Document that ~(PCRE2_SIZE)0 is a reserved value.

git-svn-id: svn://vcs.exim.org/pcre2/code/trunk@163 6239d852-aaf2-0410-a92c-79f79f948069

1 files changed, 17 insertions, 13 deletions

diff --git a/doc/pcre2limits.3 b/doc/pcre2limits.3
index c97eb61..8982546 100644
--- a/doc/pcre2limits.3
+++ b/doc/pcre2limits.3
@@ -1,4 +1,4 @@
-.TH PCRE2LIMITS 3 "29 September 2014" "PCRE2 10.00"
+.TH PCRE2LIMITS 3 "25 November 2014" "PCRE2 10.00"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .SH "SIZE AND OTHER LIMITATIONS"
@@ -20,6 +20,21 @@ documentation for details. In these cases the limit is substantially larger.
 However, the speed of execution is slower. In the 32-bit library, the internal
 linkage size is always 4.
 .P
+The maximum length (in code units) of a subject string is one less than the
+largest number a PCRE2_SIZE variable can hold. PCRE2_SIZE is an unsigned
+integer type, usually defined as size_t. Its maximum value (that is
+~(PCRE2_SIZE)0) is reserved as a special indicator for zero-terminated strings
+and unset offsets.
+.P
+Note that when using the traditional matching function, PCRE2 uses recursion to
+handle subpatterns and indefinite repetition. This means that the available
+stack space may limit the size of a subject string that can be processed by
+certain patterns. For a discussion of stack issues, see the
+.\" HREF
+\fBpcre2stack\fP
+.\"
+documentation.
+.P
 All values in repeating quantifiers must be less than 65536.
 .P
 There is no limit to the number of parenthesized subpatterns, but there can be
@@ -38,17 +53,6 @@ maximum number of named subpatterns is 10000.
 .P
 The maximum length of a name in a (*MARK), (*PRUNE), (*SKIP), or (*THEN) verb
 is 255 for the 8-bit library and 65535 for the 16-bit and 32-bit libraries.
-.P
-The maximum length of a subject string is the largest number a PCRE2_SIZE
-variable can hold. PCRE2_SIZE is an unsigned integer type, usually defined as
-size_t. However, when using the traditional matching function, PCRE2 uses
-recursion to handle subpatterns and indefinite repetition. This means that the
-available stack space may limit the size of a subject string that can be
-processed by certain patterns. For a discussion of stack issues, see the
-.\" HREF
-\fBpcre2stack\fP
-.\"
-documentation.
 .
 .
 .SH AUTHOR
@@ -65,6 +69,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 29 September 2014
+Last updated: 25 November 2014
 Copyright (c) 1997-2014 University of Cambridge.
 .fi