Re-do "waiting for all" #55
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Fixes #45.
ricea
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ricea
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lgtm from quick review. I haven't looked at the generated output yet.
| 1. <a>Resolve</a> |promise| with |stepsResult|. | ||
| 1. Let |failureStepsWrapper| be the following steps, given |reason|: | ||
| 1. Let |stepsResult| be the result of performing |failureSteps| given |reason|. If these steps threw an exception, <a>reject</a> |promise| with that exception. | ||
| 1. <a>Resolve</a> |promise| with |stepsResult|. |
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Nah. If failureSteps return something, we resolve with that thing. If they throw we reject on the previous line.
annevk
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annevk
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Unfortunately reusing Promise.all seems rather hard for this, so I guess this is the way to go.
| To <dfn id="waiting-for-all" export lt="wait for all|waiting for all">wait for all</dfn> of a <a>list</a> of promises |promises|, with success steps |successSteps| that take a <a>list</a> of JavaScript values and failure steps |failureSteps| that take a rejection reason JavaScript value, perform the following steps: | ||
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| 1. Let |rejectionHandler| be a built-in function that takes an argument |arg| and performs the following steps: | ||
| 1. Perform |failureSteps| given |arg|. |
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What's wrong with the indentation?
| To <dfn id="waiting-for-all" export lt="wait for all|waiting for all">wait for all</dfn> of a <a>list</a> of promises |promises|, with success steps |successSteps| that take a <a>list</a> of JavaScript values and failure steps |failureSteps| that take a rejection reason JavaScript value, perform the following steps: | ||
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| 1. Let |rejectionHandler| be a built-in function that takes an argument |arg| and performs the following steps: | ||
| 1. Perform |failureSteps| given |arg|. |
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If multiple promises reject, then failureSteps will be performed multiple times. Is this intentional?
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No, good catch. This was a no-op in Promise.all, because the failure steps there are just to reject a promise, and rejecting multiple times does nothing. Here it is bad. I will fix.
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Fixes #45.
/cc @ricea @annevk.
I don't know if I'll have time to update all the dependencies that would be broken by this change. I think the most prominent user is https://w3c.github.io/ServiceWorker/.