# New Ticket Created by "Brian S. Julin"
# Please include the string: [perl #125374]
# in the subject line of all future correspondence about this issue.
# <URL: https://rt.perl.org/Ticket/Display.html?id=125374 >
# I believe this is a known NYI but it is probably about time there was
# an RT for it.
# Rakudo's proto+multi grammar rules don't function as specced. They
# should be equivalent to an '|' alternative.
# These two grammars should produce identical results
grammar g1 {
proto token m {*}
multi token m:sep<2> { '==' }
multi token m:sep<1> { '=' }
multi token m:sep<0> { '' }
token TOP { d <m> foo }
}
grammar g2 {
proto token m {*}
multi token m:sep<0> { '' }
multi token m:sep<1> { '=' }
multi token m:sep<2> { '==' }
token TOP { d <m> foo }
}
g1.parse('d==foo').say; # ｢d==foo｣ m => ｢==｣
g1.parse('d=foo').say; # ｢d=foo｣ m => ｢=｣
g1.parse('dfoo').say; # ｢dfoo｣ m => ｢｣
g2.parse('d==foo').say; # (Any)
g2.parse('d=foo').say; # (Any)
g2.parse('dfoo').say; # ｢dfoo｣ m => ｢｣
# Also this:
perl6 -e 'grammar g { proto regex { f {*} g } }'
===SORRY!=== Error while compiling -e
Proto regex body must be {*} (or <*> or <...>, which are deprecated)
at -e:1
------> grammar g { proto regex ⏏{ f {*} g } }
...where the design docs say:
The proto calls into the subdispatcher when it sees a * that cannot be a
quantifier and is the only thing in its block. Therefore you can put items
before and after the subdispatch by putting the * into curlies:
proto token foo { <prestuff> {*} <poststuff> }
