Omission/vagueness in spec chapter 8.3

[DartBot]

This issue was originally filed by rodion...@unipro.ru

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What steps will reproduce the problem?

1. Run 08_3_Factories_and_Constructors_A03_t03.dart from the co19 suite
2. Observe the error

Seems to be an omission in the spec (Ch. 8.3):
It specifically mentions the compile-time error when an interface and its factory class that IMPLEMENTS that interface do not have the same number of type parameters, but there's also a perfectly identical compile-time error in the case when the factory class does not implement the interface.

[DartBot]

This comment was originally written by rodion...@unipro.ru

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In case the test still isn't committed to co19 repo by the time you look at this issue, here it is:

/**
 * @­assertion Let I be an interface named NI with factory class F, and let NF be the
 * name of F. If F implements I then it is a compile-time error if I and F do not
 * have the same number of type parameters.
 * @­description Checks that there's no compile-time error if an interface
 * has fewer or more type parameters than its declared factory class as long as the
 * latter does not implement the former.
 */

class C<S, T> {
  factory I() {}
}

interface I<T> factory C<T, T> {
  I();
}

class C2<T> {
  factory I2() {}
}

interface I2<S, T> factory C2<S> {
  I2();
}

main() {
  new I();
  new I2();
}

[DartBot]

This comment was originally written by drfibonacci@google.com

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Added Area-Language, Triaged labels.

[gbracha]

The spec will be revised next week to simplify factories. The examples will then be illegal, at which point I will close this bug.

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Set owner to @gbracha.
Added Accepted label.

[gbracha]

Added Done label.