unit Myc.Ast.RTL.Core;

interface

uses
    System.SysUtils,
    Myc.Utils,
    Myc.Data.Scalar,
    Myc.Data.Value,
    Myc.Ast.RTL;

type
    // Contains the "pure" native implementations.
    TRtlFunctions = record
    public
        // (* --- Dynamic Fallbacks (Interpreter) --- *)

        // Arithmetic
        [TRtlExport('+', Pure)]
        class function Add(const Args: TArray<TDataValue>): TDataValue; overload; static;
        [TRtlExport('-', Pure)]
        class function Subtract(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('*', Pure)]
        class function Multiply(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('/', Pure)]
        class function Divide(const Args: TArray<TDataValue>): TDataValue; static;

        [TRtlExport('div', Pure)]
        class function IntDivide(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('mod', Pure)]
        class function Modulus(const Args: TArray<TDataValue>): TDataValue; static;

        // Comparison
        [TRtlExport('=', Impure)]
        class function Equal(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('<>', Impure)]
        class function NotEqual(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('<', Impure)]
        class function LessThan(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('<=', Impure)]
        class function LessThanOrEqual(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('>', Impure)]
        class function GreaterThan(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('>=', Impure)]
        class function GreaterThanOrEqual(const Args: TArray<TDataValue>): TDataValue; static;

        // Logic / Bitwise
        [TRtlExport('not', Impure)]
        class function LogicalNot(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('and', Impure)]
        class function BitwiseAnd(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('or', Impure)]
        class function BitwiseOr(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('xor', Impure)]
        class function BitwiseXor(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('shl', Impure)]
        class function LeftShift(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('shr', Impure)]
        class function RightShift(const Args: TArray<TDataValue>): TDataValue; static;

        // (* Dynamic fallbacks for TScalar input *)
        [TRtlExport('Abs', Impure)]
        class function Abs(const Arg: TScalar): TScalar; static;
        [TRtlExport('Round', Impure)]
        class function Round(const Arg: TScalar): TScalar; static;
        [TRtlExport('Trunc', Impure)]
        class function Trunc(const Arg: TScalar): TScalar; static;
        [TRtlExport('Ceil', Impure)]
        class function Ceil(const Arg: TScalar): TScalar; static;
        [TRtlExport('Floor', Impure)]
        class function Floor(const Arg: TScalar): TScalar; static;
        [TRtlExport('Sign', Impure)]
        class function Sign(const Arg: TScalar): TScalar; static;

        // (* DateTime Constructors *)
        [TRtlExport('Now', Impure)]
        class function Now(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('Date', Impure)]
        class function Date(const Args: TArray<TDataValue>): TDataValue; static;

        // (* Other dynamic functions *)
        [TRtlExport('Memoize', Impure)]
        class function Memoize(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('Map', Impure)]
        class function Map(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('Reduce', Impure)]
        class function Reduce(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('Where', Impure)]
        class function Where(const Args: TArray<TDataValue>): TDataValue; static;
        [TRtlExport('Any', Impure)]
        class function Any(const Args: TArray<TDataValue>): TDataValue; static;

        // (* --- Static Specializations (Monomorphization Targets) --- *)

        // Add
        [TRtlExport('+', Pure)]
        class function Add_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('+', Pure)]
        class function Add_Float_Float_Float(A, B: Double): Double; static;
        [TRtlExport('+', Pure)]
        class function Add_Ordinal_Float_Float(A: Int64; B: Double): Double; static;
        [TRtlExport('+', Pure)]
        class function Add_Float_Ordinal_Float(A: Double; B: Int64): Double; static;
        [TRtlExport('+', Pure)]
        class function Add_Text_Text_Text(const A: String; const B: String): String; static;

        // Subtract
        [TRtlExport('-', Pure)]
        class function Subtract_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('-', Pure)]
        class function Subtract_Float_Float_Float(A, B: Double): Double; static;
        [TRtlExport('-', Pure)]
        class function Subtract_Ordinal_Float_Float(A: Int64; B: Double): Double; static;
        [TRtlExport('-', Pure)]
        class function Subtract_Float_Ordinal_Float(A: Double; B: Int64): Double; static;

