Documentation update

git-svn-id: svn://vcs.exim.org/pcre/code/trunk@456 2f5784b3-3f2a-0410-8824-cb99058d5e15

1 files changed, 15 insertions, 14 deletions

diff --git a/HACKING b/HACKING
index 1f30d4c..623fe5b 100644
--- a/HACKING
+++ b/HACKING
@@ -67,22 +67,22 @@ many tests of the mode that might slow it down. So I re-factored the compiling
 functions to work this way. This got rid of about 600 lines of source. It
 should make future maintenance and development easier. As this was such a major 
 change, I never released 6.8, instead upping the number to 7.0 (other quite 
-major changes are also present in the 7.0 release).
+major changes were also present in the 7.0 release).
 
-A side effect of this work is that the previous limit of 200 on the nesting
+A side effect of this work was that the previous limit of 200 on the nesting
 depth of parentheses was removed. However, there is a downside: pcre_compile()
 runs more slowly than before (30% or more, depending on the pattern) because it
-is doing a full analysis of the pattern. My hope is that this is not a big
-issue.
+is doing a full analysis of the pattern. My hope was that this would not be a
+big issue, and in the event, nobody has commented on it.
 
 Traditional matching function
 -----------------------------
 
 The "traditional", and original, matching function is called pcre_exec(), and 
 it implements an NFA algorithm, similar to the original Henry Spencer algorithm 
-and the way that Perl works. Not surprising, since it is intended to be as 
-compatible with Perl as possible. This is the function most users of PCRE will 
-use most of the time.
+and the way that Perl works. This is not surprising, since it is intended to be
+as compatible with Perl as possible. This is the function most users of PCRE
+will use most of the time.
 
 Supplementary matching function
 -------------------------------
@@ -119,6 +119,7 @@ quantifiers) are always just two bytes long.
 
 A list of the opcodes follows:
 
+
 Opcodes with no following data
 ------------------------------
 
@@ -150,12 +151,12 @@ These items are all just one byte long
   OP_EXTUNI              match an extended Unicode character 
   OP_ANYNL               match any Unicode newline sequence 
   
-  OP_ACCEPT              )
-  OP_COMMIT              ) 
-  OP_FAIL                ) These are Perl 5.10's "backtracking     
-  OP_PRUNE               ) control verbs".                         
-  OP_SKIP                )
-  OP_THEN                )
+  OP_ACCEPT              ) These are Perl 5.10's "backtracking    
+  OP_COMMIT              ) control verbs". If OP_ACCEPT is inside
+  OP_FAIL                ) capturing parentheses, it may be preceded 
+  OP_PRUNE               ) by one or more OP_CLOSE, followed by a 2-byte 
+  OP_SKIP                ) number, indicating which parentheses must be
+  OP_THEN                ) closed.
   
 
 Repeating single characters
@@ -415,4 +416,4 @@ at compile time, and so does not cause anything to be put into the compiled
 data.
 
 Philip Hazel
-April 2008
+October 2009