我想編譯一個哈斯克爾源包作爲動態庫與OCaml代碼一起使用。我試着在源文件的.cabal文件上使用--enable-shared選項,cabal install,我得到了一個Perhaps you haven't installed the "dyn" libraries for package 'zeromq4-haskell-0.6.5'錯誤。經過一番Google搜索之後,我意識到依賴項也必須
我有以下代碼: {-# LANGUAGE DefaultSignatures#-}
import Control.Monad.Trans.Class
import Control.Monad.Trans.Maybe
class Monad m => MonadMaybe m where
liftMaybe :: Maybe a -> m a
default liftM