Improve documentation for "pipe trick"

- Actually mention "pipe trick" so the code is searchable
- Use spaces rather than tabs for vertical alignment
- Clarify comment for double-width brackets and mention revision it was added

Change-Id: Iaf365e313144e378133fb16c64efa5b7e47d4a6a

diff --git a/includes/parser/Parser.php b/includes/parser/Parser.php
index b31288f..5699ef8 100644 (file)
--- a/includes/parser/Parser.php
+++ b/includes/parser/Parser.php
@@ -4478,14 +4478,14 @@ class Parser {
                        '~~~' => $sigText
                ) );
 
-               # Context links: [[|name]] and [[name (context)|]]
+               # Context links ("pipe trick"): [[|name]] and [[name (context)|]]
                $tc = '[' . Title::legalChars() . ']';
                $nc = '[ _0-9A-Za-z\x80-\xff-]'; # Namespaces can use non-ascii!
 
-               $p1 = "/\[\[(:?$nc+:|:|)($tc+?)( ?\\($tc+\\))\\|]]/";           # [[ns:page (context)|]]
-               $p4 = "/\[\[(:?$nc+:|:|)($tc+?)( ?（$tc+）)\\|]]/";           # [[ns:page（context）|]]
-               $p3 = "/\[\[(:?$nc+:|:|)($tc+?)( ?\\($tc+\\)|)((?:, |，)$tc+|)\\|]]/"; # [[ns:page (context), context|]]
-               $p2 = "/\[\[\\|($tc+)]]/";                                      # [[|page]]
+               $p1 = "/\[\[(:?$nc+:|:|)($tc+?)( ?\\($tc+\\))\\|]]/";                  # [[ns:page (context)|]]
+               $p4 = "/\[\[(:?$nc+:|:|)($tc+?)( ?（$tc+）)\\|]]/";                    # [[ns:page（context）|]] (double-width brackets, added in r40257)
+               $p3 = "/\[\[(:?$nc+:|:|)($tc+?)( ?\\($tc+\\)|)((?:, |，)$tc+|)\\|]]/"; # [[ns:page (context), context|]]
+               $p2 = "/\[\[\\|($tc+)]]/";                                             # [[|page]]
 
                # try $p1 first, to turn "[[A, B (C)|]]" into "[[A, B (C)|A, B]]"
                $text = preg_replace( $p1, '[[\\1\\2\\3|\\2]]', $text );