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Re: GOOPS constructors
From: |
Marko Rauhamaa |
Subject: |
Re: GOOPS constructors |
Date: |
Wed, 23 Jul 2014 20:42:16 +0300 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) |
Barry Fishman <address@hidden>:
> If you need to redefine "initialize" to do what you want, this is a
> clear indication that you might using the wrong abstraction.
If I have an IS-A relation, that is often described as class hierarchy.
The general question here is, is IS-A-WHOSE a valid basis for class
derivation?
For example,
A thunk IS-A function WHOSE argument list is empty.
A square IS-A rectangle WHOSE width equals its height.
Green light IS electro-magnetic radiation WHOSE wavelength is 520 nm.
A Texan IS-AN American WHOSE permanent address is in Texas.
In many programming languages, such restrictions are routinely expressed
in object constructors:
class GreenLight(Radiation):
def __init__(self):
Radiation.__init__(self, wavelength=520e-9)
Marko