Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The type system is a programmer's best friend

dusted.codes

Post reply on HN
Print view View original

271–280 of 467 posts

Re: The type system is a programmer's best friend

#271

Post by pencilguin »

hgomersall wrote: post #193
jdrek1 wrote: post #177

Earlier quoted context omitted.

> (Edit, that's not possible in c++) Mind expanding on that? Because what that readme there shows is absolutely possible in C++, I have used a similar system for dealing with natural units.

I'm happy to admit I'm wrong on that. My understanding is the bit that makes (kg.m)/s^2 type equivalent to a N, equivalent to J/m is not implementable in the same generic way.

All unit systems decompose each unit to primitives, that can then be aliased for notational convenience. So, a result of J/m decomposes the same as a N.

Re: The type system is a programmer's best friend

#272

Post by deltasevennine »

icedchai wrote: post #205
deltasevennine wrote: post #168

Earlier quoted context omitted.

But there's a paradox. Why does 100,000 lines of code of python tend to be safer and more manageable then 100,000 lines of C++ despite the fact that python has no type checker and C++ has a relatively advanced type checker? Why do startups choose a python web stack over a C++ web stack? I don't think it's "self-evident." I think there's something more nuanced going on here. Hear me out. I think type systems are GREAT…

I think it is simpler than that: C++ is an incredibly complex and verbose language. Most of web development is working with strings, and C++ kinda sucks there. There is also a compilation/build step, so overall productivity is lower. Python is "easier" all the way around (we'll ignore the dependency management/packaging debates.) It depends on how you define "safer." Run-time errors with Python happen frequently in l…

I know it happens "all the time" but these runtime errors happen fast and quick. You catch most of these issues while testing your program.

Statistically more errors are caught by python runtime then an equivalent type checked c++ program simply because the python user interface fails hard and fast with a clear error message. C++ on the other doesn't do this at all. The symptoms of the error are often not related to the cause. Python is safer then C++. And this dichotomy causes insight to emerge. Why did python beat c++?

In this case the type checker is irrelevant. Python is better because of clear and deterministic errors and hard and fast failures. If this is exemplary of the dichotomy between c++ and python and if type checkers are irrelevant in this dichotomy it points to the possibility that type checking isn't truly what makes a language easier to use and safer.

The current paradigm is rust and Haskell are great because of type checking. This is an illusion. I initially thought this was well.

Imagine a type checker that worked like c++. Non deterministic errors and obscure error messages. Sure your program can't compile but you are suffering from much of the same problems, it's just everything is moved to compile time.

It's not about type checking. It's all about traceability. This is the key.

>there is less determinism with Python

You don't understand the meaning of the word determinism. Python is almost 100 percent deterministic. The same program run anywhere with an error will produce the same error message at the same location all the time. That is determinism. Type checking and unit testing does not correlate with this at all.

This is not the case with c++.

Re: The type system is a programmer's best friend

#273

Post by Our_Benefactors »

yellowapple wrote: post #267
Our_Benefactors wrote: post #245

Earlier quoted context omitted.

Vim: I can do that too, I swear! Just configure some plugins, can’t tell you what they might be though. But I’m turing complete, and I’m the best! VScode: Of course I can do autocomplete bud. Here, search my package repo, I’ll tell you which plug-ins are the most popular and handle the entire download and install process for you. There’s no comparison.

Visual Studio: Of course I can autocomplete! Hold my beer while I bring your machine with 16 cores and 64GB of RAM to its knees for multiple minutes ;)

This is just false. Does it have a higher memory/cpu footprint than vim? Sure. But VScode is plenty performant.

Edit: vscode != visual studio. I’ll leave my comment.

Re: The type system is a programmer's best friend

#274

Post by hgomersall »

djha-skin wrote: post #40

The most successful languages are typed but weakly so. Just enough type system to avoid the biggest class of bugs, not enough to get in your way all the time. Golang strikes this balance very well. Too little typing, and your Python unit tests get too heavy to run after every commit. Too much, and you have to read a book on category theory before you can figure out how to grab that one field using Lenses in Haskel. E…

Python is strongly typed. The weakness (such as it is) in python is that in historic idioms the type is ignored in favour of the interface (duck typing).

Re: The type system is a programmer's best friend

#275

Post by SAI_Peregrinus »

czx4f4bd wrote: post #159
noveltyaccount wrote: post #151

Earlier quoted context omitted.

When I graduated college in the '00s I thought Vim was the most amazing thing I'd ever learned. Then a colleague at my first job showed me what happend when you typed . after a variable name in Visual Studio. Code completion, inline documentation...my mind was blown, and I never looked back. When I meet a young chap extolling the benefits of Vim or Emacs or really anything that doesn't have stepped debugging and code…

Both Vim and Emacs have plugins for intelligent code completion and viewing inline documentation. I personally prefer to use VS Code or Jetbrains IDEs with Vim emulation, but I've seen setups for both Vim and Emacs that basically made them into full-fledged IDEs.

