Re: Liskov substitution principle (was: list(), tuple() should not place at "Built-in functions" in documentation)

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Date	Sat, 16 Jul 2011 10:17:48 +1000
Subject	Re: Liskov substitution principle (was: list(), tuple() should not place at "Built-in functions" in documentation)
From	Chris Angelico <rosuav@gmail.com>
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On Sat, Jul 16, 2011 at 10:04 AM, Ben Finney <ben+python@benfinney.id.au> wrote:
>        def study(self, subject):
>            raise NotImplementedError
>
> See? We can have overstretched analogies *and* remain within the Liskov
> substitution principle.
>

Hehe! Of course I was speaking utterly in jest, but this raises
(sorry, never could resist a bad pun) another question: What if the
base class implemented study(), and then LazyStudent subclasses
Student but makes study() raise NotImpl? Would that break things? In a
sense, it breaks the whole "this is a student so it should act like a
student" rule. Suppose it raised UtterApathyError instead - does that
break the LSP?

Chris A
PS. The world's first horseless signature... trapped in the air!

Thread

Re: list(),tuple() should not place at "Built-in functions" in documentation Inside <fancheyujian@gmail.com> - 2011-07-15 12:53 -0700
  Type checking versus polymorphism (was: list(),tuple() should not place at "Built-in functions" in documentation) Ben Finney <ben+python@benfinney.id.au> - 2011-07-16 09:24 +1000
    Re: Type checking versus polymorphism (was: list(),tuple() should not place at "Built-in functions" in documentation) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-07-16 12:47 +1000
      Re: Type checking versus polymorphism (was: list(), tuple() should not place at "Built-in functions" in documentation) Chris Rebert <clp2@rebertia.com> - 2011-07-15 22:02 -0700
        Re: Type checking versus polymorphism (was: list(), tuple() should not place at "Built-in functions" in documentation) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-07-16 16:33 +1000
  Re: list(), tuple() should not place at "Built-in functions" in documentation Chris Angelico <rosuav@gmail.com> - 2011-07-16 09:27 +1000
    Liskov substitution principle (was: list(), tuple() should not place at "Built-in functions" in documentation) Ben Finney <ben+python@benfinney.id.au> - 2011-07-16 10:04 +1000
      Re: Liskov substitution principle (was: list(), tuple() should not place at "Built-in functions" in documentation) Chris Angelico <rosuav@gmail.com> - 2011-07-16 10:17 +1000
        Re: Liskov substitution principle Ben Finney <ben+python@benfinney.id.au> - 2011-07-16 11:47 +1000
  Re: list(),tuple() should not place at "Built-in functions" in documentation Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-07-16 14:06 +1000

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