On Sat, 16 May 2015 11:59 pm, Marko Rauhamaa wrote: > Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info>: > >> A couple more negatives: >> >> - no such thing as inheritance; > > Untrue. My simple Scheme object system (125 lines incl. documentation)
Ah yes, I've seen Javascript code like that too. Each line is thirty thousand characters long... *wink* > supports multiple inheritance without classes. Maybe I should port that > to Python... I'd like to see it, but somehow I don't think that your "Scheme object system" is another name for "closures". We were talking about closures, weren't we? It sounds like you have implemented a form of prototype-based object programming. The question of whether prototype-OOP has inheritance is an interesting one. Clearly prototypes implement something *like* inheritance, but it is based in delegation or copying. Delegation-based cloning is quite close to class-based inheritance, but copying-based cloning is not. My sense is that I prefer to say that prototypes don't have inheritance in the same sense as classes, but they have something that plays the same role as inheritance. But if you want to call it inheritance, I can't really argue. >> - "is-a" relationship tests don't work; > > From the ducktyping point of view, that is an advantage. The whole > Linnaean categorization of objects is unnecessary ontological chaff. How > many times have people here had to advise newcomers not to inspect type > and instance relations of objects and just call the method? Um, is that a trick question? I don't remember the last time. >> - an unfamiliar idiom for most people; > > That's impossible to ascertain objectively. Java and JavaScript > programmers (of all people!) routinely deal with closures. I don't think so. I can't say for Javascript, but for Java, there's a lot of confusion around closures, they've been described as "evil" with the recommendation not to use them, and people cannot even agree when they were introduced! http://java.dzone.com/articles/whats-wrong-java-8-currying-vs www.javaworld.com/javaworld/jw-06-2008/jw-06-closures.html I mean, people had to *debate* the introduction of closures? There were three competing proposals for them, plus an argument for "don't add them". Some people say closures were added in Java 7, others say closures have been there since the beginning, and James Gosling himself says that Java used inner classes instead of closures but the result was painful... It seems to me that in the Java community, there's a lot of confusion over closures, which are seen as an advanced (and rather scary) feature. Hardly routine. -- Steven -- https://mail.python.org/mailman/listinfo/python-list
