Re: Sorting with non-ASCII characters

[Jos van Uden]

On 24-9-2013 11:26, Chris wrote:
On Thursday, 19 September 2013 at 18:44:54 UTC, Jos van Uden wrote:
On 19-9-2013 17:18, Chris wrote:
Short question in case anyone knows the answer straight away:
How do I sort text so that non-ascii characters like "á" are treated in the same way as 
"a"?

Now I'm getting this:

[wow, ara, ába, marca]

===> sort(listAbove);

[ara, marca, wow, ába]

I'd like to get:

[ ába, ara, marca, wow]

If you only need to process extended ascii, then you could perhaps
make do with a transliterated sort, something like:

import std.stdio, std.string, std.algorithm, std.uni;

void main() {
    auto sa = ["wow", "ara", "ába", "Marca"];
    writeln(sa);
    trSort(sa);
    writeln(sa);
}

void trSort(C, alias less = "a < b")(C[] arr) {
    static dstring c1 = "àáâãäåçèéêëìíîïñòóôõöøùúûüýÿ";
    static dstring c2 = "aaaaaaceeeeiiiinoooooouuuuyy";
    schwartzSort!(a => tr(toLower(a), c1, c2), less)(arr);
}

Thanks a million, Jos! This does the trick for me.

Great.

Be aware that the above code does a case insensitive sort, if you need
case sensitive, you can use something like:


import std.stdio, std.string, std.algorithm, std.uni;

void main() {
    auto sa = ["wow", "ara", "ába", "Marca"];
    writeln(sa);
    trSort(sa, CaseSensitive.no);
    writeln(sa);
    
    writeln;
    
    sa = ["wow", "ara", "ába", "Marca"];
    writeln(sa);
    trSort(sa, CaseSensitive.yes);
    writeln(sa);
}

void trSort(C, alias less = "a < b")(C[] arr,
                            CaseSensitive cs = CaseSensitive.yes) {
                            
    static c1 = "àáâãäåçèéêëìíîïñòóôõöøùúûüýÿÀÁÂÃÄÅÇÈÉÊËÌÍÎÏÑÒÓÔÕÖØÙÚÛÜÝŸ"d;
    static c2 = "aaaaaaceeeeiiiinoooooouuuuyyAAAAAACEEEEIIIINOOOOOOUUUUYY"d;
    
    if (cs == CaseSensitive.no)
        arr.schwartzSort!(a => a.toLower.tr(c1, c2), less);
    else
        arr.schwartzSort!(a => a.tr(c1, c2), less);
}