Add basic queries to work as syntax highlighter on nvim.

Author: hugopl

queries/highlights.scm

@@ -0,0 +1,91 @@
+(identifier) @variable
+
+((constant) @constant
+ (#match? @constant "^[A-Z\\d_]+$"))
+
+[
+  "alias"
+  "begin"
+  "break"
+  "case"
+  "class"
+  "def"
+  "do"
+  "end"
+  "ensure"
+  "in"
+  "module"
+  "next"
+  "rescue"
+  "then"
+  "unless"
+  "until"
+  "when"
+  "while"
+] @keyword
+["return" "yield"] @keyword.return
+["if" "else" "elsif"] @keyword.conditional
+["rescue"] @keyword.exception
+
+(pseudo_constant) @constant.builtin
+
+; literals
+(string) @string
+
+(symbol) @string.special.symbol
+
+(regex) @string.regex
+
+(string_escape_sequence) @escape
+
+[(integer) (float)] @number
+
+[(true) (false)] @boolean
+
+(nil) @constant.builtin
+
+(interpolation
+  "#{" @punctuation.special
+  "}" @punctuation.special) @embedded
+
+(comment) @comment
+
+; Operators
+
+[
+"="
+"=>"
+"->"
+] @operator
+
+[
+  ","
+  ";"
+  "."
+] @punctuation.delimiter
+
+[
+  "("
+  ")"
+  "["
+  "]"
+  "{"
+  "}"
+] @punctuation.bracket
+
+(class_def name: [(constant) (generic_type)] @type)
+
+(module_def name: [(constant) (generic_type)] @module)
+
+(struct_def name: [(constant) (generic_type)] @type)
+
+(enum_def name: [(constant)] @type)
+
+(method_def name: [(identifier) (constant)] @function.method)
+
+(param name: [(identifier)] @variable.parameter)
+
+[
+  (class_var)
+  (instance_var)
+] @property