Ask HN: What made you change your mind about a programming language/paradigm? • Hacker News Board

Re: Ask HN: What made you change your mind about a programming language/paradigm?

#311

Post by clintonb » Mon, Mar 04, 2019, 4:42 PM UTC

spricket wrote: post #260

clintonb wrote: post #190

Earlier quoted context omitted.

Is that really so bad? At edX all of our services were Django. After the third service was created we built templates in Ansible and cookiecutter to create future services and standardize existing ones. We created Python libraries with common functionality (e.g. auth). We were a Django shop. Switching to SOA didn’t mean switching languages and frameworks.

If your services were all setup the same, what was the big advantage to have them separate? Wouldn't you get the same scalability from running 10x of the monolith in parallel with a lot less work?

The primary advantage was time to market. When I started five years ago edX had a monolith that was deployed weekly...after a weekend of manual testing. The organization was not ready to improve that process, so we opted for SOA. By the time the monolith had an improved process—2 years later—we had built about three separate services, all of which could be deployed multiple times per day.

Re: Ask HN: What made you change your mind about a programming language/paradigm?

#312

Post by em-bee » Mon, Mar 04, 2019, 4:48 PM UTC

o10449366 wrote: post #102

anyfoo wrote: post #88

Earlier quoted context omitted.

I started using python 3 with mypy, which provides (optional) static typing, and my gosh has it reduced the time I spend looking for stupid problems by orders of magnitude. I got a somewhat direct comparison when I mypy-ified a small program where I used a lot of async and await (basically implementing own event loops and schedulers, it was interfacing very custom hardware that handled very different but interacting…

Agreed. As part of the transition process from Python 2 to 3, I pushed for typing on all of the critical components. I had to fight the management a little on the commitment, but in the long run it's saved us a ton of time identifying and preventing bugs and its made the entire codebase much more cohesive.

does the management agree with that assessment? these kind of changes are often hard to evaluate because ot is not easy to compare. did development really go faster because of types, or do we just think it did?

i agree that typing saves time but i am struggling to produce evidence for that

Re: Ask HN: What made you change your mind about a programming language/paradigm?

#313

Post by blacksqr » Mon, Mar 04, 2019, 5:17 PM UTC

7373737373 wrote: post #2

The lack of secure composability in almost all existing languages. You cannot import untrusted code and run it in a sandbox. Unless you are completely functional, you cannot restrict the effects of your own code either. The solution to this seems to be the object capability (key) security paradigm, where you combine authority and designation (say, the right to open a specific file, a path combined with an access righ…

Tcl has the concept of "safe interpreters" which can be spawned as slaves of the main interpreter. There is a default safe interpreter policy, which is fully scriptable for customization.

Among the available customizations in a safe interpreter are: restriction of use of individual commands, ability to set a time limit for execution of code, a limit to number of commands executed, and depth of recursion.

Memory usage can't be directly limited, but Tcl has trace features that allow examination of a variable value when set, so one could write custom code that prevents total contents of variables from exceeding a specified limit.

Re: Ask HN: What made you change your mind about a programming language/paradigm?

#314

Post by AnimalMuppet » Mon, Mar 04, 2019, 5:18 PM UTC

nirse wrote: post #277

mdgrech23 wrote: post #124

Earlier quoted context omitted.

What's stopping you from thinking clearly about the code while/after you write it? As I'm writing this sentence I'm thinking clearly about it and I'll probably reread it after I hit save. There's no reason you can't do the same w/ code.

It's not that it can't be done, it's just that sometimes it is nice to have a tool that helps you think about the code. Unit tested code isn't better in any way, it's just a style of writing code that can produce good quality code, but not the only coding style that can do that. But I'd like to add that there have been quite a few refactors that I have done that would have been way harder if it hadn't been for the un…

The tests don't just help you think about the code, they force you to do so. For those who are tempted to think "I can just do this quick change this one time; nothing will go wrong", tests force you to actually think.

Or they don't. If the tests just continue to work, then you ask yourself whether the change should have broken them. If not, you go on your way with a fair amount of confidence. But if the change should have broken the tests, then you have to look at why it didn't...

Re: Ask HN: What made you change your mind about a programming language/paradigm?

#315

Post by AnimalMuppet » Mon, Mar 04, 2019, 5:23 PM UTC

pjmlp wrote: post #214

alexval wrote: post #71

Earlier quoted context omitted.

My first job I wrote c++ for a win32 desktop app. I hated unit testing. My workflow was write the code, compile it, trigger the scenario, step through the code, write some unit tests after I knew it worked. It was the expectation on my team to write UTs so I did it. Fast forward to a different team I learned from a co-worker how UTs can help you influence your design. If you find yourself doing a ton of frustrating w…

My trick question to TDD advocates is how to develop native apps following those principles, after all no GUI change is allowed without a test.

In my book, the UI isn't part of unit testing - at least, the views aren't. The models and controllers (to use the MVC paradigm) might be, though.

Re: Ask HN: What made you change your mind about a programming language/paradigm?

#316

Post by AnimalMuppet » Mon, Mar 04, 2019, 5:28 PM UTC

zaphar wrote: post #3

Almost every time I experienced a shift like this in my thinking it was due to experiencing a problem I hadn't experienced until that point. I discovered the value of compile time type checks when I worked on large codebases in dynamic languages where every change was stressful. In comparison having the compiler tell you that you missed a spot was life changing. I discovered the value of immutable objects when I work…

I might even go farther. I wonder if most of the techniques (and languages) that we think are stupid are instead aimed at problems that we don't have. (Of course, those techniques become stupid when people try to apply them on the wrong problems...)

