toLower

[Joel]

On Wednesday, 16 August 2023 at 05:40:09 UTC, FeepingCreature 
wrote:
> On Tuesday, 15 August 2023 at 20:09:28 UTC, Joel wrote:
>> On Tuesday, 15 August 2023 at 16:54:49 UTC, FeepingCreature 
>> wrote:
>>> But does *not* import `std.ascii`! So there's no ambiguity 
>>> inside the `sort` string expression between the two `toLower` 
>>> functions..
>>
>> How do I get it to work?
>>
>> I tried std.ascii.toLower. And using alias 
>> toLower=std.ascii.toLower;
>
> To elaborate more, `toLower` doesn't work because 
> function-scope aliases are not considered for UFCS.
>
> ```
>     alias toLower = std.ascii.toLower;
>
>     ...
>     // So this does actually work:
>         .map!toLower
>     // but this does not, because it looks for a UFCS-capable 
> symbol
>         .map!(c => c.toLower)
>     // but this does again
>         .map!(c => toLower(c))
>
> ```

I get an compile time error with sort after using toLower, 
putting in array before sort, didn’t work:

     ```d
     void main() {
         Import std;

         "EzraTezla"
             .to!(char[])
             .byCodeUnit
             .map!(std.uni.toLower)
             .sort!"a<b"
             .writeln;
     }
     ```
     onlineapp.d(8): Error: none of the overloads of template 
`std.algorithm.sorting.sort` are callable using argument types 
`!("a<b")(MapResult!(toLower, ByCodeUnitImpl))`
     
/dlang/dmd/linux/bin64/../../src/phobos/std/algorithm/sorting.d(1925):        Candidate is: `sort(alias less = "a < b", SwapStrategy ss = SwapStrategy.unstable, Range)(Range r)`
       with `less = "a<b",
            ss = SwapStrategy.unstable,
            Range = MapResult!(toLower, ByCodeUnitImpl)`
       must satisfy one of the following constraints:
     `       hasSwappableElements!Range
            hasAssignableElements!Range
            ss != SwapStrategy.unstable`