v0.4.0

What's Changed

New Features

Support FlatMap functions: #10 (@moznion)

This version begins to support the following new methods:

• FlatMap[T, U any](option Option[T], mapper func(v T) Option[U]) Option[U]
• FlatMapOr[T, U any](option Option[T], fallbackValue U, mapper func(v T) Option[U]) U
• FlatMapWithError[T, U any](option Option[T], mapper func(v T) (Option[U], error)) (Option[U], error)
• FlatMapOrWithError[T, U any](option Option[T], fallbackValue U, mapper func(v T) (Option[U], error)) (U, error)

Please refer to the godoc for more details: https://pkg.go.dev/github.com/moznion/go-optional