[Design] reconstruction magic methods

[khchen]

• add array of magic methods to class struct.
• current magic methods: _init, _getter, _setter, _str, _repr, _call.
• optimize method calling for magic methods.
• add _call so that object can be callable.
• add Object.getattr and Object.setattr so that attribs can be accessed via dynamic name.
• getter/setter can be called in script, no only in native code.

[khchen]

Example (this example needs "[Bugfix] native class can be inherited in script" to run):

from types import Vector

class Vector2 is Vector
  def _init(x, y, z, a)
    super(x, y, z)
    self.a = a
  end

  def _setter(name, value)
    if name in ['x', 'y', 'z'] then
      super(name, value)
    else
      # last "true" means skip the default setter to avoid infinite loop
      self.setattr(name, value, true) 
    end
  end

  def _getter(name)
    if name in ['x', 'y', 'z'] then
      return super(name)
    else
      # last "true" means skip the default getter to avoid infinite loop
      return self.getattr(name, true)
    end
  end

  def _repr
    return super()[0..-2] + ", ${self.a}]"
  end

  def *=(n)
    self.x *= n; self.y *= n; self.z *= n; self.a *= n;
    return self
  end

  def _call
    print(self)
  end
end

v = Vector2(1, 2, 3, 4)
print(v)
v *= 2
v() # object is callable

Output:

[1, 2, 3, 4]
[2, 4, 6, 8]

[rdbyk]

Please have a look at my comment/question here

7a736f1#r137787262

Thank you