Remove schedule component

[wahaj]

Summary

Deprecate the ScheduleComponent interface. Replace all ScheduleComponent occurrences with Union[Schedule, Instruction] in typing

Details and comments

Refer to PR #5137

Anywhere that currently accepts a ScheduleComponent should instead accept a Union[Schedule, Instruction]. The docstrings for the removed properties have been propagated to the Instruction and the Schedule classes themselves. Schedule and Instruction both now uses a 'Schedule' / 'Instruction' forwardRef of the class in the typed arguments

Fixes #5076

[taalexander]

Hello, @wahaj. I apologize for the long delay in my response, my focus was turned away from Qiskit. After a discussion with @lcapelluto, we believe the move to define a root NamedValue is preemptive since there is parallel work underway to define a universal IR for Qiskit and we do not want to interfere. Therefore, if you could remove NamedValue and have Instruction and Schedule just be root classes this would be excellent. I apologize for the wasted work, but I do believe it was on the right track.

[wahaj]

Hello, @wahaj. I apologize for the long delay in my response, my focus was turned away from Qiskit. After a discussion with @lcapelluto, we believe the move to define a root NamedValue is preemptive since there is parallel work underway to define a universal IR for Qiskit and we do not want to interfere. Therefore, if you could remove NamedValue and have Instruction and Schedule just be root classes this would be excellent. I apologize for the wasted work, but I do believe it was on the right track.

Hi @taalexander, the delay led me to believe that I was to open a new PR. Anyways I'll be removing the values module. If there is anything at all that is required to do in this PR except that ?

PS : Can we remove the channels argument in the ch_start_time channel argument

[taalexander]

I understand and this falls on me, I am sorry. Please do deprecate the channels argument, we can remove it in the following release after warning for an appropriate time. I do not see any additional changes that are required.

[taalexander]

This import is unnecessary and is causing circular import/linting issues. For the type hints just use 'Instruction'.

[wahaj]

Thank you for that. Hope it passes this time around

[wahaj]

Warning, treated as error:
Cannot resolve forward reference in type annotations of "qiskit.pulse.Schedule": name 'Instruction' is not defined
___________________________________ summary ____________________________________
ERROR:   docs: commands failed

This is the error Azure build gives me. The problem is with the forward References in Schedule and Instruction. According to PEP484 forward references section, this would cause a circular dependency either way. Can you help resolve this problem?

[wahaj]

Warning, treated as error:
Cannot resolve forward reference in type annotations of "qiskit.pulse.Schedule": name 'Instruction' is not defined
___________________________________ summary ____________________________________
ERROR:   docs: commands failed

Hi @taalexander,
This is the error Azure build gives me. The problem is with the forward References in Schedule and Instruction. According to PEP484 forward references section, this would cause a circular dependency either way. Can you help resolve this problem?

[taalexander]

Warning, treated as error:
Cannot resolve forward reference in type annotations of "qiskit.pulse.Schedule": name 'Instruction' is not defined
___________________________________ summary ____________________________________
ERROR:   docs: commands failed

Hi @taalexander,
This is the error Azure build gives me. The problem is with the forward References in Schedule and Instruction. According to PEP484 forward references section, this would cause a circular dependency either way. Can you help resolve this problem?

Agreed, the circular references are a byproduct of trying to be both a data structure and have a nice DSL like user interface. I think this was a mistake, and the qiskit.pulse.builder is taking the role of the user interface to construct a Schedule. I'll see if I can figure out how to make this work for now.

[taalexander]

I pushed a commit which should hopefully resolve these issues, lets see :)