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Why do some TypedArray methods not use let Pk = ! ToString(𝔽(k)), unlike Array.prototype.indexOf? #3530

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yossydev opened this issue Feb 1, 2025 · 2 comments · May be fixed by #3531
Open

Why do some TypedArray methods not use let Pk = ! ToString(𝔽(k)), unlike Array.prototype.indexOf? #3530

yossydev opened this issue Feb 1, 2025 · 2 comments · May be fixed by #3531

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@yossydev
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yossydev commented Feb 1, 2025 •
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While reviewing the specifications of TypedArray.prototype.indexOf (ECMA-262 § 23.2.3.17) and Array.prototype.indexOf (ECMA-262 § 23.1.3.17), I noticed a difference in the way ToString(𝔽(k)) is handled.

The difference is that Array.prototype.indexOf stores the result of ToString(𝔽(k)) in a variable Pk using let Pk = ! ToString(𝔽(k)), whereas TypedArray.prototype.indexOf does not seem to follow this pattern.

Array.prototype.indexOf TypedArray.prototype.indexOf
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Is this difference intentional, or is it simply a matter of whether or not the result is assigned to a variable?

If it’s the latter, wouldn’t it be better to standardize the approach? It seems that using Pk to store the result is preferred, so I think it would be better to align with that. What do you think?

Also, this same issue applies to lastIndexOf as well.
@michaelficarra
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Thank you for the well-written issue! This difference should be inconsequential. ! ToString(𝔽(k)) is infallible and unobservable, so whether it appears once or twice is exactly the same for conformance purposes. I would be willing to accept a PR that makes these steps mirror each other (in either direction) for consistency.

@yossydev
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yossydev commented Feb 4, 2025

Thank you for your reply!

Thank you for the well-written issue! This difference should be inconsequential. ! ToString(𝔽(k)) is infallible and unobservable, so whether it appears once or twice is exactly the same for conformance purposes.

First of all, I’m glad to know this. As I expected.

I would be willing to accept a PR that makes these steps mirror each other (in either direction) for consistency.

Since the behavior doesn’t change, it’s not really a problem, but since it’s part of the specification, I was a bit curious about it.
Either way is fine, but I think I’d prefer to modify it so that pk is used instead of calling it multiple times!

@yossydev yossydev linked a pull request Feb 4, 2025 that will close this issue
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Editorial: Store ToString(𝔽(k)) in a variable for consistency yossydev/ecma262
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@michaelficarra @yossydev