They'd be kinda necessary for infix operators for which standard sub conventions are insufficient and need to diddle the parse tree instead, such as short-circuiting operators.
It would also allow Damien's original <~ operator (R2L method call) to be implemented with something like this...
(warning: I had to invent a lot here, but it should hopefully make at least a little bit sense :-)
macro infix:<~ (Perl6::Node $x, Perl6::Node $y) is tighter(&infix:=) { # regular case, turn foo $x, $y <~ $obj into $obj.foo($x, $y) if ($x ~~ Perl6::SubCall) { return new Perl6::MethodCall: $x.name, $y, $x.args; }
# ugly hack in case foo $x, $y <~ $o was parsed as foo($x), $y <~ $o
# however foo, $x <~ $obj should still give an error, so beware
if ($x ~~ Perl6::List && !$x.parens && $x.items > 0) {
my $z = $x.items[0];
if ($z ~~ Perl6::SubCall && !$z.parens && $z.args > 0) {
my @args = $z.args, $x.items[1...];
return new Perl6::MethodCall: $z.name, $y, @args;
}
}# helpful error message ;-) croak "Can't deal with the stuff left of <~ operator"; }
-- Matthijs van Duin -- May the Forth be with you!
