highlights(hack): add some basic highlights

Fixes #2041

queries/hack/highlights.scm

@@ -0,0 +1,162 @@
+(comment) @comment
+
+[
+ "function"
+] @keyword.function
+
+[
+ "async"
+ "await"
+ "type"
+ "interface"
+ "class"
+] @keyword
+
+[
+  "new"
+  "print"
+  "echo"
+  "newtype"
+  "clone"
+] @keyword.operator
+
+[
+ "return"
+] @keyword.return
+
+[
+  "shape"
+  "tupe"
+  (array_type)
+  "bool"
+  "float"
+  "int"
+  "string"
+  "arraykey"
+  "void"
+  "nonnull"
+  (null)
+  "mixed"
+  "dynamic"
+  "noreturn"
+] @type
+
+(type_specifier
+  (qualified_identifier) @type)
+
+[
+  "="
+  "??="
+  ".="
+  "|="
+  "^="
+  "&="
+  "<<="
+  ">>="
+  "+="
+  "-="
+  "*="
+  "/="
+  "%="
+  "**="
+
+  "==>"
+  "|>"
+  "??"
+  "||"
+  "&&"
+  "|"
+  "^"
+  "&"
+  "=="
+  "!="
+  "==="
+  "!=="
+  "<"
+  ">"
+  "<="
+  ">="
+  "<=>"
+  "<<"
+  ">>"
+  "+"
+  "-"
+  "."
+  "*"
+  "/"
+  "%"
+  "**"
+
+  "++"
+  "--"
+  "!"
+
+  "?:"
+
+  "="
+  "??="
+  ".="
+  "|="
+  "^="
+  "&="
+  "<<="
+  ">>="
+  "+="
+  "-="
+  "*="
+  "/="
+  "%="
+  "**="
+
+  ;; type modifiers
+  "@"
+  "?"
+  "~"
+] @operator
+
+(integer) @number
+(float) @float
+
+(parameter
+  (variable) @parameter)
+
+(call_expression
+  function: (qualified_identifier) @function)
+
+(function_declaration
+  name: (identifier) @function)
+
+(type_arguments
+  [ "<" ">" ] @punctuation.bracket)
+[ "(" ")" "[" "]" "{" "}" "<<" ">>"] @punctuation.bracket
+
+[ "." ";" "::" ":" "," ] @punctuation.delimiter
+
+(ternary_expression
+  ["?" ":"] @conditional)
+
+[
+  "if"
+  "else"
+  "elseif"
+  "switch"
+  "case"
+] @conditional
+
+[
+  "try"
+  "catch"
+  "finally"
+] @exception
+
+[
+  "for"
+  "while"
+  "do"
+  "continue"
+  "break"
+] @repeat
+
+(string) @string
+
+(ERROR) @error