        // Multiply
        [TRtlExport('*', Pure)]
        class function Multiply_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('*', Pure)]
        class function Multiply_Float_Float_Float(A, B: Double): Double; static;
        [TRtlExport('*', Pure)]
        class function Multiply_Ordinal_Float_Float(A: Int64; B: Double): Double; static;
        [TRtlExport('*', Pure)]
        class function Multiply_Float_Ordinal_Float(A: Double; B: Int64): Double; static;

        // Divide (Impure due to EDivByZero potential)
        [TRtlExport('/', Impure)]
        class function Divide_Ordinal_Ordinal_Float(A, B: Int64): Double; static;
        [TRtlExport('/', Impure)]
        class function Divide_Float_Float_Float(A, B: Double): Double; static;
        [TRtlExport('/', Impure)]
        class function Divide_Ordinal_Float_Float(A: Int64; B: Double): Double; static;
        [TRtlExport('/', Impure)]
        class function Divide_Float_Ordinal_Float(A: Double; B: Int64): Double; static;

        // Integer Math (Impure due to EDivByZero)
        [TRtlExport('div', Impure)]
        class function Div_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('mod', Impure)]
        class function Mod_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;

        // Comparisons
        [TRtlExport('=', Pure)]
        class function Equal_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('=', Pure)]
        class function Equal_Float_Float_Ordinal(A, B: Double): Int64; static;
        [TRtlExport('=', Pure)]
        class function Equal_Ordinal_Float_Ordinal(A: Int64; B: Double): Int64; static;
        [TRtlExport('=', Pure)]
        class function Equal_Float_Ordinal_Ordinal(A: Double; B: Int64): Int64; static;
        [TRtlExport('=', Pure)]
        class function Equal_Keyword_Keyword_Ordinal(A, B: Int64): Int64; static;

        [TRtlExport('<>', Pure)]
        class function NotEqual_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('<>', Pure)]
        class function NotEqual_Float_Float_Ordinal(A, B: Double): Int64; static;
        [TRtlExport('<>', Pure)]
        class function NotEqual_Ordinal_Float_Ordinal(A: Int64; B: Double): Int64; static;
        [TRtlExport('<>', Pure)]
        class function NotEqual_Float_Ordinal_Ordinal(A: Double; B: Int64): Int64; static;
        [TRtlExport('<>', Pure)]
        class function NotEqual_Keyword_Keyword_Ordinal(A, B: Int64): Int64; static;

        [TRtlExport('<', Pure)]
        class function Less_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('<', Pure)]
        class function Less_Float_Float_Ordinal(A, B: Double): Int64; static;
        [TRtlExport('<', Pure)]
        class function Less_Ordinal_Float_Ordinal(A: Int64; B: Double): Int64; static;
        [TRtlExport('<', Pure)]
        class function Less_Float_Ordinal_Ordinal(A: Double; B: Int64): Int64; static;

        [TRtlExport('<=', Pure)]
        class function LessOrEqual_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('<=', Pure)]
        class function LessOrEqual_Float_Float_Ordinal(A, B: Double): Int64; static;
        [TRtlExport('<=', Pure)]
        class function LessOrEqual_Ordinal_Float_Ordinal(A: Int64; B: Double): Int64; static;
        [TRtlExport('<=', Pure)]
        class function LessOrEqual_Float_Ordinal_Ordinal(A: Double; B: Int64): Int64; static;

        [TRtlExport('>', Pure)]
        class function Greater_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('>', Pure)]
        class function Greater_Float_Float_Ordinal(A, B: Double): Int64; static;
        [TRtlExport('>', Pure)]
        class function Greater_Ordinal_Float_Ordinal(A: Int64; B: Double): Int64; static;
        [TRtlExport('>', Pure)]
        class function Greater_Float_Ordinal_Ordinal(A: Double; B: Int64): Int64; static;

