MycLib/Src/Data/Myc.Data.Types.pas

unit Myc.Data.Types;

interface

uses
    System.Generics.Collections,
    System.SysUtils,
    System.RTTI;

type
    TDataKind = (dkVoid, dkOrdinal, dkFloat, dkText, dkTimestamp, dkDecimal, dkRecord, dkTuple, dkArray, dkEnum, dkMethod);

    IDataType = interface
        {$region 'private'}
        function GetName: String;
        function GetKind: TDataKind;
        {$endregion}
        property Name: String read GetName;
        property Kind: TDataKind read GetKind;
    end;

    IDataValue = interface
        {$region 'private'}
        function GetDataType: IDataType;
        function GetAsString: string;
        {$endregion}
        function AsTValue: TValue;
        property DataType: IDataType read GetDataType;
        property AsString: string read GetAsString;
    end;

    IDataVoidValue = interface(IDataValue)
    end;

    IDataVoidType = interface(IDataType)
        function GetValue: IDataVoidValue;
        property Value: IDataVoidValue read GetValue;
    end;

    IDataOrdinalValue = interface(IDataValue)
        {$region 'private'}
        function GetValue: Int64;
        {$endregion}
        property Value: Int64 read GetValue;
    end;

    IDataOrdinalType = interface(IDataType)
        function CreateValue(Init: Int64): IDataOrdinalValue;
    end;

    IDataFloatValue = interface(IDataValue)
        {$region 'private'}
        function GetValue: Double;
        {$endregion}
        property Value: Double read GetValue;
    end;

    IDataFloatType = interface(IDataType)
        function CreateValue(Init: Double): IDataFloatValue;
    end;

    IDataTextValue = interface(IDataValue)
        {$region 'private'}
        function GetValue: string;
        {$endregion}
        property Value: string read GetValue;
    end;

    IDataTextType = interface(IDataType)
        function CreateValue(const AValue: string): IDataTextValue;
    end;

    IDataTimestampValue = interface(IDataValue)
        {$region 'private'}
        function GetValue: TDateTime;
        {$endregion}
        property Value: TDateTime read GetValue;
    end;

    IDataTimestampType = interface(IDataType)
        function CreateValue(const AValue: TDateTime): IDataTimestampValue;
    end;

    // Represents a fixed-point decimal data value.
    IDataDecimalValue = interface(IDataValue)
        {$region 'private'}
        function GetValue: Int64;
        {$endregion}
        property Value: Int64 read GetValue;
    end;

    // Represents the type of a fixed-point decimal data value.
    IDataDecimalType = interface(IDataType)
        {$region 'private'}
        function GetScale: Integer;
        {$endregion}
        function CreateValue(const AValue: Int64): IDataDecimalValue;
        property Scale: Integer read GetScale;
    end;

    IDataEnumValue = interface(IDataValue)
        {$region 'private'}
        function GetValue: Integer;
        {$endregion}
        property Value: Integer read GetValue;
    end;

    IDataEnumType = interface(IDataType)
        {$region 'private'}
        function GetIdentifier(Idx: Integer): string;
        function GetIdentifierCount: Integer;
        {$endregion}
        function IndexOf(const AIdentifier: string): Integer;
        function CreateValue(const AValue: Integer): IDataEnumValue;
        property IdentifierCount: Integer read GetIdentifierCount;
        property Identifiers[Idx: Integer]: string read GetIdentifier; default;
    end;

    // A method that transforms one data value into another.
    TDataMethodProc = reference to function(const AValue: IDataValue): IDataValue;

    // Represents an executable method data value.
    IDataMethodValue = interface(IDataValue)
        {$region 'private'}
        function GetValue: TDataMethodProc;
        {$endregion}
        property Value: TDataMethodProc read GetValue;
    end;

    // Represents the type of a method data value, including its signature.
    IDataMethodType = interface(IDataType)
        {$region 'private'}
        function GetArgType: IDataType;
        function GetResultType: IDataType;
        {$endregion}
        property ArgType: IDataType read GetArgType;
        property ResultType: IDataType read GetResultType;
        function CreateValue(const AValue: TDataMethodProc): IDataMethodValue;
    end;

    IDataRecordValue = interface(IDataValue)
        {$region 'private'}
        function GetItem(Idx: Integer): IDataValue;
        {$endregion}
        property Items[Idx: Integer]: IDataValue read GetItem; default;
    end;

    TRecordField = record
        DataType: IDataType;
        Name: string;
        constructor Create(const AName: string; const ADataType: IDataType);
    end;

    IDataRecordType = interface(IDataType)
        {$region 'private'}
        function GetFieldCount: Integer;
        function GetField(Idx: Integer): TRecordField;
        {$endregion}
        function IndexOf(const AName: string): Integer;
        function CreateValue(const AItems: array of IDataValue): IDataRecordValue;
        property FieldCount: Integer read GetFieldCount;
        property Fields[Idx: Integer]: TRecordField read GetField; default;
    end;

    IDataTupleValue = interface(IDataValue)
        {$region 'private'}
        function GetItemCount: Integer;
        function GetItem(Idx: Integer): IDataValue;
        {$endregion}
        property ItemCount: Integer read GetItemCount;
        property Items[Idx: Integer]: IDataValue read GetItem; default;
    end;

