oo.ast

来自「一个编译器修改的例子」· AST 代码 · 共 36 行

(* Test function overriding *)
 
include io.inc
 
class A is
    function f() : int is return 1;
end
 
class B inherits A is
    function f() : int is return 2;
end
 
class C inherits B is
    function f() : int is return 3;
end
 
function main(argv : array of string) : int is
 
var obj : B;
 
begin
    obj := new C;
    WriteString("Expect 3 : ");
    WriteInt(obj.f());            (* Note: obj.C::f() is not allowed *)
    WriteLine();
    WriteString("Expect 2 : ");
    WriteInt(obj.B::f());
    WriteLine();
    WriteString("Expect 1 : ");
    WriteInt(obj.A::f());
    WriteLine();
    delete obj;

    return 0;
end