Author: larry Date: Mon Feb 26 11:05:31 2007 New Revision: 13704 Modified: doc/trunk/design/syn/S02.pod
Log: Made one-pass parsing rule explicit so that tests can refer to it. Modified: doc/trunk/design/syn/S02.pod ============================================================================== --- doc/trunk/design/syn/S02.pod (original) +++ doc/trunk/design/syn/S02.pod Mon Feb 26 11:05:31 2007 @@ -12,9 +12,9 @@ Maintainer: Larry Wall <[EMAIL PROTECTED]> Date: 10 Aug 2004 - Last Modified: 22 Feb 2007 + Last Modified: 26 Feb 2007 Number: 2 - Version: 89 + Version: 90 This document summarizes Apocalypse 2, which covers small-scale lexical items and typological issues. (These Synopses also contain @@ -23,6 +23,26 @@ These updates are not marked--if a Synopsis disagrees with its Apocalypse, assume the Synopsis is correct.) +=head1 One-pass parsing + +To the extent allowed by sublanguages parsers, Perl is parsed using a +one-pass, predictive parser. That is, lookahead of more than one +"longest token" is discouraged. The currently known exceptions to +this are where the parser must: + +=over 4 + +=item * + +Locate the end of interpolated expressions that begin with a sigil +and might or might not end with brackets. + +=item * + +Recognize that a reduce operator is not really beginning a C<[...]> composer. + +=back + =head1 Lexical Conventions =over 4