Unicode/UTF-8 support

[marty1885]

Hi, I want to contribute Unicode support for the library. Do you know how much/what have to be done for the feature?

[tmplt]

None, I'm afraid. I'm unsure if the underlying Levenshtein implementation supports it.

[marty1885]

Hmmm.. You said that you use the same Levenshtein library as the original fuzzywuzzy does. How does fuzzywuzzy handles Unicode?

[tmplt]

I recall seatgeek/fuzzywuzzy supporting two implementations; it will use python-Levenshtein if installed. But from their past issues it seems that the library supports unicode.

I interpret that the Levenshtein implementation could work with any integral type, from
https://github.com/Tmplt/fuzzywuzzy/blob/a4f8b717b3f30208436f82054413660a8d2f7613/include/levenshtein.h#L23-L32

So I figure the Python interop maps unicode characters to integral values? I cannot say for sure. I would personally start there: see how Unicode is treated when Python calls C code and figure out if the Levenshtein implementation have to be changed.

[marty1885]

I guess there's no easy way to get Unicode support (Without switching std::string to a Unicode aware one for the entire library). Thanks .

[tmplt]

On 20-10-2019 00:09, Martin Chang wrote: I guess there's no easy way to get Unicode support (Without switching std::string to a Unicode aware one for the entire library). Thanks .

`std::string` can still be used (at least on Linux-based distros), but there will be a lot of intermediate `std::wstring` instances along with `std::mbstowcs` calls. Likely some hacks to interface with `levenshtein.c` unless reimplemented, too.

[marty1885]

I think the proper solution would be to use something like Qt's QString and re-implement levenshtein.c to support it. No hacks and Qt is popular enough on *nix systems. (Windows will be a problem)

[tmplt]

On 20-10-2019 21:38, Martin Chang wrote: I think the proper solution would be to use something like Qt's `QString` and re-implement levenshtein.c to support it.

I don't want to pull in Qt just for string comparison; Levenshtein could instead be reimplemented via templates where we let the user decide what string type they want to use.

[marty1885]

Levenshtein could instead be reimplemented

I'll look into that.