On Wed, Jun 3, 2009 at 8:08 AM, Håkon Skaarud Karlsen < perl6-bugs-follo...@perl.org> wrote:
> # New Ticket Created by Håkon Skaarud Karlsen > # Please include the string: [perl #66250] > # in the subject line of all future correspondence about this issue. > # <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=66250 > > > > This works: > grammar A { rule TOP { 'a ' 'b' {*} } }; my $m = A.parse('a b'); say $/; > Result: "a b" > Expected result: "a b" > > This doesn't work: > grammar A { rule TOP { 'a' ' b' {*} } }; my $m = A.parse('a b'); say $/; > Result: Empty string > Expected result: "a b" > > > And this doesn't work: > grammar A { rule TOP { 'a' <blank> 'b' {*} } }; my $m = A.parse('a > b'); say $/; > Result: Empty string > Expected result: "a b" These results seem logical to me. As I understand things, significant whitespace means that whitespace within rules gets replaced with either \s* or \s+ depending on context. Since rules are also greedy (no backtracking), the significant whitespace in your second example ate all of the spaces in your string leaving no spaces for ' b' to match. A similar thing happens with your third example; there is nothing for <blank> to match (though I haven't looked at the spec, so I'm not entirely sure what <blank> should match) -Scott -- Jonathan Scott Duff perlpi...@gmail.com
