syntax question on parameter lists
S06 shows how to define named-only parameters, marked with a prefix :. But no example shows anything more than a bare parameter name. No type is ever given! Looking through my copy of STD.pm, I'm baffled, as it seems not to take types in parameter lists at all. So, is it method bytes ( Encoding :$encoding ) returns Int or method bytes ( : Encoding $encoding ) returns Int ? I'm guessing that the latter would be confused with use of : after the invocant, and it follows that method bytes (Encoding :encoding($override_encoding)) returns Int would work.
Re: syntax question on parameter lists
On Fri, Apr 11, 2008 at 03:26:02AM -, John M. Dlugosz wrote: : S06 shows how to define named-only parameters, marked with a prefix :. But no example shows anything more than a bare parameter name. No type is ever given! : : Looking through my copy of STD.pm, I'm baffled, as it seems not to take types in parameter lists at all. It's at the top of token parameter where there is a type_constraint*. : So, is it : method bytes ( Encoding :$encoding ) returns Int : : or : : method bytes ( : Encoding $encoding ) returns Int : : ? : : I'm guessing that the latter would be confused with use of : after the invocant, and it follows that : : method bytes (Encoding :encoding($override_encoding)) returns Int : : would work. Indeed. Larry
Re: syntax question on parameter lists
On Thu, Apr 10, 2008 at 09:18:38PM -0700, Larry Wall wrote: On Fri, Apr 11, 2008 at 03:26:02AM -, John M. Dlugosz wrote: : S06 shows how to define named-only parameters, marked with a prefix :. But no example shows anything more than a bare parameter name. No type is ever given! : : Looking through my copy of STD.pm, I'm baffled, as it seems not to take types in parameter lists at all. It's at the top of token parameter where there is a type_constraint*. Yes, but where does type_constraint resolve down to a typename? My reading of STD.pm is that type_constraint becomes a value (since it's not a 'where' clause in this case), and value is currently one of quote, number, or version. Pm
