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rust-num / num-rational

Generic Rational numbers for Rust
Apache License 2.0
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Parse mixed numerals #97

Closed ConnyOnny closed 3 years ago

ConnyOnny commented 3 years ago

I added parsing of mixed numerals (e.g. "3/1/2" for three and a half), because I need it for implementing pesto.

Unfortunately it's a breaking change, because I had to add CheckedMul and CheckedAdd constraint for parsing. But I expect that every sane Integer also implements these two.

Feedback is very welcome.

cuviper commented 3 years ago

I have never seen that notation before, and I'm really hesitant to add it if it's really specific to one format (pesto). Is there a reason you can't just implement this in your own pesto parser?

ConnyOnny commented 3 years ago

Is the notation with a space (e.g. "3 1/2") more common? Would you accept the feature, if it could also accept this format?

Is there a reason you can't just implement this in your own pesto parser?

That is exactly what I am going to do, if this feature does not make it into num-rational ;-)

cuviper commented 3 years ago

Is the notation with a space (e.g. "3 1/2") more common? Would you accept the feature, if it could also accept this format?

Yes, a space is more common, but in mathematical use it's most common to just use improper fractions.

I'm inclined to say that even that mixed format would be better as a separate method, to make it clear about different expectations. I still probably wouldn't include the pesto format in that, unless maybe we made the "separator" an explicit argument?

Is there a reason you can't just implement this in your own pesto parser?

That is exactly what I am going to do, if this feature does not make it into num-rational ;-)

Honestly, I think that's probably best for such a specialized format.