        [TRtlExport('>=', Pure)]
        class function GreaterOrEqual_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('>=', Pure)]
        class function GreaterOrEqual_Float_Float_Ordinal(A, B: Double): Int64; static;
        [TRtlExport('>=', Pure)]
        class function GreaterOrEqual_Ordinal_Float_Ordinal(A: Int64; B: Double): Int64; static;
        [TRtlExport('>=', Pure)]
        class function GreaterOrEqual_Float_Ordinal_Ordinal(A: Double; B: Int64): Int64; static;

        // Bitwise Static
        [TRtlExport('and', Pure)]
        class function And_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('or', Pure)]
        class function Or_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('xor', Pure)]
        class function Xor_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('shl', Pure)]
        class function Shl_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;
        [TRtlExport('shr', Pure)]
        class function Shr_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64; static;

        // Unary
        [TRtlExport('-', Pure)]
        class function Negate_Ordinal_Ordinal(A: Int64): Int64; static;
        [TRtlExport('-', Pure)]
        class function Negate_Float_Float(A: Double): Double; static;

        [TRtlExport('not', Pure)]
        class function Not_Ordinal_Ordinal(A: Int64): Int64; static;

        // Standard functions
        [TRtlExport('Abs', Pure)]
        class function Abs_Ordinal_Ordinal(A: Int64): Int64; static;
        [TRtlExport('Abs', Pure)]
        class function Abs_Float_Float(A: Double): Double; static;

        [TRtlExport('Round', Pure)]
        class function Round_Ordinal_Ordinal(A: Int64): Int64; static;
        [TRtlExport('Round', Pure)]
        class function Round_Float_Ordinal(A: Double): Int64; static;

        [TRtlExport('Trunc', Pure)]
        class function Trunc_Ordinal_Ordinal(A: Int64): Int64; static;
        [TRtlExport('Trunc', Pure)]
        class function Trunc_Float_Ordinal(A: Double): Int64; static;
    end;

implementation

uses
    System.Generics.Collections,
    System.Math,
    System.Dateutils,
    Myc.Data.Decimal;

{ TRtlFunctions - Operator Implementations }

class function TRtlFunctions.Add(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator + requires 2 arguments.');
    if (Args[0].Kind = vkText) and (Args[1].Kind = vkText) then
        Result := Args[0].AsText + Args[1].AsText
    else
        Result := Args[0].AsScalar + Args[1].AsScalar;
end;

class function TRtlFunctions.Subtract(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) = 1 then
        Result := -Args[0].AsScalar
    else if Length(Args) = 2 then
        Result := Args[0].AsScalar - Args[1].AsScalar
    else
        raise EArgumentException.Create('Operator - requires 1 or 2 arguments.');
end;

class function TRtlFunctions.Multiply(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator * requires 2 arguments.');
    Result := Args[0].AsScalar * Args[1].AsScalar;
end;

class function TRtlFunctions.Divide(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator / requires 2 arguments.');
    // Explicit check is handled in TScalar.Divide
    Result := Args[0].AsScalar / Args[1].AsScalar;
end;

class function TRtlFunctions.IntDivide(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator div requires 2 arguments.');
    Result := Args[0].AsScalar div Args[1].AsScalar;
end;

class function TRtlFunctions.Modulus(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator mod requires 2 arguments.');
    Result := Args[0].AsScalar mod Args[1].AsScalar;
end;

class function TRtlFunctions.Equal(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator = requires 2 arguments.');
    Result := TScalar.FromBoolean(Args[0].AsScalar = Args[1].AsScalar);
end;

class function TRtlFunctions.NotEqual(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator <> requires 2 arguments.');
    Result := TScalar.FromBoolean(Args[0].AsScalar <> Args[1].AsScalar);
end;

class function TRtlFunctions.LessThan(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator < requires 2 arguments.');
    Result := TScalar.FromBoolean(Args[0].AsScalar < Args[1].AsScalar);
end;

class function TRtlFunctions.LessThanOrEqual(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator <= requires 2 arguments.');
    Result := TScalar.FromBoolean(Args[0].AsScalar <= Args[1].AsScalar);
end;

class function TRtlFunctions.GreaterThan(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator > requires 2 arguments.');
    Result := TScalar.FromBoolean(Args[0].AsScalar > Args[1].AsScalar);
end;

class function TRtlFunctions.GreaterThanOrEqual(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator >= requires 2 arguments.');
    Result := TScalar.FromBoolean(Args[0].AsScalar >= Args[1].AsScalar);
end;

