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I use BigInt often, but you can't (for example) do most substring operations with it, even though floating point indexes make no sense. Map goes part of the wa

I use BigInt often, but you can't (for example) do most substring operations with it, even though floating point indexes make no sense. Map goes part of the way to what I want. But I really want to control which objects are considered equivalent keys, rather than being limited to reference equality.

WorldMaker 6y ago
There's a Stage 2 proposal before TC-39 to add immutable Record and Tuple types [1] which would be structurally compared and perfect for complex Map keys. It's also easy enough to find or write quick simple Map wrappers that use a hash function on an object as keys when provided (either piggy-backing on the existing Object.prototype.valueOf, which always exists on every object and easily falls back to the reference-based current behavior, and expecting classes to have custom overrides for that, or using a Symbol named function of their own to avoid polluting own-property-keys/name clashes with other libraries). [1] https://github.com/tc39/proposal-record-tuple https://github.com/tc39/proposal-record-tuple