Update reader read methods to include pre/post read checks

[drewejohnson]

Implement reader-specific methods for inspections before and after reading. Pre-checks could include ensuring the file exists, simple validation that the file is of the correct type (e.g. not reading a detector file with a depletion reader), or counting the number of time steps present in the results file #7. Post-read checks could include verifying that data was indeed stored. If nothing is stored, Exceptions should be raised, perhaps a new one like EmptyReader that inherits from SerpentToolsException

In order to accomplish this, I propose refactoring the public read methods for all readers to private _read methods. The base reader will contain the public read method, and seek for precheck and postcheck methods specific to each file type. These do not have to be overwritten for each reader.

Implementation Suggestion

class BaseReader(object):

    def read(self):
        self._precheck()
        # maybe some debug/info statements
        self._read()
        self._postcheck()
    def _precheck():
         pass
    def _postcheck():
        pass
    def _read():
        raise NotImplementedError

class SubClass(BaseReader):

    def _read():
        # do the things
    def _postcheck():
        assert thingsWereDone

Pre/post check functions should log errors/warnings accordingly, such as an error if the word DET does not appear in the first fuel lines of a supposed detector file. When applicable, Exceptions should be raised if things go really poorly.

[gridley]

I tried parsing a COE file the other day which only finished partially. Seems that this doesn’t get caught as-is.

[drewejohnson]

Agreed. I read a handful of depletion files as detectors and nothing was mentioned/raised 🙁 This will definitely help

[gridley]

I would absolutely be willing to take this issue, if you want.

[drewejohnson]

Sounds great! All yours

[drewejohnson]

Closed with #88