// --- Logic / Bitwise ---

class function TRtlFunctions.LogicalNot(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 1 then
        raise EArgumentException.Create('Operator not requires 1 argument.');
    Result := not Args[0].AsScalar;
end;

class function TRtlFunctions.BitwiseAnd(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator and requires 2 arguments.');
    Result := Args[0].AsScalar and Args[1].AsScalar;
end;

class function TRtlFunctions.BitwiseOr(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator or requires 2 arguments.');
    Result := Args[0].AsScalar or Args[1].AsScalar;
end;

class function TRtlFunctions.BitwiseXor(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator xor requires 2 arguments.');
    Result := Args[0].AsScalar xor Args[1].AsScalar;
end;

class function TRtlFunctions.LeftShift(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator shl requires 2 arguments.');
    Result := Args[0].AsScalar shl Args[1].AsScalar;
end;

class function TRtlFunctions.RightShift(const Args: TArray<TDataValue>): TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Operator shr requires 2 arguments.');
    Result := Args[0].AsScalar shr Args[1].AsScalar;
end;

{ TRtlFunctions - Standard Functions }

class function TRtlFunctions.Abs(const Arg: TScalar): TScalar;
begin
    case Arg.Kind of
        TScalar.TKind.Ordinal: Result := TScalar.FromInt64(System.Abs(Arg.Value.AsInt64));
        TScalar.TKind.Float, TScalar.TKind.DateTime: Result := TScalar.FromDouble(System.Abs(Arg.Value.AsDouble));
    else
        raise EArgumentException.Create('Abs requires a numeric argument.');
    end;
end;

class function TRtlFunctions.Round(const Arg: TScalar): TScalar;
begin
    case Arg.Kind of
        TScalar.TKind.Ordinal: Result := Arg;
        TScalar.TKind.Float, TScalar.TKind.DateTime:
        begin
            var val: Double := Arg.Value.AsDouble;
            Result := TScalar.FromInt64(System.Round(val));
        end;
    else
        raise EArgumentException.Create('Round requires a numeric argument.');
    end;
end;

class function TRtlFunctions.Trunc(const Arg: TScalar): TScalar;
begin
    case Arg.Kind of
        TScalar.TKind.Ordinal: Result := Arg;
        TScalar.TKind.Float, TScalar.TKind.DateTime:
        begin
            var val: Double := Arg.Value.AsDouble;
            Result := TScalar.FromInt64(System.Trunc(val));
        end;
    else
        raise EArgumentException.Create('Trunc requires a numeric argument.');
    end;
end;

class function TRtlFunctions.Ceil(const Arg: TScalar): TScalar;
begin
    case Arg.Kind of
        TScalar.TKind.Ordinal: Result := Arg;
        TScalar.TKind.Float, TScalar.TKind.DateTime: Result := TScalar.FromInt64(System.Math.Ceil(Arg.Value.AsDouble));
    else
        raise EArgumentException.Create('Ceil requires a numeric argument.');
    end;
end;

class function TRtlFunctions.Floor(const Arg: TScalar): TScalar;
begin
    case Arg.Kind of
        TScalar.TKind.Ordinal: Result := Arg;
        TScalar.TKind.Float, TScalar.TKind.DateTime: Result := TScalar.FromInt64(System.Math.Floor(Arg.Value.AsDouble));
    else
        raise EArgumentException.Create('Floor requires a numeric argument.');
    end;
end;

class function TRtlFunctions.Sign(const Arg: TScalar): TScalar;
begin
    case Arg.Kind of
        TScalar.TKind.Ordinal: Result := TScalar.FromInt64(System.Math.Sign(Arg.Value.AsInt64));
        TScalar.TKind.Float, TScalar.TKind.DateTime: Result := TScalar.FromInt64(System.Math.Sign(Arg.Value.AsDouble));
    else
        raise EArgumentException.Create('Sign requires a numeric argument.');
    end;
end;

