A generic cache

Update: Eric Grange suggested a change to TStringList that speeds it up significantly and place it well in front of TCache. I will update the article to reflect this in the end of the week. See the article comments for the details.

In my previous article about a generics based case statement for strings, I commited many sins towards the Church Of Pure Pascal 🙂

One of them was to not check for prior art. Sergey Antonov aka 0xffff did something similar back in April 2010 (Note: two links!).

So, to make penance for my lack of purity (and have a chance to sin some more), I have tried to take the good parts of the concept and create something less ugly, and more comfortable to use.

I rewrote the generic class and named it TCache. I kept the configurable key type, and I made the lookup value configurable as well. Basically, it all ends up as a thin wrapper around a dictionary, but I quite like the simple declaration you can achieve with this approach.

Example declaration

var
Cache : TCache;
i : Integer;
begin
if not Assigned(Cache)
then TCache
.Define(Cache, 0)
['alpha', 11]
['bravo', 22]
['charlie', 33]
['delta', 44]
['echo', 55]
['foxtrot', 66];

i := Cache.Lookup('charlie');

Remember that can be almost any type you like, including code (for the value part, at least).

Here is the class. Note that I also keep track of the index of the order each key/value was added. This could be removed. Also note that I still do dirty deeds, such as a dangerous cast. I guess I just suck at writing clean code ;).

unit GenericsCache;

/// Written by Lars Fosdal , December 5, 2010

interface
uses
SysUtils, Generics.Collections;

type
TCacheEntry = record
Value: T;
Index: Integer;
end;

TCache = class(TObjectDictionary<KeyT, TCacheEntry>)
private
FCache: TCache;
FDefaultValue: ValT;
function AddValue(const Id: KeyT; const Value: ValT): TCache;
protected
function ValidateId(Id: KeyT): KeyT; virtual;
public
class function Define(var Cache; const aDefaultValue:ValT): TCache;
function Lookup(const Id: KeyT):ValT;
function Index(const Id: KeyT):Integer;
property DefaultValue: ValT read FDefaultValue write FDefaultValue;
property Values[const Id: KeyT; const Value: ValT]: TCache read AddValue; default;
end;

TCaseStringCache = class(TCache)
function ValidateId(Id: String): String; override;
end;

implementation

{ TCache }

function TCache.AddValue(const Id: KeyT; const Value: ValT): TCache;
var
Rec : TCacheEntry;
begin
Result := Self;
Rec.Value := Value;
Rec.Index := Count;
Add(ValidateId(Id), Rec);
end;

class function TCache.Define(var Cache; const aDefaultValue: ValT): TCache;
begin
Result := Create;
Result.FCache := Result;
Result.DefaultValue := aDefaultValue;
TCache(Cache) := Result;
end;

function TCache.Index(const Id: KeyT): Integer;
var
Rec : TCacheEntry;
begin
if TryGetValue(ValidateId(Id), Rec)
then Result := Rec.Index
else Result := -1;
end;

function TCache.Lookup(const Id: KeyT): ValT;
var
Rec : TCacheEntry;
begin
if FCache.TryGetValue(ValidateId(Id), Rec)
then Result := Rec.Value
else Result := DefaultValue;
end;

function TCache.ValidateId(Id: KeyT): KeyT;
begin
Result := Id;
end;

{ TCaseStringCache }

function TCaseStringCache.ValidateId(Id: String): String;
begin
Result := LowerCase(Id);
end;

end.

I wrote a simple benchmark, testing different ways to use this, and also comparing it to do String2Index / Case -type lookup mechanisms as well as if/then/else, and the ugly method from my previous article. Several people suggested using a string to index / case approach. I have also used that many times. The painful part of strings to index, is that if you change the order of the strings, you also have to change the indices. TCache makes the index entirely optional, since the string is the index – if you see what I mean.

See below for the test code.

The Good, The Bad, and the Ugly.

