Class Chain<B>Experimental Beta

Type declaration

• • <R>(transformFn: TransformFn<BaseOrDeferred<B>, R>, lookupFn?: null | LookupFn<BaseOrDeferred<B>, R>, validateFn?: null | ValidateFn<BaseOrDeferred<B>, R>, errLookupFn?: null | ErrLookupFn): Chain<R>

  • Functor

    1. u['fantasy-land/map'](a => a) is equivalent to u (identity)
    2. u['fantasy-land/map'](x => f(g(x))) is equivalent to u['fantasy-land/map'](g)['fantasy-land/map'](f) (composition)

    fantasy-land/map method

    fantasy-land/map :: Functor f => f a ~> (a -> b) -> f b
    

    A value which has a Functor must provide a fantasy-land/map method. The fantasy-land/map method takes one argument:

    u['fantasy-land/map'](f)
    

    1. f must be a function,

       1. If f is not a function, the behaviour of fantasy-land/map is unspecified.
       2. f can return any value.
       3. No parts of f's return value should be checked.

    2. fantasy-land/map must return a value of the same Functor

    fantasy-laws jsverify sanctuary-show sanctuary-type-classes

    Type Parameters

    • R

    Parameters

    • transformFn: TransformFn<BaseOrDeferred<B>, R>

    • Optional lookupFn: null | LookupFn<BaseOrDeferred<B>, R>

    • Optional validateFn: null | ValidateFn<BaseOrDeferred<B>, R>

    • Optional errLookupFn: null | ErrLookupFn

    Returns Chain<R>