Pipe Operator (|>) For JavaScript

Post by galaxyLogic » Sat, Jan 21, 2023, 4:04 AM UTC

hajile wrote: post #407

galaxyLogic wrote: post #386

Earlier quoted context omitted.

Why not use |> for that?

It's more common for pattern matching Java's new syntax, Erlang, Elixir, StandardML (fat arrow), F#, Kotlin, Ocaml, Haskell, Rust (fat arrow), Ada (fat arrow), Scala (fat arrow), Zig (fat arrow), and probably a bunch of others too. That's a lot of prior art for people to be comfortable with and as the fat arrow already has another meaning, overloading it in pattern matching might complicate things.

Post by MathMonkeyMan » Sat, Jan 21, 2023, 4:17 AM UTC

wruza wrote: post #384

BigJono wrote: post #52

Earlier quoted context omitted.

TC39 proposals often have rubbish real world examples that should never see the light of day in a JS codebase. It makes me really question the judgement of the people that are working on this language, and it explains how some of the shittier proposals manage to slip in and why the good ones are misused all over the place in every real world codebase when this is the kind of guidance devs have on where to use fancy n…

React component should be chock full of do expressions If the motivation behind these features are React components, javascript clearly lacks proper logic in array (and object) literals, like '[' if (cond) […]expr1 [else […]expr2] ']' Although it seems pretty strange to add syntax only because some specific user interface library together with a specific language extension could benefit from it.

    [cond ? expr1 : expr2]

    [(() => {/*code*/})()]

Post by runald » Sat, Jan 21, 2023, 4:44 AM UTC

MathMonkeyMan wrote: post #388

Can't javascript already do [this][1]? const thrush = (value, func, ...funcs) => func ? thrush(func(value), ...funcs) : value; // no new syntax required thrush( envars, Object.entries, x => x.map(([key, val]) => `${key}=${val}`), x => x.join(' '), x => chalk.dim('$ ' + x, 'node', args.join(' ')), console.log); [1]: http://www.davidgoffredo.com/thrush.html

  const thrush2 = (value, ...funcs) => funcs.reduce((value, func) => func(value), value);

  const thrush3 = (value, ...funcs) => { for (const func of funcs) value = func(value);  return value }

Post by greggman3 » Sat, Jan 21, 2023, 5:46 AM UTC

captainmuon wrote: post #403

greggman3 wrote: post #246

Earlier quoted context omitted.

> That brings me to something I really want in JS, actual unmutable values. If you use `const x = new SomeClass()`, you cannot reassign it, but you can change fields. The first time I encountered `const`, I thought it did the opposite. It would be cool if you could declare something (object, array) to be an immutable value. That sounds like a fundamental mis-understanding. Variables do not hold objects, they hold ref…

I don't want to freeze the object, I want to have a handle that doesn't allow me to modify the object. (Whether that would be at all possible in JS is another question.) So let foo = {field:1}; immutable let bar = foo; bar.field = 2; // error foo.field = 3; // ok This is what I actually want when I think "const". I don't really care that you can reuse a variable, or re-seat a value. What I care about is that I reciev…

Post by wruza » Sat, Jan 21, 2023, 6:28 AM UTC

MathMonkeyMan wrote: post #413

wruza wrote: post #384

Earlier quoted context omitted.

React component should be chock full of do expressions If the motivation behind these features are React components, javascript clearly lacks proper logic in array (and object) literals, like '[' if (cond) […]expr1 [else […]expr2] ']' Although it seems pretty strange to add syntax only because some specific user interface library together with a specific language extension could benefit from it.

Do you mean this? [cond ? expr1 : expr2] Or maybe this: [(() => {/*code*/})()]

  [...(cond ? [expr1] : [])]