Perl5 map and grep allow the first argument to be an expression which is passed to the function instead of being evaluated. (Sort of a bare block.) What does the signature for this look like? Is it done with "is parsed" tricks, or will perl6 require the "map BLOCK LIST" syntax?
I was recently bit by the BLOCK/hashref-EXPR ambiguity here, but maybe that won't happen as often if hashrefs are required to use => instead of comma. ~ John Williams
