optimize : remove needless array when joining surrogate pairs

michal-kurz · michal-kurz · commit 600195f12942 · 2022-10-04T23:41:12.000+02:00
diff --git a/javascript/diff_match_patch_uncompressed.js b/javascript/diff_match_patch_uncompressed.js
@@ -2216,9 +2216,8 @@ diff_match_patch.prototype.patch_splitMax = function(patches) {
 };
 
 diff_match_patch.prototype.diffs_joinSurrogatePairs = function(diffs) {
-	var newDiffs = [];
-	
 	var lastEnd;
+	var overwrittenDiffsCounter = 0;
 	
 	for (var x = 0 ; x < diffs.length ; x++) {
 		var thisDiff = diffs[x];
@@ -2244,10 +2243,11 @@ diff_match_patch.prototype.diffs_joinSurrogatePairs = function(diffs) {
 			continue;
 		}
 		
-		newDiffs.push(thisDiff)
+		diffs[overwrittenDiffsCounter] = thisDiff;
+		overwrittenDiffsCounter ++;
 	}
 	
-	return newDiffs
+	return diffs.splice(0, overwrittenDiffsCounter)
 }
 
 diff_match_patch.prototype.patch_joinSurrogatePairs = function(patch) {

Original file line number	Diff line number	Diff line change
`@@ -2216,9 +2216,8 @@ diff_match_patch.prototype.patch_splitMax = function(patches) {`
`2216`	`2216`	`};`
`2217`	`2217`
`2218`	`2218`	`diff_match_patch.prototype.diffs_joinSurrogatePairs = function(diffs) {`
`2219`		`- var newDiffs = [];`
`2220`		`-`
`2221`	`2219`	`var lastEnd;`
	`2220`	`+ var overwrittenDiffsCounter = 0;`
`2222`	`2221`
`2223`	`2222`	`for (var x = 0 ; x < diffs.length ; x++) {`
`2224`	`2223`	`var thisDiff = diffs[x];`
`@@ -2244,10 +2243,11 @@ diff_match_patch.prototype.diffs_joinSurrogatePairs = function(diffs) {`
`2244`	`2243`	`continue;`
`2245`	`2244`	`}`
`2246`	`2245`
`2247`		`- newDiffs.push(thisDiff)`
	`2246`	`+ diffs[overwrittenDiffsCounter] = thisDiff;`
	`2247`	`+ overwrittenDiffsCounter ++;`
`2248`	`2248`	`}`
`2249`	`2249`
`2250`		`- return newDiffs`
	`2250`	`+ return diffs.splice(0, overwrittenDiffsCounter)`
`2251`	`2251`	`}`
`2252`	`2252`
`2253`	`2253`	`diff_match_patch.prototype.patch_joinSurrogatePairs = function(patch) {`