Dotnet inlinable iterables (enumerables) WIP

Program.cs

using System.Collections;
using System.Runtime.CompilerServices;
// using DelegateTo;

namespace ConsoleApp1;

class Program
{
    [MethodImpl(MethodImplOptions.NoInlining | MethodImplOptions.AggressiveOptimization)]
    static void Main(string[] args)
    {
        MyArrayWrap<int> arr = CreateArray();

        // (new int[5]).AsSpan()
        var kek = arr.Where(new PredIntIsEven());
        
        // var kek = arr.GetEnumerator().Where(new PredIntIsEven());
        foreach (int item in kek)
        {
            Console.WriteLine(item);
        }
    }
    

    [MethodImpl(MethodImplOptions.NoInlining)]
    private static MyArrayWrap<int> CreateArray()
    {
        return new MyArrayWrap<int>{array = new []{1,1,1,1,2,2,3,4,5,6,7,8,9}};
    }
}

public struct PredIntIsEven: IPredicate<int>
{
    // [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public bool Matches(in int item)
    {
        return (item & 1) == 0;
        // return item > 5 ;
    }
}


public interface IPredicate<T>{
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    bool Matches(in T item);


}

// public static class MyArrayWrapExt {
//     
//     [MethodImpl(MethodImplOptions.AggressiveInlining)]
//     public static WhereEnumerable<T, TInner, TInnerIter, TPredicate> Where<T, TInner, TInnerIter, TPredicate>(this TInner @this, TPredicate predicate)
//         where TInner : IIterable<T, TInnerIter>
//         where TInnerIter:IITerator<T>
//         where TPredicate : IPredicate<T>
//     {
//         return new WhereEnumerable<T, TInner, TInnerIter, TPredicate>(@this, predicate);
//     }
//     
// }

public struct WhereEnumerable<T, TInner, TInnerIter, TPredicate > : IIterable<T, WhereEnumerable<T, TInner, TInnerIter, TPredicate >, WhereEnumerator<T, TInnerIter, TPredicate>>
where TInner : IIterable<T, TInner, TInnerIter>
where TInnerIter:IITerator<T>
where TPredicate:IPredicate<T>
{
    private TInner _inner;
    private TPredicate _predicate;

    public WhereEnumerable(TInner inner, TPredicate predicate)
    {
        _inner = inner;
        _predicate = predicate;
    }

    public WhereEnumerator<T, TInnerIter, TPredicate> GetEnumerator() => new(_inner.GetEnumerator(), _predicate);
}

public struct WhereEnumerator<T, TInnerIter, TPredicate> : IITerator<T> where TInnerIter:IITerator<T> where TPredicate:IPredicate<T>
{
    private TInnerIter _inner;
    private TPredicate _predicate;
        
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public WhereEnumerator(TInnerIter inner, TPredicate predicate)
    {
        _inner = inner;
        _predicate = predicate;
    }
        
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public bool MoveNext()
    {
        do
        {
            if (!_inner.MoveNext())
                return false;

        } while (!_predicate.Matches(_inner.Current));
            
        return true;
    }

    public ref T Current
    {
        [MethodImpl(MethodImplOptions.AggressiveInlining)] get => ref this._inner.Current;
    }

  
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public void Dispose()
    {
            
    }
}

public interface IITerator<T>:IDisposable
{
    bool MoveNext();
    public ref T Current { get; }
}

public interface IIterable<T, Self, TIter>
where TIter : IITerator<T>
where Self : IIterable<T, Self, TIter>
{
    TIter GetEnumerator();
    
    // [MethodImpl(MethodImplOptions.AggressiveInlining)]
    // public WhereEnumerable<T, Self, TIter, TPredicate> Where<TPredicate>( TPredicate predicate)
    //     where TPredicate : IPredicate<T>
    // {
    //     return new WhereEnumerable<T, Self, TIter, TPredicate>((Self)this, predicate);
    // }
}

public struct  MethodsImpl<T, Self, TIter>
    where TIter : IITerator<T>
    where Self : IIterable<T, Self, TIter>
{
    private Self self;

    public MethodsImpl(Self self)
    {
        this.self = self;
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public WhereEnumerable<T, Self, TIter, TPredicate> Where<TPredicate>( TPredicate predicate)
        where TPredicate : IPredicate<T>
    {
        return new WhereEnumerable<T, Self, TIter, TPredicate>(self, predicate);
    }
}





public partial struct MyArrayWrap<T> : IIterable<T, MyArrayWrap<T>, MyArrayWrap<T>.Enumerator>
{
    public T[] array;
    

    public Enumerator GetEnumerator() => new Enumerator(this.array);



