my &half := &divide.assuming( $y => 2 )

Larry

Apart from being substantially prettier, is this functionally or efficiently different from

my $half =  sub { $_[1]=2; goto ÷ };

print $half->( 120 ),$/;
__END__
60
[download]

?

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Well It's better than the Abottoire, but Yorkshire!

Yes, it looks a little bit like OCaml (i.e. I'm not sure this has never been seen in any other language). :-)

# let divide ~x ~y = x / y;;
val divide : x:int -> y:int -> int = <fun>
# let half = divide ~y:2;;
val half : x:int -> int = <fun>
# half 120;;
- : int = 60
[download]

How is that an improvement over sub half { divide($_[0]/2) };? Especially when you consider that to write sub half assuming... as shown you have (apparently) to know that divide has a $y to which to assign 2.

You can create functions with defaults. I don't know about you, but that's an instant winner for me. And you can reduce temporary variables by setting up a function in stages, perhaps by asking the user for the parameters one by one, and then it fires when you have them all filled in. Saves temporary variables and looks neater. Of course you don't need to use this - you can keep writing temporary variables if you really want.

As I understand it, this is another effect of the much repeated 'closures are first class objects'.

____________________
Jeremy
I didn't believe in evil until I dated it.