readline: remove the caching variable

Lyall Sun · tniessen · commit 97c4033ebf2c · 2017-07-21T15:21:45.000+02:00
Line 486 and 525 contain for loops where a length property is cached in a variable (for example, itemLen). This used to be a performance optimization, but current V8 handles the optimization internally. These caching variables are removed, and the length property is used directly instead. PR-URL: #14275 Reviewed-By: Refael Ackermann <refack@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Rich Trott <rtrott@gmail.com> Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com> Reviewed-By: Timothy Gu <timothygu99@gmail.com> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Tobias Nießen <tniessen@tnie.de> Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com> Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
diff --git a/lib/readline.js b/lib/readline.js
@@ -482,7 +482,7 @@ Interface.prototype._tabComplete = function(lastKeypressWasTab) {
           maxColumns = 1;
         }
         var group = [];
-        for (var i = 0, compLen = completions.length; i < compLen; i++) {
+        for (var i = 0; i < completions.length; i++) {
           var c = completions[i];
           if (c === '') {
             handleGroup(self, group, width, maxColumns);
@@ -521,7 +521,7 @@ function handleGroup(self, group, width, maxColumns) {
       var item = group[idx];
       self._writeToOutput(item);
       if (col < maxColumns - 1) {
-        for (var s = 0, itemLen = item.length; s < width - itemLen; s++) {
+        for (var s = 0; s < width - item.length; s++) {
           self._writeToOutput(' ');
         }
       }

Original file line number	Diff line number	Diff line change
`@@ -482,7 +482,7 @@ Interface.prototype._tabComplete = function(lastKeypressWasTab) {`
`482`	`482`	`maxColumns = 1;`
`483`	`483`	`}`
`484`	`484`	`var group = [];`
`485`		`- for (var i = 0, compLen = completions.length; i < compLen; i++) {`
	`485`	`+ for (var i = 0; i < completions.length; i++) {`
`486`	`486`	`var c = completions[i];`
`487`	`487`	`if (c === '') {`
`488`	`488`	`handleGroup(self, group, width, maxColumns);`
`@@ -521,7 +521,7 @@ function handleGroup(self, group, width, maxColumns) {`
`521`	`521`	`var item = group[idx];`
`522`	`522`	`self._writeToOutput(item);`
`523`	`523`	`if (col < maxColumns - 1) {`
`524`		`- for (var s = 0, itemLen = item.length; s < width - itemLen; s++) {`
	`524`	`+ for (var s = 0; s < width - item.length; s++) {`
`525`	`525`	`self._writeToOutput(' ');`
`526`	`526`	`}`
`527`	`527`	`}`