Add a type-checking fast path for primitive types #755
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When `Draft<T>` is applied to a large enum type, TypeScript has to do a lot of unnecessary structural comparisons to confirm that no element of the enum matches `Function`, `Date`, `RegExp`, etc. Determining that they do match `string` or `number`, on the other hand, is trivial. This change splits `PrimitiveType` out of `AtomicObject` so that the fast path can be checked first. In microsoft/TypeScript#42824, this cut the check time from ~2.5 seconds to ~0.3 seconds.
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Supersedes #754. |
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Merged, thanks! |
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🎉 This PR is included in version 8.0.2 🎉 The release is available on: Your semantic-release bot 📦🚀 |
This was referenced Mar 18, 2021
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When
Draft<T>is applied to a large enum type, TypeScript has to do a lot of unnecessary structural comparisons to confirm that no element of the enum matchesFunction,Date,RegExp, etc. Determining that they do matchstringornumber, on the other hand, is trivial. This change splitsPrimitiveTypeout ofAtomicObjectso that the fast path can be checked first.In microsoft/TypeScript#42824, this cut the check time from ~2.5 seconds to ~0.3 seconds.