Parse int larger than u8

[rupurt]

Currently it looks like you can only parse integer arguments represented as u8.

I get the following error when trying to use u16:

    const params = comptime clap.parseParamsComptime(
        \\-h, --help                       Display this help and exit.
        \\-l, --line-buffer <LINEBUFFER>   An option parameter, which takes a value.
        \\<FILE1>                          The base file
        \\<FILE2>                          The file to compare
        \\
    );
    const parsers = comptime .{
        .LINEBUFFER = clap.parsers.int(u16, 1024),
        .FILE1 = clap.parsers.string,
        .FILE2 = clap.parsers.string,
    };

src/main.zig:17:45: error: type 'u8' cannot represent integer value '1024'

The tests only cover u8 https://github.com/Hejsil/zig-clap/blob/master/clap/parsers.zig#L39

[Hejsil]

The second argument to clap.parsers.int is the radix aka, the base in which we parse the number. For 10, this means that "10" => 10. For 2 this means "10" => 2. I don't think the standard library parseInt supports base 1024.

[Hejsil]

I could rename it from radix to base to make this more clear. I think the standard library used to call it radix, but changed to base at some point after I wrote that function. Consistency is hard :)

[Hejsil]

This seems to be a misunderstanding of what the second argument of clap.parsers.int does. I've added some documentation to the function in this PR. Hopefully that should avoid future confusion

[rupurt]

Ah, gotcha!

Thanks for the clarification. That's just me being a newb in zig... More docs are always welcome though 😄 Thanks for the useful library!