// --- Date Constructors ---

class function TRtlFunctions.Now(const Args: TArray<TDataValue>): TDataValue;
begin
    Result := TScalar.FromDateTime(System.SysUtils.Now);
end;

class function TRtlFunctions.Date(const Args: TArray<TDataValue>): TDataValue;

    function GetInt(const V: TDataValue; ArgIndex: Integer): Word;
    begin
        if V.AsScalar.Kind <> TScalar.TKind.Ordinal then
            raise EArgumentException.CreateFmt('Date argument %d must be an Integer.', [ArgIndex]);
        Result := V.AsScalar.Value.AsInt64;
    end;

begin
    if Length(Args) = 3 then
    begin
        var y := GetInt(Args[0], 1);
        var m := GetInt(Args[1], 2);
        var d := GetInt(Args[2], 3);
        Result := TScalar.FromDateTime(EncodeDate(y, m, d));
    end
    else if Length(Args) = 0 then
        Result := TScalar.FromDateTime(System.SysUtils.Date)
    else
        raise EArgumentException.Create('Date expects 0 or 3 arguments (Year, Month, Day).');
end;

// --- High-Order / Series ---

class function TRtlFunctions.Memoize(const Args: TArray<TDataValue>): TDataValue;
var
    funcToMemoize: TDataValue.TFunc;
    memoizedFunc: TDataValue.TFunc;
begin
    if Length(Args) <> 1 then
        raise EArgumentException.Create('Memoize requires exactly one argument.');
    if Args[0].Kind <> vkMethod then
        raise EArgumentException.Create('The argument to Memoize must be a function.');

    var cCache: TDataValue;
    cCache.FromObj(TDictionary<Int64, TDataValue>.Create);

    funcToMemoize := Args[0].AsMethod();

    memoizedFunc :=
        function(const AArgs: TArray<TDataValue>): TDataValue
        var
            argScalar: TScalar;
            key: Int64;
        begin
            if (Length(AArgs) <> 1) or (AArgs[0].Kind <> vkScalar) then
                raise EArgumentException.Create('This memoized function can only be called with a single scalar argument.');

            argScalar := AArgs[0].AsScalar;
            if argScalar.Kind <> TScalar.TKind.Ordinal then
                raise EArgumentException.Create('This memoized function expects an ordinal argument for caching.');

            key := argScalar.Value.AsInt64;

            var cache := TDictionary<Int64, TDataValue>(cCache.AsObject);

            if cache.TryGetValue(key, Result) then
                exit;

            Result := funcToMemoize(AArgs);
            cache.Add(key, Result);
        end;

    Result := TDataValue(memoizedFunc);
end;

class function TRtlFunctions.Map(const Args: TArray<TDataValue>): TDataValue;
var
    sourceArg: TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Map requires exactly two arguments: a series and a function.');

    sourceArg := Args[0];
    if not (sourceArg.Kind in [vkSeries]) then
        raise EArgumentException.Create('The first argument to Map must be a series.');

    if Args[1].Kind <> vkMethod then
        raise EArgumentException.Create('The second argument to Map must be a function.');

