Json.Decoder.int Bug / Ints in Elm

[agrafix]

The javascript spec allows numbers up to 2^53-1 (9007199254740991) and Elm generally is fine with these large integers, too. The json decoder fails for inputs larger than 2147483647.

I've found the error in the Native.Json part:
https://github.com/elm-lang/core/blob/2a8dcb522f71541c299a8a465bb39bc17bb9ec67/src/Native/Json.js#L53

It checks that (value|0) === value, but this check will fail for any input larger than 2147483647 because binary operators only work on 32bit ints.

I did not send a pull request (yet?) because I'm not sure what the correct step is. The Bitwise module allows parameters of type Int, and this will produce broken results iff the number is larger. Should elm distinguish between Int (32 Bit) and LargeInt (53 Bit)? Or should we just fix the json parser?

[evancz]

PR #153 was open with a potential fix, but we closed it so @ajhager or @krisajenkins could do a PR with the faster version of the fix.

[evancz]

PR #153 was open with a potential fix, but we closed it so @ajhager or @krisajenkins could do a PR with the faster version of the fix.

[ajhager]

And the new PR is on its way. :)

[ajhager]

And the new PR is on its way. :)

[agrafix]

Very cool, looking forward to it! :-) @ajhager

[agrafix]

Very cool, looking forward to it! :-) @ajhager

[agrafix]

@evancz what do you think about the behavior of the bitwise module? maybe there should at lease be a warning that is only works for 32 Bits Ints?

[agrafix]

@evancz what do you think about the behavior of the bitwise module? maybe there should at lease be a warning that is only works for 32 Bits Ints?

[evancz]

Not sure what happened here, so I am going to close. Someone please reopen with fresh information if something else needs to happen.

[evancz]

Not sure what happened here, so I am going to close. Someone please reopen with fresh information if something else needs to happen.