Types added to Tuples

This commit is contained in:
Michael Schimmel
2025-08-27 16:05:13 +02:00
parent 284fb95985
commit dc4066097c
5 changed files with 290 additions and 190 deletions
+10 -17
View File
@@ -39,8 +39,6 @@ type
class constructor CreateClass;
class destructor DestroyClass;
// Factory method to get a cached or new record type instance.
class function GetInstance(const AFields: TArray<TDataRecordField>): IDataRecordType; overload; static;
class function GetInstance(const AFields: array of TDataRecordField): IDataRecordType; overload; static;
// TODO Create a record ba analyzing the RTTI of T
@@ -302,16 +300,22 @@ begin
FRecordTypeRegistry := nil;
end;
class function TImplDataRecordType.GetInstance(const AFields: TArray<TDataRecordField>): IDataRecordType;
class function TImplDataRecordType.GetInstance(const AFields: array of TDataRecordField): IDataRecordType;
var
tFields: TArray<TDataRecordField>;
i: Integer;
res: IDataRecordType;
begin
SetLength(tFields, Length(AFields));
for i := 0 to High(AFields) do
tFields[i] := AFields[i];
TMonitor.Enter(FRecordTypeRegistry);
try
if not FRecordTypeRegistry.TryGetValue(AFields, res) then
if not FRecordTypeRegistry.TryGetValue(tFields, res) then
begin
res := TImplDataRecordType.Create(AFields);
FRecordTypeRegistry.Add(AFields, res);
res := TImplDataRecordType.Create(tFields);
FRecordTypeRegistry.Add(tFields, res);
end;
finally
TMonitor.Exit(FRecordTypeRegistry);
@@ -319,17 +323,6 @@ begin
Result := res;
end;
class function TImplDataRecordType.GetInstance(const AFields: array of TDataRecordField): IDataRecordType;
var
tFields: TArray<TDataRecordField>;
i: Integer;
begin
SetLength(tFields, Length(AFields));
for i := 0 to High(AFields) do
tFields[i] := AFields[i];
Result := GetInstance(tFields);
end;
class function TImplDataRecordType.GetInstance<T>: IDataRecordType;
var
ctx: TRttiContext;
+226 -138
View File
@@ -3,121 +3,283 @@ unit Myc.Data.Types.Tuple;
interface
uses
System.Generics.Collections,
System.SysUtils,
System.Generics.Defaults,
System.Hash,
Myc.Data.Types;
type
// Implements the singleton tuple data type.
// Custom comparer for TArray<IDataType> to be used as a dictionary key.
TDataTupleTypeComparer = class(TInterfacedObject, IEqualityComparer<TArray<IDataType>>)
public
function Equals(const Left, Right: TArray<IDataType>): Boolean; reintroduce;
function GetHashCode(const Value: TArray<IDataType>): Integer; reintroduce;
end;
// Implements the tuple data type.
TImplDataTupleType = class(TInterfacedObject, IDataType, IDataTupleType)
strict private
// Class-level registry to cache and reuse tuple type definitions.
class var
FSingleton: IDataTupleType;
class constructor CreateClass;
FTupleTypeRegistry: TDictionary<TArray<IDataType>, IDataTupleType>;
private
FItemTypes: TArray<IDataType>;
FEmptyValue: IDataTupleValue; // Cached instance for zero-field tuples
function GetName: String;
function GetKind: TDataKind;
public
function CreateValue(const AItems: array of IDataValue): IDataTupleValue;
class property Singleton: IDataTupleType read FSingleton;
function GetItemCount: Integer;
function GetItemType(Idx: Integer): IDataType;
public
constructor Create(const AItemTypes: TArray<IDataType>);
destructor Destroy; override;
class constructor CreateClass;
class destructor DestroyClass;
class function GetInstance(const AItemTypes: array of IDataType): IDataTupleType; static;
end;
implementation
uses
System.SyncObjs,
System.Rtti;
type
// Implements the simple tuple data value.
// Implements the tuple data value.
TImplDataTupleValue = class(TInterfacedObject, IDataValue, IDataTupleValue)
private
FDataType: IDataTupleType;
FItems: TArray<IDataValue>;
function GetDataType: IDataType;
function GetAsString: string;
function GetItemCount: Integer;
function GetItem(Idx: Integer): IDataValue;
public
constructor Create(const AItems: array of IDataValue);
constructor Create(const ADataType: IDataTupleType; const AItems: array of IDataValue);
end;
// Optimized singleton implementation for a tuple with 0 elements.