    Result := TDataValue.Map(sourceArg.AsSeries, Args[1].AsMethod());
end;

class function TRtlFunctions.Reduce(const Args: TArray<TDataValue>): TDataValue;
var
    sourceArg: TDataValue;
    sourceSeries: ISeries;
    accumulator: TDataValue;
    reducerFunc: TDataValue.TFunc;
    i: Integer;
    currentItem: TScalar;
    reducerArgs: TArray<TDataValue>;
begin
    if Length(Args) <> 3 then
        raise EArgumentException.Create('Reduce requires exactly three arguments: a series, an initial value, and a reducer function.');

    sourceArg := Args[0];
    if sourceArg.Kind <> vkSeries then
        raise EArgumentException.Create('The first argument to Reduce must be a series.');

    if Args[2].Kind <> vkMethod then
        raise EArgumentException.Create('The third argument to Reduce must be a function.');

    sourceSeries := sourceArg.AsSeries;
    accumulator := Args[1];
    reducerFunc := Args[2].AsMethod();

    for i := sourceSeries.Count - 1 downto 0 do
    begin
        currentItem := sourceSeries.Items[i];
        reducerArgs := [accumulator, TDataValue(currentItem)];
        accumulator := reducerFunc(reducerArgs);
    end;

    Result := accumulator;
end;

class function TRtlFunctions.Where(const Args: TArray<TDataValue>): TDataValue;
var
    sourceArg: TDataValue;
    sourceSeries: ISeries;
    predicateFunc: TDataValue.TFunc;
    matchingIndices: TList<Integer>;
    i: Integer;
    item: TScalar;
    predicateResult: TDataValue;
    indexSeries: ISeries;
    mapperFunc: TDataValue.TFunc;
    finalSeries: ISeries;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Where requires exactly two arguments: a series and a predicate function.');

    sourceArg := Args[0];
    if sourceArg.Kind <> vkSeries then
        raise EArgumentException.Create('The first argument to Where must be a series.');

    if Args[1].Kind <> vkMethod then
        raise EArgumentException.Create('The second argument to Where must be a function.');

    sourceSeries := sourceArg.AsSeries;
    predicateFunc := Args[1].AsMethod();

    matchingIndices := TList<Integer>.Create;
    try
        for i := sourceSeries.Count - 1 downto 0 do
        begin
            item := sourceSeries.Items[i];
            predicateResult := predicateFunc([TDataValue(item)]);

            // Use the implicit Boolean operator of TScalar
            if (predicateResult.Kind = vkScalar) and (Boolean(predicateResult.AsScalar)) then
                matchingIndices.Add(i);
        end;

        indexSeries := TIndexSeries.Create(matchingIndices.ToArray);
    finally
        matchingIndices.Free;
    end;

    mapperFunc :=
        function(const AArgs: TArray<TDataValue>): TDataValue
        var
            idx: Integer;
        begin
            idx := AArgs[0].AsScalar.Value.AsInt64;
            Result := TDataValue(sourceSeries.Items[idx]);
        end;

    Result := TDataValue.Map(indexSeries, mapperFunc);
end;

class function TRtlFunctions.Any(const Args: TArray<TDataValue>): TDataValue;
var
    sourceArg: TDataValue;
    sourceSeries: ISeries;
    predicateFunc: TDataValue.TFunc;
    i: Integer;
    item: TScalar;
    predicateResult: TDataValue;
begin
    if Length(Args) <> 2 then
        raise EArgumentException.Create('Any requires exactly two arguments: a series and a predicate function.');

    sourceArg := Args[0];
    if sourceArg.Kind <> vkSeries then
        raise EArgumentException.Create('The first argument to Any must be a series.');

    if Args[1].Kind <> vkMethod then
        raise EArgumentException.Create('The second argument to Any must be a function.');

    sourceSeries := sourceArg.AsSeries;
    predicateFunc := Args[1].AsMethod();

    for i := 0 to sourceSeries.Count - 1 do
    begin
        item := sourceSeries.Items[i];
        predicateResult := predicateFunc([TDataValue(item)]);

        if (predicateResult.Kind = vkScalar) and (Boolean(predicateResult.AsScalar)) then
        begin
            Result := TScalar.FromBoolean(True);
            exit;
        end;
    end;

    Result := TScalar.FromBoolean(False);
end;

