feat(language/yaml): enable tree-sitter syntax highlighting

Provide full tree-sitter highlight queries for YAML mode, and enable
tree-sitter-mode within yaml-mode buffers.

modules/languages/siren-yaml.el

@@ -8,6 +8,7 @@
 
 (require 'siren-lsp)
 (require 'siren-prog-mode)
+(require 'siren-tree-sitter)
 
 (use-package yaml-mode
   :mode "\\.yml\\'" "\\.yaml\\'"
@@ -19,10 +20,47 @@
   (yaml-mode . siren-yaml-mode-setup)
 
   :preface
+  ;; Manually set full tree-sitter highlight queries for yaml-mode. This is a
+  ;; temporary workaround until this PR is merged:
+  ;; https://github.com/emacs-tree-sitter/tree-sitter-langs/pull/134
+  (defun siren-yaml-mode-tree-sitter-setup ()
+    (setq-local tree-sitter-hl-default-patterns
+                [;; keys
+                 (block_mapping_pair
+                  key: (flow_node [(double_quote_scalar) (single_quote_scalar)] @variable))
+                 (block_mapping_pair
+                  key: (flow_node (plain_scalar (string_scalar) @variable)))
+
+                 ;; keys within inline {} blocks
+                 (flow_mapping
+                  (_ key: (flow_node [(double_quote_scalar) (single_quote_scalar)] @variable)))
+                 (flow_mapping
+                  (_ key: (flow_node (plain_scalar (string_scalar) @variable))))
+
+                 ["[" "]" "{" "}"] @punctuation.bracket
+                 ["," "-" ":" "?" ">" "|"] @punctuation.delimiter
+                 ["*" "&" "---" "..."] @punctuation.special
+
+                 [(null_scalar) (boolean_scalar)] @constant.builtin
+                 [(integer_scalar) (float_scalar)] @number
+                 [(double_quote_scalar) (single_quote_scalar) (block_scalar)] @string
+                 (escape_sequence) @escape
+
+                 (comment) @comment
+                 [(anchor_name) (alias_name)] @function
+                 (yaml_directive) @type
+
+                 (tag) @type
+                 (tag_handle) @type
+                 (tag_prefix) @string
+                 (tag_directive) @property ]))
+
   (defun siren-yaml-mode-setup ()
     (run-hooks 'prog-mode-hook)
 
     (setq-local tab-width 2)
+    (siren-yaml-mode-tree-sitter-setup)
+    (tree-sitter-mode t)
     (subword-mode t)))
 
 (use-package lsp-yaml