Empty Messages are pushed on stack as empty tuples []

[novusnota]

Are you using the latest released (or pre-released, a.k.a. "next") version?

• I'm using the latest Tact version

Tact source code

import "@stdlib/deploy";

// Empty Message
message(7) Seven {}
asm fun pushSeven(msg: Seven) { }

// Message with one field
message(8) NotSeven { but: Int }
asm fun pushNotSeven(msg: NotSeven) { }

// Utility
asm fun drop() { DROP }

contract Showcase with Deployable {
    receive("showcase") {
        dumpStack();
        pushSeven(Seven{}); // pushes []
        dumpStack();
        pushNotSeven(NotSeven{ but: 8 }); // pushes 8
        dumpStack();

        // To leave the stack as we've found it at the start of the function
        drop(); // dropping the tuple of Seven
        drop(); // dropping the `but` of NotSeven
    }
}

Relevant Tact/build system log output

# Pay attention to the values to the right of C{96...C7}

#DEBUG#: File showcase.tact:16:9:
#DEBUG#: dumpStack()
#DEBUG#: stack(3 values) : 500000000 C{96...C7} 0

#DEBUG#: File showcase.tact:18:9:
#DEBUG#: dumpStack()
#DEBUG#: stack(4 values) : 500000000 C{96...C7} 0 []

#DEBUG#: File showcase.tact:20:9:
#DEBUG#: dumpStack()
#DEBUG#: stack(5 values) : 500000000 C{96...C7} 0 [] 8

What happened?

No response

What did you expect?

Instead of the following:

(tuple) $Seven$_constructor_() inline {
    return empty_tuple();
}

Tact can produce:

() $Seven$_constructor_() inline {
    return ();
}

Steps to reproduce

No response

How do you run Tact?

Blueprint, Tact CLI

Anything else?

This is especially inconvenient when working with values that cannot be expressed in the Tact's current type system, such as tuples: #1127 (comment)