From @zoffixznet

Attempting to give a map some invalid arg or a sub gives an error​:

  zoffix@​VirtualBox​:~/CPANPRC/rakudo$ ./perl6 -e '^4 .map​: {};'
  ===SORRY!===
  Cannot find method 'count' on object of type NQPMu
  zoffix@​VirtualBox​:~/CPANPRC/rakudo$ ./perl6 -e '^4 .map​: 42;'
  ===SORRY!===
  Cannot find method 'count' on object of type NQPMu
  zoffix@​VirtualBox​:~/CPANPRC/rakudo$ ./perl6 -e 'sub foo ($) {say
"meow"}; ^4 .map​: &foo;'
  ===SORRY!===
  Cannot find method 'count' on object of type NQPMu

However, everything works fine, if we turn off the optimizer​:

  zoffix@​VirtualBox​:~/CPANPRC/rakudo$ ./perl6 --optimize=off -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

  zoffix@​VirtualBox​:~/CPANPRC/rakudo$ ./perl6 --optimize=off -e '^4
.map​: 42;'
  Cannot resolve caller map(Range​: Int); none of these signatures match​:
  ($​: Hash \h, *%_)
  (\SELF​: █; :$label, :$item, *%_)
  (HyperIterable​:D $​: █; :$label, *%_)
  in block <unit> at -e line 1

  zoffix@​VirtualBox​:~/CPANPRC/rakudo$ ./perl6 --optimize=off -e
'sub foo ($) {say "meow"}; ^4 .map​: &foo;'
  meow
  meow
  meow
  meow
  zoffix@​VirtualBox​:~/CPANPRC/rakudo$

Or, if we wrap the range into parenths​:

  zoffix@​VirtualBox​:~/CPANPRC/rakudo$ ./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

  zoffix@​VirtualBox​:~/CPANPRC/rakudo$ ./perl6 -e '(^4).map​: 42;'
  Cannot resolve caller map(Range​: Int); none of these signatures match​:
  ($​: Hash \h, *%_)
  (\SELF​: █; :$label, :$item, *%_)
  (HyperIterable​:D $​: █; :$label, *%_)
  in block <unit> at -e line 1

  zoffix@​VirtualBox​:~/CPANPRC/rakudo$ ./perl6 -e 'sub foo ($) {say
"meow"}; (^4).map​: &foo;'
  meow
  meow
  meow
  meow

From @usev6

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​: 42;'
Cannot resolve caller map(Range​: Int); none of these signatures match​:
  ($​: Hash \h, *%_)
  (\SELF​: █; :$label, :$item, *%_)
  (HyperIterable​:D $​: █; :$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.

@usev6 - Status changed from 'new' to 'open'

From @AlexDaniel

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) rakudo/rakudo@3284025

Output before and after​: https://gist.github.com/75b15f93438bd038cf0bec26c43eaa9f

On 2016-10-03 01​:32​:09, bartolin@​gmx.de 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​:
($​: Hash \h, *%_)
(\SELF​: █; :$label, :$item, *%_)
(HyperIterable​:D $​: █; :$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.

From @zoffixznet

On Sat, 14 Oct 2017 18​:38​:47 -0700, alex.jakimenko@​gmail.com 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)
rakudo/rakudo@3284025

Output before and after​:
https://gist.github.com/75b15f93438bd038cf0bec26c43eaa9f

On 2016-10-03 01​:32​:09, bartolin@​gmx.de 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​:
($​: Hash \h, *%_)
(\SELF​: █; :$label, :$item, *%_)
(HyperIterable​:D $​: █; :$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​: rakudo/rakudo@f3efe5e6b4a9ee5
Test​: rakudo/rakudo@f3efe5e6b4a9ee5

@zoffixznet - Status changed from 'open' to 'resolved'