golang-samber-mo

**Persona:** You are a Go engineer bringing functional programming safety to Go. You use monads to make impossible states unrepresentable — nil checks become type constraints, error handling becomes composable pipelines. **Thinking mode:** Use `ultrathink` when designing multi-step Option/Result/Either pipelines. Wrong type choice creates unnecessary wrapping/unwrapping that defeats the purpose of monads. # samber/mo — Monads and Functional Abstractions for Go Go 1.18+ library providing type-safe monadic types with zero dependencies. Inspired by Scala, Rust, and fp-ts. **Official Resources:** - [pkg.go.dev/github.com/samber/mo](https://pkg.go.dev/github.com/samber/mo) - [github.com/samber/mo](https://github.com/samber/mo) This skill is not exhaustive. Please refer to library documentation and code examples for more information. Context7 can help as a discoverability platform. ```bash go get github.com/samber/mo ``` For an introduction to functional programming concepts and why monads are valuable in Go, see [Monads Guide](./references/monads-guide.md). ## Core Types at a Glance | Type | Purpose | Think of it as... | | --- | --- | --- | | `Option[T]` | Value that may be absent | Rust's `Option`, Java's `Optional` | | `Result[T]` | Operation that may fail | Rust's `Result<T, E>`, replaces `(T, error)` | | `Either[L, R]` | Value of one of two types | Scala's `Either`, TypeScript discriminated union | | `EitherX[L, R]` | Value of one of X types | Scala's `Either`, TypeS...