    IDataTupleType = interface(IDataType)
        function CreateValue(const AItems: array of IDataValue): IDataTupleValue;
    end;

    IDataArrayValue = interface(IDataValue)
        {$region 'private'}
        function GetElementCount: Integer;
        function GetItem(Idx: Integer): IDataValue;
        {$endregion}
        property ElementCount: Integer read GetElementCount;
        property Items[Idx: Integer]: IDataValue read GetItem; default;
    end;

    IDataArrayType = interface(IDataType)
        {$region 'private'}
        function GetElementType: IDataType;
        {$endregion}
        function CreateValue(const AItems: array of IDataValue): IDataArrayValue;
        property ElementType: IDataType read GetElementType;
    end;

    TDataType = record
        type
            TValue = record
            private
                FDataValue: IDataValue;
                function GetDataType: IDataType; inline;
            public
                constructor Create(const ADataValue: IDataValue);

                // Casting
                function AsOrdinal: IDataOrdinalValue; inline;
                function AsFloat: IDataFloatValue; inline;
                function AsText: IDataTextValue; inline;
                function AsTimestamp: IDataTimestampValue; inline;
                function AsDecimal: IDataDecimalValue; inline;
                function AsRecord: IDataRecordValue; inline;
                function AsTuple: IDataTupleValue; inline;
                function AsArray: IDataArrayValue; inline;
                function AsEnum: IDataEnumValue; inline;
                function AsMethod: IDataMethodValue; inline;
                function AsVoid: IDataVoidValue; inline;

                class operator Implicit(const A: IDataValue): TDataType.TValue; overload; inline;
                class operator Implicit(const A: TDataType.TValue): IDataValue; overload; inline;

                class operator Implicit(const A: IDataOrdinalValue): TDataType.TValue; overload; inline;
                class operator Implicit(const A: IDataFloatValue): TDataType.TValue; overload; inline;
                class operator Implicit(const A: IDataTextValue): TDataType.TValue; overload; inline;
                class operator Implicit(const A: IDataTimestampValue): TDataType.TValue; overload; inline;
                class operator Implicit(const A: IDataDecimalValue): TDataType.TValue; overload; inline;
                class operator Implicit(const A: IDataEnumValue): TDataType.TValue; overload; inline;
                class operator Implicit(const A: IDataMethodValue): TDataType.TValue; overload; inline;
                class operator Implicit(const A: IDataRecordValue): TDataType.TValue; overload; inline;
                class operator Implicit(const A: IDataTupleValue): TDataType.TValue; overload; inline;
                class operator Implicit(const A: IDataArrayValue): TDataType.TValue; overload; inline;
                class operator Implicit(const A: IDataVoidValue): TDataType.TValue; overload; inline;

                property DataValue: IDataValue read FDataValue;
                property DataType: IDataType read GetDataType;
            end;

            TVoid = record
            private
                FVoidType: IDataVoidType;
                function GetValue: IDataVoidValue; inline;
            public
                constructor Create(const AVoidType: IDataVoidType);
                class operator Implicit(const A: IDataVoidType): TDataType.TVoid; overload; inline;
                class operator Implicit(const A: TDataType.TVoid): IDataVoidType; overload; inline;
                property Value: IDataVoidValue read GetValue;
            end;

            TOrdinal = record
            private
                FOrdinalType: IDataOrdinalType;
            public
                constructor Create(const AOrdinalType: IDataOrdinalType);
                class operator Implicit(const A: IDataOrdinalType): TDataType.TOrdinal; overload; inline;
                class operator Implicit(const A: TDataType.TOrdinal): IDataOrdinalType; overload; inline;
                function CreateValue(Init: Int64): IDataOrdinalValue; inline;
            end;

            TFloat = record
            private
                FFloatType: IDataFloatType;
            public
                constructor Create(const AFloatType: IDataFloatType);
                class operator Implicit(const A: IDataFloatType): TDataType.TFloat; overload; inline;
                class operator Implicit(const A: TDataType.TFloat): IDataFloatType; overload; inline;
                function CreateValue(Init: Double): IDataFloatValue; inline;
            end;

            TText = record
            private
                FTextType: IDataTextType;
            public
                constructor Create(const ATextType: IDataTextType);
                class operator Implicit(const A: IDataTextType): TDataType.TText; overload; inline;
                class operator Implicit(const A: TDataType.TText): IDataTextType; overload; inline;
                function CreateValue(const AValue: string): IDataTextValue; inline;
            end;

            TTimestamp = record
            private
                FTimestampType: IDataTimestampType;
            public
                constructor Create(const ATimestampType: IDataTimestampType);
                class operator Implicit(const A: IDataTimestampType): TDataType.TTimestamp; overload; inline;
                class operator Implicit(const A: TDataType.TTimestamp): IDataTimestampType; overload; inline;
                function CreateValue(const AValue: TDateTime): IDataTimestampValue; inline;
            end;

            TDecimal = record
                type
                    TValue = record
                    private
                        // The wrapped interface instance.
                        FDecimalValue: IDataDecimalValue;
                        function GetValue: Int64; inline;
                    public
                        constructor Create(const ADecimalValue: IDataDecimalValue);

