Re: PATCH: New options for the PCRE module (to replace my previous)

[Jon Strait <jstrait@xxxxxxxxxxxx>]

Peter Stephenson wrote:

On Wed, 25 Mar 2009 02:20:02 -0700
Jon Strait <jstrait@xxxxxxxxxxxx> wrote:
  

A few adjustments since last time, with documentation.

No reset of the special variables is done on a match failure.
    

Er, I can't remember what Phil said (I haven't been following this in any
detail), but the documentation now says variables aren't altered on a
failure, so presumably that is now incorrect.  I don't think this is
crucial as long as it's documented correctly.

Could you in any case send a documentation patch against the current source
and with lines wrapped to 80 columns?

Thanks.

  

No, I ended up keeping the original behavior:  On match failure, none of the special variables are modified (reset).

Here is the updated doc patch.

Please let me know if anything I added isn't clear enough.  Thanks.

--- mod_pcre-old.yo	2009-01-15 01:49:06.000000000 -0800
+++ mod_pcre.yo	2009-03-25 03:55:58.000000000 -0700
@@ -6,7 +6,7 @@
 
 startitem()
 findex(pcre_compile)
-item(tt(pcre_compile) [ tt(-aimx) ] var(PCRE))(
+item(tt(pcre_compile) [ tt(-aimxs) ] var(PCRE))(
 Compiles a perl-compatible regular expression.
 
 Option tt(-a) will force the pattern to be anchored.
@@ -15,6 +15,8 @@
 tt(^) and tt($) will match newlines within the pattern.
 Option tt(-x) will compile an extended pattern, wherein
 whitespace and tt(#) comments are ignored.
+Option tt(-s) makes the dot metacharacter match all characters, 
+including those that indicate newline.
 )
 findex(pcre_study)
 item(tt(pcre_study))(
@@ -22,7 +24,8 @@
 matching.
 )
 findex(pcre_match)
-item(tt(pcre_match) [ tt(-v) var(var) ] [ tt(-a) var(arr) ] var(string))(
+item(tt(pcre_match) [ tt(-v) var(var) ] [ tt(-a) var(arr) ] \
+[ tt(-n) var(offset) ] [ tt(-b) ] var(string))(
 Returns successfully if tt(string) matches the previously-compiled
 PCRE.
 
@@ -33,8 +36,38 @@
 case it will set the array var(arr).  Similarly, the variable
 var(MATCH) will be set to the entire matched portion of the
 string, unless the tt(-v) option is given, in which case the variable
-var(var) will be set.
-No variables are altered if there is no successful match.
+var(var) will be set. 
+No variables are altered if there is no successful match. 
+A tt(-n) option starts searching for a match from the 
+byte var(offset) position in var(string).  If the tt(-b) option is given, 
+the variable var(ZPCRE_OP) will be set to an offset pair string, 
+representing the byte offset positions of the entire matched portion 
+within the var(string).  For example, a var(ZPCRE_OP) set to "32 45" indicates
+that the matched portion began on byte offset 32 and ended on byte offset 44. 
+Here, byte offset position 45 is the position directly after the matched
+portion.  Keep in mind that the byte position isn't necessarily the same 
+as the character position when UTF-8 characters are involved.  
+Consequently, the byte offset positions are only to be relied on in the
+context of using them for subsequent searches on var(string), using an offset
+position as an argument to the tt(-n) option.  This is mostly
+used to implement the "find all non-overlapping matches" functionality.
+
+A simple example of "find all non-overlapping matches":
+
+example(
+string="The following zip codes: 78884 90210 99513"
+pcre_compile -m "\d{5}"
+accum=()
+pcre_match -b -- $string
+while [[ $? -eq 0 ]] do
+    b=($=ZPCRE_OP)
+    accum+=$MATCH
+    pcre_match -b -n $b[2] -- $string
+done
+print -l $accum
+
+
+)
 )
 enditem()