initial commit for yaml support

[oneubauer]

First attempt at YAML support.
Choice of yaml or json parsing is made based on filetype which can be explicitly set, if needed:

:set filetype=yaml

Related: #1

[oneubauer]

Also, it might be necessary to add yaml to treesitter:

require 'nvim-treesitter.configs'.setup {
  ensure_installed = { "yaml"},
 }

[phelipetls]

Just tested this against the YAMl document at https://learnxinyminutes.com/docs/yaml/ and I think it works well enough.

It just doesn't work for:

• sets (not sure how to get a value out of a set with yq either).
• complex keys (probably a wontfix due to complexity).

But I think it'd be nice if it'd work for JSON inside YAML.

[phelipetls]

Currently, this doesn't handle JSON inside YAML.

For instance, with my cursor on

json_map: { |"key": "value" }

It returns json_map. I'd expect it to return json_map.key.

I could make it work by changing also handle the node type flow_pair

Suggested change

	if node:type() == "block_mapping_pair" then
	local key_node = unpack(node:field("key"))
	local key = get_node_text(key_node)
	if key and starts_with_number(key) or contains_special_characters(key) then
	if node:type() == "block_mapping_pair" or node:type() == "flow_pair" then
	local key_node = unpack(node:field("key"))
	local key = get_node_text(key_node)
	if key and starts_with_number(key) or contains_special_characters(key) then

But then the result would be also unexpected, json_map[""key""] instead of json_map.key. So we should handle the node double_scalar_key separately.

The node string_scalar seems to work fine, for instance in this line:

and quotes are optional: { |key: [ 3, 2, 1, takeoff ] }

[phelipetls]

It could improve this here by also handling the nodes of type flow_sequence. I didn't find something unexpected with the following change:

Suggested change

	if node:type() == "block_sequence" then
	if node:type() == "block_sequence" or node:type() == "flow_sequence" then

For instance, in this line:

json_seq: [ 3, 2, 1, "takeoff" ]

[joshzcold]

If this gets too complicated I opened a PR for similar functionality to enable winbar to yaml.nvim
cuducos/yaml.nvim#25

I don't know how good yaml.nvim is when it comes to parsing, but it seems to work for my use case.
If you wanted to keep to just json logic here and point people to yaml.nvim.

[phelipetls]

Thanks @joshzcold, that's a good recommendation.

YAML is much more complicated and I think the current implementation is hacky enough for JSON, so I'm not 100% comfortable extending support to YAML.