Require curly braces for same-name key-value shorthand

[TrevorBurnham]

This has been discussed a bit in other issues, but I don't think anyone has raised the matter directly.

{a} is shorthand for {a: a}. That's cool. And in a function call, I can write

foo a, b: 2

as shorthand for

foo a, {b: 2}

Also cool. But if I write

foo b: 2, a

then this is parsed as

foo {b: 2, a: a}

I see this as seriously ambiguous. I'd prefer that only consecutive explicit key: value pairs without curly braces be interpreted as object declarations. Do others agree?

[ghost]

I agree 100%.

I have 6969 lines of CoffeeScript code in my current project and never, ever, had a need for the a to {a: a} expansion.

The change TrevorBurnham proposes however, allows us to have, for example, string parameters after the implicit key: value pairs...

...This alone, in my current project, would allow the removal of curly braces in over 30 places.

Furthermore, whenever I'm rereading my code, those curly braces always stop me in my tracks, making me think: "Why are these here? Why haven't I removed them?"

Food for thought.

[satyr]

ref. #618

[hen-x]

I love the {a} → {a: a} expansion, but agree that it should only happen inside of explicit curly braces. Otherwise, when a bare expression follows a colon-separted pair and a comma, it should always indicate the end of the implicit hash.

[jashkenas]

Yep, I'm afraid this is a duplicate of #618 -- meaning that I don't know how to make it parseable. If anyone can come up with a patch or an idea for how to fix it, please post it to that ticket; closing this one.

[ghost]

Oh, well, this makes me sad... But only a bit -- programming in CoffeeScript is still a joy. :)

[jashkenas]

A patch to fix this issue is now on master, as of #1061. Please give it a try and see if it works for your use cases.