// Optimized implementation for a tuple with 0 fields.
TImplDataTupleValue0 = class(TInterfacedObject, IDataValue, IDataTupleValue)
strict private
class var
FSingleton: IDataTupleValue;
class constructor CreateClass;
private
FDataType: IDataTupleType;
function GetDataType: IDataType;
function GetAsString: string;
function GetItemCount: Integer;
function GetItem(Idx: Integer): IDataValue;
public
class property Singleton: IDataTupleValue read FSingleton;
constructor Create(const ADataType: IDataTupleType);
end;
// Optimized implementation for a tuple with 1 element.
// Optimized implementation for a tuple with 1 field.
TImplDataTupleValue1 = class(TInterfacedObject, IDataValue, IDataTupleValue)
private
FDataType: IDataTupleType;
FItem0: IDataValue;
function GetDataType: IDataType;
function GetAsString: string;
function GetItemCount: Integer;
function GetItem(Idx: Integer): IDataValue;
public
constructor Create(const AItems: array of IDataValue);
constructor Create(const ADataType: IDataTupleType; const AItems: array of IDataValue);
end;
// Optimized implementation for a tuple with 2 elements.
// Optimized implementation for a tuple with 2 fields.
TImplDataTupleValue2 = class(TInterfacedObject, IDataValue, IDataTupleValue)
private
FDataType: IDataTupleType;
FItem0, FItem1: IDataValue;
function GetDataType: IDataType;
function GetAsString: string;
function GetItemCount: Integer;
function GetItem(Idx: Integer): IDataValue;
public
constructor Create(const AItems: array of IDataValue);
constructor Create(const ADataType: IDataTupleType; const AItems: array of IDataValue);
end;
// Optimized implementation for a tuple with 3 elements.
// Optimized implementation for a tuple with 3 fields.
TImplDataTupleValue3 = class(TInterfacedObject, IDataValue, IDataTupleValue)
private
FDataType: IDataTupleType;
FItem0, FItem1, FItem2: IDataValue;
function GetDataType: IDataType;
function GetAsString: string;
function GetItemCount: Integer;
function GetItem(Idx: Integer): IDataValue;
public
constructor Create(const AItems: array of IDataValue);
constructor Create(const ADataType: IDataTupleType; const AItems: array of IDataValue);
end;
// Optimized implementation for a tuple with 4 elements.
// Optimized implementation for a tuple with 4 fields.
TImplDataTupleValue4 = class(TInterfacedObject, IDataValue, IDataTupleValue)
private
FDataType: IDataTupleType;
FItem0, FItem1, FItem2, FItem3: IDataValue;
function GetDataType: IDataType;
function GetAsString: string;
function GetItemCount: Integer;
function GetItem(Idx: Integer): IDataValue;
public
constructor Create(const AItems: array of IDataValue);
constructor Create(const ADataType: IDataTupleType; const AItems: array of IDataValue);
end;
// Optimized implementation for a tuple with 5 elements.
TImplDataTupleValue5 = class(TInterfacedObject, IDataValue, IDataTupleValue)
private
FItem0, FItem1, FItem2, FItem3, FItem4: IDataValue;
function GetDataType: IDataType;
function GetAsString: string;
function GetItemCount: Integer;
function GetItem(Idx: Integer): IDataValue;
public
constructor Create(const AItems: array of IDataValue);
{ TDataTupleTypeComparer }
function TDataTupleTypeComparer.Equals(const Left, Right: TArray<IDataType>): Boolean;
var
i: Integer;
begin
if (Length(Left) <> Length(Right)) then
exit(False);
for i := 0 to High(Left) do
begin
// Compare by interface reference.
// It's safe because all IDataType instances are managed by GetInstance singletons.
if (Left[i] <> Right[i]) then
exit(False);
end;
Result := True;
end;
{ TImplDataTupleValue (generic implementation for N > 5 elements) }
function TDataTupleTypeComparer.GetHashCode(const Value: TArray<IDataType>): Integer;
var
dataType: IDataType;
begin
Result := 0;
for dataType in Value do
begin
// Use the hash of the interface's memory address.
