Chapel: Type method with a param-typed return-type

[ben-albrecht]

Summary of Problem

A class with a type method that returns a type that depends on a type or param argument of the method, results in an error (shown below).

Steps to Reproduce

Source Code:

class Sandwich {
  type eltType; // Same thing occurs if this is a 'param' instead

  proc type make(type t): Sandwich(t) {
    return new Sandwich(t);
  }
}


var realSandwich = Sandwich.make(real);

Compile output:

sandwich.chpl:10: error: unresolved type specifier 'Sandwich()'
sandwich.chpl:1: note: candidates are: Sandwich(type eltType)

Associated Future Test(s):
TODO

Configuration Information

• Output of chpl --version: chpl Version 1.16.0 pre-release (a110861)

[ben-albrecht]

@noakesmichael was interested in this - hope I didn't butcher this issue title too bad.

[ben-albrecht]

Context: This came up when discussing alternatives to the QueueFactory class in #6812 with @LouisJenkinsCS

[cassella]

I think this has to do with calling a type method on a generic
class. not with what the type method returns or depends on.

I get the same error with this:

class Sandwich {
  var filling;
  proc type eat() {
    writeln("Mmm");
  }
}

Sandwich.eat();

But it works with the last line changed to

Sandwich(string).eat();

And conversely, a non-generic class with a type method that
returns a type that depends on a type argument of the method
works:

```chapel
class Soup {
type eltType;
}

class Sandwich {
proc type make(type t) {
writeln("Out of sandwiches. Have some ", t:string, " soup!");
return new Soup(t);
}
}

var s = Sandwich.make(string);
writeln(s);
delete s;

[cassella]

I don't know what the QueueFactory was going to look like, but I
modified my last example and sudo made you a sandwich factory,
which works for me:

class Sandwich {
  type eltType;
}

class SandwichFactory {
  proc type make(type t) {
    return new Sandwich(t);
  }
}

var s = SandwichFactory.make(string);
writeln(s.type:string);
delete s;

[cassella]

Is this not-a-bug?

[bradcray]

Doesn't seem like it, does it? @ben-albrecht?

[ben-albrecht]

Agreed. Thank you for @cassella