globs: "exists" filter

[alixander]

e.g. target all shapes that have links, or all connections that have labels.

not sure how it'll be represented in the syntax

[alixander]

oh this can just use globs within.

this would filter for existence of link

*: {
  &link: *
}

i think we need a "not" operator too. maybe !? not sure. @nhooyr any thoughts?

*: {
  !&link: *
}

[asanjabi]

! seems like a reasonable symbol for "not" operator. What would the syntax look like for nulling all shapes that don't have a connection? (** !-> *)[*]: null ?

[alixander]

we'd just introduce a keyword for that. something like

*: null {
  &connected: false
}

[nhooyr]

Seems reasonable to have !& to me.

[gavin-ts]

Regarding globs for selecting all existing edges:

I tried * -> * but this creates edges between all shapes and does not apply to existing edges, interestingly (* -> *)[*] does apply only to existing edges.

I think https://d2lang.com/tour/globs#glob-connections needs a note to clarify that the parens + brackets syntax is needed to select existing edges(* -> *)[*]. It is present in the example but a explicit note would make it clear.

https://play.d2lang.com/?l=&script=ys9LtVKo5lJQSFTQtVNIAhHJICKFi0tBQQvE0oLIKyiAbdWDuMNKoSg1hUtBoZarlourpDwftxkaEEM0o7ViCRkECAAA__8%3D&

[alixander]

#1567 (comment) will be tracked in #2010