The test uses GetTickCount and 5.000.000 iterations, for each method, repeated 10 times, with 12 strings (the numbers are consistant at 6 strings as well – except that string to index will be slightly faster) and the process priority was set to High to avoid other parts of the PC affecting the numbers. I weighted the results towards the results for the if/then/else. So Perf tells you how many times slower than if/then/else each test was.

Method Perf AvgRun Comment
TStringSwitch 52.94 35340.7 The ugly was really ugly performance-wise as well.
AnsiIndexTextFunc 12.40 8277.3 String to Index, then case/anon.method is no speed demon either.
StringIndex 12.05 8041.7 Jolyon’s variant is around the same speed.
AnsiIndexText 12.03 8032.6 If you remove anon.methods, the impact is not huge.
TStringList 6.94 4631.6 Using a pre-created sorted string list is nearly twice the speed of AnsiIndexText.
TCacheProc 3.70 2471.1 Cool, TCache and anon.methods are nearly twice the speed of a string list.
TCacheFunc 3.71 2475.8 No signficant difference between a procedure and function.
TCacheFuncStack 3.72 2480.5 Passing the anon.method by stack doesn’t cost much either.
TCaseStringCache 3.12 2085.6 Case insensitive string to string saves some time over using anon.methods.
TCacheString 2.93 1957.9 So does eliminating the LowerCase function. TCache with string/string is 3 times slower than if/then/else, but it is 4 times faster than AnsiIndexText, and more than twice as fast as a string list.
If/then/else 1 667.6 You can’t beat this. You also can’t enjoy maintaining it.
LastKey 0.39 260.4 No surprise that indexed array lookups are fast. Yes, I know I am not looking up the same strings, but the cost is the same.

If you need to repeatedly do lookup by strings, you can benefit from using something like TCache. Also – for the AnsiIndexText – it does a sequential search for the match, hence if the list is long, or the later entries are more commonly used – it will degrade performancewise. Without having dissected TDictionary in detail, I would believe that it’s hash table will allow TCache to remain relativly constant in performance, even if you add thousands of entries.

You could also shave off some more by eliminating the ValidateId methods.

Here is the test program (which also use the unit from my previous article).

program TestGenericsSwitch;
{$apptype Console}
uses
ExceptionLog,
Windows,
Classes,
SysUtils,
StrUtils,
GenericsCache in 'GenericsCache.pas',
GenericsSwitch in 'GenericsSwitch.pas';

{$define Twelve} // remove this to run with 6 strings

const
{$ifndef Twelve}
Elements = 6;
{$else}
Elements = 12;
{$endif}
TestCount = 5000000;
Keys : Array[0..Elements] of String
= ('alpha','bravo', 'charlie', 'delta', 'echo', 'foxtrot',
{$ifdef Twelve}
'golf', 'hotel', 'india', 'juliet', 'kilo', 'lima',
{$endif}
'what');

type
TFunc = reference to function:String;
TProc = reference to procedure;

function RandomKey:String;
begin
Result := Keys[Random(Elements + 1)];
end;

function AssignTest:String;
var
ix : Integer;
s: String;
begin
for ix := 0 to TestCount - 1
do TStringSwitch.CaseOf(RandomKey)
['alpha', procedure begin
s := 'Definitively any case';
end]
['bravo', procedure begin
s := 'B all you can B';
end]
['charlie', procedure begin
s := 'Checkpoint C';
end]
['delta', procedure begin
s := 'Checkpoint D';
end]
['echo', procedure begin
s := 'Checkpoint E';
end]
['foxtrot', procedure begin
s := 'Checkpoint F';
end]
{$ifdef Twelve}
['golf', procedure begin
s:= 'golf';
end]
['hotel',procedure begin
s:= 'hotel';
end]
['india',procedure begin
s:= 'india';
end]
['juliet', procedure begin
s:= 'juliet';
end]
['kilo', procedure begin
s:= 'kilo';
end]
['lima', procedure begin
s:= 'lima';
end]
{$endif}
.ElseCase(procedure begin
s := 'Else what?';
end)
.EndCase;
Result := s;
end;

