The type system is a programmer's best friend • Hacker News Board

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

#161

Post by tsimionescu » Sat, Nov 05, 2022, 5:23 PM UTC

noveltyaccount wrote: post #151

highwaylights wrote: post #145

Earlier quoted context omitted.

I’d take this further. I was listening to the John Carmack episode of Lex Fridman from the summer, and he makes a comment about being frustrated that in the Valley there’s an almost religious opposition to IDEs, debuggers, and static analysis. Some of those tools have only become more powerful over time and I’m perplexed as to the mindset that would make a person averse to automating the drudgiest parts of their job…

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…

Note that Emacs had these features and more for Lisp since about the 1990s or even earlier, while being free.

Now, for C or Java or most other popular languages, you're absolutely right.

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

#162

Post by maxbond » Sat, Nov 05, 2022, 5:24 PM UTC

noveltyaccount wrote: post #151

highwaylights wrote: post #145

Earlier quoted context omitted.

I’d take this further. I was listening to the John Carmack episode of Lex Fridman from the summer, and he makes a comment about being frustrated that in the Valley there’s an almost religious opposition to IDEs, debuggers, and static analysis. Some of those tools have only become more powerful over time and I’m perplexed as to the mindset that would make a person averse to automating the drudgiest parts of their job…

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…

Just so you know, you can do those things in vim now (I do), and the whippersnappers may well be.

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

#163

Post by constantcrying » Sat, Nov 05, 2022, 5:24 PM UTC

noveltyaccount wrote: post #151

highwaylights wrote: post #145

Earlier quoted context omitted.

I’d take this further. I was listening to the John Carmack episode of Lex Fridman from the summer, and he makes a comment about being frustrated that in the Valley there’s an almost religious opposition to IDEs, debuggers, and static analysis. Some of those tools have only become more powerful over time and I’m perplexed as to the mindset that would make a person averse to automating the drudgiest parts of their job…

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…

Vim is not really an editor. It is a way to edit text, you can use vim in almost any environment. You are also totally wrong about vim or emacs not having code completion, that is just nonsense.

I use (a version of) visual studio, the first thing that I did was installing a vim extension.

Also vim itself already supports almost any of these features with some basic plugins for the completion logic. If I type "." in my vim I get the same thing I would in visual studio. If you are saying "vim is bad because it lacks X IDE feature" you are missing the point.

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

#164

Post by noobermin » Sat, Nov 05, 2022, 5:25 PM UTC

emodendroket wrote: post #154

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…

I don’t disagree that it makes things much more pleasant, but I started doing this around 2013, which, while old, was still a year beginning with 20, and consensus was trending the opposite way and people were bullish about stuff like Ruby. The pendulum has really swung in the other direction.

No, there really is no new insight OP or anyone else has.

At the end of the day, the only thing that matters is writing something that works and works well. Hackers go through too many moodswings to be worth paying attention to when they start telling you how you should code.

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

#165

Post by maxbond » Sat, Nov 05, 2022, 5:26 PM UTC

PainfullyNormal wrote: post #73

Articles like this bug me. You've given me a list of why types are awesome. Great. Now, tell me what the tradeoff is. Nothing is free in engineering. To get something, you have to give up something else. Even grug[0] understands this. [0]: https://grugbrain.dev/#grug-on-type-systems

Ever so slightly longer compile times. It's pretty close to a free lunch.

There are only tradeoffs when we are at the frontier of what's possible with a set of technologies, and so must trade off on something in order to move along that frontier[1]. Many languages aren't operating at that frontier, and adding static typing is free (in the marginal case, ignoring the substantial effort to implement the type system). If you start a greenfield Python project, and you start typing right away and incorporate MyPy into your CI and IDE - it's as close to free as you can get, and the benefit is substantial.

[1] Eg, like in this diagram, http://image1.slideserve.com/2488675/production-possibilitie... - we only need to trade off on guns & butter if we're along the frontier (the blue line), if we find ourselves somewhere in the middle we can just make more stuff until we reach the frontier.

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

#166

Post by sidlls » Sat, Nov 05, 2022, 5:29 PM UTC

noveltyaccount wrote: post #151

highwaylights wrote: post #145

Earlier quoted context omitted.