// This is safe and fast due to the singleton pattern for types.
Result := Integer(PPointer(@dataType)^) xor Result;
end;
end;
constructor TImplDataTupleValue.Create(const AItems: array of IDataValue);
{ TImplDataTupleType }
class constructor TImplDataTupleType.CreateClass;
begin
// Initialize the global registry for tuple types.
FTupleTypeRegistry := TDictionary<TArray<IDataType>, IDataTupleType>.Create(TDataTupleTypeComparer.Create);
end;
class destructor TImplDataTupleType.DestroyClass;
begin
FTupleTypeRegistry.Free;
FTupleTypeRegistry := nil;
end;
constructor TImplDataTupleType.Create(const AItemTypes: TArray<IDataType>);
begin
inherited Create;
FItemTypes := AItemTypes;
// Pre-create the singleton value instance if this is a zero-field tuple.
if (Length(FItemTypes) = 0) then
FEmptyValue := TImplDataTupleValue0.Create(Self);
end;
destructor TImplDataTupleType.Destroy;
begin
inherited;
end;
function TImplDataTupleType.CreateValue(const AItems: array of IDataValue): IDataTupleValue;
var
i: Integer;
begin
if (Length(AItems) <> Length(FItemTypes)) then
raise EArgumentException
.CreateFmt('Invalid number of items for this tuple type. Expected %d, but got %d.', [Length(FItemTypes), Length(AItems)]);
for i := 0 to High(AItems) do
if not Assigned(AItems[i]) or (AItems[i].DataType <> FItemTypes[i]) then
raise EArgumentException.CreateFmt(
'Invalid data type for item at index %d. Expected %s, but got %s.',
[i, FItemTypes[i].Name, AItems[i].DataType.Name]);
// Use optimized implementations for tuples with 0, 1, 2, 3, or 4 fields.
case Length(FItemTypes) of
0: Result := FEmptyValue; // Return the pre-cached instance.
1: Result := TImplDataTupleValue1.Create(Self, AItems);
2: Result := TImplDataTupleValue2.Create(Self, AItems);
3: Result := TImplDataTupleValue3.Create(Self, AItems);
4: Result := TImplDataTupleValue4.Create(Self, AItems);
else
// Use the generic implementation for tuples with more than 4 fields.
Result := TImplDataTupleValue.Create(Self, AItems);
end;
end;
class function TImplDataTupleType.GetInstance(const AItemTypes: array of IDataType): IDataTupleType;
var
tItems: TArray<IDataType>;
i: Integer;
res: IDataTupleType;
begin
SetLength(tItems, Length(AItemTypes));
for i := 0 to High(AItemTypes) do
tItems[i] := AItemTypes[i];
TMonitor.Enter(FTupleTypeRegistry);
try
if not FTupleTypeRegistry.TryGetValue(tItems, res) then
begin
res := TImplDataTupleType.Create(tItems);
FTupleTypeRegistry.Add(tItems, res);
end;
finally
TMonitor.Exit(FTupleTypeRegistry);
end;
Result := res;
end;
function TImplDataTupleType.GetItemCount: Integer;
begin
Result := Length(FItemTypes);
end;
function TImplDataTupleType.GetItemType(Idx: Integer): IDataType;
begin
Result := FItemTypes[Idx];
end;
function TImplDataTupleType.GetName: String;
var
i: Integer;
sb: TStringBuilder;
begin
sb := TStringBuilder.Create;
try
sb.Append('Tuple<');
for i := 0 to High(FItemTypes) do
begin
sb.Append(FItemTypes[i].Name);
if (i < High(FItemTypes)) then
sb.Append(', ');
end;
sb.Append('>');
Result := sb.ToString;
finally
sb.Free;
end;
end;
function TImplDataTupleType.GetKind: TDataKind;
begin
Result := dkTuple;
end;
{ TImplDataTupleValue (generic implementation for N > 4 fields) }
constructor TImplDataTupleValue.Create(const ADataType: IDataTupleType; const AItems: array of IDataValue);
var
i: Integer;
begin
inherited Create;
FDataType := ADataType;
SetLength(FItems, Length(AItems));
for i := 0 to High(AItems) do
FItems[i] := AItems[i];
@@ -125,7 +287,7 @@ end;
function TImplDataTupleValue.GetDataType: IDataType;
begin
Result := TImplDataTupleType.Singleton;
Result := FDataType;
end;
function TImplDataTupleValue.GetAsString: string;
@@ -161,9 +323,10 @@ end;
{ TImplDataTupleValue0 }
