我想编译一个哈斯克尔源包作为动态库与OCaml代码一起使用。我试着在源文件的.cabal文件上使用--enable-shared选项,cabal install,我得到了一个Perhaps you haven't installed the "dyn" libraries for package 'zeromq4-haskell-0.6.5'错误。经过一番Google搜索之后,我意识到依赖项也必须
我有以下代码: {-# 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