Printing comments without text coordinates

[juliankrispel]

Hi @benjamn. As part of this decaf pr I've been investigating how to print comments in relation to nodes, but without any line/column info. Here's how far I've come:

It's technically possible, but only if I attach comments to nodes like blockStatement or program. What then happens is the comment gets inserted at the beginning or at the end of the block, depending on whether the comment is set as leading or trailing. This happens in the printComments function.

As far as I understand it's not currently possible to attach comments directly to nodes.

I'm turning to you because you probably have a better idea of what parts of recast I'd need to touch in order to do this.

Here's a cake as a thank you in advance -> :cake:

[benjamn]

Thanks for looking into it as far as you have!

Quick question before I take a look: do you have any need for creating comments that are not .leading comments? In other words, are you adding any trailing comments, or comments inside empty BlockStatements, or empty function parameter lists? Weird places, I mean.

If .leading comments are good enough for your purposes, then I think the comment-printing code could assume that a Comment node is .leading if it has no .original node, which would at least save you from having to set comment.leading = true by hand.

[juliankrispel]

That was rather quick @benjamn thanks!

I have no pressing need for creating non-leading comments, trying to sort this out step by step :)

[flying-sheep]

hmm, what happens to this?

function foo() {
    return some(stuff)
    // comment
}

won’t this be a trailing comment?