class constructor TImplDataTupleValue0.CreateClass;
constructor TImplDataTupleValue0.Create(const ADataType: IDataTupleType);
begin
FSingleton := TImplDataTupleValue0.Create;
inherited Create;
FDataType := ADataType;
end;
function TImplDataTupleValue0.GetAsString: string;
@@ -173,7 +336,7 @@ end;
function TImplDataTupleValue0.GetDataType: IDataType;
begin
Result := TImplDataTupleType.Singleton;
Result := FDataType;
end;
function TImplDataTupleValue0.GetItem(Idx: Integer): IDataValue;
@@ -188,20 +351,21 @@ end;
{ TImplDataTupleValue1 }
constructor TImplDataTupleValue1.Create(const AItems: array of IDataValue);
constructor TImplDataTupleValue1.Create(const ADataType: IDataTupleType; const AItems: array of IDataValue);
begin
inherited Create;
FDataType := ADataType;
FItem0 := AItems[0];
end;
function TImplDataTupleValue1.GetAsString: string;
begin
Result := '(' + FItem0.AsString + ')';
Result := Format('(%s)', [FItem0.AsString]);
end;
function TImplDataTupleValue1.GetDataType: IDataType;
begin
Result := TImplDataTupleType.Singleton;
Result := FDataType;
end;
function TImplDataTupleValue1.GetItem(Idx: Integer): IDataValue;
@@ -220,21 +384,34 @@ end;
{ TImplDataTupleValue2 }
constructor TImplDataTupleValue2.Create(const AItems: array of IDataValue);
constructor TImplDataTupleValue2.Create(const ADataType: IDataTupleType; const AItems: array of IDataValue);
begin
inherited Create;
FDataType := ADataType;
FItem0 := AItems[0];
FItem1 := AItems[1];
end;
function TImplDataTupleValue2.GetAsString: string;
var
sb: TStringBuilder;
begin
Result := '(' + FItem0.AsString + ', ' + FItem1.AsString + ')';
sb := TStringBuilder.Create;
try
sb.Append('(');
sb.Append(FItem0.AsString);
sb.Append(', ');
sb.Append(FItem1.AsString);
sb.Append(')');
Result := sb.ToString;
finally
sb.Free;
end;
end;
function TImplDataTupleValue2.GetDataType: IDataType;
begin
Result := TImplDataTupleType.Singleton;
Result := FDataType;
end;
function TImplDataTupleValue2.GetItem(Idx: Integer): IDataValue;
@@ -254,9 +431,10 @@ end;
{ TImplDataTupleValue3 }
constructor TImplDataTupleValue3.Create(const AItems: array of IDataValue);
constructor TImplDataTupleValue3.Create(const ADataType: IDataTupleType; const AItems: array of IDataValue);
begin
inherited Create;
FDataType := ADataType;
FItem0 := AItems[0];
FItem1 := AItems[1];
FItem2 := AItems[2];
@@ -283,7 +461,7 @@ end;
function TImplDataTupleValue3.GetDataType: IDataType;
begin
Result := TImplDataTupleType.Singleton;
Result := FDataType;
end;
function TImplDataTupleValue3.GetItem(Idx: Integer): IDataValue;
@@ -304,9 +482,10 @@ end;
{ TImplDataTupleValue4 }
constructor TImplDataTupleValue4.Create(const AItems: array of IDataValue);
constructor TImplDataTupleValue4.Create(const ADataType: IDataTupleType; const AItems: array of IDataValue);
begin
inherited Create;
FDataType := ADataType;
FItem0 := AItems[0];
FItem1 := AItems[1];
FItem2 := AItems[2];
@@ -336,7 +515,7 @@ end;
function TImplDataTupleValue4.GetDataType: IDataType;
begin
Result := TImplDataTupleType.Singleton;
Result := FDataType;
end;
function TImplDataTupleValue4.GetItem(Idx: Integer): IDataValue;
@@ -356,95 +535,4 @@ begin
Result := 4;
end;
{ TImplDataTupleValue5 }
constructor TImplDataTupleValue5.Create(const AItems: array of IDataValue);
begin
inherited Create;
FItem0 := AItems[0];
FItem1 := AItems[1];
FItem2 := AItems[2];
FItem3 := AItems[3];
FItem4 := AItems[4];
end;
function TImplDataTupleValue5.GetAsString: string;
var
sb: TStringBuilder;
begin
sb := TStringBuilder.Create;
try
sb.Append('(');
sb.Append(FItem0.AsString);
sb.Append(', ');
sb.Append(FItem1.AsString);
sb.Append(', ');
sb.Append(FItem2.AsString);
sb.Append(', ');
sb.Append(FItem3.AsString);
sb.Append(', ');
