I was expecting to find a function
integer :: Stream s m Char => ParsecT s u m Integer
or maybe even
natural :: Stream s m Char => ParsecT s u m Integer
in the standard libraries, but I did not find one.
What is the standard way of parsing plain natural numbers directly to an Integer?
Here is what I often do is to use the expression
read <$> many1 digit
which can have type Stream s m Char => ParsecT s u m Integer (or simply Parser Integer).
I don’t like the use of the the partial function read, but when the parser succeeds I know that the read will succeed, and it is somewhat readable.