Improving two comments, and eliding a macro.

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@4891 35c25a1d-7b9e-4130-9fde-d3aeb78583b8

ChangeLog

@@ -1,6 +1,7 @@
 2014-05-15  Benno Schulenberg  <bensberg@justemail.net>
 	* doc/syntax/c.nanorc: Improve the magic regex, plus tweaks.
 	* src/color.c (color_update): Adjust comment, and be clear.
+	* src/nano.h: Improve two comments, and elide one macro.
 
 2014-05-14  Benno Schulenberg  <bensberg@justemail.net>
 	* src/winio.c (edit_draw): Poke a non-breaking space into the last

src/nano.h

@@ -57,10 +57,9 @@
 /* Suppress warnings for __attribute__((warn_unused_result)). */
 #define IGNORE_CALL_RESULT(call) do { if (call) {} } while(0)
 
-/* Macros for flags. */
-#define FLAGOFF(flag) ((flag) / (sizeof(unsigned) * 8))
+/* Macros for flags, indexing each bit in a small array. */
+#define FLAGS(flag) flags[((flag) / (sizeof(unsigned) * 8))]
 #define FLAGMASK(flag) (1 << ((flag) % (sizeof(unsigned) * 8)))
-#define FLAGS(flag) flags[FLAGOFF(flag)]
 #define SET(flag) FLAGS(flag) |= FLAGMASK(flag)
 #define UNSET(flag) FLAGS(flag) &= ~FLAGMASK(flag)
 #define ISSET(flag) ((FLAGS(flag) & FLAGMASK(flag)) != 0)
@@ -497,8 +496,7 @@ enum
     NUMBER_OF_ELEMENTS
 };
 
-/* Enumeration to be used in flags table. See FLAGBIT and FLAGOFF
- * definitions. */
+/* Enumeration used in the flags array.  See the definition of FLAGMASK. */
 enum
 {
     DONTUSE,