Re: Ask HN: What made you change your mind about a programming language/paradigm?

#317

Post by vp8989 » Mon, Mar 04, 2019, 5:30 PM UTC

lukifer wrote: post #306

spudlyo wrote: post #146

Earlier quoted context omitted.

Often times MySQL is set up with auto-commit set to true, where every DML statement (like UPDATE) is wrapped in an implicit BEGIN and COMMIT. It doesn’t have to be that way though, you can manage the transaction yourself, and you don’t have to COMMIT if you don’t want to, you can undo (ROLLBACK) if necessary.

It’s true, transactions in MySQL work great. But once the change is committed, the previous value is overwritten permanently. If the user wants to undo five minutes later, or I want to audit based on the value a month ago, we’re hosed unless we’ve jumped backflips to bake versioning into the schema. I think Hickey’s comparison to git is apt: we don’t stand for that in version control for our code, why should we find…

Because there is vastly more state in the world than there is code. And frankly, most state is not that important. Just wait until you work with a sufficiently large immutable system, they are an operational nightmare.

You should opt-in to immutability when the state calculations are very complex and very expensive to get wrong.

I do wish mainstream languages had better tools for safe, opt-in immutability. Something like a "Pure" attribute you assign to a function. It can only call other pure functions and the compiler can verify that it has no state changes in it's own code.

Re: Ask HN: What made you change your mind about a programming language/paradigm?

#318

Post by dmux » Mon, Mar 04, 2019, 5:35 PM UTC

pacala wrote: post #144

arduinomancer wrote: post #60

Static Type Checking. I used to think Node.js was the greatest thing ever. I won't bother explaining the benefits but suffice it to say I much prefer writing a server in Java compared to node. I think it takes getting burned at least once for new developers to understand why a lot of seasoned developers like types. Over time I've realized that there's a simple principle that applies to a lot of stuff in software and…

Good insights. Modern platforms are neither full dynamic nor rigidly static, but gradual, https://en.wikipedia.org/wiki/Gradual_typing . Start with a dynamic script, add typing as you go to strengthen the system. Notable mentions: Typescript, Python + mypy, C#, Dart.

And Groovy!

Re: Ask HN: What made you change your mind about a programming language/paradigm?

#319

Post by ken » Mon, Mar 04, 2019, 5:42 PM UTC

chalst wrote: post #288

ken wrote: post #210

Earlier quoted context omitted.

(I hammered out that answer right before I had to run on stage. A couple other big items I forgot:) A proper numeric tower. Python has complex numbers, but they don't seem well integrated (why is math.cos(1+2j) a TypeError?). Fractions are frequently very useful, too, and Python has them, in a library, but "import fractions; fractions.Fraction(1,2)" is so much more verbose than "1/2" that nobody seems to ever use the…

Conditions, yes. If you have multiple dispatch, then building/supporting a numeric tower is natural. In your other reply you pointed out macros. They are a mixed blessing, easily misused. Other languages have them but use them more sparingly and making it harder to overlook their special status, which leads to better "code smell" in my opinion. Do take a look at Julia. It has learned deeply from CL and innovated furt…

I can imagine how multiple dispatch could make a numeric tower a little easier to implement, but the limitations I see in Python and other languages don't appear to stem from that. You can already take the math.cos of most types of numbers (int, float, even fractions.Fraction, ...) just fine, or add a complex and a Fraction. Python has long dealt with two types of strings, several types of numbers, etc., with the same interfaces. This isn't a difficult problem to solve with single dispatch.

Macros are easily misused, true, but so can any language feature. I can go on r/programminghorror and see misuses of if-statements. It's the classic argument against macros, and I hear it a lot, but I can't say I've seen it happen.

25 years ago, conventional wisdom said that closures were too complex for the average programmer, and today they're a necessary part of virtually every language. Could we be reaching the point where syntactic abstraction is simply a concept that every programmer needs to be able to understand?

I think "macros are easy to misuse" comes from viewing macros as an island. In some languages (like C), they are: they don't really integrate with any other part of the language. In Lisp, they're a relatively small feature that builds on the overall design of the language. Omitting macros would be like a periodic table with one box missing. It'd mean we get language expressions as native data types, and can manipulate them, and control the time of evaluation, but we just can't manipulate them at compile time.

Re: Ask HN: What made you change your mind about a programming language/paradigm?

#320

Post by nanomonkey » Mon, Mar 04, 2019, 5:58 PM UTC

cauthon wrote: post #196

salex89 wrote: post #81

Using it as my main language: Python (2.7). How the hell did this thing become so popular? I've used it for all sorts of stuff earlier, less complex than the other. Scripts, devops, ETL... But then I got into a company that is using it for some quite serious stuff, a large codebase. Holly smokes this thing does not scale (in terms of development efficiency and quality) well. I swear at least 70% of our bugs is becaus…

Is there a language that has a better (i.e. more user friendly and decently performant) implementation of iterators and stream processing?

Clojure's stream processing, and sequence functions are worlds better than Python. Clojure's sequences can be lazily evaluated which allows for much more performant computation. And for stream processing you can't beat composable reducer functions.

The user friendliness comes both with how uncomplicated it is to write them, but also how easy it is to process them in parallel (a nightmare in Python).