sb.Append(FItem4.AsString);
sb.Append(')');
Result := sb.ToString;
finally
sb.Free;
end;
end;
function TImplDataTupleValue5.GetDataType: IDataType;
begin
Result := TImplDataTupleType.Singleton;
end;
function TImplDataTupleValue5.GetItem(Idx: Integer): IDataValue;
begin
case Idx of
0: Result := FItem0;
1: Result := FItem1;
2: Result := FItem2;
3: Result := FItem3;
4: Result := FItem4;
else
raise EArgumentException.Create('Index out of bounds');
end;
end;
function TImplDataTupleValue5.GetItemCount: Integer;
begin
Result := 5;
end;
{ TImplDataTupleType }
class constructor TImplDataTupleType.CreateClass;
begin
FSingleton := TImplDataTupleType.Create;
end;
function TImplDataTupleType.CreateValue(const AItems: array of IDataValue): IDataTupleValue;
begin
// Use optimized implementations for tuples with 0 to 5 elements.
case Length(AItems) of
0: Result := TImplDataTupleValue0.Singleton;
1: Result := TImplDataTupleValue1.Create(AItems);
2: Result := TImplDataTupleValue2.Create(AItems);
3: Result := TImplDataTupleValue3.Create(AItems);
4: Result := TImplDataTupleValue4.Create(AItems);
5: Result := TImplDataTupleValue5.Create(AItems);
else
// Use the generic implementation for tuples with more than 5 elements.
Result := TImplDataTupleValue.Create(AItems);
end;
end;
function TImplDataTupleType.GetName: String;
begin
Result := 'Tuple';
end;
function TImplDataTupleType.GetKind: TDataKind;
begin
Result := dkTuple;
end;
end.
+28 -11
View File
@@ -591,11 +591,11 @@ type
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 TupleOf(const AItemTypes: array of IDataType): TDataType.TTuple; overload; static;
class function TupleOf(const AItemValues: array of IDataValue): TDataType.TTuple.TValue; overload; static;
class function MethodOf(const AArgType, AResultType: IDataType): TDataType.TMethod; static;
class function ArrayOf(const AElementType: IDataType): TDataType.TArray; static;
class function VectorOf(const AElementType: IDataType; const AElementCount: Integer): TDataType.TVector; static;
class function RecordOf(const Fields: TArray<TDataRecordField>): TDataType.TRecord; overload; static;
class function RecordOf(const Fields: array of TDataRecordField): TDataType.TRecord; overload; static;
class function RecordOf<T>: TDataType.TRecord; overload; static;
class function EnumOf(const AName: string; const AIdentifiers: array of string): TDataType.TEnum; static;
@@ -669,7 +669,7 @@ var
scaleValue: Integer;
begin
scaleValue := GetDataType.Scale;
if scaleValue > 0 then
if (scaleValue > 0) then
Result := FDecimalValue.Value / Power(10, scaleValue)
else
Result := FDecimalValue.Value;
@@ -1031,7 +1031,7 @@ var
idx: Integer;
begin
idx := IndexOf(AIdentifier);
if idx < 0 then
if (idx < 0) then
raise EArgumentException.CreateFmt('Unknown identifier: %s', [AIdentifier]);
Result := CreateValue(idx);
end;
@@ -1454,11 +1454,6 @@ begin
Result.Create(TImplDataOrdinalType.Singleton);
end;
class function TDataType.RecordOf(const Fields: TArray<TDataRecordField>): TDataType.TRecord;
begin
Result.Create(TImplDataRecordType.GetInstance(Fields));
end;
class function TDataType.RecordOf(const Fields: array of TDataRecordField): TDataType.TRecord;
begin
Result.Create(TImplDataRecordType.GetInstance(Fields));
@@ -1479,9 +1474,31 @@ begin
Result.Create(TImplDataTimestampType.Singleton);
end;
class function TDataType.Tuple: TDataType.TTuple;
class function TDataType.TupleOf(const AItemTypes: array of IDataType): TDataType.TTuple;
var
tItems: TArray<IDataType>;
i: Integer;
begin
Result.Create(TImplDataTupleType.Singleton);
SetLength(tItems, Length(AItemTypes));
for i := 0 to High(AItemTypes) do
tItems[i] := AItemTypes[i];
// Use the instance manager to get a tuple type for the given element types.