                        class operator Implicit(const A: IDataDecimalValue): TDataType.TDecimal.TValue; overload; inline;
                        class operator Implicit(const A: TDataType.TDecimal.TValue): IDataDecimalValue; overload; inline;

                        property Value: Int64 read GetValue;
                    end;

            private
                FDecimalType: IDataDecimalType;
                function GetScale: Integer; inline;
            public
                constructor Create(const ADecimalType: IDataDecimalType);
                class operator Implicit(const A: IDataDecimalType): TDataType.TDecimal; overload; inline;
                class operator Implicit(const A: TDataType.TDecimal): IDataDecimalType; overload; inline;
                function CreateValue(const AValue: Int64): TDataType.TDecimal.TValue; inline;
                property Scale: Integer read GetScale;
            end;

            TEnum = record
            private
                FEnumType: IDataEnumType;
                function GetIdentifier(Idx: Integer): string; inline;
                function GetIdentifierCount: Integer; inline;
            public
                constructor Create(const AEnumType: IDataEnumType);
                class operator Implicit(const A: IDataEnumType): TDataType.TEnum; overload; inline;
                class operator Implicit(const A: TDataType.TEnum): IDataEnumType; overload; inline;
                function IndexOf(const AIdentifier: string): Integer; inline;
                function CreateValue(const AValue: Integer): IDataEnumValue; overload; inline;
                function CreateValue(const AIdentifier: string): IDataEnumValue; overload; inline;
                property IdentifierCount: Integer read GetIdentifierCount;
                property Identifiers[Idx: Integer]: string read GetIdentifier; default;
            end;

            TRecord = record
            private
                FRecordType: IDataRecordType;
                function GetFieldCount: Integer; inline;
                function GetField(Idx: Integer): TRecordField; inline;
            public
                constructor Create(const ARecordType: IDataRecordType);
                class operator Implicit(const A: IDataRecordType): TDataType.TRecord; overload; inline;
                class operator Implicit(const A: TDataType.TRecord): IDataRecordType; overload; inline;
                function IndexOf(const AName: string): Integer; inline;
                function CreateValue(const AItems: array of IDataValue): IDataRecordValue;
                property FieldCount: Integer read GetFieldCount;
                property Fields[Idx: Integer]: TRecordField read GetField; default;
            end;

            TTuple = record
            private
                FTupleType: IDataTupleType;
            public
                constructor Create(const ATupleType: IDataTupleType);
                class operator Implicit(const A: IDataTupleType): TDataType.TTuple; overload; inline;
                class operator Implicit(const A: TDataType.TTuple): IDataTupleType; overload; inline;
                function CreateValue(const AItems: array of IDataValue): IDataTupleValue;
            end;

            TArray = record
            private
                FArrayType: IDataArrayType;
                function GetElementType: IDataType; inline;
            public
                constructor Create(const AArrayType: IDataArrayType);
                class operator Implicit(const A: IDataArrayType): TDataType.TArray; overload; inline;
                class operator Implicit(const A: TDataType.TArray): IDataArrayType; overload; inline;
                function CreateValue(const AItems: array of IDataValue): IDataArrayValue;
                property ElementType: IDataType read GetElementType;
            end;

            TMethod = record
                type
                    TProc = reference to function(const AValue: TDataType.TValue): TDataType.TValue;
            private
                FMethodType: IDataMethodType;
                function GetArgType: IDataType; inline;
                function GetResultType: IDataType; inline;
            public
                constructor Create(const AMethodType: IDataMethodType);
                class operator Implicit(const A: IDataMethodType): TDataType.TMethod; overload; inline;
                class operator Implicit(const A: TDataType.TMethod): IDataMethodType; overload; inline;
                property ArgType: IDataType read GetArgType;
                property ResultType: IDataType read GetResultType;
                function CreateValue(const Proc: TProc): IDataMethodValue; inline;
            end;

    strict private
        FDataType: IDataType;
        function GetName: String; inline;
        function GetKind: TDataKind; inline;
        class var
            FArrayTypeRegistry: TDictionary<IDataType, IDataArrayType>;
            FRecordTypeRegistry: TDictionary<TArray<TRecordField>, IDataRecordType>;
            FMethodTypeRegistry: TDictionary<TPair<IDataType, IDataType>, IDataMethodType>;
            FDecimalTypes: TArray<IDataDecimalType>;
        class constructor CreateClass;
        class destructor DestroyClass;
    public
        constructor Create(const ADataType: IDataType);

        class operator Implicit(const A: IDataType): TDataType; overload; inline;
        class operator Implicit(const A: TDataType): IDataType; overload; inline;
        class operator Implicit(const A: TDataType.TVoid): TDataType; overload; inline;
        class operator Implicit(const A: TDataType.TOrdinal): TDataType; overload; inline;
        class operator Implicit(const A: TDataType.TFloat): TDataType; overload; inline;
        class operator Implicit(const A: TDataType.TText): TDataType; overload; inline;
        class operator Implicit(const A: TDataType.TTimestamp): TDataType; overload; inline;
        class operator Implicit(const A: TDataType.TDecimal): TDataType; overload; inline;
        class operator Implicit(const A: TDataType.TEnum): TDataType; overload; inline;
        class operator Implicit(const A: TDataType.TMethod): TDataType; overload; inline;
        class operator Implicit(const A: TDataType.TRecord): TDataType; overload; inline;
        class operator Implicit(const A: TDataType.TTuple): TDataType; overload; inline;
        class operator Implicit(const A: TDataType.TArray): TDataType; overload; inline;

