Rewrite SplitLocale to not allocate

[Jacalz]

This improves performance and makes the code more readable. It also updates to use Go 1.19 as the base in go.mod so we get pruned module graphs (old Go compilers can still compile the code).

Benchstat:

goos: linux
goarch: amd64
pkg: github.com/fyne-io/go-locale
cpu: Intel(R) Core(TM) i7-7700 CPU @ 3.60GHz
              │   old.txt    │              new.txt               │
              │    sec/op    │   sec/op     vs base               │
SplitLocale-8   119.75n ± 1%   20.55n ± 1%  -82.84% (p=0.002 n=6)

              │  old.txt   │              new.txt              │
              │    B/op    │   B/op     vs base                │
SplitLocale-8   64.00 ± 0%   0.00 ± 0%  -100.00% (p=0.002 n=6)

              │  old.txt   │              new.txt               │
              │ allocs/op  │ allocs/op   vs base                │
SplitLocale-8   2.000 ± 0%   0.000 ± 0%  -100.00% (p=0.002 n=6)

[Jacalz]

Looks like the workflows need to be updated to run on Go 1.19.

[Jacalz]

I can get that fixed later today.

[jeandeaual]

Thanks for the PR, this does simplify the code and makes it easier to read 👍

This improves performance and makes the code more readable. It also updates to use Go 1.19 as the base in go.mod so we get pruned module graphs (old Go compilers can still compile the code).

I don't think that's true, since you're using strings.Cut, Go 1.18+ will be required to compile the code.

This improves performance and makes the code more readable. It also updates to use Go 1.19 as the base in go.mod so we get pruned module graphs (old Go compilers can still compile the code).

Since graph pruning was introduced in Go 1.17 and we now rely on strings.Cut, we can set the minimum supported version to be Go 1.18.

Looks like the workflows need to be updated to run on Go 1.19.

At least, removing Go 1.17 from the pipeline should be enough to run the tests.

[jeandeaual]

Suggested change

	go 1.19
	go 1.18

[jeandeaual]

Looks good to me, thanks for your contribution!

[Jacalz]

I'm happy to help. You might get more contributions for the team given that we are planning on using your package in Fyne going forward :)