[perl #129790] [OPTIMIZER] Giving a sub to a map fails

On Sat, 14 Oct 2017 18:38:47 -0700, [email protected] wrote:
> Maybe it is worth noting that this is pretty much a regression (even
> though an
> old one, and caused by a non-optimizer change).
> 
> (2016-08-09)
> https://github.com/rakudo/rakudo/commit/328402599c16077e182bb38baf68e435b8bc1082
> 
> Output before and after:
> https://gist.github.com/75b15f93438bd038cf0bec26c43eaa9f
> 
> On 2016-10-03 01:32:09, [email protected] wrote:
> > Playing around I found that the following change made your examples
> > work as expected:
> >
> > diff --git a/src/Perl6/Optimizer.nqp b/src/Perl6/Optimizer.nqp
> > index 12398ba..9102b7f 100644
> > --- a/src/Perl6/Optimizer.nqp
> > +++ b/src/Perl6/Optimizer.nqp
> > @@ -1082,7 +1082,8 @@ class Perl6::Optimizer {
> > || nqp::istype($op[0][0], QAST::Stmts) &&
> > nqp::istype(($c1 := $op[0][0][0]), QAST::Op)
> > &&
> > nqp::existskey(%range_bounds, $c1.name)) &&
> > - $!symbols.is_from_core($c1.name) {
> > + $!symbols.is_from_core($c1.name) &&
> > + nqp::defined($op[0][1].ann('code_object')) {
> > self.optimize_for_range($op, $op[0][1], $c1);
> > self.visit_op_children($op);
> > return $op;
> >
> > $ ./perl6 -e '^4 .map: {};'
> > Cannot map a Range to a Hash.
> > Did you mean to add a stub ({...}) or did you mean to .classify?
> > in block <unit> at -e line 1
> >
> > $ ./perl6 -e '^4 .map: 42;'
> > Cannot resolve caller map(Range: Int); none of these signatures
> > match:
> > ($: Hash \h, *%_)
> > (\SELF: &block;; :$label, :$item, *%_)
> > (HyperIterable:D $: &block;; :$label, *%_)
> > in block <unit> at -e line 1
> >
> > $ ./perl6 -e 'sub foo ($) {say "meow"}; ^4 .map: &foo;'
> > meow
> > meow
> > meow
> > meow
> >
> > The original error came from the first two lines in 'method
> > optimize_for_ranges' in src/Perl6/Optimizer.nqp. For some reason
> > $callee.ann('code_object') did not return a code object as expected.
> >
> > method optimize_for_range($op, $callee, $c2) {
> > my $code := $callee.ann('code_object');
> > my $count := $code.count;
> >
> > Now, I have no idea whether my change from above makes sense or
> > whether the annotation for 'code_object' was wrong in the first
> > place.


Thank you for the report. This is now fixed in branch `post-release`.

Fix:  https://github.com/rakudo/rakudo/commit/f3efe5e6b4a9ee5
Test: https://github.com/rakudo/rakudo/commit/f3efe5e6b4a9ee5