        // Type factories
        class function Void: TDataType.TVoid; static; inline;
        class function Ordinal: TDataType.TOrdinal; static; inline;
        class function Float: TDataType.TFloat; static; inline;
        class function Text: TDataType.TText; static; inline;
        class function Timestamp: TDataType.TTimestamp; static; inline;
        class function DecimalOf(const AScale: Integer): TDataType.TDecimal; static;
        class function Tuple: TDataType.TTuple; static; inline;
        class function MethodOf(const AArgType, AResultType: IDataType): TDataType.TMethod; static;
        class function ArrayOf(const AElementType: IDataType): TDataType.TArray; static;
        class function RecordOf(const Fields: TArray<TRecordField>): TDataType.TRecord; overload; static;
        class function RecordOf(const Fields: array of TRecordField): TDataType.TRecord; overload; static;
        class function EnumOf(const AName: string; const AIdentifiers: array of string): TDataType.TEnum; static;

        function AsOrdinal: TDataType.TOrdinal; inline;
        function AsFloat: TDataType.TFloat; inline;
        function AsText: TDataType.TText; inline;
        function AsTimestamp: TDataType.TTimestamp; inline;
        function AsDecimal: TDataType.TDecimal; inline;
        function AsRecord: TDataType.TRecord; inline;
        function AsTuple: TDataType.TTuple; inline;
        function AsArray: TDataType.TArray; inline;
        function AsEnum: TDataType.TEnum; inline;
        function AsMethod: TDataType.TMethod; inline;

        property DataType: IDataType read FDataType;
        property Name: String read GetName;
        property Kind: TDataKind read GetKind;
    end;

implementation

uses
    System.SyncObjs,
    System.Generics.Defaults,
    Myc.Data.Types.Void,
    Myc.Data.Types.Ordinal,
    Myc.Data.Types.Float,
    Myc.Data.Types.Text,
    Myc.Data.Types.Timestamp,
    Myc.Data.Types.Decimal,
    Myc.Data.Types.Arrays,
    Myc.Data.Types.Records,
    Myc.Data.Types.Tuple,
    Myc.Data.Types.Enum,
    Myc.Data.Types.Method;

{ TRecordField }

constructor TRecordField.Create(const AName: string; const ADataType: IDataType);
begin
    Name := AName;
    DataType := ADataType;
end;

{ TDataType.TDecimal.TValue }

constructor TDataType.TDecimal.TValue.Create(const ADecimalValue: IDataDecimalValue);
begin
    FDecimalValue := ADecimalValue;
end;

function TDataType.TDecimal.TValue.GetValue: Int64;
begin
    Result := FDecimalValue.Value;
end;

class operator TDataType.TDecimal.TValue.Implicit(const A: IDataDecimalValue): TDataType.TDecimal.TValue;
begin
    Result.FDecimalValue := A;
end;

class operator TDataType.TDecimal.TValue.Implicit(const A: TDataType.TDecimal.TValue): IDataDecimalValue;
begin
    Result := A.FDecimalValue;
end;

{ TDataType.TVoid }

constructor TDataType.TVoid.Create(const AVoidType: IDataVoidType);
begin
    FVoidType := AVoidType;
end;

function TDataType.TVoid.GetValue: IDataVoidValue;
begin
    Result := FVoidType.Value;
end;

class operator TDataType.TVoid.Implicit(const A: IDataVoidType): TDataType.TVoid;
begin
    Result.FVoidType := A;
end;

class operator TDataType.TVoid.Implicit(const A: TDataType.TVoid): IDataVoidType;
begin
    Result := A.FVoidType;
end;

{ TDataType.TOrdinal }

constructor TDataType.TOrdinal.Create(const AOrdinalType: IDataOrdinalType);
begin
    FOrdinalType := AOrdinalType;
end;

function TDataType.TOrdinal.CreateValue(Init: Int64): IDataOrdinalValue;
begin
    Result := FOrdinalType.CreateValue(Init);
end;

class operator TDataType.TOrdinal.Implicit(const A: TDataType.TOrdinal): IDataOrdinalType;
begin
    Result := A.FOrdinalType;
end;

class operator TDataType.TOrdinal.Implicit(const A: IDataOrdinalType): TDataType.TOrdinal;
begin
    Result.FOrdinalType := A;
end;

{ TDataType.TFloat }

constructor TDataType.TFloat.Create(const AFloatType: IDataFloatType);
begin
    FFloatType := AFloatType;
end;

function TDataType.TFloat.CreateValue(Init: Double): IDataFloatValue;
begin
    Result := FFloatType.CreateValue(Init);
end;

class operator TDataType.TFloat.Implicit(const A: IDataFloatType): TDataType.TFloat;
begin
    Result.FFloatType := A;
end;

class operator TDataType.TFloat.Implicit(const A: TDataType.TFloat): IDataFloatType;
begin
    Result := A.FFloatType;
end;

