feat(languages): Elm (#1514)

* Add Elm language support

* Fix docs gen

* Updates based on PR feedback

8 files changed, 136 insertions, 0 deletions

diff --git a/.gitmodules b/.gitmodules
index 1ccbe43b..118fa2d8 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -206,3 +206,7 @@
 	path = helix-syntax/languages/tree-sitter-git-config
 	url = https://github.com/the-mikedavis/tree-sitter-git-config.git
 	shallow = true
+[submodule "helix-syntax/languages/tree-sitter-elm"]
+	path = helix-syntax/languages/tree-sitter-elm
+	url = https://github.com/elm-tooling/tree-sitter-elm
+	shallow = true
diff --git a/book/src/generated/lang-support.md b/book/src/generated/lang-support.md
index fce14846..bfaac97b 100644
--- a/book/src/generated/lang-support.md
+++ b/book/src/generated/lang-support.md
@@ -10,6 +10,7 @@
 | dart | ✓ |  | ✓ | `dart` |
 | dockerfile | ✓ |  |  | `docker-langserver` |
 | elixir | ✓ |  |  | `elixir-ls` |
+| elm | ✓ |  |  | `elm-language-server` |
 | fish | ✓ | ✓ | ✓ |  |
 | git-commit | ✓ |  |  |  |
 | git-config | ✓ |  |  |  |
diff --git a/helix-syntax/languages/tree-sitter-elm b/helix-syntax/languages/tree-sitter-elm
new file mode 160000
+Subproject bd50ccf66b42c55252ac8efc1086af4ac6bab8c
diff --git a/languages.toml b/languages.toml
index 2896dd32..ea93df3a 100644
--- a/languages.toml
+++ b/languages.toml
@@ -567,3 +567,14 @@ file-types = [".gitmodules", ".gitconfig"]
 injection-regex = "git-config"
 comment-token = "#"
 indent = { tab-width = 4, unit = "\t" }
+
+[[language]]
+name = "elm"
+scope = "source.elm"
+injection-regex = "elm"
+file-types = ["elm"]
+roots = ["elm.json"]
+auto-format = true
+comment-token = "--"
+language-server = { command = "elm-language-server" }
+indent = { tab-width = 4, unit = "    " }
diff --git a/runtime/queries/elm/highlights.scm b/runtime/queries/elm/highlights.scm
new file mode 100644
index 00000000..3c8fd12d
--- /dev/null
+++ b/runtime/queries/elm/highlights.scm
@@ -0,0 +1,83 @@
+; Keywords
+[
+    "if"
+    "then"
+    "else"
+    "let"
+    "in"
+ ] @keyword.control
+(case) @keyword.control
+(of) @keyword.control
+
+(colon) @keyword.operator
+(backslash) @keyword
+(as) @keyword
+(port) @keyword
+(exposing) @keyword
+(alias) @keyword
+(infix) @keyword
+
+(arrow) @keyword.operator
+(dot) @keyword.operator
+
+(port) @keyword
+
+(type_annotation(lower_case_identifier) @function)
+(port_annotation(lower_case_identifier) @function)
+(file (value_declaration (function_declaration_left(lower_case_identifier) @function)))
+
+(field name: (lower_case_identifier) @attribute)
+(field_access_expr(lower_case_identifier) @attribute)
+
+(operator_identifier) @keyword.operator
+(eq) @keyword.operator.assignment
+
+[
+  "("
+  ")"
+  "["
+  "]"
+  "{"
+  "}"
+] @punctuation.bracket
+
+"|" @keyword
+"," @punctuation.delimiter
+
+[
+  "|>"
+] @keyword
+
+
+(import) @keyword.contol.import
+(module) @keyword.other
+
+(number_constant_expr) @constant.numeric
+
+(type) @type
+
+(type_declaration(upper_case_identifier) @type)
+(type_ref) @type
+(type_alias_declaration name: (upper_case_identifier) @type)
+
+(union_pattern constructor: (upper_case_qid (upper_case_identifier) @label (dot) (upper_case_identifier) @variable.other.member)) 
+(union_pattern constructor: (upper_case_qid (upper_case_identifier) @variable.other.member)) 
+
+(union_variant(upper_case_identifier) @variable.other.member)
+(value_expr name: (value_qid (upper_case_identifier) @label))
+(value_expr (upper_case_qid (upper_case_identifier) @label (dot) (upper_case_identifier) @variable.other.member))
+(value_expr(upper_case_qid(upper_case_identifier)) @variable.other.member)
+
+; comments
+(line_comment) @comment
+(block_comment) @comment
+
+; strings
+(string_escape) @constant.character.escape
+
+(open_quote) @string
+(close_quote) @string
+(regular_string_part) @string
+
+(open_char) @constant.character
+(close_char) @constant.character
diff --git a/runtime/queries/elm/injections.scm b/runtime/queries/elm/injections.scm
new file mode 100644
index 00000000..83f8245c
--- /dev/null
+++ b/runtime/queries/elm/injections.scm
@@ -0,0 +1,4 @@
+; Parse glsl where defined
+
+((glsl_content) @injection.content
+ (#set! injection.language "glsl"))
diff --git a/runtime/queries/elm/locals.scm b/runtime/queries/elm/locals.scm
new file mode 100644
index 00000000..ab103115
--- /dev/null
+++ b/runtime/queries/elm/locals.scm
@@ -0,0 +1,14 @@
+(value_declaration) @local.scope
+(type_alias_declaration) @local.scope
+(type_declaration) @local.scope
+(type_annotation) @local.scope
+(port_annotation) @local.scope
+(infix_declaration) @local.scope
+(let_in_expr) @local.scope
+
+(function_declaration_left (lower_pattern (lower_case_identifier)) @local.definition)
+(function_declaration_left (lower_case_identifier) @local.definition)
+
+(value_expr(value_qid(upper_case_identifier)) @local.reference)
+(value_expr(value_qid(lower_case_identifier)) @local.reference)
+(type_ref (upper_case_qid) @local.reference)
diff --git a/runtime/queries/elm/tags.scm b/runtime/queries/elm/tags.scm
new file mode 100644
index 00000000..03999fb1
--- /dev/null
+++ b/runtime/queries/elm/tags.scm
@@ -0,0 +1,19 @@
+(value_declaration (function_declaration_left (lower_case_identifier) @name)) @definition.function
+
+(function_call_expr (value_expr (value_qid) @name)) @reference.function
+(exposed_value (lower_case_identifier) @name) @reference.function
+(type_annotation ((lower_case_identifier) @name) (colon)) @reference.function
+
+(type_declaration ((upper_case_identifier) @name) ) @definition.type
+
+(type_ref (upper_case_qid (upper_case_identifier) @name)) @reference.type
+(exposed_type (upper_case_identifier) @name) @reference.type
+
+(type_declaration (union_variant (upper_case_identifier) @name)) @definition.union
+
+(value_expr (upper_case_qid (upper_case_identifier) @name)) @reference.union
+
+
+(module_declaration 
+    (upper_case_qid (upper_case_identifier)) @name
+) @definition.module