         (uv) < 0x400       ? 2 : \
-		         (uv) < 0x4000      ? 3 : \
-		         (uv) < 0x40000     ? 4 : \
-		         (uv) < 0x400000    ? 5 : \
-		         (uv) < 0x4000000   ? 6 : 7 )
+#define OFFUNISKIP(uv) ( (uv) < 0xA0        ? 1 :                   \
+		         (uv) < 0x400       ? 2 :                   \
+		         (uv) < 0x4000      ? 3 :                   \
+		         (uv) < 0x40000     ? 4 :                   \
+		         (uv) < 0x400000    ? 5 :                   \
+		         (uv) < 0x4000000   ? 6 :                   \
+		         (uv) < 0x40000000  ? 7 : UTF8_MAXBYTES )
 
 #define OFFUNI_IS_INVARIANT(c) (((UV)(c)) <  0xA0)
 
@@ -185,7 +193,7 @@ END_EXTERN_C
 		        (uv) < 0x4000           ? 3 :                       \
 		        (uv) < 0x40000          ? 4 :                       \
 		        (uv) < 0x400000         ? 5 :                       \
-		        (uv) < 0x4000000        ? 6 : 7 )
+		        (uv) < 0x4000000        ? 6 : UTF8_MAXBYTES )
 
 /* UTF-EBCDIC semantic macros - We used to transform back into I8 and then
  * compare, but now only have to do a single lookup by using a bit in
@@ -221,13 +229,6 @@ 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