{ TDataType.TText }

constructor TDataType.TText.Create(const ATextType: IDataTextType);
begin
    FTextType := ATextType;
end;

function TDataType.TText.CreateValue(const AValue: string): IDataTextValue;
begin
    Result := FTextType.CreateValue(AValue);
end;

class operator TDataType.TText.Implicit(const A: IDataTextType): TDataType.TText;
begin
    Result.FTextType := A;
end;

class operator TDataType.TText.Implicit(const A: TDataType.TText): IDataTextType;
begin
    Result := A.FTextType;
end;

{ TDataType.TTimestamp }

constructor TDataType.TTimestamp.Create(const ATimestampType: IDataTimestampType);
begin
    FTimestampType := ATimestampType;
end;

function TDataType.TTimestamp.CreateValue(const AValue: TDateTime): IDataTimestampValue;
begin
    Result := FTimestampType.CreateValue(AValue);
end;

class operator TDataType.TTimestamp.Implicit(const A: IDataTimestampType): TDataType.TTimestamp;
begin
    Result.FTimestampType := A;
end;

class operator TDataType.TTimestamp.Implicit(const A: TDataType.TTimestamp): IDataTimestampType;
begin
    Result := A.FTimestampType;
end;

{ TDataType.TDecimal }

constructor TDataType.TDecimal.Create(const ADecimalType: IDataDecimalType);
begin
    FDecimalType := ADecimalType;
end;

function TDataType.TDecimal.CreateValue(const AValue: Int64): TDataType.TDecimal.TValue;
begin
    Result.Create(FDecimalType.CreateValue(AValue));
end;

function TDataType.TDecimal.GetScale: Integer;
begin
    Result := FDecimalType.Scale;
end;

class operator TDataType.TDecimal.Implicit(const A: IDataDecimalType): TDataType.TDecimal;
begin
    Result.FDecimalType := A;
end;

class operator TDataType.TDecimal.Implicit(const A: TDataType.TDecimal): IDataDecimalType;
begin
    Result := A.FDecimalType;
end;

{ TDataType.TEnum }

constructor TDataType.TEnum.Create(const AEnumType: IDataEnumType);
begin
    FEnumType := AEnumType;
end;

function TDataType.TEnum.CreateValue(const AValue: Integer): IDataEnumValue;
begin
    Result := FEnumType.CreateValue(AValue);
end;

function TDataType.TEnum.CreateValue(const AIdentifier: string): IDataEnumValue;
var
    idx: Integer;
begin
    idx := IndexOf(AIdentifier);
    if idx < 0 then
        raise EArgumentException.CreateFmt('Unknown identifier: %s', [AIdentifier]);
    Result := CreateValue(idx);
end;

function TDataType.TEnum.GetIdentifier(Idx: Integer): string;
begin
    Result := FEnumType.GetIdentifier(Idx);
end;

function TDataType.TEnum.GetIdentifierCount: Integer;
begin
    Result := FEnumType.IdentifierCount;
end;

function TDataType.TEnum.IndexOf(const AIdentifier: string): Integer;
begin
    Result := FEnumType.IndexOf(AIdentifier);
end;

class operator TDataType.TEnum.Implicit(const A: IDataEnumType): TDataType.TEnum;
begin
    Result.FEnumType := A;
end;

class operator TDataType.TEnum.Implicit(const A: TDataType.TEnum): IDataEnumType;
begin
    Result := A.FEnumType;
end;

{ TDataType.TMethod }

constructor TDataType.TMethod.Create(const AMethodType: IDataMethodType);
begin
    FMethodType := AMethodType;
end;

function TDataType.TMethod.CreateValue(const Proc: TProc): IDataMethodValue;
begin
    if not Assigned(Proc) then
        raise EArgumentException.Create('Proc');

    var cProc: TProc := Proc;
    Result := FMethodType.CreateValue(function(const Value: IDataValue): IDataValue begin Result := cProc(Value); end);
end;

function TDataType.TMethod.GetArgType: IDataType;
begin
    Result := FMethodType.ArgType;
end;

function TDataType.TMethod.GetResultType: IDataType;
begin
    Result := FMethodType.ResultType;
end;

class operator TDataType.TMethod.Implicit(const A: IDataMethodType): TDataType.TMethod;
begin
    Result.FMethodType := A;
end;

class operator TDataType.TMethod.Implicit(const A: TDataType.TMethod): IDataMethodType;
begin
    Result := A.FMethodType;
end;

{ TDataType.TRecord }

constructor TDataType.TRecord.Create(const ARecordType: IDataRecordType);
begin
    FRecordType := ARecordType;
end;

function TDataType.TRecord.CreateValue(const AItems: array of IDataValue): IDataRecordValue;
begin
    Result := FRecordType.CreateValue(AItems);
end;

function TDataType.TRecord.GetField(Idx: Integer): TRecordField;
begin
    Result := FRecordType.GetField(Idx);
end;

function TDataType.TRecord.GetFieldCount: Integer;
begin
    Result := FRecordType.FieldCount;
end;

function TDataType.TRecord.IndexOf(const AName: string): Integer;
begin
    Result := FRecordType.IndexOf(AName);
end;

class operator TDataType.TRecord.Implicit(const A: IDataRecordType): TDataType.TRecord;
begin
    Result.FRecordType := A;
end;

class operator TDataType.TRecord.Implicit(const A: TDataType.TRecord): IDataRecordType;
begin
    Result := A.FRecordType;
end;

