FileReader

`FileReader(filename, preprocess=False, defines={}, message_handler=None)`

Read file line by line with error reporting and preprocessor.

PARAMETER	DESCRIPTION
`filename`	file to read TYPE: `str`
`preprocess`	whether to run preprocessor TYPE: `bool` DEFAULT: `False`
`defines`	dictionary with preprocessor defines TYPE: `dict` DEFAULT: `{}`
`message_handler`	message handler to use for error reporting TYPE: `MessageHandler \| None` DEFAULT: `None`

Get next line from file, or None if at end of file.

RETURNS	DESCRIPTION
`str \| None`	next line from file, or None if at end of file