Add fish highlighting (helix-editor#1308)

The highlights were copied and modified from
https://github.com/nvim-treesitter/nvim-treesitter/blob/master/queries/fish/highlights.scm

.gitmodules

@@ -162,3 +162,7 @@
 	path = helix-syntax/languages/tree-sitter-dart
 	url = https://github.com/UserNobody14/tree-sitter-dart.git
 	shallow = true
+[submodule "helix-syntax/languages/tree-sitter-fish"]
+	path = helix-syntax/languages/tree-sitter-fish
+	url = https://github.com/ram02z/tree-sitter-fish
+	shallow = true

book/src/generated/lang-support.md

@@ -9,6 +9,7 @@
 | css | ✓ |  |  |  |
 | dart | ✓ |  | ✓ | `dart` |
 | elixir | ✓ |  |  | `elixir-ls` |
+| fish | ✓ | ✓ | ✓ |  |
 | glsl | ✓ |  | ✓ |  |
 | go | ✓ | ✓ | ✓ | `gopls` |
 | html | ✓ |  |  |  |

languages.toml

@@ -45,6 +45,17 @@ comment-token = "#"
 language-server = { command = "elixir-ls" }
 indent = { tab-width = 2, unit = "  " }
 
+[[language]]
+name = "fish"
+scope = "source.fish"
+injection-regex = "fish"
+file-types = ["fish"]
+shebangs = ["fish"]
+roots = []
+comment-token = "#"
+
+indent = { tab-width = 4, unit = "    " }
+
 [[language]]
 name = "mint"
 scope = "source.mint"

runtime/queries/fish/highlights.scm

@@ -0,0 +1,156 @@
+;; Operators
+
+[
+ "&&"
+ "||"
+ "|"
+ "&"
+ "="
+ "!="
+ ".."
+ "!"
+ (direction)
+ (stream_redirect)
+ (test_option)
+] @operator
+
+[
+ "not"
+ "and"
+ "or"
+] @keyword.operator
+
+;; Conditionals
+
+(if_statement
+[
+ "if"
+ "end"
+] @keyword.control.conditional)
+
+(switch_statement
+[
+ "switch"
+ "end"
+] @keyword.control.conditional)
+
+(case_clause
+[
+ "case"
+] @keyword.control.conditional)
+
+(else_clause 
+[
+ "else"
+] @keyword.control.conditional)
+
+(else_if_clause 
+[
+ "else"
+ "if"
+] @keyword.control.conditional)
+
+;; Loops/Blocks
+
+(while_statement
+[
+ "while"
+ "end"
+] @keyword.control.repeat)
+
+(for_statement
+[
+ "for"
+ "end"
+] @keyword.control.repeat)
+
+(begin_statement
+[
+ "begin"
+ "end"
+] @keyword.control.repeat)
+
+;; Keywords
+
+[
+ "in"
+ (break)
+ (continue)
+] @keyword
+
+"return" @keyword.control.return
+
+;; Punctuation
+
+[
+ "["
+ "]"
+ "{"
+ "}"
+ "("
+ ")"
+] @punctuation.bracket
+
+"," @punctuation.delimiter
+
+;; Commands
+
+(command
+  argument: [
+             (word) @variable.parameter (#match? @variable.parameter "^-")
+            ]
+)
+
+; non-bultin command names
+(command name: (word) @function)
+
+; derived from builtin -n (fish 3.2.2)
+(command
+  name: [
+        (word) @function.builtin
+        (#match? @function.builtin "^(\.|:|_|alias|argparse|bg|bind|block|breakpoint|builtin|cd|command|commandline|complete|contains|count|disown|echo|emit|eval|exec|exit|fg|functions|history|isatty|jobs|math|printf|pwd|random|read|realpath|set|set_color|source|status|string|test|time|type|ulimit|wait)$")
+        ]
+)
+
+(test_command "test" @function.builtin)
+
+;; Functions
+
+(function_definition ["function" "end"] @keyword.function)
+
+(function_definition
+  name: [
+        (word) (concatenation)
+        ] 
+@function)
+
+(function_definition
+  option: [
+          (word)
+          (concatenation (word))
+          ] @variable.parameter (#match? @variable.parameter "^-")
+)
+
+;; Strings
+
+[(double_quote_string) (single_quote_string)] @string
+(escape_sequence) @constant.character.escape
+
+;; Variables
+
+(variable_name) @variable
+(variable_expansion) @constant
+
+;; Nodes
+
+(integer) @constant.numeric.integer
+(float) @constant.numeric.float
+(comment) @comment
+(test_option) @string
+
+((word) @constant.builtin.boolean
+(#match? @constant.builtin.boolean "^(true|false)$"))
+
+;; Error
+
+(ERROR) @error

runtime/queries/fish/indents.toml

@@ -0,0 +1,12 @@
+indent = [
+  "function_definition",
+  "while_statement",
+  "for_statement",
+  "if_statement",
+  "begin_statement",
+  "switch_statement",
+]
+
+outdent = [
+  "end"
+]

runtime/queries/fish/injections.scm

@@ -0,0 +1,2 @@
+((comment) @injection.content
+ (#set! injection.language "comment"))

runtime/queries/fish/textobjects.scm

@@ -0,0 +1 @@
+(function_definition) @function.around