Unable to use parser for indentation with significant whitespace syntax

[ckipp01]

Commit of tree-sitter-scala you tested this on

97d5e7c

A code sample showing the error

object Main:

Show the error node

So this is sort of a discussion, but also something that I think we'll need to change if we want to support indents. The issue is that in the above code sample the tree at that point would look like this:

object_definition [0, 0] - [0, 11]
  "object" [0, 0] - [0, 6]
  name: identifier [0, 7] - [0, 11]
ERROR [0, 11] - [2, 0]
  ":" [0, 11] - [0, 12]

If your cursor is here:

object Main:<cursor>

And you hit <enter> then you'd expect it to be indented. An indent query for this would look like this:

[
  (object_definition)
] @indent

From the nvim-treesitter docs it says:

@indent ; indent children when matching this node

The project is that this won't match here since the ERROR node isn't a child of the object_definition and : is actually a child of the current ERROR node.

Realistically even if you have an opening { you have the same issue:

object_definition [0, 0] - [0, 11]
  "object" [0, 0] - [0, 6]
  name: identifier [0, 7] - [0, 11]
ERROR [0, 12] - [0, 13]
  "{" [0, 12] - [0, 13]

But since the vast majority of editors will give you a closing } by default it will really look like this:

object_definition [0, 0] - [0, 15]
  "object" [0, 0] - [0, 6]
  name: identifier [0, 7] - [0, 11]
  body: template_body [0, 12] - [0, 15]
    "{" [0, 12] - [0, 13]
    "}" [0, 14] - [0, 15]

Meaning that you're in object_definition, so the <enter> will indent like you'd expect.

What do you expect the tree to look like

I'd expect that when you have the following:

object Main:<cursor>

And I hit <enter> there is a way that we can indent correctly.

Where are you experiencing this error?

nvim-treesitter

[susliko]

@ckipp01 🖖🏻
I haven't found a way to influence the position of ERROR node in the tree.
However, we can write a query for what we have now, i.e. match the ERROR node! The following one seems to solve the described issue:

((ERROR ":") @indent.align (#set! indent.open_delimiter ":")) 

or, specifically for object definitions:

((object_definition) (ERROR ":") @indent.align (#set! indent.open_delimiter ":")) 

Inspired by Python indents.scm

[KaranAhlawat]

One problem I run into is that after inserting the :, if I hit return, the node detected at point can be either no node, or an (ERROR ":") node, which is kinda weird. This is on emacs, and I'm kinda sure it's Emacs doing something. Will look into it further Seems to be an emacs thing, please disregard

[susliko]

Adding indents to nvim-treesitter: nvim-treesitter/nvim-treesitter#7056