// --- Static Specializations ---

// Add
class function TRtlFunctions.Add_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := A + B;
end;
class function TRtlFunctions.Add_Float_Float_Float(A, B: Double): Double;
begin
    Result := A + B;
end;
class function TRtlFunctions.Add_Ordinal_Float_Float(A: Int64; B: Double): Double;
begin
    Result := A + B;
end;
class function TRtlFunctions.Add_Float_Ordinal_Float(A: Double; B: Int64): Double;
begin
    Result := A + B;
end;

// Subtract
class function TRtlFunctions.Subtract_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := A - B;
end;
class function TRtlFunctions.Subtract_Float_Float_Float(A, B: Double): Double;
begin
    Result := A - B;
end;
class function TRtlFunctions.Subtract_Ordinal_Float_Float(A: Int64; B: Double): Double;
begin
    Result := A - B;
end;
class function TRtlFunctions.Subtract_Float_Ordinal_Float(A: Double; B: Int64): Double;
begin
    Result := A - B;
end;

// Multiply
class function TRtlFunctions.Multiply_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := A * B;
end;
class function TRtlFunctions.Multiply_Float_Float_Float(A, B: Double): Double;
begin
    Result := A * B;
end;
class function TRtlFunctions.Multiply_Ordinal_Float_Float(A: Int64; B: Double): Double;
begin
    Result := A * B;
end;
class function TRtlFunctions.Multiply_Float_Ordinal_Float(A: Double; B: Int64): Double;
begin
    Result := A * B;
end;

// Divide
class function TRtlFunctions.Divide_Ordinal_Ordinal_Float(A, B: Int64): Double;
begin
    if B = 0 then
        raise EDivByZero.Create('Division by zero.');
    Result := A / B;
end;
class function TRtlFunctions.Divide_Float_Float_Float(A, B: Double): Double;
begin
    if B = 0.0 then
        raise EDivByZero.Create('Division by zero.');
    Result := A / B;
end;
class function TRtlFunctions.Divide_Ordinal_Float_Float(A: Int64; B: Double): Double;
begin
    if B = 0.0 then
        raise EDivByZero.Create('Division by zero.');
    Result := A / B;
end;
class function TRtlFunctions.Divide_Float_Ordinal_Float(A: Double; B: Int64): Double;
begin
    if B = 0 then
        raise EDivByZero.Create('Division by zero.');
    Result := A / B;
end;

// Integer Math
class function TRtlFunctions.Div_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := A div B;
end; // Delphi runtime handles EDivByZero for integers
class function TRtlFunctions.Mod_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := A mod B;
end;

// Comparisons
class function TRtlFunctions.Equal_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := Ord(A = B);
end;
class function TRtlFunctions.Equal_Float_Float_Ordinal(A, B: Double): Int64;
begin
    Result := Ord(SameValue(A, B));
end;
class function TRtlFunctions.Equal_Ordinal_Float_Ordinal(A: Int64; B: Double): Int64;
begin
    Result := Ord(SameValue(A, B));
end;
class function TRtlFunctions.Equal_Float_Ordinal_Ordinal(A: Double; B: Int64): Int64;
begin
    Result := Ord(SameValue(A, B));
end;
class function TRtlFunctions.Equal_Keyword_Keyword_Ordinal(A, B: Int64): Int64;
begin
    Result := Ord(A = B);
end;

class function TRtlFunctions.NotEqual_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := Ord(A <> B);
end;
class function TRtlFunctions.NotEqual_Float_Float_Ordinal(A, B: Double): Int64;
begin
    Result := Ord(not SameValue(A, B));
end;
class function TRtlFunctions.NotEqual_Ordinal_Float_Ordinal(A: Int64; B: Double): Int64;
begin
    Result := Ord(not SameValue(A, B));
end;
class function TRtlFunctions.NotEqual_Float_Ordinal_Ordinal(A: Double; B: Int64): Int64;
begin
    Result := Ord(not SameValue(A, B));
end;
class function TRtlFunctions.NotEqual_Keyword_Keyword_Ordinal(A, B: Int64): Int64;
begin
    Result := Ord(A <> B);
end;

