In creating some new Perl 6 programs I've run across several instances I'm confused about, to wit:
Example 1 --------------- > my %h; say 'false' if !%h<a>:exists; Unexpected named parameter 'exists' passed Example 2 --------------- > my %h; say 'false' if not %h<a>:exists; false It looks like '!' doesn't work as I thought it was supposed to. But, I just discovered that when I use parens, it works. Example 3 --------------- > my %h; say 'false' if !(%h<a>:exists); false I presume the parens would cure the similar things I've noticed with other classes. When I look at the docs on Operators I see this: <quote> prefix ! multi sub prefix:<!>(Mu) returns Bool:D Negated boolean context operator. Coerces the argument to Bool by calling the Bool method on it, and returns the negation of the result. Note that this collapses Junctions. </quote> <quote> prefix not multi sub prefix:<not>(Mu $x) returns Bool:D Evaluates its argument in boolean context (and thus collapses Junctions), and negates the result. </quote> Those two definitions look very similar to my eyes, but I think the subtle difference is intentional.But they are not identical. Is there some rule of thumb here that a Perl 6 wannabe can grasp in Perl 5 terms (e.g., prefer 'not' over '!')? Or am I going to have to go deep early into the object class structure? Many thanks. -Tom
