Allow list-valued constants

src/Metamodel.pm

@@ -908,6 +908,17 @@ sub Op::CallMethod::begin {
     }
 }
 
+sub Op::ConstantDecl::begin {
+    my $self = shift;
+
+    if ($self->path) {
+        $opensubs[-1]->add_common_name($self->name,
+            $opensubs[-1]->find_pkg($self->path), $self->name);
+    } else {
+        $opensubs[-1]->add_my_name($self->name);
+    }
+}
+
 sub Op::PackageVar::begin {
     my $self = shift;
 

src/Niecza/Actions.pm

@@ -1036,6 +1036,10 @@ sub INFIX { my ($cl, $M) = @_;
                 Op::Start->new(condvar => $cv, body => $M->{_ast}),
                 Op::Lexical->new(name => $l->name)]);
         }
+        elsif ($s eq '&infix:<=>' && $l->isa('Op::ConstantDecl') && !$l->init) {
+            $l->init($r);
+            $M->{_ast} = $l;
+        }
     }
     $M->{_ast} = $cl->whatever_postcheck($M, $st, $M->{_ast});
 }
@@ -1926,13 +1930,8 @@ sub type_declarator__S_constant { my ($cl, $M) = @_;
     }
     my $slot  = ($M->{identifier} // $M->{variable})->Str;
 
-    # This is a cheat.  Constants should be, well, constant, and we should be
-    # using the phaser rewrite mechanism to get the initializer here.  XXX
-    # terms need to use a context hash.
-    $M->{_ast} = ($::SCOPE eq 'our') ?
-        Op::PackageVar->new(node($M), name => $slot, slot => $slot,
-            path => [ 'OUR' ]) :
-        Op::Lexical->new(node($M), name => $slot, declaring => 1);
+    $M->{_ast} = Op::ConstantDecl->new(node($M), name => $slot,
+        path => ($::SCOPE eq 'our' ? [ 'OUR' ] : undef));
 }
 
 sub package_declarator {}

src/Op.pm

@@ -840,6 +840,24 @@ use CgOp;
     no Moose;
 }
 
+{
+    package Op::ConstantDecl;
+    use Moose;
+    extends 'Op';
+
+    has name => (isa => 'Str', is => 'ro', required => 1);
+    has init => (isa => 'Op', is => 'rw');
+    has path => (isa => 'Maybe[ArrayRef]', is => 'ro');
+
+    sub code {
+        my ($self, $body) = @_;
+        CgOp::rnull(CgOp::scopedlex($self->name, $self->init->cgop($body)));
+    }
+
+    __PACKAGE__->meta->make_immutable;
+    no Moose;
+}
+
 {
     package Op::ContextVar;
     use Moose;

v6/STD.pm6

@@ -5402,7 +5402,7 @@ method add_my_name ($n, $d?, $p?) {
         $*DECLARAND<inlex> = $curstash.idref;
         $*DECLARAND<signum> = $*SIGNUM if $*SIGNUM;
         $*DECLARAND<const> = $*DECLARAND<const> || 1 if $*IN_DECL eq 'constant';
-        $*DECLARAND<used> = 1 if substr($name,0,1) eq '&' and %::MYSTERY{substr($name,1)};
+        $*DECLARAND<used> = 1 if substr($name,0,1) eq '&' and %*MYSTERY{substr($name,1)};
         if !$*DECLARAND<const> and $shortname ~~ /^\w+$/ {
             $curstash.{"\&$shortname"} = $curstash.{"\&$shortname"} // $curstash.{$shortname};
             $curstash.{"\&$shortname"}<used> = 1;