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There is something I dont understand in the new Exegesis, namely (page 7 bottom):
# Named binding...
($who, $why) := (why => $because, who => "me");
# same as: $who := "me"; $why := $because;
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This makes no sence to me. Simply because a pair has the same key value as one of the variables on the left side, it is assigned to that?

Not assigned, bound. Binding in perl 6 does the same thing as the aliasing of foreach's loop variable, only you can do it everywhere. Once you execute this statement, $why and $because are essentially the same variable--they both point to the same underlying structure. $who is bound to the constant "me", which means printing $who prints "me" and trying to assign to it throws an error because you're trying to assign to a constant.

Perl 6 is making a string distinction between the name of a variable and the structure of the variable. Assignment copies the contents of one structure to another, while binding changes what structure a variable name refers to.

In reply to Re: Exegesis 6 - Named binding by Elian
in thread Exegesis 6 - Named binding by Cine

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