Full-fledged Plugin-based development environments. An IDE is an Integrated Development Environment; it comes with the features necessary for efficient development built-in.

Re: The type system is a programmer's best friend

#276

Post by za3faran »

Our_Benefactors wrote: post #256
constantcrying wrote: post #247

Earlier quoted context omitted.

Why do you even reply to a post that you didn't bother to read? VScode is a neovim frontend. >There’s no comparison. Read the first line of my post. There literally is no comparison, because there is a category error.

> Why do you even reply to a post that you didn't bother to read? VScode is a neovim frontend. I did read your post Mr. snark. > There literally is no comparison, because there is a category error. Pure pedantry. VScode takes far less effort to get a high quality feature set when compared to vim. That’s the only point of debate that matters for most people.

I think OP wanted to make a categorical difference between vim-the-editor vs vim-motions. The latter of which are supported in all major IDEs as plugins/extensions.

Re: The type system is a programmer's best friend

#277

Post by pipeline_peak »

dgan wrote: post #246
pipeline_peak wrote: post #140

Type systems cause programmers to write 300 classes no one references and many duplicates of each other. Dynamic typing allows you to focus on what really matters, not trivial business logic OOP hierarchies that get inevitably ignored. I feel like in app development, there’s something honest about dynamic typing. You’re focusing on the instance rather than the unnecessary model definition that again, nobody uses and…

Seems like you mix up classes, and types ... like many others in this thread

I don’t understand, classes are user defined types.

Re: The type system is a programmer's best friend

#278

Post by deltasevennine »

mamcx wrote: post #217
deltasevennine wrote: post #168

Earlier quoted context omitted.

But there's a paradox. Why does 100,000 lines of code of python tend to be safer and more manageable then 100,000 lines of C++ despite the fact that python has no type checker and C++ has a relatively advanced type checker? Why do startups choose a python web stack over a C++ web stack? I don't think it's "self-evident." I think there's something more nuanced going on here. Hear me out. I think type systems are GREAT…

> and C++ has a relatively advanced type checker? But why it NEEDS that? Because C++ is FAR MORE DANGEROUS. And worse language, in so many aspects, that you need everything to tame it. In contrast, other langs like python have the luxury of see what C/C++ do wrong and improve over it. Just having a `String` type, for example, is a massive boost. So for them, the type system already have improved the experience! --- S…

Hindley mindler allows for flexibility in your types and this high abstraction and usability in code. The full abstraction of categories allows for beautiful and efficient use of logic and code but it's not safety per se.

Simple type systems can also offer equivalent safety with less flexibility. What make Haskell seem more safe is more the functional part combined with type safety. Functional programming eliminates out of order errors where imperative procedure were done in the wrong order.

Re: The type system is a programmer's best friend

#279

Post by xigoi »

pencilguin wrote: post #263
yellowapple wrote: post #249

> I want that data type to have helpful methods such as .Domain() or .NonAliasValue() which would return gmail.com and foo@gmail.com respectively for an input of foo+bar@gmail.com. No the hell you don't. Please please please do not attempt to separate the alias from an email address I submit. It's there for a reason - specifically, to hold you accountable if I experience a sudden influx of spam, and generally to keep…

True enough, as far as it goes. But if you are concerned about subscribing to something twice, you may want to try to check delivery uniqueness. They might be your own addresses. Of more interest to me, omitted from the presentation--as almost always--is anything about what is disliked about a malformed address. You see this when some web form says it doesn't like your address, but won't say why, leaving you to guess…

> But if you are concerned about sending an e-mail to the same address twice, you need to check delivery uniqueness.

For one, you shouldn't be concerned about that, and for two, you can't tell delivery uniqueness anyway, since someone can have multiple completely different addresses going to the same inbox.

Re: The type system is a programmer's best friend

#280

Post by jejones3141 »

deltasevennine wrote: post #168
gary17the wrote: post #104

This is, IMvHO, such old news that it feels... weird to still read about it in a year with the prefix of 20. Every programmer who has ever single-handedly written a 100,000+ LOC software system will tell you the same thing: shift as much responsibility on the compiler as you can and have the compiler check the code you write to any extent technologically possible. Getting rid of bugs by experiencing, diagnosing and f…

But there's a paradox. Why does 100,000 lines of code of python tend to be safer and more manageable then 100,000 lines of C++ despite the fact that python has no type checker and C++ has a relatively advanced type checker? Why do startups choose a python web stack over a C++ web stack? I don't think it's "self-evident." I think there's something more nuanced going on here. Hear me out. I think type systems are GREAT…

> If you have errors in your program, does it matter that much if those errors are caught during runtime or compile time?

The passengers on the fly-by-wire jet running the program might well say that it matters.

Post reply on HN