Result.Create(TImplDataTupleType.GetInstance(tItems));
end;
class function TDataType.TupleOf(const AItemValues: array of IDataValue): TDataType.TTuple.TValue;
var
tItems: TArray<IDataType>;
i: Integer;
begin
SetLength(tItems, Length(AItemValues));
for i := 0 to High(AItemValues) do
tItems[i] := AItemValues[i].DataType;
var tTuple := TImplDataTupleType.GetInstance(tItems);
Result := tTuple.CreateValue(AItemValues);
end;
class function TDataType.VectorOf(const AElementType: IDataType; const AElementCount: Integer): TDataType.TVector;
+6 -10
View File
@@ -172,7 +172,7 @@ begin
floatValue := TDataType.Float.CreateValue(45.67);
// --- 2. Test Value Creation and basic properties ---
tuple1 := TDataType.Tuple.CreateValue([intValue, floatValue]);
tuple1 := TDataType.TupleOf([intValue, floatValue]);
Assert.IsNotNull(IDataTupleValue(tuple1), 'Tuple value should be created');
Assert.AreEqual(2, tuple1.ItemCount, 'ItemCount should be on the value');
@@ -181,8 +181,8 @@ begin
// --- 3. Test Singleton Type Behavior ---
// Create more tuples with different structures
tuple2 := TDataType.Tuple.CreateValue([TDataType.Ordinal.CreateValue(99), TDataType.Float.CreateValue(1.1)]);
tuple3 := TDataType.Tuple.CreateValue([intValue]);
tuple2 := TDataType.TupleOf([TDataType.Ordinal.CreateValue(99), TDataType.Float.CreateValue(1.1)]);
tuple3 := TDataType.TupleOf([intValue]);
// Access the DataType via the underlying interface
type1 := tuple1.DataType;
@@ -190,11 +190,7 @@ begin
type3 := tuple3.DataType;
Assert.IsNotNull(type1, 'DataType interface should be accessible');
Assert.AreEqual('Tuple', type1.Name, 'The type name for all tuples should be Tuple');
// The core test: All tuples, regardless of their content, must share the exact same singleton type object.
Assert.AreSame(type1, type2, 'All tuple types should be the same singleton instance');
Assert.AreSame(type1, type3, 'All tuple types should be the same singleton instance');
Assert.AreEqual('Tuple<Integer, Float>', type1.Name, 'The type name for all tuples should be Tuple');
end;
procedure TMyTestObject.TestTuples_Generic;
@@ -204,7 +200,7 @@ var
begin
// Test the generic implementation for tuples with > 5 elements.
tupleValue :=
TDataType.Tuple.CreateValue(
TDataType.TupleOf(
[
TDataType.Ordinal.CreateValue(1),
TDataType.Ordinal.CreateValue(2),
@@ -542,7 +538,7 @@ begin
Assert.AreEqual('<ID: 1, Name: Bob>', IDataValue(recordValue).AsString, 'Record AsString incorrect');
// Tuple
tupleValue := TDataType.Tuple.CreateValue([TDataType.Ordinal.CreateValue(10), TDataType.Text.CreateValue('Tuple')]);
tupleValue := TDataType.TupleOf([TDataType.Ordinal.CreateValue(10), TDataType.Text.CreateValue('Tuple')]);
Assert.AreEqual('(10, Tuple)', IDataValue(tupleValue).AsString, 'Tuple AsString incorrect');
end;