Bring Out the Type System

By the way, about void-safety: for a decade now, Eiffel has been void-safe, meaning a compile-time guarantee of no run-time null pointer dereferencing. It is beyond my understanding how the rest of the world can still live with programs that run under myriad swords of Damocles: x.op (…) calls that might any minute, without any warning or precedent, hit a null x and crash.
—Bertrand Meyer, Why not program right?

I knew this would be exasperating, but really now. At this point, my eyes rolled completely out of my head and I no longer have eyes. 🙄

References don't just randomly become null without warning. You chose to call a function that might return null, and didn't bother to put in an if or assert when that's a possibility. Typically the exception system catches it if you do miss it.

The Objective-C model of nil messaging just returning nil or 0 was theoretically dangerous, but in practice incredibly useful. Crashing out in Javascript means I have to wrap everything with (x ? x.op() : null) to get the same effect, which might require a lot of temp vars.

Do type devotees actually believe in randomly-appearing errors, or that dynamic programmers just flail our limbs on a keyboard until something manages to pass tests, or do they just exaggerate a rare edge case they saw once, or are they completely fabricating this stuff to justify their waste of time/perversion?

Type systems are self-inflicted BDSM, and it is not self-evident that everyone wants to wear a gimp suit.

12 thoughts on “Bring Out the Type System”

  1. @mdhughes You seem to be conflating two things. Having a type system doesnt automatically prevent null references. I mean, some languages may work like that, and that would be great. But to take Java, for example, since it’s he one I know best: checking for null values is depressingly the norm.

    That said, I find the idea of setting a variable without specifying — or maybe even knowing — its type, to be... worrying, let’s say.

  2. @devilgate Well, specifically Eiffel, since that's the linked article. But Swift also bans nulls from normal use (! ? punctuation to do various "wrong" things).

    Dynamic objects have a class, but a reference or expression doesn't need to know it, which is what a "type system" is.

  3. @devilgate Java's a little BDSM with Generics, but there are much more dominating and abusive languages now, where it's all but impossible to express free thought and just shove objects in a collection.

  4. @mdhughes The thing with BDSM, though, is that there’s always someone dominating and someone submitting. I don’t see myself being dominated by generics: I’m using them to enforce my will. This Collection can only have Strings in it, or it’s going to be inserious trouble.

  5. @devilgate Or: You tied yourself up so you can only wiggle around enough to put a string in that list, and that's getting you off. And it's dom/sub is when the language designer does it to you. Bjarne has a lotta subs.

  6. @adiabatic I'm a C, not a C++, how does any resolve method dispatch? Or do you just have a giant if typeof/cast tree after pulling something out? somelist.pop().quack() plus or minus some null checking works in dynamic langs…

  7. @mdhughes Fair enough. I still prefer to specify the type, I think.

    Now, don’t get me started on the lack of a compiler in scripting languages. I think that’s a blog post I’ll soon be writing.

  8. @mdhughes Sure. I've been using some R lately, and it's so frustrating that you have to deploy and run a test just to find a syntax error. IDEs should help, but R doesn't seem to have great support.

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