Author: larry Date: Thu Apr 12 17:11:56 2007 New Revision: 14370 Modified: doc/trunk/design/syn/S02.pod
Log: Clarify the single-character backslash escapes, including \c control forms. Note that \c[ is not legal to mean \c[ESCAPE] Modified: doc/trunk/design/syn/S02.pod ============================================================================== --- doc/trunk/design/syn/S02.pod (original) +++ doc/trunk/design/syn/S02.pod Thu Apr 12 17:11:56 2007 @@ -12,9 +12,9 @@ Maintainer: Larry Wall <[EMAIL PROTECTED]> Date: 10 Aug 2004 - Last Modified: 16 Mar 2007 + Last Modified: 12 Apr 2007 Number: 2 - Version: 100 + Version: 101 This document summarizes Apocalypse 2, which covers small-scale lexical items and typological issues. (These Synopses also contain @@ -2274,7 +2274,15 @@ Backslash sequences still interpolate, but there's no longer any C<\v> to mean I<vertical tab>, whatever that is... (C<\v> now match vertical -whitespace in a regex.) +whitespace in a regex.) Literal character representations are: + + \a BELL + \b BACKSPACE + \t TAB + \n LINE FEED + \f FORM FEED + \r CARRIAGE RETURN + \e ESCAPE =item * @@ -2302,6 +2310,22 @@ [Note: none of the official Unicode character names contains comma.] +(Within a regex you may also use C<\C> to match a character that is +not the specified character.) + +If the character following C<\c> or C<\C> is not a left square bracket, +the single following character is turned into a control character by +the usual trick of XORing the 64 bit. This allows C<\c@> for NULL +and C<\c?> for DELETE, but note that the ESCAPE character may not be +represented that way; it must be represented something like: + + \e + \c[ESCAPE] + \x1B + \o33 + +Obviously C<\e> is preferred when brevity is needed. + =item * There are no barewords in Perl 6. An undeclared bare identifier will
