What is the difference between Writer and WriterT in Haskell? Is one preferred over the other?
What is the difference between Writer and WriterT in Haskell? Is one preferred over
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What is the difference between Writer and WriterT in Haskell? Is one preferred over the other?
The difference is that
Writeris a monad, whereasWriterTis a monad transformer, i.e. you give it some underlying monad, and it gives you back a new monad with “writer” features on top. If you only need the writer-specific features, useWriter. If you need to combine its effects with some other monad, such asIO, useWriterT.