class function TRtlFunctions.Less_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := Ord(A < B);
end;
class function TRtlFunctions.Less_Float_Float_Ordinal(A, B: Double): Int64;
begin
    Result := Ord(A < B);
end;
class function TRtlFunctions.Less_Ordinal_Float_Ordinal(A: Int64; B: Double): Int64;
begin
    Result := Ord(A < B);
end;
class function TRtlFunctions.Less_Float_Ordinal_Ordinal(A: Double; B: Int64): Int64;
begin
    Result := Ord(A < B);
end;

class function TRtlFunctions.LessOrEqual_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := Ord(A <= B);
end;
class function TRtlFunctions.LessOrEqual_Float_Float_Ordinal(A, B: Double): Int64;
begin
    Result := Ord(A <= B);
end;
class function TRtlFunctions.LessOrEqual_Ordinal_Float_Ordinal(A: Int64; B: Double): Int64;
begin
    Result := Ord(A <= B);
end;
class function TRtlFunctions.LessOrEqual_Float_Ordinal_Ordinal(A: Double; B: Int64): Int64;
begin
    Result := Ord(A <= B);
end;

class function TRtlFunctions.Greater_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := Ord(A > B);
end;
class function TRtlFunctions.Greater_Float_Float_Ordinal(A, B: Double): Int64;
begin
    Result := Ord(A > B);
end;
class function TRtlFunctions.Greater_Ordinal_Float_Ordinal(A: Int64; B: Double): Int64;
begin
    Result := Ord(A > B);
end;
class function TRtlFunctions.Greater_Float_Ordinal_Ordinal(A: Double; B: Int64): Int64;
begin
    Result := Ord(A > B);
end;

class function TRtlFunctions.GreaterOrEqual_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := Ord(A >= B);
end;
class function TRtlFunctions.GreaterOrEqual_Float_Float_Ordinal(A, B: Double): Int64;
begin
    Result := Ord(A >= B);
end;
class function TRtlFunctions.GreaterOrEqual_Ordinal_Float_Ordinal(A: Int64; B: Double): Int64;
begin
    Result := Ord(A >= B);
end;
class function TRtlFunctions.GreaterOrEqual_Float_Ordinal_Ordinal(A: Double; B: Int64): Int64;
begin
    Result := Ord(A >= B);
end;

// Bitwise Static
class function TRtlFunctions.And_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := A and B;
end;
class function TRtlFunctions.Or_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := A or B;
end;
class function TRtlFunctions.Xor_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := A xor B;
end;
class function TRtlFunctions.Shl_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := A shl B;
end;
class function TRtlFunctions.Shr_Ordinal_Ordinal_Ordinal(A, B: Int64): Int64;
begin
    Result := A shr B;
end;

// Unary
class function TRtlFunctions.Negate_Ordinal_Ordinal(A: Int64): Int64;
begin
    Result := -A;
end;
class function TRtlFunctions.Negate_Float_Float(A: Double): Double;
begin
    Result := -A;
end;

class function TRtlFunctions.Not_Ordinal_Ordinal(A: Int64): Int64;
begin
    Result := Ord(A = 0);
end; // Logical NOT for Int64

// Standard
class function TRtlFunctions.Abs_Ordinal_Ordinal(A: Int64): Int64;
begin
    Result := System.Abs(A);
end;
class function TRtlFunctions.Abs_Float_Float(A: Double): Double;
begin
    Result := System.Abs(A);
end;

class function TRtlFunctions.Add_Text_Text_Text(const A: String; const B: String): String;
begin
    Result := A + B;
end;

class function TRtlFunctions.Round_Ordinal_Ordinal(A: Int64): Int64;
begin
    Result := A;
end;
class function TRtlFunctions.Round_Float_Ordinal(A: Double): Int64;
begin
    Result := System.Round(A);
end;

class function TRtlFunctions.Trunc_Ordinal_Ordinal(A: Int64): Int64;
begin
    Result := A;
end;
class function TRtlFunctions.Trunc_Float_Ordinal(A: Double): Int64;
begin
    Result := System.Trunc(A);
end;

end.