Pipe Operator (|>) For JavaScript

Re:Pipe Operator (|>) For JavaScript by jameshart on Friday January 20, 2023 @01:44PM (#34457723)

The thing I dislike about it most is the constantly-rebound % variable. It means something different in each line. In this case they have elected to keep it as a string throughout the pipe, but this ‘more pipey’ version of the code has it start out as an array then turn into a string halfway through the pipe, which feels dangerous (and is presumably why they didn’t take the example this far):

    Object.keys(envars)
      |> %.map(envar => `${envar}=${envars[envar]}`)
      |> %.join(' ')
      |> `$ ${%}`
      |> chalk.dim(%, 'node', args.join(' '))
      |> console.log(%);

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Re:Pipe Operator (|>) For JavaScript by tracker1 on Friday January 20, 2023 @02:23PM (#34458356)

Not really... F#-style pipeline syntax would be a bit more explicit about it, assuming you could use % for a variable name...

    Object.keys(envars)
      |> % => %.map(envar => `${envar}=${envars[envar]}`)
      |> % => %.join(' ')
      |> % => `$ ${%}`
      |> % => chalk.dim(%, 'node', args.join(' '))
      |> % => console.log(%);

To be honest, I've pretty much given up the hopes that TC39 would actually resolve pipelines and decorators at this point... I think it's been around a decade now.

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Re:Pipe Operator (|>) For JavaScript by jameshart on Friday January 20, 2023 @02:54PM (#34458851)

But then why would you call all those different variables ‘%’?

Reading this version though I also notice something else that the F# style enables that the Hack style doesn’t which is that it supports destructuring. So in F# style, I can more easily make pipe steps that pass on multiple values in a structured object or array, then access them easily down-pipe.

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Re:Pipe Operator (|>) For JavaScript by tracker1 on Friday January 20, 2023 @02:59PM (#34458932)

Unfortunately F# pipelines have been rejected a few times by TC39 to advance... I used it for a while via Babel/6to5, but I gave up (like with decorators) after many years of no advancement. I doubt I'll see either any time soon.

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