function AssignTestIf:String;
var
ix : Integer;
s, t: String;
begin
for ix := 0 to TestCount - 1 do
begin
t := LowerCase(RandomKey);
if t = 'alpha' then
s := 'Definitively any case'
else if t = 'bravo' then
s := 'B all you can B'
else if t = 'charlie' then
s := 'Checkpoint C'
else if t = 'delta' then
s := 'Checkpoint D'
else if t = 'echo' then
s := 'Checkpoint E'
else if t = 'foxtrot' then
s := 'Checkpoint F'
{$ifdef Twelve}
else if t = 'golf' then
s := 'golf'
else if t = 'hotel' then
s := 'hotel'
else if t = 'india' then
s := 'india'
else if t = 'juliet' then
s := 'juliet'
else if t = 'kilo' then
s := 'kilo'
else if t = 'lima' then
s := 'lima'
{$endif}
else
s := 'Else what?';
end;
Result := s;
end;

function AssignTestS2I:String;
var
ix : Integer;
s: String;
begin
for ix := 0 to TestCount - 1
do case AnsiIndexText(RandomKey, ['alpha', 'bravo', 'charlie', 'delta', 'echo', 'foxtrot'
{$ifdef Twelve}
, 'golf', 'hotel', 'india', 'juliet', 'kilo', 'lima'
{$endif}
]) of
0 : s := 'Definitively any case';
1 : s := 'B all you can B';
2 : s := 'Checkpoint C';
3 : s := 'Checkpoint D';
4 : s := 'Checkpoint E';
5 : s := 'Checkpoint F';
{$ifdef Twelve}
6 : s := 'golf';
7 : s := 'hotel';
8 : s := 'india';
9 : s := 'juliet';
10 : s := 'kilo';
11 : s := 'lima';
{$endif}
else s := 'Else what?';
end;
Result := s;
end;

function StringIndex(const aString: string; const aCases: array of string;
const aCaseSensitive: Boolean): Integer;
begin
if aCaseSensitive then
begin
for Result := 0 to Pred(Length(aCases)) do
if ANSISameText(aString, aCases[Result]) then
EXIT;
end
else
begin
for Result := 0 to Pred(Length(aCases)) do
if ANSISameStr(aString, aCases[Result]) then
EXIT;
end;

Result := -1;
end;

function AssignStringIndexFunc:String;
var
ix : Integer;
func : TFunc;
begin
for ix := 0 to TestCount - 1
do case StringIndex(RandomKey, ['alpha', 'bravo', 'charlie', 'delta', 'echo', 'foxtrot'
{$ifdef Twelve}
, 'golf', 'hotel', 'india', 'juliet', 'kilo', 'lima'
{$endif}], false) of
0 : func := function:String begin
Result := 'Definitively any case';
end;
1 : func := function:String begin
Result := 'B all you can B';
end;
2 : func := function:String begin
Result := 'Checkpoint C';
end;
3 : func := function:String begin
Result := 'Checkpoint D';
end;
4 : func := function:String begin
Result := 'Checkpoint E';
end;
5 : func := function:String begin
Result := 'Checkpoint F';
end;
{$ifdef Twelve}
6 : func := function:String begin
Result:= 'golf';
end;
7 : func := function:String begin
Result:= 'hotel';
end;
8 : func := function:String begin
Result:= 'india';
end;
9 : func := function:String begin
Result:= 'juliet';
end;
10: func := function:String begin
Result:= 'kilo';
end;
11: func := function:String begin
Result:= 'lima';
end;
{$endif}
else func := function:String begin
Result := 'Else what?';
end;
end;
Result := Func;
end;

