this

The keyword this represents the current instance of a class whose definition lexically encloses the expression. If the keyword is unqualified, then the closest-containing class definition provides the result type:

this[48]:

RULE: Expression ::= 'this' COMPUTE
  PrimaryContext(Expression,INCLUDING TypeDeclaration.Type);
END;

RULE: Expression ::= Name $pTypeName '.' 'this' COMPUTE
  PrimaryContext(Expression,pTypeName.Type);
END;

This macro is invoked in definition 45.