hcl: Add terraform-specific highlighting patterns

Author: ubolonton

queries/hcl/highlights.scm

@@ -1,36 +1,48 @@
-[
-  "for"
-] @keyword
+("for" @keyword (identifier) @variable)
 
+;; (attribute (identifier) @variable)
+;; (object_elem key: (_) @variable)
 (attribute (identifier) @property)
-(object_elem (identifier) @property)
+(object_elem key: (_) @property)
+
+(get_attr (identifier) @property)
 
 (block (identifier) @type)
-(one_line_block (identifier) @type)
+;; (one_line_block (identifier) @type)
 
-(function_call (identifier) @function)
+(function_call (identifier) @function.call)
 
 [
-  (string_literal)
-  (quoted_template)
-  (heredoc)
-] @string
+ ;; (string_lit)
+ (quoted_template_start)
+ (quoted_template_end)
+ (template_literal)
+ ;; (heredoc)
+ ] @string
 
-(numeric_literal) @number
+(numeric_lit) @number
 
-[
-  (true)
-  (false)
-  (null)
-] @constant.builtin
+[(bool_lit)
+ (null_lit)
+ ] @constant.builtin
 
 (comment) @comment
 
-[
-  "("
-  ")"
-  "["
-  "]"
-  "{"
-  "}"
-]  @punctuation.bracket
+["("
+ ")"
+ "["
+ "]"
+ "{"
+ "}"
+ ]  @punctuation.bracket
+
+["&&" "?" ":" "!=" "==" "=>"] @operator
+
+["if" "in"] @keyword
+
+;; "." @punctuation.special
+
+(template_interpolation
+ (template_interpolation_start) @punctuation.special
+ (expression) @embedded
+ (template_interpolation_end) @punctuation.special)

queries/hcl/highlights.terraform-mode.scm

@@ -0,0 +1,73 @@
+;; data.aws_iam_policy_document.cluster_assume_role_policy.json
+(expression
+ ((variable_expr (identifier)) @keyword
+  (.eq? @keyword "data"))
+ . (get_attr (identifier) @type)
+ . (get_attr (identifier) @function.call)
+ . (get_attr (identifier) @property)?
+ )
+
+;; module.path
+((expression
+  ((variable_expr (identifier)) @keyword
+   (.eq? @keyword "module"))
+  . (get_attr) @type
+  ))
+
+((expression
+  ((variable_expr (identifier)) @keyword
+   (.match? @keyword "^(var|local|count|each|path)$"))
+  . (get_attr)? @property
+  ))
+
+;; aws_iam_role.shared-sagemaker-execution.name
+(expression
+ (variable_expr (identifier)) @type
+ . (get_attr) @function.call
+ . (get_attr)? @property
+ .)
+
+;; TODO: Highlight `content'.
+((block (identifier) @keyword
+        [(string_lit (template_literal) @variable)])
+ (.eq? @keyword "dynamic"))
+
+;; ((block (identifier) @keyword
+;;         [(string_lit (template_literal) @variable)]
+;;         (body ((attribute (identifier) @keyword)
+;;                (.eq? @keyword "for_each"))))
+;;  (.eq? @keyword "dynamic"))
+
+((block (identifier) @keyword
+        . [(string_lit (template_literal) @function)
+           (identifier) @function])
+ (.eq? @keyword "output"))
+
+((block (identifier) @keyword
+        [(string_lit (template_literal) @variable.special)
+         (identifier) @variable.special])
+ (.eq? @keyword "variable"))
+
+((block (identifier) @keyword
+        [(string_lit (template_literal) @type)
+         (identifier) @type])
+ (.eq? @keyword "module"))
+
+;; resource "aws_launch_template" "default"
+(block (identifier)
+       [(string_lit (template_literal) @type)
+        (identifier) @type]
+       . [(string_lit (template_literal) @function)
+          (identifier) @function]
+       . (block_start))
+
+((block (identifier) @keyword)
+ (.match? @keyword "(resource|data|output|locals|lifecycle)"))
+
+((attribute (identifier) @keyword)
+ (.match? @keyword "^(count|depends_on|for_each)$"))
+
+(attribute (identifier) @variable)
+(object_elem key: (_) @variable)
+
+(block (identifier) @label . (block_start))

tree-sitter-langs.el

@@ -110,6 +110,7 @@ See `tree-sitter-langs-repos'."
                 (elixir-mode     . elixir)
                 (go-mode         . go)
                 (hcl-mode        . hcl)
+                (terraform-mode  . hcl)
                 (html-mode       . html)
                 (mhtml-mode      . html)
                 (nix-mode        . nix)
@@ -144,13 +145,18 @@ See `tree-sitter-langs-repos'."
 ;;; Normal load.
 (tree-sitter-langs--init-major-mode-alist)
 
-(defun tree-sitter-langs--hl-query-path (lang-symbol)
+(defun tree-sitter-langs--hl-query-path (lang-symbol &optional mode)
+  "Return the highlighting query file for LANG-SYMBOL.
+If MODE is non-nil, return the file containing additional MODE-specfic patterns
+instead. An example is `terraform-mode'-specific highlighting patterns for HCL."
   (concat (file-name-as-directory
            (concat tree-sitter-langs--queries-dir
                    (symbol-name lang-symbol)))
-          "highlights.scm"))
+          (if mode
+              (format "highlights.%s.scm" mode)
+            "highlights.scm")))
 
-(defun tree-sitter-langs--hl-default-patterns (lang-symbol)
+(defun tree-sitter-langs--hl-default-patterns (lang-symbol &optional mode)
   "Return the bundled default syntax highlighting patterns for LANG-SYMBOL.
 Return nil if there are no bundled patterns."
   (condition-case nil
@@ -162,6 +168,11 @@ Return nil if there are no bundled patterns."
                              ('typescript '(javascript))
                              ('tsx '(typescript javascript))
                              (_ nil))))
+          (when mode
+            (ignore-error 'file-missing
+              (insert-file-contents (tree-sitter-langs--hl-query-path sym mode))
+              (goto-char (point-max))
+              (insert "\n")))
           (insert-file-contents (tree-sitter-langs--hl-query-path sym))
           (goto-char (point-max))
           (insert "\n"))
@@ -174,7 +185,7 @@ Return nil if there are no bundled patterns."
   (unless tree-sitter-hl-default-patterns
     (let ((lang-symbol (tsc--lang-symbol tree-sitter-language)))
       (setq tree-sitter-hl-default-patterns
-            (tree-sitter-langs--hl-default-patterns lang-symbol)))))
+            (tree-sitter-langs--hl-default-patterns lang-symbol major-mode)))))
 
 ;;;###autoload
 (advice-add 'tree-sitter-hl--setup :before