Andres Löh on Nostr: nprofile1q…4rs4v This is tricky because it mixes behaviour specific to GHCi with ...

nprofile1qy2hwumn8ghj7un9d3shjtnddaehgu3wwp6kyqpq0p4hclaqjlup0fwjt5ke3mgxq6rtjth8u62yfv0s62xkxp04wjaqa4rs4v (nprofile…rs4v) This is tricky because it mixes behaviour specific to GHCi with the Haskell IO semantics. Typing `x <- action` in GHCi executes the action and binds its result to `x` for further use. As the type of `putStrLn "hello"` is `IO ()`, the result of that action is always `()`.

The GHCi syntax is reminiscent of the syntax used in do blocks, where `do x <- action1; somethingElse x` gets desugared to `action1 >>= \ x -> somethingElse x`.