RTTI - Functions/Procedures

[gii]

Is it possible to identify whether a method is a procedure or a function, and if it is a function, get the data type of the return?

[lucamar]

The function GetTypeData() in unit TypInfo should give you that information. It's described (more or less) in the RTL help file.

Note: I'm not much versed in this so I may be wrong 

[PascalDragon]

Currently it's only possible to do this for procedure and method variable types (already in 3.0.x) and interfaces (in the upcoming 3.2.0). The remainder, namely the methods of classes, objects and records as well as standalone procedures/functions are not yet supported.

[Thaddy]

@PascalDragon
For standalone  procedures and functions  it looks possible like so:

Code: Pascal  [Select][+][-]

1. {$mode objfpc}
2. uses typinfo;
3.  
4. procedure TestIt(const value:Boolean);
5. begin
6.   writeln(value);
7. end;
8.  
9. function testme(const test:Boolean):Boolean;
10. begin
11.  Result :=test;
12. end;
13.  
14. var
15.   Info:PTypeInfo = nil;
16.   Data:PTypeData = nil;
17. begin
18.   Info := TypeInfo(@Testme);
19.   Data := GetTypeData(Info);
20.   writeln('function test: ',Info^.Kind);
21.   // test if it is a procedure or function.
22.   // If resulttyperef is nil, it's a procedure
23.   // otherwise retrieve the result type
24.   if (Info^.kind = tkProcVar) and (Data^.ProcSig.ResultTypeRef <> nil) then
25.     writeln('This is a Function with result type ',Data^.ProcSig.ResultType^.Kind)
26.   else writeln(' This is a procedure');
27.   Info := TypeInfo(@Testit);
28.   Data := GetTypeData(Info);
29.   writeln('procedure test: ',Info^.Kind);
30.   if (Info^.kind = tkProcVar) and (Data^.ProcSig.ResultTypeRef <> nil) then
31.     writeln('This is a Function with result type',Data^.ProcSig.ResultType^.Kind)
32.   else writeln('This is a procedure');
33. end.

Methods can be done like this:

Code: Pascal  [Select][+][-]

1.  // methods
2. {$mode objfpc}
3.  uses typinfo, classes;
4. var
5.   O:Tobject;
6.    List:Tstringlist;
7.    Info:PTypeInfo;
8.    Data:PTypeData;
9. begin
10.   O := Tobject.Create;
11.   try
12.   Info :=TypeInfo(@O.ToString);
13.   Data :=GetTypeData(Info);
14.   writeln(Info^.Kind);
15.   if (Info^.kind = tkMethod) and (Data^.MethodKind = mkFunction) then
16.   begin
17.     List := TStringlist.Create;
18.     try
19.       List.Text := Data^.ParamList;
20.       writeln('This is a method Function with result type ', list[2])
21.     finally
22.      list.free;
23.     end
24.   end;
25.   finally
26.   O.free;
27.   end;
28. end.

[gii]

The function GetTypeData() in unit TypInfo should give you that information. It's described (more or less) in the RTL help file.

Note: I'm not much versed in this so I may be wrong 

@PascalDragon

..

Methods can be done like this:

Code: Pascal  [Select][+][-]

1.  // methods
2. {$mode objfpc}
3.  uses typinfo, classes;
4. var
5.   O:Tobject;
6.    List:Tstringlist;
7.    Info:PTypeInfo;
8.    Data:PTypeData;
9. begin
10.   O := Tobject.Create;
11.   try
12.   Info :=TypeInfo(@O.ToString);
13.   Data :=GetTypeData(Info);
14.   writeln(Info^.Kind);
15.   if (Info^.kind = tkMethod) and (Data^.MethodKind = mkFunction) then
16.   begin
17.     List := TStringlist.Create;
18.     try
19.       List.Text := Data^.ParamList;
20.       writeln('This is a method Function with result type ', list[2])
21.     finally
22.      list.free;
23.     end
24.   end;
25.   finally
26.   O.free;
27.   end;
28. end.

I tested with some methods and it worked.

Thank you.

The only problem I found was in:

Code: Pascal  [Select][+][-]

1. List.Text := Data^.ParamList

For example, it is returned:

Code: Pascal  [Select][+][-]

1. Data^.ParamList = #7'LongIntp'#163'X'#0#0#0#0#0#15#6'TForm1' ....

And the return is not broken into rows in the StringList, but this I can solve.

Another question, is it possible to get the parameter list (name and data type)?