Remove "isPaused" thingy

[PaulRBerg]

The isPaused isn't helpful. It's outright confusing. This is the current implementation:

flow/src/abstracts/SablierFlowBase.sol

Lines 166 to 168 in 3e76d36

	function isPaused(uint256 streamId) external view override notNull(streamId) returns (bool result) {
	result = _streams[streamId].ratePerSecond.unwrap() == 0;
	}

This getterthingy basically provides an alternative definition for what 'paused' means in SablierFlow.

'Paused' doesn't mean just one of the two enum statuses PAUSED_SOLVENT or PAUSED_SOLVENT — it also means the state of the RPS being zero.

That means that isPaused can return zero even when the stream's status is VOIDED.

There's really no need for this thingy. It's a very thin abstraction that does more harm than good by existing. It also complicates our invariants a lot.

[PaulRBerg]

How do you determine if a stream is paused in the UI, @sablier-labs/frontend?

Do you use this getter isPaused, or do you check the status via statusOf?

[razgraf]

Neither, we watch for the Pause/Restart events.

[smol-ninja]

Are you proposing to rely on status than getter function? If yes, then can we not use the same argument for isVoided getter as well?

[PaulRBerg]

We can keep isPaused but it'd have to read the status and look for the PAUSED_ statuses.

isVoided is OK because it doesn't introduce an alternative meaning for the 'voided' concept.

My only beef is with the dual meaning of 'paused'.

[smol-ninja]

Makes sense. Thanks for answering my question. I agree with you. Also, I just realized that classifying it a getter is also misleading since there is no state variables tracking paused status. A more appropriate getter is getRatePerSecond which is already there.

[PaulRBerg]

You're welcome, and yeah good point!