fix: factor dotRegexp out of the loop

Author: aminya

lib/dom-styles-reader.js

@@ -58,7 +58,7 @@ export default class DOMStylesReader {
     for (let i = 0, len = scopes.length; i < len; i++) {
       const scope = scopes[i]
       const node = document.createElement('span')
-      node.className = scope.replace(/\.+/g, ' ')
+      node.className = scope.replace(dotRegexp, ' ')
 
       if (parent != null) { parent.appendChild(node) }
 
@@ -132,6 +132,8 @@ export default class DOMStylesReader {
 //    ##     ## ##       ##       ##        ##       ##    ##  ##    ##
 //    ##     ## ######## ######## ##        ######## ##     ##  ######
 
+const dotRegexp = /\.+/g
+
 /**
  * Computes the output color of `value` with a rotated hue defined
  * in `filter`.