Improve String.toFloat and String.toInt

[evancz]

This should allow each parser to accept a broader range of inputs and parse them more quickly.

For example, toFloat can now handle scientific notation like 1e40, and toInt can handle hexadecimal like 0xBEEF.

This change relies on the fact that +str and Number(str) do the same thing, and that Number is more restrictive in parsing than parseInt and parseFloat. This is based on information from this and this.

I believe it will be faster, but I have not confirmed this.

Remaining Tasks

• Confirm that this works with strictly larger range of numbers.
• Actually race the new and old implementations against each other to compare speed.
• Attempt to make it crash.

[process-bot]

Thanks for the pull request! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[process-bot]

Thanks for the pull request! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[evancz]

Just a heads up, I'm working on the perf part / fixing some errors.

[evancz]

Just a heads up, I'm working on the perf part / fixing some errors.

[evancz]

Okay, this is superseded by https://github.com/elm-lang/core/pull/818

[evancz]

Okay, this is superseded by https://github.com/elm-lang/core/pull/818