No, the standard library doesn't contain many of the things that Haskell's does because it's not Haskell, and people haven't really been asking for them like th

No, the standard library doesn't contain many of the things that Haskell's does because it's not Haskell, and people haven't really been asking for them like they have a variety of other things. And the reason people don't use them widely is that there's often better designs than passing around closures - lifetimes make useful mutation of closures' environments difficult, Rust largely revolves around mutation, so it's more common to invert the control flow (have functions return a command and interpret it, possibly in a loop, rather than have them take a closure) except in certain self-contained situations. That doesn't change the existence of HOFs.