Golang: How to correctly parse UTF-8 string from C

Question

I'm a newbie to the go world, so maybe this is obvious.

I have a Go function which I'm exposing to C with the go build -buildmode=c-shared and corresponding //export funcName comment. (You can see it here: https://github.com/udl/bmatch/blob/master/ext/levenshtein.go#L42 )

My conversion currently works like this:

func distance(s1in, s2in *C.char) int {
    s1 := C.GoString(s1in)
    s2 := C.GoString(s2in)

How would I handle UTF-8 input here? I've seen there is a UTF-8 package but I don't quite get how it works. https://golang.org/pkg/unicode/utf8/

Thank you!

Answer 1

You don't need to do anything special. UTF-8 is Go's "native" character encoding, so you can use the functions from the utf8 package you mentioned, eg utf8.RuneCountInString to get the number of Unicode runes in a string. Keep in mind that len(s) will still return the number of bytes in the string.

See this post in the official blog or this article for some details.