    // [GenerateDelegate(Inline = true)]
    // public MethodsImpl<T, MyArrayWrap<T>, Enumerator> Methods
    // {
    //     [MethodImpl(MethodImplOptions.AggressiveInlining)]
    //     get
    //     {
    //         return new MethodsImpl<T, MyArrayWrap<T>, Enumerator>( this);
    //     }
    // }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public WhereEnumerable<T, MyArrayWrap<T>, Enumerator, TPredicate> Where<TPredicate>( TPredicate predicate)
        where TPredicate : IPredicate<T>
    {
        return new WhereEnumerable<T, MyArrayWrap<T>, Enumerator, TPredicate>(this, predicate);
    }

    public struct Enumerator : IITerator<T>
    {
        private T[] _array;
        private int _index;
        
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public Enumerator(T[] array)
        {
            _array = array;
            _index = -1;
        } 
        
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public bool MoveNext()
        {
            int num = this._index + 1;
            if (num >= this._array.Length)
                return false;
            this._index = num;
            return true;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void Reset()
        {
            _index = -1;
        }
        
        public ref T Current
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)] get => ref this._array[this._index];
        }

  
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void Dispose()
        {
            
        }
    }

}

Res.md

Output

C:\Users\winnie\AppData\Local\Programs\Rider\plugins\dpa\DotFiles\JetBrains.DPA.Runner.exe --handle=13056 --backend-pid=15976 --etw-collect-flags=67108622 --detach-event-name=dpa.detach.15976.2 --refresh-interval=1 -- C:/Users/winnie/RiderProjects/StructIterables/ConsoleApp1/bin/Release/net9.0/ConsoleApp1.exe
; Assembly listing for method ConsoleApp1.Program:Main(System.String[]) (FullOpts)
; Emitting BLENDED_CODE for X64 with AVX - Windows
; FullOpts code
; optimized code
; optimized using Synthesized PGO
; rsp based frame
; fully interruptible
; with Synthesized PGO: fgCalledCount is 100
; No PGO data
; 0 inlinees with PGO data; 12 single block inlinees; 2 inlinees without PGO data

G_M000_IG01:                ;; offset=0x0000
       sub      rsp, 56
       vxorps   xmm4, xmm4, xmm4
       vmovdqa  xmmword ptr [rsp+0x20], xmm4
       xor      eax, eax
       mov      qword ptr [rsp+0x30], rax

G_M000_IG02:                ;; offset=0x0015
       call     [ConsoleApp1.Program:CreateArray():ConsoleApp1.MyArrayWrap`1[int]]
       xor      ecx, ecx
       mov      gword ptr [rsp+0x20], rax
       mov      dword ptr [rsp+0x28], -1
       mov      byte  ptr [rsp+0x30], cl
       jmp      SHORT G_M000_IG04

G_M000_IG03:                ;; offset=0x0030
       call     [System.Console:WriteLine(int)]

G_M000_IG04:                ;; offset=0x0036
       mov      ecx, dword ptr [rsp+0x28]
       inc      ecx
       mov      rax, gword ptr [rsp+0x20]
       cmp      dword ptr [rax+0x08], ecx
       jg       SHORT G_M000_IG06

G_M000_IG05:                ;; offset=0x0046
       add      rsp, 56
       ret

G_M000_IG06:                ;; offset=0x004B
       mov      dword ptr [rsp+0x28], ecx
       mov      rcx, gword ptr [rsp+0x20]
       mov      eax, dword ptr [rsp+0x28]
       cmp      eax, dword ptr [rcx+0x08]
       jae      SHORT G_M000_IG07
       mov      ecx, dword ptr [rcx+4*rax+0x10]
       test     cl, 1
       jne      SHORT G_M000_IG04
       jmp      SHORT G_M000_IG03

G_M000_IG07:                ;; offset=0x0068
       call     CORINFO_HELP_RNGCHKFAIL
       int3

; Total bytes of code 110

2
2
4
6
8

Process finished with exit code 0.