# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1296865319 -3600
# Node ID d9316d0e772d1e4f371ede45f4a2ad05241cf98d
# Parent  1e0cdf78d59c731532c1821fe7bd860fc897a89f
Made "invocation"-style bracketed arguments optional for formatting terms that
employ range information.
Added regular expression commentary.

diff -r 1e0cdf78d59c -r d9316d0e772d ImprovedMoinSearch.py
--- a/ImprovedMoinSearch.py	Sun Oct 03 21:38:06 2010 +0200
+++ b/ImprovedMoinSearch.py	Sat Feb 05 01:21:59 2011 +0100
@@ -2,7 +2,7 @@
 """
     MoinMoin - ImprovedMoinSearch library
 
-    @copyright: 2010 Paul Boddie <paul@boddie.org.uk>
+    @copyright: 2010, 2011 Paul Boddie <paul@boddie.org.uk>
     @license: GNU GPL (v2 or later), see COPYING.txt for details.
 """
 
@@ -15,13 +15,21 @@
 paragraph_regexp = re.compile(r"(?P<paragraph>(?:^[^#=\s].*$\n)+)", re.UNICODE | re.MULTILINE)
 
 def range_groups(min_name, max_name):
-    return r"(?:\((?P<%s>-?\d+)?(?:\s*-\s*(?P<%s>-?\d+))?\))" % (min_name, max_name)
+    return \
+        r"(?:"                              # non-grouping containment of...
+        r"\("                               # brackets around the arguments
+        r"(?P<%s>-?\d+)?"                   # optional first numeric argument
+        r"(?:\s*-\s*"                       # non-grouping containment of dash and spaces
+        r"(?P<%s>-?\d+)"                    # second numeric argument
+        r")?"                               # end containment, making dash and numeric argument optional
+        r"\)"                               # closing bracket
+        r")?" % (min_name, max_name)        # end containment, making entire bracketed region optional
 
 format_options_regexp = re.compile(
-    r"("
-    r"(?P<link>(link|l):)"
-    r"|(?P<strong>(strong|str|bold|b):)"
-    r"|(?P<em>(emphasis|em|italic|i):)"
+    r"("                                    # optional formatting qualifiers...
+    r"(?P<link>(link|l):)"                  # link:
+    r"|(?P<strong>(strong|str|bold|b):)"    # strong:
+    r"|(?P<em>(emphasis|em|italic|i):)"     # emphasis:
     r")*"
     r"("
     r"(?P<heading>(heading|title|h)\s*" + range_groups("min_heading", "max_heading") + ")"