Author: larry
Date: Wed Aug 2 09:00:38 2006
New Revision: 10539
Modified:
doc/trunk/design/syn/S05.pod
Log:
Tweaks to allow <foo+bar>.
Modified: doc/trunk/design/syn/S05.pod
==============================================================================
--- doc/trunk/design/syn/S05.pod (original)
+++ doc/trunk/design/syn/S05.pod Wed Aug 2 09:00:38 2006
@@ -16,7 +16,7 @@
Date: 24 Jun 2002
Last Modified: 2 Aug 2006
Number: 5
- Version: 30
+ Version: 31
This document summarizes Apocalypse 5, which is about the new regex
syntax. We now try to call them I<regex> because they haven't been
@@ -629,6 +629,38 @@
/ <sign>? <mantissa> <exponent>? /
+The first character after the identifier determines the treatment of
+the rest of the text before the closing angle. The underlying semantics
+is that of a function or method call, so if the first character is
+a left parenthesis, it really is a call:
+
+ <foo('bar')>
+
+If the first character is a colon, the rest of the text (following any
+whitespace) is passed as a string, so the previous may also be written as:
+
+ <foo: bar>
+
+If the first character is whitespace, the subsequent text is passed as regex,
+so:
+
+ <foo bar>
+
+is more or less equivalent to
+
+ <foo(/bar/)>
+
+If the first character is a plus or minus, the initial identifier taken
+as a character class, so
+
+ <foo+bar-baz>
+
+is equivalent to
+
+ <+foo+bar-baz>
+
+(See below.)
+
=item *
The special named assertions include:
@@ -816,6 +848,10 @@
/ <-[a..z_]> <-alpha> /
+This is essentially the same as using negative lookahead and dot:
+
+ / <![a..z_]> . <!alpha> . /
+
=item *
Character classes can be combined (additively or subtractively) within
@@ -824,9 +860,11 @@
/ <[a..z]-[aeiou]+xdigit> / # consonant or hex digit
If such a combination starts with a named character class, a leading
-C<+> is required:
+C<+> is allowed but not required, provided the next character is a
+character set operation:
- / <+alpha-[Jj]> / # J-less alpha
+ / <+alpha-[Jj]> / # J-less alpha
+ / <alpha-[Jj]> / # same thing
=item *
