For example, ParsecT has multiple type variables in its definition.
newtype ParsecT s u m a
= ParsecT {unParser :: forall b .
State s u
-> (a -> State s u -> ParseError -> m b)
-> (ParseError -> m b)
-> (a -> State s u -> ParseError -> m b)
-> (ParseError -> m b)
-> m b
}
Can we do it like this ?
newtype ParsecT m a s u -- Only the order of s u m a is changed to m a s u.
= ParsecT {unParser :: forall b .
State s u
-> (a -> State s u -> ParseError -> m b)
-> (ParseError -> m b)
-> (a -> State s u -> ParseError -> m b)
-> (ParseError -> m b)
-> m b
}
I am wondering whether there is a rule or principle about the order of type variables when we define a newtype.