incomplete.pl

use v6;

multi sub trait_mod:<is>(Method $m, :$must!){
    note "trait only if stub is present in base class activated"
}

multi sub trait_mod:<is>(Method $m, :$override!){
    note "trait only if method overrides activated";
} 

#multi trait_mod:<is>(Any $type, :$OverrideContractedClass!) {
#    die $type;
#}



my class OverrideContractedClassHOW is Metamodel::ClassHOW {
    method new_type(:$name, :$repr, :$ver, :$auth){
	die "new type";

    }
    method add_method($obj, $name, $code){
	note "add_method";
	nextsame;

   }

   method add_parent(Mu $obj, Mu $parent){
	note "add_parent";
       nextsame;
   }

    method add_role(Mu $obj, Mu $role ){
	note "??DSAd";
    }


}

my module EXPORTHOW {}
EXPORTHOW.WHO.<class> = OverrideContractedClassHOW;

   

role Incomplete {

    method bar {...}
    method foo {"bar"}


}


class Complete does Incomplete {
    method bar is must { 42}
    method foo is override { "42" }
}

#say Incomplete.^methods;

my Complete $cl = Complete.new;
say $cl.bar;
say $cl.^roles;

meta.pl

use v6;

multi trait_mod:<is>(Method:D $c, :$must!) {
   # my $name = $c.name;
    die $c.invocant;

    #unless $declared-in.^can($name) {
        #die "Method $name claims to be declared in {$declared-in.^name}, but there's no such method in {$declared-in.^name}!\n";
    #}
}

role R {
    method m1() { 42 };
    method m2() { ... };

}

class C does R  {
    method m1() {
        # all fine here
    }
    method m2() is must {
        # should bomb
    }
}

output

===SORRY!=== Error while compiling meta.pl
Method 'm1' must be implemented by R because it is required by a role
at meta.pl:15
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