Re^9: OO Getters/Setters

Not quite sure what you mean by blindly here.

I meant putting an accessor/mutator on every field, or even a large ammount of fields, without putting thought into it.

As for making them public, the whole point of encapsulation is to hide implementation with an interface. Thus why should I make them public.

No, encapsulation is the reason why you should avoid them in the first place, or (perhaps better) make them private or protected.

I don't know where you came up with this idea, that a mutator may only set a member variable directly without processing, but you need to leave that definition behind.

No, that's the accepted definition in most OO lituature. If your method does something besides direct access, it's not an accessor or mutator.

. . . we have a mutator (temperature or as I prefer setTemperature, but to each his own) that will accept temperatures in either celcius, farenheit, and perhaps other scales as well . . . If we took your approach then a farenheit temperature may be stored into the object, and then calculations further down the chain will get really messed up. So the solution to your method would be to create a conversion routine that you would have to pass the foreign value through and then pass the celcius temp back to the mutator.

I was thinking about just such a situation a few days ago, and thought up this solution: the setTemperature (or whatever you call it) method should take an object of type Temperature. The Temperature class provides methods like get_celsius and get_farenheit which do all the conversions for you. Likewise, its constructor would take temperatures in various scales. Methods that set and return complex objects are no more accessors/mutators then those that are doing the complexity themselves, so this method can't be considered a use of accessors/mutators.

----
I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident.
-- Schemer

: () { :|:& };:

Note: All code is untested, unless otherwise stated

Comment on Re^9: OO Getters/Setters Select or Download Code

Replies are listed 'Best First'.
Re: Re^9: OO Getters/Setters by linux454 (Pilgrim) on Jan 02, 2004 at 21:12 UTC
Of course this is your opinion. You are certainly entitled, as are we all. Though while you are coding in your pedantic world, I'll be over here writing less, easier-to-maintain, easier-to-use, and possibly more efficient OOP code.	[reply]
Re: Re: Re^9: OO Getters/Setters by hardburn (Abbot) on Jan 02, 2004 at 21:47 UTC
I'll be over here writing less, easier-to-maintain "Less" and "easier-to-maintain", as long as your requirements don't change. OO isn't about reducing complexity, it's about managing it. We should expect to write more code now in order to simplify things later. In your temperature example, having the `setTemperature` method do all the conversions, you've forced yourself to doing all the conversions in a single method (perhaps dispatching to other internal methods to do the conversion via a lookup table). If you need to convert to some other scale, you have to add in that code within that method. If you using a Temperature class instead, the conversions are all inside that method. One method does exactly one conversion. Much easier to maintain. easier-to-use `$obj->setTemperature({ celsius => 50 });` [download] Or: `$obj->setTemperature( Temperature->new({ celsius => 50 }) );` [download] A little more typing. It's other benifits make it worth it. possibly more efficient OOP code If you're that concerned about efficiency, why are you using Perl's `bless`'d OO? ---- I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident. -- Schemer `: () { :\|:& };:` Note: All code is untested, unless otherwise stated	[reply] [d/l] [select]