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by morelisp 1606 days ago
Maybe I'm being downvoted for insufficient examples? OK, here's a big one:

OpenMetrics's production rule for the format says:

    labels = "{" [label *(COMMA label)] "}"
And yet, the Prometheus Java client library exports a trailing comma with no subsequent label.

As for fp, I've seen parsers break on `e` v. `E`, and `NaN`/`Inf`/ vs. `nan`/`inf`. The latest IETF draft even has a comment,

     ; Not 100% sure this captures all float corner cases.
Control characters are allowed in descriptors and label values and no normalization form is specified.
1 comments
SuperQue 1605 days ago
Yea, there still some corner cases and implementation bugs out there. We spent months deliberating how to deal with some of these. Because the base libraries in some languages just don't produce string output from IEEE 754 the same way.

IIRC, Java is different from Python is different from Go. So, really, this is a standardization in languages problem. We tried to work around these as best we could in the OM format.

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