Optimize performance

lib/calc-text-width.js

@@ -10,9 +10,15 @@ function calcWidth (charWidthTable) {
     if (typeof text !== 'string') {
       return 0
     } else {
-      return Array.from(text).reduce((total, curr) => {
-        return total + (widthTable[curr.charCodeAt()] || widthTable[64]) // "@"
-      }, 0)
+      let total = 0
+      let i = text.length
+      let charCode = 0
+      while (i--) {
+        charCode = text[i].charCodeAt()
+        total += widthTable[charCode < 127 ? charCode : 64] // "@" for overflows
+      }
+      console.log(total)
+      return total
     }
   }
 }