NumberFormat maxSignificantDigits Limit
waldemar at google.com
Mon Feb 4 22:26:05 UTC 2019
There is precedence for using numbers around 20 for significant digit cutoffs in the spec. For example, if you look at how number tokens are parsed in the spec (§220.127.116.11), the implementation has the option to ignore significant digits after the 20th. That's not a bug; we did that intentionally in the early days of ECMAScript as a compromise between always requiring exact precision and cutting off after the 17th digit, which would get a significant fraction of values wrong.
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