False positive "nullary function should not be overloaded" for functions that accept tuple patterns

[jurgenvinju]

Describe the bug

[PaulKlint]

Can you give more details? I cannot reproduce this.

[jurgenvinju]

I've reduced it to the following minimal module:

module BugTest

data Enum = x();

value f(<x>) = [];    // Nullary function `f` should not be overloaded
value f(<x,y>) = []; // Nullary function `f` should not be overloaded

[jurgenvinju]

• the data Enum = x(); is essential; without it the errors are not reported.
• the interpreter executes this code correctly for any x that is wrapped by singleton or binary tuple.
• this code should have types for the x and y patterns, per the static semantics of Rascal. So this is not correct code in any way.