compiler: syntactic sugar for combine

[josephjclark]

One thing that's very hard to do in job writing is do muliple steps in one.

each is the usual usecase, where I want to do:

each($.data, get, fn, post)

Where what I really want in the each is a little pipeline which processes each item through multiple operations

I can do this today with promises:

each($.data, get.then(fn).then(post))

But it's ugly, the compiler creaks, and error handling isn't great

You can also use combine, which is cool but no-one knows about it:

each($.data, combine(get(), fn(), post()))

I'm just wondering if we can do some syntactic sugar for combine, like:

each($.data, [get, fn, post])

But we probably can't distinguish this piping sort of expression from an array.

What if we used something more like piping?

each($.data, get |> fn |> post)
each($.data, get | fn | post)
each($.data, get > fn > post)
each($.data, @[get,fn , post])

Not terribly neat or intuitive.

using a pipe is OK but the synax isn't reserved, so how would I catch it?

JS does have a proposal for a pipeline operator: https://github.com/tc39/proposal-pipeline-operator

So it's this then:

each($.data, get |> fn |> post)

The compiler detects the chain and compiles it to:

each($.data, combine(get, fn, post))

You cannot use the pipe operator inside a block statement. Use it only in place of an operation.