function AssignTestS2IFunc:String;
var
ix : Integer;
func : TFunc;
begin
for ix := 0 to TestCount - 1
do case AnsiIndexText(RandomKey, ['alpha', 'bravo', 'charlie', 'delta', 'echo', 'foxtrot'
{$ifdef Twelve}
, 'golf', 'hotel', 'india', 'juliet', 'kilo', 'lima'
{$endif}]) of
0 : func := function:String begin
Result := 'Definitively any case';
end;
1 : func := function:String begin
Result := 'B all you can B';
end;
2 : func := function:String begin
Result := 'Checkpoint C';
end;
3 : func := function:String begin
Result := 'Checkpoint D';
end;
4 : func := function:String begin
Result := 'Checkpoint E';
end;
5 : func := function:String begin
Result := 'Checkpoint F';
end;
{$ifdef Twelve}
6 : func := function:String begin
Result:= 'golf';
end;
7 : func := function:String begin
Result:= 'hotel';
end;
8 : func := function:String begin
Result:= 'india';
end;
9 : func := function:String begin
Result:= 'juliet';
end;
10: func := function:String begin
Result:= 'kilo';
end;
11: func := function:String begin
Result:= 'lima';
end;
{$endif}
else func := function:String begin
Result := 'Else what?';
end;
end;
Result := Func;
end;

function AssignCaseStringCache:String;
var
ix : Integer;
s: String;
Cache : TCaseStringCache;
begin
TCaseStringCache.Define(Cache,
'Else what?')
['alpha', 'Definitively any case']
['bravo', 'B all you can B']
['charlie', 'Checkpoint C']
['delta', 'Checkpoint D']
['echo', 'Checkpoint E']
['foxtrot', 'Checkpoint F']
{$ifdef Twelve}
['golf', 'golf']
['hotel', 'hotel']
['india', 'india']
['juliet', 'juliet']
['kilo', 'kilo']
['lima', 'lima']
{$endif};
for ix := 0 to TestCount - 1
do s := Cache.Lookup(RandomKey);
Result := s;
end;

function AssignCacheString:String;
var
ix : Integer;
s: String;
Cache : TCache;
begin
TCache
.Define(Cache, 'Else what?')
['alpha', 'Definitively any case']
['bravo', 'B all you can B']
['charlie', 'Checkpoint C']
['delta', 'Checkpoint D']
['echo', 'Checkpoint E']
['foxtrot', 'Checkpoint F']
{$ifdef Twelve}
['golf', 'golf']
['hotel', 'hotel']
['india', 'india']
['juliet', 'juliet']
['kilo', 'kilo']
['lima', 'lima']
{$endif};
for ix := 0 to TestCount - 1
do s := Cache.Lookup(RandomKey);
Result := s;
end;

function AssignCacheProc:String;
var
ix : Integer;
s: String;
Cache : TCache;
begin
TCache.Define(Cache,
procedure begin
s := 'Else what?';
end)
['alpha', procedure begin
s := 'Definitively any case';
end]
['bravo', procedure begin
s := 'B all you can B';
end]
['charlie', procedure begin
s := 'Checkpoint C';
end]
['delta', procedure begin
s := 'Checkpoint D';
end]
['echo', procedure begin
s := 'Checkpoint E';
end]
['foxtrot', procedure begin
s := 'Checkpoint F';
end]
{$ifdef Twelve}
['golf', procedure begin
s:= 'golf';
end]
['hotel', procedure begin
s:= 'hotel';
end]
['india', procedure begin
s:= 'india';
end]
['juliet', procedure begin
s:= 'juliet';
end]
['kilo', procedure begin
s:= 'kilo';
end]
['lima', procedure begin
s:= 'lima';
end]
{$endif};

for ix := 0 to TestCount - 1
do Cache.Lookup(RandomKey)();
Result := s;
end;

function AssignCacheFuncStack:String;
var
ix : Integer;
s: String;
Cache : TCache;
begin
TCache.Define(Cache,
function:String begin
Result := 'Else what?';
end)
['alpha', function:String begin
Result := 'Definitively any case';
end]
['bravo', function:String begin
Result := 'B all you can B';
end]
['charlie', function:String begin
Result := 'Checkpoint C';
end]
['delta', function:String begin
Result := 'Checkpoint D';
end]
['echo', function:String begin
Result := 'Checkpoint E';
end]
['foxtrot', function:String begin
Result := 'Checkpoint F';
end]
{$ifdef Twelve}
['golf', function:String begin
Result := 'golf';
end]
['hotel',function:String begin
Result := 'hotel';
end]
['india',function:String begin
Result := 'india';
end]
['juliet', function:String begin
Result := 'juliet';
end]
['kilo', function:String begin
Result := 'kilo';
end]
['lima', function:String begin
Result := 'lima';
end]
{$endif};

