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> In dynamically typed languages you kind of just grep and hope the name is not too common. For four days, I spent debugging a python production script becaus
by gopalv 9y ago
> In dynamically typed languages you kind of just grep and hope the name is not too common.
For four days, I spent debugging a python production script because in one place I had typo'd ".recived=true" on an object and just couldn't understand why my state machine wouldn't work.
And very quickly, the whole team became fans of __slots__ in Python.
I still write 90% of my useful code in python, but that one week of debugging was exhausting & basically wouldn't have even compiled in a statically declared language. Even in python, the error is at runtime, after I got the __slots__ in place.
- y4mi 9y ago> I still write 90% of my useful code in python, but that one week of debugging was exhausting & basically wouldn't have even compiled in a statically declared language.[...] nothing stops you from using static typing with python3
- nightski 9y agoI haven't used optional typing in python. However, the problem I see with optional typing is that while I may choose to use it my team mates might not. Even more importantly, the 3rd party dependencies I use probably don't. So the amount of code that actually uses the types would be very limiting. Saying the choice is entirely up to you personally is a misnomer.
- gipp 9y agoStrict use of type annotations has to be a team decision, yes. Checking for them can be integrated into a CI build, though. The typing spec provides for supplementary "stub files" that can be provided for third-party dependencies without their own annotations. The typeshed project provides these for a fair and quickly increasing number of common dependencies, and is plugged into pycharm and mypy by default: https://github.com/python/typeshed https://github.com/python/typeshed
- yawaramin 9y agoI think GP meant 'you' as in 'your team'. Anyway, Python has a type repository for popular libraries, just like TypeScript does. And mypy can still typecheck your code even without type annotations.
- sidlls 9y agoIn fairness the hints available in Python 3 aren't really a static typing system. It would take a lot of extra work to make it one.
- lomnakkus 9y agoWell, nothing except almost the whole ecosystem of libraries not having type annotations, those type annotations that exist themselves being quite limited (IIRC), etc. etc.? Can we stop pretending that adding type annotations to a 'dynamic' language solves the "good static typing" problem? It's just silly. (About as silly as pretending that static types solve all problems.)
- bandrami 9y agoIs that really a typing problem, though? If I tried to use a "recived" slot on a Lisp struct that only had a "received" slot defined, I'd get a read-time error, and there's zero typing involved there.
- deleted 9y ago[deleted]
- protomyth 9y ago> For four days, I spent debugging a python production script because in one place I had typo'd ".recived=true" on an object and just couldn't understand why my state machine wouldn't work Is that really a dynamic typing problem or a language that allows you to create instance members anywhere? It seems like that is a flaw in the declaration model of the language and not a static / dynamic issue.
- avip 9y agoCould you clarify - did you go over all classes in your codebase and added __slots__ attribute? Or you have some tooling to do that for you? I don't have any clear counterargument but that sounds wildly unpythonic thing to do.
- kazinator 9y agoTXR Lisp, a dialect I created: $ txr This is the TXR Lisp interactive listener of TXR 185. Quit with :quit or Ctrl-D on empty line. Ctrl-X ? for cheatsheet. 1> (set a.b 3) ** warning: (expr-1:1) qref: symbol b isn't the name of a struct slot ** warning: (expr-1:1) unbound variable a ** (expr-1:1) unbound variable a ** during evaluation of form (slotset a 'b 3) ** ... an expansion of (set a.b 3) ** which is located at expr-1:1 Both warnings are static. If we put that into a function body and put that function into a file, and then load the file, we get the warnings. The diagnostics after the warnings are then from evaluation. Those are nothing; TXR Lisp will get better diagnostics over time. I'm just starting the background work for a compiler. There is dynamic and then there is crap dynamic. Don't confuse the two. There is crap static too. Shall we use C as the strawman examples of static? Hey look, two argument function called with three arguments; and there's a buffer overrun ...
- zzzcpan 9y agoPlus you can eliminate all typos in any language with a simple statistical linter that you can implement in like an hour or two.
- flavio81 9y ago>There is dynamic and then there is crap dynamic. (...) There is crap static too. Excellent. My point exactly. I have no fear of using a static or dynamic language, as long as it is a good implementation of a statically (or dynamically) typed language.
- passivepinetree 9y agoWhat would you consider good implementations of either?
- flavio81 9y agoGood "statics": Haskell, ML family, maybe Rust. Good "dynamics": All the Lisp-family languages. Smalltalk. Julia. Lua. Tcl.
- 9y ago
- smallnamespace 9y agoThis seems like something a linter can catch though. ESLint certainly seems to give me warnings for use of undefined properties.
- lrem 9y agoThat's a kind of error caught by the popular static analysis tools. Better add that pylint and mypy to your travis.yml as soon as possible.