enforce constraints on implemented functions; start by at least checking their signatures #4
Description
Barring static types, it would be nice to have checks ensuring that if a protocol intends a field to be a method that an implementation at least defines is as a function (preferably of the same length).
protocol A {
a; // maybe a function
b(); // definitely a function
c(d, e); // definitely a function of at least length two
}
class B {
[A.c](d, e){}
}
B.prototype[A.a] = 'a';
B.prototype[A.b] = 'b';
B implements A; // Error: Symbol(A.b) must be a function
class C {
[A.b](){}
[A.c](){}
}
C.prototype[A.a] = 42;
C implements A; // Error: Symbol(A.c) must be a function of length >= 2