Make shared static this() encoding table compilable

[Salih Dincer]

On Monday, 14 March 2022 at 09:40:00 UTC, zhad3 wrote:
> [...]
> I usually compile my projects using LDC where this works fine, 
> but I don't want to force others to use LDC because of this one 
> problem.
>
> Hence I'd like to ask on how to change the code so that it 
> compiles on DMD in release mode (with optimizations). I thought 
> about having a computational algorithm instead of an encoding 
> table but sadly I could not find any references in that regard. 
> Apparently encoding tables seem to be the standard.



OMG, I gasp at my computer screen and waited for minutes. :)

When you edit the code at the back-end level, you can use system 
resources in the best way. I think you should start with 
[dlang.dmd.backend.aarray](https://github.com/dlang/dmd/blob/master/src/dmd/backend/aarray.d)

If we use the following codes with Ali's code by separate the 
keys and values, it compiles fast on DMD and works correctly:

```d
import std.stdio;
import dmd.backend.aarray;
import zencoding.windows949;

     struct Make_CP949Table(T)
     {
       private AArray!(Tinfo!T, T) aa;

       this(T[] keys, T[] values)
       {
         foreach (i, T value; values)
         {
           T * set = aa.get(&keys[i]);
           *set = value;
         }
         aa.rehash();
       }

       T* opBinaryRight(string op)(T index)
       if (op == "in")
       {
         T* key = aa.get(&index);
         if(*key > 0) return key;

         return null;
       }

       T get(T key)
       {
         return *aa.get(&key);
       }

       size_t length()
       {
         return aa.nodes;
       }
     }

Make_CP949Table!ushort cp949_table;
shared static this() { cp949_table = Make_CP949Table!ushort(keys, 
values); }
//        Ali had already prepared these for you ----------------^

     void main()
     {
       const(ubyte[]) cp949 = [
         0x64, 0x61, 0x74, 0x61, 0x5C, 0x69, 0x6D, 0x66,
         0x5C, 0xB1, 0xB8, 0xC6, 0xE4, 0xC4, 0xDA, 0x5F,
         0xC5, 0xA9, 0xB7, 0xE7, 0xBC, 0xBC, 0xC0, 0xCC,
         0xB4, 0xF5, 0x5F, 0xB3, 0xB2, 0x2E, 0x69, 0x6D,
         0x66, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
         0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
         0x00, 0x00, 0x00, 0x00];

       const(ushort[]) utf16 = [
         0x64, 0x61, 0x74, 0x61, 0x5C, 0x69, 0x6D, 0x66,
         0x5C, 0xAD6C, 0xD398, 0xCF54, 0x5F, 0xD06C, 0xB8E8, 
0xC138,
         0xC774, 0xB354, 0x5F, 0xB0A8, 0x2E, 0x69, 0x6D, 0x66];

       cp949.fromWindows949.writeln; // data\imf\구페코_크루세이더_남.imf
     }
```

SDB at 79