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@puffnfresh
Last active Jan 20, 2017
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declare namespace F {
class Either<A, B> {
private constructor();
// Hack to make A and B covariant.
private a: A;
private b: B;
static Left<A, B>(a: A): Either<A, B>;
static Right<A, B>(b: B): Either<A, B>;
static either<A, B, C>(f: (a: A) => C, g: (b: B) => C, e: Either<A, B>): C;
static of<A, B>(b: B): Either<A, B>;
static isLeft<A, B>(e: Either<A, B>): boolean;
static isRight<A, B>(e: Either<A, B>): boolean;
map<C>(f: (b: B) => C): Either<A, C>;
chain<C>(f: (b: B) => Either<A, C>): Either<A, C>;
bimap<C, D>(f: (a: A) => C, g: (b: B) => D): Either<C, D>;
equals(e: Either<A, B>): boolean;
}
}
declare module 'ramda-fantasy' {
export = F;
}
@srijs

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@srijs srijs commented Jan 20, 2017

The example you gave:

const x: F.Either<{}, number> = F.Either.Right<{}, string>('wat')

doesn't compile for me, even after removing the private variables.

It does compile however after removing the methods on the class, since then the rules of structural equivalence ignore the two generics due to them not being part of the structure itself.

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