not package:classy-prelude

Boolean "not"

Adds a location description and maybe a file path and file handle to an IOException. If any of the file handle or file path is not given the corresponding value in the IOException remains unaltered.

I/O error where the operation failed because one of its arguments does not exist.

An error indicating that an IO operation failed because one of its arguments does not exist.

I/O error where the operation failed because one of its arguments does not exist.

The isNothing function returns True iff its argument is Nothing.

Examples

Basic usage:

>>> isNothing (Just 3)
False

>>> isNothing (Just ())
False

>>> isNothing Nothing
True

Only the outer constructor is taken into consideration:

>>> isNothing (Just Nothing)
False