Microfeatures I'd like to see in more languages • Hacker News Board

Re: Microfeatures I'd like to see in more languages

#321

Post by zdragnar » Fri, Jan 06, 2023, 6:05 AM UTC

ilyash wrote: post #317

Bilal_io wrote: post #315

Earlier quoted context omitted.

You can do something similar in JavaScript > const love = "love"; > { // Section > console.log(`What is ${love}`); > }

Not the same ergonomic. The language doesn't "understand" it's a section (no opportunities listed in the original comment).

Actually, it does, though the only real use is with the `break` keyword for breaking out of a labelled block (or break / continue in a for loop): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

Things like stack traces don't track them, unfortunately.

Re: Microfeatures I'd like to see in more languages

#322

Post by j-james » Fri, Jan 06, 2023, 6:12 AM UTC

tremon wrote: post #42

xigoi wrote: post #4

My favorite is uniform function call syntax. In several languages (Nim, Koka, D, …), you can always write bar.foo(baz) instead of foo(bar, baz) and vice-versa. Another one from Nim is the implicit result variable. Instead of having to do this: func sum(nums: seq[int]): int = var result = 0 for num in nums: result += num return result you just do this: func sum(nums: seq[int]): int = for num in nums: result += num It…

and vice-versa Doesn't the reverse pollute the function namespace? If every obj.fun() can be written as fun(obj), doesn't that cause ambiguity with a previously imported global function fun()?

Not unless the function signatures overlap entirely. That's rare enough that I don't think I've ever? encountered it in several years of writing Nim.

Re: Microfeatures I'd like to see in more languages

#323

Post by CGamesPlay » Fri, Jan 06, 2023, 6:20 AM UTC

WalterBright wrote: post #303

CGamesPlay wrote: post #296

If unit testing makes the cut, then I think standardized documentation and doctests should be included also. Python (string literal at the beginning of a class/function), C# (structured comments) and Rust (doc attributes) are three different, valid ways of adding this to the language.

D has had these for a long time.

Looks like these fall into the "structured comments" category, based on seeing /** */ and /// in a repository I found. Does it also have a story for doc tests?

Re: Microfeatures I'd like to see in more languages

#324

Post by signaru » Fri, Jan 06, 2023, 6:24 AM UTC

dataflow wrote: post #264

Doctor_Fegg wrote: post #47

Negative array subscripts. So a[-1] means the last element of an array, a[-2] means the second last, and so on.

I'm fine with an array type that supports this, but not as the default. I've been bitten in the past by code that ran error-free while giving incorrect output due to this feature suddenly making the indexing valid. I'd prefer it to be opt-in somehow so that the default behavior for negatives is invalid, not silently wrong yet valid behavior.

Matlab has the opposite where your syntactically valid but mysteriously non-working code suddenly has a large array.

EDIT: On the other hand, I think Matlab's array(end - number) indexing syntax is a good compromise of convenience and less error prone explicitness.

Re: Microfeatures I'd like to see in more languages

#325

Post by gdwatson » Fri, Jan 06, 2023, 6:27 AM UTC

swyx wrote: post #312

ddejohn wrote: post #298

I really adore Python's iterable- and keyword-unpacking operators (*some_iterable, **some_mapping): arr = [0, 1, 2, 3, 4] head, *body, tail = arr # head=0, body=[1, 2, 3], tail=4 head, *rest = arr head, *_, tail = arr *_, tail = arr first, second, third, *rest = arr foo = {"a": 1, "b": 2, "c": 3} bar = {"b": 9, "x": -1} {**foo, **bar} # -> {"a": 1, "b": 9, "c": 3, "x": -1}

why bother with the distinction between one * and two *? in javascript the … operator neatly does both

Python has keyword arguments to functions. In that context, a single star packs or unpacks a list of positional arguments and a double star packs or unpacks a dictionary of keyword arguments.

Re: Microfeatures I'd like to see in more languages

#326

Post by vbezhenar » Fri, Jan 06, 2023, 6:37 AM UTC

About kebab-case identifiers.

What I always wanted is proper spaces! Designing syntax where identifier could have spaces (without backticks or something like that) might be tricky of course. But may be it's not impossible.

All those space imitations, whether they're dashes, underscores or camels - they're just imitations. Nothing compares to real spaces.

If anything, underscores are closest ones, if you ask me.

Re: Microfeatures I'd like to see in more languages

#327

Post by pmontra » Fri, Jan 06, 2023, 6:38 AM UTC

JSON compatibility, to be able to copy and paste from JSON to valid nested dynamic arrays.

  a = {
    "a": "a",
    "b": {"b": 2} 
  }

Optional commas at the end of lines, so this is also valid

  a = {
    “a“: "a"
    "b": {"b": 2} 
  }

and we are able to swap or append lines without editing the commas or forgetting to do it and get a syntax error. Mandatory commas on all lines would do but it gets in the way of JSON compatibility.

This must also be legal code and equivalent to the previous one

  a1 = {
    a: "a",
    b: {"b": 2} 
  }
  a == a1 # true

The developer decides when saving typing time is more important than JSON compatibility.

PS: a big yes to kebab-case too. That's in part CSS compatibility because CSS class names are often kebab cased.

Re: Microfeatures I'd like to see in more languages

#328

Post by mLuby » Fri, Jan 06, 2023, 6:39 AM UTC

culi wrote: post #277

this is usually a style thing not an enforced syntax and maybe a hot take but I actually really like leading commas in comma-delineated lists (like Elm and Haskell). Makes changing the order of things really convenient

Agreed. Especially the more diff-driven development we do.

Re: Microfeatures I'd like to see in more languages

#329

Post by gdwatson » Fri, Jan 06, 2023, 6:39 AM UTC

tlb wrote: post #286

I might add kebab-case to my current language project. From all the code I've written, I only found a handful of - operators not surrounded by spaces, so that ambiguity wouldn't bite me often. Also, I wish the unary negation operator was more visually salient. `foo * -bar` is very different from `foo * bar`, but it's only a handful of pixels on the screen. I've thought about trying to render it as an em-dash or somet…

There are coding fonts that make the "-" look more like a minus than a hyphen. I know that Iosevka and its variants do.

Re: Microfeatures I'd like to see in more languages

#330

Post by estebank » Fri, Jan 06, 2023, 6:41 AM UTC

masklinn wrote: post #154

andix wrote: post #138

Earlier quoted context omitted.

Also on a function? var getDate() { return „no date“; }

That is often considered undesirable because it makes code less clear and compilation errors inscrutable. For instance the rust developers consciously decided to remove that from the language, named functions must be fully typed.

Easter egg: you can use -> _ to ask the compiler what type it thinks the return type should be, given your body. Because it is only used for diagnostics it isn't fully featured and there are things it doesn't cope well with, but it is there and works most of the time.