for ix := 0 to TestCount - 1
do s := Cache.Lookup(RandomKey)();
Result := s;
end;

function AssignCacheFunc:String;
var
ix : Integer;
s: String;
func: TFunc;
Cache : TCache;
begin
TCache.Define(Cache,
function:String begin
Result := 'Else what?';
end)
['alpha', function:String begin
Result := 'Definitively any case';
end]
['bravo', function:String begin
Result := 'B all you can B';
end]
['charlie', function:String begin
Result := 'Checkpoint C';
end]
['delta', function:String begin
Result := 'Checkpoint D';
end]
['echo', function:String begin
Result := 'Checkpoint E';
end]
['foxtrot', function:String begin
Result := 'Checkpoint F';
end]
{$ifdef Twelve}
['golf', function:String begin
Result := 'golf';
end]
['hotel',function:String begin
Result := 'hotel';
end]
['india',function:String begin
Result := 'india';
end]
['juliet', function:String begin
Result := 'juliet';
end]
['kilo', function:String begin
Result := 'kilo';
end]
['lima', function:String begin
Result := 'lima';
end]
{$endif};

for ix := 0 to TestCount - 1
do begin
func := Cache.Lookup(RandomKey);
s := func;
end;
Result := s;
end;

function AssignStringList:String;
var
ix, fx : Integer;
s: String;
func : TFunc;
obj : TObject absolute func;
StrList : TStringList;
begin
StrList := TStringList.Create;

StrList.AddObject('alpha', TObject(function:String begin
Result := 'Definitively any case';
end));
StrList.AddObject('bravo', TObject(function:String begin
Result := 'B all you can B';
end));
StrList.AddObject('charlie', TObject(function:String begin
Result := 'Checkpoint C';
end));
StrList.AddObject('delta', TObject(function:String begin
Result := 'Checkpoint D';
end));
StrList.AddObject('echo', TObject(function:String begin
Result := 'Checkpoint E';
end));
StrList.AddObject('foxtrot', TObject(function:String begin
Result := 'Checkpoint F';
end));
//{$ifdef Twelve}
StrList.AddObject('golf', TObject(function:String begin
Result := 'golf';
end));
StrList.AddObject('hotel',TObject(function:String begin
Result := 'hotel';
end));
StrList.AddObject('india',TObject(function:String begin
Result := 'india';
end));
StrList.AddObject('juliet', TObject(function:String begin
Result := 'juliet';
end));
StrList.AddObject('kilo', TObject(function:String begin
Result := 'kilo';
end));
StrList.AddObject('lima', TObject(function:String begin
Result := 'lima';
end));
//{$endif}

StrList.Sorted := True;

for ix := 0 to TestCount - 1
do begin
fx := StrList.IndexOf(RandomKey);
if fx >= 0
then begin
obj := StrList.Objects[fx];
s := func;
end
else s := 'ElseWhat';
end;
Result := s;
end;

function TimeIt(proc: TFunc; name:String):Integer;
var
start : Cardinal;
LastLookup : String;
oldSeed : Integer;
begin
OldSeed := RandSeed;
start := GetTickCount;
LastLookup := Proc;
Result := GetTickCount - start;
Writeln(Format('%-18s %6d - %s', [name, Result, LastLookup]));
RandSeed := OldSeed;
end;

function LastKey:String;
var
ix : Integer;
s : String;
OldSeed : Integer;
begin
OldSeed := RandSeed;
for ix := 0 to TestCount - 1
do s := RandomKey;
RandSeed := OldSeed;
Result := s;
end;

