I agree with every sentence in this post. +1K :)
-Mikeal On Nov 2, 2011, at November 2, 20119:05 AM, Jeremy Ashkenas wrote: > On Wed, Nov 2, 2011 at 11:01 AM, David Bruant <[email protected]> wrote: > Could you elaborate on this point? > All object-lockdown I can think (non-configurability, non-writability, > non-enumerability, private names, const variables, const classes) of is > optional. Why are you against them? > > I was about to say "if you're unsatisfied, create a language which doesn't > provide features you don't like, like Coffeescript", but... humm... > So, why being against the introduction of features in the language? > > I'd be glad to elaborate -- but since it's off topic for minimal classes, > changing the Subject here. > > What draws people to dynamic languages is freedom. > > And JavaScript is one of the *most* dynamic of the mainstream programming > languages. Not only can you can pass any object to any function, but you can > call a method with any number of arguments, easily modify the prototypes of > other objects, introspect on any object's properties with a simple loop, > replace any member function with a wrapped version, attach new properties to > any object ... the list goes on. > > If I had my druthers, JS.next would generally embrace the spirit of > JavaScript's dynamism (and freedom), and try to push those aspects further -- > with better introspection and more flexibility -- instead of compromising > with more restrictive static languages and adding lock-down keywords so that > some programmers might "feel safer". > > Let's set arguments about security and constraint guarantees aside for a > moment (although I'd be glad to have those as well), and talk about these > keywords as pure features: > > "private" does not add anything new to a property. If you don't want the > property to be used outside of the class ... don't use the property outside > of the class. > > "const" does not add anything new to a variable. If you don't want to change > the value of a variable ... don't change the value of the variable. > > "freeze" does not add anything new to an object. If you don't want to change > the shape of an object ... don't change the shape of the object. > > Note that Ruby, another very dynamic language, has "private" and constants. > And yet private methods can be called from the outside, with "send", and > contants can be explicitly overwritten with new values. They are simply red > tape, not concrete walls. For better or for worse, I have very rarely seen a > large-scale Ruby project that does *not* call a private method externally, or > overwrite a constant during configuration. > > The recent JavaScript renaissance that we're all enjoying owes debts to > JavaScript's foresight as a "free", dynamic language. If all of the > JavaScript core object had been frozen, locked down with private methods, and > set as const properties on the global object, libraries like Prototype.js > never would have happened. Libraries like jQuery would have been much more > difficult to imagine. We might not have the new Array#map, #reduce, #every, > or #filter methods at all. > > Can a free, dynamic language be abused? Certainly. Is Prototype.js dangerous? > For some websites, it can be (including NYTimes.com, where I work). > > The freedom of having every object and every property be configurable, > settable, introspectable, readable and writable, at least at the language > level, is worth the trade off. If we add const, private, and other lock-down > syntax, or make class properties private by default (shudder), I guarantee > you that many potential innovative libraries that otherwise might spring up > will never even be conceived, and frustrating situations that could have > otherwise been solved by a quick patch will instead require convoluted > work-arounds. > > JavaScript should be about making it easier to write the right thing, and not > so much about making it harder to do the wrong thing. After all, the former > is purely positive, and the latter assumes that you know better than the > engineer who comes after you. In the real world, you often don't. > > Cheers, > Jeremy > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss
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