Hello, (used to post on google group but found it does not deliver)
I'm implementing "MiniPerl6" in pugs which is the first step of writing perl 6 parser in perl 6. In module Pugs::Grammar::MiniPerl6, http://svn.openfoundry.org/pugs/misc/pX/Common/Pugs-Grammar-MiniPerl6, I use another perl 6 grammar to describe it. It works well several days before when the parsing engine written in perl 5 did not implemented :ratchet and :sigspace flags. The grammar file can be found here: http//svn.openfoundry.org/pugs/misc/pX/Common/Pugs-Grammar-MiniPerl6/lib/Pugs/Grammar/MiniPerl6.grammar The "token" part is fine, but the "rule" part is extremely ugly. I can not add additional spaces to format it. I'd like to suggest two changes to make it easier to write rules: 1. Spaces at beginning and end of rule blocks should be ignored since space before and after current rule are most likely be defined in rules using current one. 1a. I'm not sure if it's "clear" to define as this, but the spaces around the rule-level alternative could also be ignored. For instance, look at the rule FunctionAppExpr defined in MiniPerl6 grammar file. rule FunctionAppExpr {<Variable>|<Constants>|<ArrayRef>|<FunctionName>[<?ws>?<'('><?ws>?<Parameters><')'>]?} I could not even put a new line in it. In the file, since there are production rules, I put the brases on strange positions to format it better. 2. I am not sure the default rule of <ws>, I couldn't found it in S05. Currently the engine use :P5/\s+/ but I would like it to be :P/\s*/ when it's before or after non-words and remains the same (\s+) otherwise. I do not subscribe this group but subscribe daily digest, so it's OK to reply on the list. Suggestions welcome! Cheers, Shu-Chun Weng