{ TDataType.TTuple }

constructor TDataType.TTuple.Create(const ATupleType: IDataTupleType);
begin
    FTupleType := ATupleType;
end;

function TDataType.TTuple.CreateValue(const AItems: array of IDataValue): IDataTupleValue;
begin
    Result := FTupleType.CreateValue(AItems);
end;

class operator TDataType.TTuple.Implicit(const A: IDataTupleType): TDataType.TTuple;
begin
    Result.FTupleType := A;
end;

class operator TDataType.TTuple.Implicit(const A: TDataType.TTuple): IDataTupleType;
begin
    Result := A.FTupleType;
end;

{ TDataType.TArray }

constructor TDataType.TArray.Create(const AArrayType: IDataArrayType);
begin
    FArrayType := AArrayType;
end;

function TDataType.TArray.CreateValue(const AItems: array of IDataValue): IDataArrayValue;
begin
    Result := FArrayType.CreateValue(AItems);
end;

function TDataType.TArray.GetElementType: IDataType;
begin
    Result := FArrayType.ElementType;
end;

class operator TDataType.TArray.Implicit(const A: IDataArrayType): TDataType.TArray;
begin
    Result.FArrayType := A;
end;

class operator TDataType.TArray.Implicit(const A: TDataType.TArray): IDataArrayType;
begin
    Result := A.FArrayType;
end;

{ TDataType }

constructor TDataType.Create(const ADataType: IDataType);
begin
    Assert(Assigned(ADataType));
    FDataType := ADataType;
end;

class constructor TDataType.CreateClass;
var
    i: Integer;
begin
    FArrayTypeRegistry := TDictionary<IDataType, IDataArrayType>.Create;
    FRecordTypeRegistry := TDictionary<TArray<TRecordField>, IDataRecordType>.Create(TRecordFieldComparer.Create);

    SetLength(FDecimalTypes, 19);
    for i := 0 to 18 do
        FDecimalTypes[i] := TImplDataDecimalType.Create(i);

    FMethodTypeRegistry :=
        TDictionary<TPair<IDataType, IDataType>, IDataMethodType>.Create(
            TEqualityComparer<TPair<IDataType, IDataType>>.Construct(
                function(const Left, Right: TPair<IDataType, IDataType>): Boolean
                begin
                    Result := (Left.Key = Right.Key) and (Left.Value = Right.Value);
                end,
                function(const Value: TPair<IDataType, IDataType>): Integer
                var
                    hash1, hash2: NativeInt;
                begin
                    hash1 := NativeInt(Value.Key);
                    hash2 := NativeInt(Value.Value);
                    // Simple XOR combination for pointer hashes
                    Result := Integer(hash1 xor hash2);
                end
            )
        );
end;

class destructor TDataType.DestroyClass;
begin
    FArrayTypeRegistry.Free;
    FRecordTypeRegistry.Free;
    FDecimalTypes := nil;
    FMethodTypeRegistry.Free;
end;

class function TDataType.ArrayOf(const AElementType: IDataType): TDataType.TArray;
var
    res: IDataArrayType;
begin
    if not Assigned(AElementType) then
        raise EArgumentException.Create('Cannot create an array type with a nil element type.');

    TMonitor.Enter(FArrayTypeRegistry);
    try
        if not FArrayTypeRegistry.TryGetValue(AElementType, res) then
        begin
            res := TImplDataArrayType.Create(AElementType);
            FArrayTypeRegistry.Add(AElementType, res);
        end;
    finally
        TMonitor.Exit(FArrayTypeRegistry);
    end;
    Result.Create(res);
end;

class function TDataType.DecimalOf(const AScale: Integer): TDataType.TDecimal;
begin
    if (AScale < 0) or (AScale > 18) then
        raise EArgumentException.Create('Scale for decimal must be between 0 and 18.');
    Result.Create(FDecimalTypes[AScale]);
end;

class function TDataType.EnumOf(const AName: string; const AIdentifiers: array of string): TDataType.TEnum;
begin
    Result.Create(TImplDataEnumType.Create(AName, AIdentifiers));
end;

class function TDataType.Float: TDataType.TFloat;
begin
    Result.Create(TImplDataFloatType.Singleton);
end;

function TDataType.GetKind: TDataKind;
begin
    Result := FDataType.Kind;
end;

function TDataType.GetName: String;
begin
    if Assigned(FDataType) then
        Result := FDataType.Name
    else
        Result := '';
end;

class function TDataType.MethodOf(const AArgType, AResultType: IDataType): TDataType.TMethod;
var
    key: TPair<IDataType, IDataType>;
    res: IDataMethodType;
begin
    key := TPair<IDataType, IDataType>.Create(AArgType, AResultType);
    TMonitor.Enter(FMethodTypeRegistry);
    try
        if not FMethodTypeRegistry.TryGetValue(key, res) then
        begin
            res := TImplDataMethodType.Create(AArgType, AResultType);
            FMethodTypeRegistry.Add(key, res);
        end;
    finally
        TMonitor.Exit(FMethodTypeRegistry);
    end;
    Result.Create(res);
end;

class function TDataType.Ordinal: TDataType.TOrdinal;
begin
    Result.Create(TImplDataOrdinalType.Singleton);
end;

