Hi Todd, On 03/10/2018 02:14, ToddAndMargo wrote: > sub postcircumfix:<[ ]>(@container, **@index, > :$k, :$v, :$kv, :$p, :$exists, :$delete) > > 1 Why the <[]>? I have always used [] with out the <>. > Why would I want to use one over the other? > > 2) Where does it state that the <> is optional?
postcircumfix:<[ ]> is the "real name" of the [ ] postfix operator. In this case the < > are just how it's quoted, i.e. this is how you communicate to perl6 where the name starts and ends. It is also in other operator's names, like infix:<+> for the + operator, or postfix:<++> for the ++ postfix operator. If your operator itself contains a < or a >, you can instead use ['blah'] for the quoting, like infix:['<'] for the < operator. As you can see, it's more or less different ways to write what is essentially a string. Just like you have "foo" and 'foo' but also q<foo>, q«foo», and anything else you want to come up with. > 6) Where is the --> return described? The "-->" part of the signature is optional. If there isn't one, it defaults to Mu, which is the type that everything conforms to, i.e. the sub or method that either has "--> Mu" explicitly, or has it by leaving it out, may return absolutely whatever it wants. After all, the "-->" part is a constraint, and it gets validated at compile time every time a sub or method returns. > Yours in confusion, > -T Hope that helps a little - Timo
