Run-Time Type Information (RTTI)

RTTI provides mechanism to inspect and interact with types and their metadata at runtime.

Core Functions

Function	Description
`TypeInfo(type)`	Returns `TTypeInfo` for a given type name.
`TypeOf(variable)`	Returns `TTypeInfo` for the runtime type of a variable.
`RTTIRawAttributes`	Returns an array of all attribute instances applied in the program.

TTypeInfo Members

Member	Description
`Name`	The name of the type.
`Kind`	Type category (e.g. `tkInteger`, `tkClass`).
`InheritsFrom(other)`	Checks for inheritance relationship.

Symbol Inspection

The TSymbols class allows for low-level inspection of the program's symbol table.

Method	Description
`CreateMain`	Constructor for the root symbol table.
`CreateUnit(name)`	Constructor for a specific unit's symbol table.
`First / Next / Last`	Iteration methods.
`Eof`	True if at the end of the table.
`Name / Caption`	Symbol identification.
`SymbolType`	Category of the current symbol.
`GetMembers`	Returns a symbol table for the members of the current symbol.

Example: Type Inspection

type
  TBase = class end;
  TSub = class(TBase) end;

var c : TClass := TSub;
var info := TypeOf(c);

PrintLn('Type: ' + info.Name);
if info.InheritsFrom(TypeInfo(TBase)) then
   PrintLn('Inherits from TBase');

Accessing Attributes

You can retrieve all attribute instances in a program using RTTIRawAttributes and filter them based on their target.

type
  TTest = class end;

var attrs := RTTIRawAttributes;
for var i := 0 to attrs.Length - 1 do begin
  if attrs[i].T = TypeOf(TTest) then begin
     if attrs[i].A is TCustomAttribute then
        PrintLn('Found attribute');
  end;
end;

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