class function TDataType.RecordOf(const Fields: TArray<TRecordField>): TDataType.TRecord;
var
    res: IDataRecordType;
begin
    TMonitor.Enter(FRecordTypeRegistry);
    try
        if not FRecordTypeRegistry.TryGetValue(Fields, res) then
        begin
            res := TImplDataRecordType.Create(Fields);
            FRecordTypeRegistry.Add(Fields, res);
        end;
    finally
        TMonitor.Exit(FRecordTypeRegistry);
    end;
    Result.Create(res);
end;

class function TDataType.RecordOf(const Fields: array of TRecordField): TDataType.TRecord;
var
    tFields: TArray<TRecordField>;
    i: Integer;
begin
    SetLength(tFields, Length(Fields));
    for i := 0 to High(Fields) do
        tFields[i] := Fields[i];
    Result := RecordOf(tFields);
end;

class function TDataType.Text: TDataType.TText;
begin
    Result.Create(TImplDataTextType.Singleton);
end;

class function TDataType.Timestamp: TDataType.TTimestamp;
begin
    Result.Create(TImplDataTimestampType.Singleton);
end;

class function TDataType.Tuple: TDataType.TTuple;
begin
    Result.Create(TImplDataTupleType.Singleton);
end;

class function TDataType.Void: TDataType.TVoid;
begin
    Result.Create(TImplDataVoidType.Singleton);
end;

class operator TDataType.Implicit(const A: TDataType): IDataType;
begin
    Result := A.FDataType;
end;

class operator TDataType.Implicit(const A: IDataType): TDataType;
begin
    Result.FDataType := A;
end;

class operator TDataType.Implicit(const A: TDataType.TArray): TDataType;
begin
    Result.FDataType := A.FArrayType;
end;

class operator TDataType.Implicit(const A: TDataType.TDecimal): TDataType;
begin
    Result.FDataType := A.FDecimalType;
end;

class operator TDataType.Implicit(const A: TDataType.TEnum): TDataType;
begin
    Result.FDataType := A.FEnumType;
end;

class operator TDataType.Implicit(const A: TDataType.TFloat): TDataType;
begin
    Result.FDataType := A.FFloatType;
end;

class operator TDataType.Implicit(const A: TDataType.TMethod): TDataType;
begin
    Result.FDataType := A.FMethodType;
end;

class operator TDataType.Implicit(const A: TDataType.TOrdinal): TDataType;
begin
    Result.FDataType := A.FOrdinalType;
end;

class operator TDataType.Implicit(const A: TDataType.TRecord): TDataType;
begin
    Result.FDataType := A.FRecordType;
end;

class operator TDataType.Implicit(const A: TDataType.TText): TDataType;
begin
    Result.FDataType := A.FTextType;
end;

class operator TDataType.Implicit(const A: TDataType.TTimestamp): TDataType;
begin
    Result.FDataType := A.FTimestampType;
end;

class operator TDataType.Implicit(const A: TDataType.TTuple): TDataType;
begin
    Result.FDataType := A.FTupleType;
end;

class operator TDataType.Implicit(const A: TDataType.TVoid): TDataType;
begin
    Result.FDataType := A.FVoidType;
end;

{ TDataType.TValue }

constructor TDataType.TValue.Create(const ADataValue: IDataValue);
begin
    Assert(Assigned(ADataValue));
    FDataValue := ADataValue;
end;

function TDataType.TValue.AsArray: IDataArrayValue;
begin
    if (FDataValue.DataType.Kind <> dkArray) then
        raise EInvalidCast.Create('Array expected');
    Result := IDataArrayValue(FDataValue);
end;

function TDataType.TValue.AsDecimal: IDataDecimalValue;
begin
    if (FDataValue.DataType.Kind <> dkDecimal) then
        raise EInvalidCast.Create('Decimal expected');
    Result := IDataDecimalValue(FDataValue);
end;

function TDataType.TValue.AsEnum: IDataEnumValue;
begin
    if (FDataValue.DataType.Kind <> dkEnum) then
        raise EInvalidCast.Create('Enum expected');
    Result := IDataEnumValue(FDataValue);
end;

function TDataType.TValue.AsFloat: IDataFloatValue;
begin
    if (FDataValue.DataType.Kind <> dkFloat) then
        raise EInvalidCast.Create('Float expected');
    Result := IDataFloatValue(FDataValue);
end;

function TDataType.TValue.AsMethod: IDataMethodValue;
begin
    if (FDataValue.DataType.Kind <> dkMethod) then
        raise EInvalidCast.Create('Method expected');
    Result := IDataMethodValue(FDataValue);
end;

function TDataType.TValue.AsOrdinal: IDataOrdinalValue;
begin
    if (FDataValue.DataType.Kind <> dkOrdinal) then
        raise EInvalidCast.Create('Ordinal expected');
    Result := IDataOrdinalValue(FDataValue);
end;

function TDataType.TValue.AsRecord: IDataRecordValue;
begin
    if (FDataValue.DataType.Kind <> dkRecord) then
        raise EInvalidCast.Create('Record expected');
    Result := IDataRecordValue(FDataValue);
end;

function TDataType.TValue.AsText: IDataTextValue;
begin
    if (FDataValue.DataType.Kind <> dkText) then
        raise EInvalidCast.Create('Text expected');
    Result := IDataTextValue(FDataValue);
end;

