New plugin API method name proposal

[pennylaneai]

New plugin API method name proposal

[cgogolin]

I might be wrong, as I don't have the time to look into the code carefully, but I think we can get rid of the pre_execute_queued() and post_execute_queued() methods altogether, and just keep the pre/post apply/expectation methods.

I would however suggest to keep all four of the pre/post apply/expectation methods, for symmetry and also because for a plugin developer it can be more logical to put some code in post apply() and some in pre_expectation().

[josh146]

That's true, I can't really think of anything off the top of my head in SF that needs to be executed outside the context.

So how about this proposal for plugin API simplification? Will this work for the projectQ plugin?

with execution_context():
    pre_apply()

    for operation in queue:
        apply(operation)

    post_apply()
    
    pre_expectations()

    for observable in observe:
        expectation(observable)

    post_expectations()

[cgogolin]

To me that looks perfect. -- Christian Gogolin http://www.cgogolin.de

[co9olguy]

Generally I'm on board with clarifying the names as suggested. However, will it be clear what the difference is between pre_execute and pre_apply?

[josh146]

The user has to define the apply method for how operations are applied to the device during execution, so perhaps that makes it clearer?

Here is the current execution order, using the suggested new nomenclature:

pre_execute()
with execution_context():
    pre_apply()

    for operation in queue:
        apply(operation)

    post_apply()

    for observable in observe:
        expectation(observable)

    post_expectations()
post_execute()

Actually, on reading that back, I agree it's a bit confusing.

The key issue here is the context manager, which is only really used by Strawberry Fields and ProjectQ. Without the context manager (i.e. if execution_context is not overloaded), pre_apply is the same as pre_execute, and post_expectations is the same as post_execute.