[AC21.5] small doc patch for regex

APPROVE COMMIT 21.5 Not needed for 21.4. Index: src/ChangeLog =================================================================== RCS file: /pack/xemacscvs/XEmacs/xemacs/src/ChangeLog,v retrieving revision 1.801 diff -u -U0 -r1.801 ChangeLog --- src/ChangeLog 2 Mar 2005 18:31:55 -0000 1.801 +++ src/ChangeLog 9 Mar 2005 04:57:21 -0000 ＠＠ -0,0 +1,6 ＠＠ +2005-01-13 Stephen J. Turnbull <stephen(a)xemacs.org&gt; + + * regex.c (re_match_2_internal): + * regex.h (struct re_pattern_buffer): + Improve comments. Add a DEBUG_PRINT2 for null matches. + Index: src/regex.c =================================================================== RCS file: /pack/xemacscvs/XEmacs/xemacs/src/regex.c,v retrieving revision 1.55 diff -u -r1.55 regex.c --- src/regex.c 24 Jan 2005 23:34:08 -0000 1.55 +++ src/regex.c 9 Mar 2005 04:58:05 -0000 ＠＠ -5178,8 +5178,9 ＠＠ : ((regoff_t) (d - string2 + size1))); } - /* Go through the first `min (num_regs, regs->num_regs)' - registers, since that is all we initialized. */ + /* Map over the NUM_NONSHY_REGS non-shy internal registers. + Copy each into the corresponding external register. + MCNT indexes external registers. */ for (mcnt = 1; mcnt < MIN (num_nonshy_regs, regs->num_regs); mcnt++) { ＠＠ -5198,9 +5199,10 ＠＠ } /* regs && !bufp->no_sub */ /* If we have regs and the regs structure has more elements than - were in the pattern, set the extra elements to -1. If we - (re)allocated the registers, this is the case, because we - always allocate enough to have at least one -1 at the end. + were in the pattern, set the extra elements starting with + NUM_NONSHY_REGS to -1. If we (re)allocated the registers, + this is the case, because we always allocate enough to have + at least one -1 at the end. We do this even when no_sub is set because some applications (XEmacs) reuse register structures which may contain stale ＠＠ -5406,8 +5408,11 ＠＠ p1 = p; /* To send to group_match_null_string_p. */ if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE) - REG_MATCH_NULL_STRING_P (reg_info[*p]) - = group_match_null_string_p (&p1, pend, reg_info); + REG_MATCH_NULL_STRING_P (reg_info[*p]) + = group_match_null_string_p (&p1, pend, reg_info); + + DEBUG_PRINT2 (" group CAN%s match null string\n", + REG_MATCH_NULL_STRING_P (reg_info[*p]) ? "NOT" : ""); /* Save the position in the string where we were the last time we were at this open-group operator in case the group is Index: src/regex.h =================================================================== RCS file: /pack/xemacscvs/XEmacs/xemacs/src/regex.h,v retrieving revision 1.13 diff -u -r1.13 regex.h --- src/regex.h 14 Oct 2004 17:26:24 -0000 1.13 +++ src/regex.h 9 Mar 2005 04:58:05 -0000 ＠＠ -357,8 +357,8 ＠＠ when it is matched. */ RE_TRANSLATE_TYPE translate; - /* Number of returnable groups found by the compiler. (This does - not count shy groups.) */ + /* Number of subpatterns (returnable groups) found by the compiler. + (This does not count shy groups.) */ int re_nsub; /* Total number of groups found by the compiler. (Including -- Institute of Policy and Planning Sciences http://turnbull.sk.tsukuba.ac.jp University of Tsukuba Tennodai 1-1-1 Tsukuba 305-8573 JAPAN Ask not how you can "do" free software business; ask what your business can "do for" free software.