GHC's REPL wraps all expressions in a giant do-block with an IO monad. It's practically useless without the meta-language of the colon commands. That said, trul

GHC's REPL wraps all expressions in a giant do-block with an IO monad. It's practically useless without the meta-language of the colon commands. That said, truly modern versions of GHC have deferred type checking for REPL use, which is impressive, useful and, ultimately, a simple emulation of a dynamic language. Never mind that not even Python or Ruby, and especially not JavaScript, provide sensible useful REPLs with sane code reloading semantics. People who shit on crappy type systems turn around and then shit on crappy REPLs in broken dynamic languages. I'd take a statically typed language over a language with a bad REPL any day.