The package maybe implements the Maybe
monad. Here method implementations for fmap(), bind() and join()
are provided for the maybe S3 class from the package. The methods are
simple wrappers for the corresponding functions in maybe.
See also
maybe::maybe_map() which implements fmap() for maybe values.
maybe::and_then() which implements bind() for maybe values.
Other monads:
list
Examples
# The fmap operator corresponds to maybe::maybe_map().
maybe::just(1) %>>% `+`(1)
#> Just
#> [1] 2
maybe::nothing() %>>% `+`(1)
#> Nothing
# The bind operator corresponds to maybe::and_then().
maybe::just(1) %>-% \(x) maybe::just(x + 1)
#> Just
#> [1] 2
maybe::just(1) %>-% \(x) maybe::nothing()
#> Nothing
maybe::nothing() %>-% \(x) maybe::just(1)
#> Nothing