readIO is:exact

The readIO function is similar to read except that it signals parse failure to the IO monad instead of terminating the program. This operation may fail with:

• isUserError if there is no unambiguous parse.

Examples

>>> fmap (+ 1) (readIO "1")
2

>>> readIO "not quite ()" :: IO ()
*** Exception: user error (Prelude.readIO: no parse)

The readIO function is similar to read except that it signals parse failure to the IO monad instead of terminating the program.

The readIO function is similar to read except that it signals parse failure to the IO monad instead of terminating the program.