Use named regex match for param array type extraction

Author: frodrigo

lib/grape-swagger/doc_methods.rb

@@ -47,8 +47,8 @@ def parse_params(params, path, method)
                           'double'
                         when 'Symbol'
                           'string'
-                        when /^\[(.*)\]$/
-                          items[:type] = Regexp.last_match[1].downcase
+                        when /^\[(?<type>.*)\]$/
+                          items[:type] = Regexp.last_match[:type].downcase
                           if PRIMITIVE_MAPPINGS.key?(items[:type])
                             items[:type], items[:format] = PRIMITIVE_MAPPINGS[items[:type]]
                           end