procedure Test;
const
Repeats = 10;
var
ix : Integer;
begin
for ix := 0 to Repeats - 1
do begin
Randomize;
// RandSeed := 2003112605;
Writeln;
Writeln(Format('strings=%d, repeats=%d, seed=%d', [Elements, TestCount, RandSeed]));
TimeIt(AssignTest,'TStringSwitch');
TimeIt(AssignTestS2IFunc, 'AnsiIndexText Func');
TimeIt(AssignStringIndexFunc, 'StringIndex');
TimeIt(AssignTestS2I, 'AnsiIndexText');
TimeIt(AssignStringList,'TStringList');
TimeIt(AssignCacheProc, 'TCache Proc');
TimeIt(AssignCacheFunc, 'TCache Func');
TimeIt(AssignCacheFuncStack, 'TCache Func Stack');
TimeIt(AssignCaseStringCache, 'TCaseStringCache');
TimeIt(AssignCacheString, 'TCache String');
TimeIt(AssignTestIf, 'If/then/else');
TimeIt(LastKey, 'LastKey');
end;
end;

begin
try
Write('Press Enter to start: ');
Readln;

Test;

finally
Writeln;
Write('Press Enter: ');
Readln;
end;
end.

A generic case for strings

Do you remember the discussion about a case statement for strings?

I got this flash idea after reading Jolyon Smith’s “The case for case[]”, and remembering a comment from Francisco Ruiz on Nick Hodges’ article on THTMLWriter which suggested using a default array property in a creative fashion.

Honestly, it is not really a true case statement, and it might not be as fast as an if then else, but here is how it looks when used. A bit ugly. but good fun 🙂

program TestGenericsSwitch;
{$apptype Console}
uses
  GenericsSwitch;
begin
TStringSwitch.CaseOf('chARLie')
['Any', procedure begin
Writeln('Definitively any case');
end]
['B', procedure begin
Writeln('B all you can B');
end]
['Charlie', procedure begin
Writeln('Checkpoint C');
end]
.ElseCase(procedure begin
Writeln('Else what?');
end)
.EndCase;
end.

And here is how it is implemented.

unit GenericsSwitch;

/// Written by Lars Fosdal , December 1, 2010

interface
uses
SysUtils, Generics.Collections;

type
TSwitchProc = reference to procedure;
TGenericSwitch = class(TObjectDictionary)
private
FTheElseCase: TSwitchProc;
FTheTargetKey: KeyType;
function AddSwitchCase(const name: KeyType;
const value: TSwitchProc): TGenericSwitch;
procedure SetTheElseCase(const Value: TSwitchProc);
procedure SetTheTargetKey(const Value: KeyType);
protected
function ValidateKey(Key:KeyType):KeyType; virtual;
property TheTargetKey:KeyType read FTheTargetKey write SetTheTargetKey;
property TheElseCase:TSwitchProc read FTheElseCase write SetTheElseCase;
public
class function CaseOf(const Key: KeyType):TGenericSwitch;
function ElseCase(const Action: TSwitchProc): TGenericSwitch;
procedure EndCase;
property Cases[const name:KeyType; const value:TSwitchProc]: TGenericSwitch
read AddSwitchCase; default;
end;

TStringSwitch = class(TGenericSwitch)
function ValidateKey(key:String):String; override;
end;

implementation

{ TGenericSwitch }

function TGenericSwitch.AddSwitchCase(const name: KeyType; const value: TSwitchProc): TGenericSwitch;
begin
Result := Self;
Add(ValidateKey(Name), Value);
end;

class function TGenericSwitch.CaseOf(const Key: KeyType): TGenericSwitch;
begin
Result := Create;
Result.TheTargetKey := Key;
end;

function TGenericSwitch.ElseCase(const Action: TSwitchProc): TGenericSwitch;
begin
Result := Self;
TheElseCase := Action;
end;

procedure TGenericSwitch.EndCase;
var
DoIt : TSwitchProc;
begin
if TryGetValue(TheTargetKey, DoIt)
then DoIt
else
if Assigned(TheElseCase)
then TheElseCase;
Destroy;
end;

procedure TGenericSwitch.SetTheElseCase(const Value: TSwitchProc);
begin
FTheElseCase := Value;
end;

procedure TGenericSwitch.SetTheTargetKey(const Value: KeyType);
begin
FTheTargetKey := ValidateKey(Value);
end;

function TGenericSwitch.ValidateKey(Key: KeyType):KeyType;
begin
Result := Key;
end;

{ TStringSwitch }

function TStringSwitch.ValidateKey(key: String): String;
begin
Result := LowerCase(Key);
end;


end.