I’d take this further. I was listening to the John Carmack episode of Lex Fridman from the summer, and he makes a comment about being frustrated that in the Valley there’s an almost religious opposition to IDEs, debuggers, and static analysis. Some of those tools have only become more powerful over time and I’m perplexed as to the mindset that would make a person averse to automating the drudgiest parts of their job…

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…

emacs has plenty of plug-ins that turn it into an IDE. For people who are already comfortable with it, these tools are great. I’m more productive in it than with “modern” tools. For newcomers the learning curve is going to be steeper. I’d recommend learning at least either vim or emacs (or perhaps other text-based editors with similar features, if they exist) though, as it does provide versatility for oneself. Those GUI IDEs aren’t available in every environment where one might want to code or debug.

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

#167

Post by pcthrowaway » Sat, Nov 05, 2022, 5:29 PM UTC

noveltyaccount wrote: post #151

highwaylights wrote: post #145

Earlier quoted context omitted.

I’d take this further. I was listening to the John Carmack episode of Lex Fridman from the summer, and he makes a comment about being frustrated that in the Valley there’s an almost religious opposition to IDEs, debuggers, and static analysis. Some of those tools have only become more powerful over time and I’m perplexed as to the mindset that would make a person averse to automating the drudgiest parts of their job…

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…

For the people responding to you who are saying you can get all the same things in vim, they're right of course, but a lot of this modern functionality is now built on top of the Language Server Protocol[1], which is an open standard created by microsoft for VS Code.

Kudos on the people who have ported this to Vim[2], but I suspect the support for LSP features will still be better in VS Code

[1] https://microsoft.github.io/language-server-protocol/

[2] https://github.com/prabirshrestha/vim-lsp

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

#168

Post by deltasevennine » Sat, Nov 05, 2022, 5:29 PM UTC

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. I think python type hints and typescripts are the way forward. HOWEVER, the paradox is real.

Think about it this way. If you have errors in your program, does it matter that much if those errors are caught during runtime or compile time? An error in compile time is caught sooner rather then later but either way it's caught. YOU are protected regardless.

So basically compile time type checking just makes some of the errors get caught earlier which is a slight benefit but not a KEY differentiator. I mean we all run our code and test it anyways despite whether the system is typed or not so the programmer usually finds most of these errors anyways.

So what was it that makes python easier to use then C++?

Traceability and determinism. Errors are easily reproduced, languages that always display the same symptoms from certain errors and in turn deliver error messages that are clear and are readable. These are really the key factors. C++ on top of non-deterministic segfaults, astonishingly even has compile time messages that can confuse users even further.

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

#169

Post by hither_shores » Sat, Nov 05, 2022, 5:29 PM UTC

Smaug123 wrote: post #119

throway232lasdf wrote: post #81

Earlier quoted context omitted.

> Why is it better to have two email types, VerifiedEmail and UnverifiedEmail vs. one Email type with an "isVerified" field? You obviously have no idea what a type is. type VerifiedEmail = { email: string; is_verified: true; }; type UnverifiedEmail = { email: string; is_verified: false; };

In fairness this takes an unusually strong type system to express, doesn't it? Typescript can do it, but I don't think e.g. Haskell98 can do it out of the box in an analogous way? (Of course, it's hard to prove a negative and I'm not super familiar with Haskell, but my evidence is that I'm pretty certain F# can't.)

> but I don't think e.g. Haskell98 can do it out of the box in an analogous way?

This is basically the runtime representation of `data Email = Verified { email :: string } | Unverified { email :: string }`, but promoting `Verified` and `Unverified` to type level requires an extension:

    data Email (verified :: bool) where
         Verified :: string -> Email true
         Unverified :: string -> Email false

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

#170

Post by blackbrokkoli » Sat, Nov 05, 2022, 5:30 PM UTC

cardanome wrote: post #52

Oh god, please just use primitive types. Don't make assumptions about things. Everyone thinks they are so smart validating emails, phone numbers, zip codes and all until their great design goes live and they discover that users in the real world do not follow their assumptions. I have seen that happen again and again. No, if your idea of validating an email is more complicated than "should have an @ symbol", I guaran…

Thank you, I feel like I am going insane here.

About 90% of stuff I ever worked does email things here or there, and I never had the desire for some hyper complex abstraction with 10 pages of documentation just to store email. I also never experienced a bug that would have been fixed by this.

I mean if the user is putting in some bullshit there, the basic validation of type="email" or pendant if I am not working in HTML is gonna tell him that and after that he does or does not get his verification email. Boom, problem solved along with other one's.

Need just the domain? Well I'll use a damn 1 liner function with split() or something for this hyper specific use case, don't encumber me with the probably faulty abstraction of email some library designer cooked up 8 years ago just for this?!

I do use types when they are actually convenient, but these types-are-the-best-everywhere-all-the-time articles keep failing to convince me...