function TDataType.TValue.AsTimestamp: IDataTimestampValue;
begin
    if (FDataValue.DataType.Kind <> dkTimestamp) then
        raise EInvalidCast.Create('Timestamp expected');
    Result := IDataTimestampValue(FDataValue);
end;

function TDataType.TValue.AsTuple: IDataTupleValue;
begin
    if (FDataValue.DataType.Kind <> dkTuple) then
        raise EInvalidCast.Create('Tuple expected');
    Result := IDataTupleValue(FDataValue);
end;

function TDataType.TValue.AsVoid: IDataVoidValue;
begin
    if (FDataValue.DataType.Kind <> dkVoid) then
        raise EInvalidCast.Create('Void expected');
    Result := IDataVoidValue(FDataValue);
end;

function TDataType.TValue.GetDataType: IDataType;
begin
    if Assigned(FDataValue) then
        Result := FDataValue.DataType
    else
        Result := nil;
end;

class operator TDataType.TValue.Implicit(const A: TDataType.TValue): IDataValue;
begin
    Result := A.FDataValue;
end;

class operator TDataType.TValue.Implicit(const A: IDataArrayValue): TDataType.TValue;
begin
    Result.FDataValue := A;
end;

class operator TDataType.TValue.Implicit(const A: IDataDecimalValue): TDataType.TValue;
begin
    Result.FDataValue := A;
end;

class operator TDataType.TValue.Implicit(const A: IDataEnumValue): TDataType.TValue;
begin
    Result.FDataValue := A;
end;

class operator TDataType.TValue.Implicit(const A: IDataFloatValue): TDataType.TValue;
begin
    Result.FDataValue := A;
end;

class operator TDataType.TValue.Implicit(const A: IDataMethodValue): TDataType.TValue;
begin
    Result.FDataValue := A;
end;

class operator TDataType.TValue.Implicit(const A: IDataOrdinalValue): TDataType.TValue;
begin
    Result.FDataValue := A;
end;

class operator TDataType.TValue.Implicit(const A: IDataRecordValue): TDataType.TValue;
begin
    Result.FDataValue := A;
end;

class operator TDataType.TValue.Implicit(const A: IDataTextValue): TDataType.TValue;
begin
    Result.FDataValue := A;
end;

class operator TDataType.TValue.Implicit(const A: IDataTimestampValue): TDataType.TValue;
begin
    Result.FDataValue := A;
end;

class operator TDataType.TValue.Implicit(const A: IDataTupleValue): TDataType.TValue;
begin
    Result.FDataValue := A;
end;

class operator TDataType.TValue.Implicit(const A: IDataValue): TDataType.TValue;
begin
    Result.FDataValue := A;
end;

class operator TDataType.TValue.Implicit(const A: IDataVoidValue): TDataType.TValue;
begin
    Result.FDataValue := A;
end;

function TDataType.AsArray: TDataType.TArray;
begin
    if (FDataType.Kind <> dkArray) then
        raise EInvalidCast.Create('Array expected');
    Result.Create(IDataArrayType(FDataType));
end;

function TDataType.AsDecimal: TDataType.TDecimal;
begin
    if (FDataType.Kind <> dkDecimal) then
        raise EInvalidCast.Create('Decimal expected');
    Result.Create(IDataDecimalType(FDataType));
end;

function TDataType.AsEnum: TDataType.TEnum;
begin
    if (FDataType.Kind <> dkEnum) then
        raise EInvalidCast.Create('Enum expected');
    Result.Create(IDataEnumType(FDataType));
end;

function TDataType.AsFloat: TDataType.TFloat;
begin
    if (FDataType.Kind <> dkFloat) then
        raise EInvalidCast.Create('Float expected');
    Result.Create(IDataFloatType(FDataType));
end;

function TDataType.AsMethod: TDataType.TMethod;
begin
    if (FDataType.Kind <> dkMethod) then
        raise EInvalidCast.Create('Method expected');
    Result.Create(IDataMethodType(FDataType));
end;

function TDataType.AsOrdinal: TDataType.TOrdinal;
begin
    if (FDataType.Kind <> dkOrdinal) then
        raise EInvalidCast.Create('Ordinal expected');
    Result.Create(IDataOrdinalType(FDataType));
end;

function TDataType.AsRecord: TDataType.TRecord;
begin
    if (FDataType.Kind <> dkRecord) then
        raise EInvalidCast.Create('Record expected');
    Result.Create(IDataRecordType(FDataType));
end;

function TDataType.AsText: TDataType.TText;
begin
    if (FDataType.Kind <> dkText) then
        raise EInvalidCast.Create('Text expected');
    Result.Create(IDataTextType(FDataType));
end;

function TDataType.AsTimestamp: TDataType.TTimestamp;
begin
    if (FDataType.Kind <> dkTimestamp) then
        raise EInvalidCast.Create('Timestamp expected');
    Result.Create(IDataTimestampType(FDataType));
end;

function TDataType.AsTuple: TDataType.TTuple;
begin
    if (FDataType.Kind <> dkTuple) then
        raise EInvalidCast.Create('Tuple expected');
    Result.Create(IDataTupleType(FDataType));
end;

end.