Another Generics / RTTI bug. Attributes are ignored in parametrized types.

The output from the code below, shows that you cannot enumerate attributes for properties of a parametrized type such as TOpenClass.

If you close the class as a TDecidedClass = TOpenClass, any attributes declared in TDecidedClass may have enumerable attributes, but the attributes declared for properties in TOpenClass are still not enumerable.

Output from the code:

Properties for TBaseClass
Normal
Blinged [Bling]

Properties for TBaseParam
BlingTFails <- Note the lack of a [Bling] attribute here 
BlingIntFails <- Note the lack of a [Bling] attribute here 
Normal 
Blinged [Bling] 

Properties for TBaseInt 
BlingInt [Bling] 
BlingTFails <- Note the lack of a [Bling] attribute here 
BlingIntFails <- Note the lack of a [Bling] attribute here 
Normal 
Blinged [Bling]

program AttributeFailsForParametricGenericType;

{$APPTYPE CONSOLE}

uses
ExceptionLog,
Classes,
Generics.Defaults,
RTTI;

type
Bling = class(TCustomAttribute);

TBaseClass = class
private
function GetBling: Integer;
function GetNormal: Integer;
procedure SetBling(const Value: Integer);
procedure SetNormal(const Value: Integer);
public
procedure Inspect;
property Normal:Integer read GetNormal write SetNormal;
[bling] property Blinged:Integer read GetBling write SetBling;
end;

TBaseParam = class(TBaseClass)
private
function GetBlingTFails: T;
procedure SetBlingTFails(const Value: T);
function GetBlingIntFails: Integer;
procedure SetBlingIntFails(const Value: Integer);
public
[bling] property BlingTFails:T read GetBlingTFails write SetBlingTFails;
[bling] property BlingIntFails:Integer read GetBlingIntFails write SetBlingIntFails;
end;

TBaseInt = class(TBaseParam)
private
function GetBlingInt: Integer;
procedure SetBlingInt(const Value: Integer);
public
[bling] property BlingInt:Integer read GetBlingInt write SetBlingInt;
end;


{ TBaseClass }

function TBaseClass.GetBling: Integer; begin end;
function TBaseClass.GetNormal: Integer; begin end;

procedure TBaseClass.Inspect;
var
Context : TRttiContext;
SourceType : TRttiType;
SourceProp : TRttiProperty;
SourceAttribute : TCustomAttribute;
s : String;
begin
Context := TRttiContext.Create;
try
SourceType := Context.GetType(Self.ClassType);
Writeln('');
Writeln(ClassName);

for SourceProp in SourceType.GetProperties
do begin
s := SourceProp.Name;

for SourceAttribute in SourceProp.GetAttributes
do begin
s := s + ' [' + SourceAttribute.ClassName + ']';
end;
Writeln(s);
end;
finally
Context.Free;
end;
end;

procedure TBaseClass.SetBling(const Value: Integer); begin end;
procedure TBaseClass.SetNormal(const Value: Integer); begin end;

{ TBaseParam }
function TBaseParam.GetBlingTFails: T; begin end;
function TBaseParam.GetBlingIntFails: Integer; begin end;
procedure TBaseParam.SetBlingTFails(const Value: T); begin end;
procedure TBaseParam.SetBlingIntFails(const Value: Integer); begin end;

{ TBaseInt }
function TBaseInt.GetBlingInt: Integer; begin end;
procedure TBaseInt.SetBlingInt(const Value: Integer); begin end;


var
Base : TBaseClass;
BaseT : TBaseParam;
BaseInt : TBaseInt;
begin
Base := TBaseClass.Create;
Base.Inspect;

BaseT := TBaseParam.Create;
BaseT.Inspect;

BaseInt := TBaseInt.Create;
BaseInt.Inspect;

Readln;
end.