From 0eb6569674a6bf6f1be635007e9d5896512225f6 Mon Sep 17 00:00:00 2001
From: yaisog <m@rcuswinter.de>
Date: Sat, 4 Mar 2023 11:40:25 +0100
Subject: [PATCH] Add words and lines options to makepatches (#7326)

---
 core/modules/filters/strings.js | 89 ++++++++++++++++++++++++++++++---
 1 file changed, 81 insertions(+), 8 deletions(-)

diff --git a/core/modules/filters/strings.js b/core/modules/filters/strings.js
index 1e015ff46..ddef2eed9 100644
--- a/core/modules/filters/strings.js
+++ b/core/modules/filters/strings.js
@@ -84,13 +84,86 @@ exports.levenshtein = makeStringBinaryOperator(
 	}
 );
 
-exports.makepatches = makeStringBinaryOperator(
-	function(a,b) {
-		var dmpObject = new dmp.diff_match_patch(),
-			patches = dmpObject.patch_make(a,b);
-		return [dmpObject.patch_toText(patches)];
-	}
-);
+// these two functions are adapted from https://github.com/google/diff-match-patch/wiki/Line-or-Word-Diffs
+function diffLineWordMode(text1,text2,mode) {
+	var dmpObject = new dmp.diff_match_patch();
+	var a = diffPartsToChars(text1,text2,mode);
+	var lineText1 = a.chars1;
+	var lineText2 = a.chars2;
+	var lineArray = a.lineArray;
+	var diffs = dmpObject.diff_main(lineText1,lineText2,false);
+	dmpObject.diff_charsToLines_(diffs,lineArray);
+	return diffs;
+}
+
+function diffPartsToChars(text1,text2,mode) {
+	var lineArray = [];
+	var lineHash = {};
+	lineArray[0] = '';
+
+    function diff_linesToPartsMunge_(text,mode) {
+        var chars = '';
+        var lineStart = 0;
+        var lineEnd = -1;
+        var lineArrayLength = lineArray.length,
+            regexpResult;
+        const searchRegexp = /\W+/g;
+        while(lineEnd < text.length - 1) {
+	        if(mode === "words") {
+                regexpResult = searchRegexp.exec(text);
+                lineEnd = searchRegexp.lastIndex;
+                if(lineEnd === null) {
+                lineEnd = text.length;
+                }
+                lineEnd = --lineEnd;
+            } else {
+                lineEnd = text.indexOf('\n', lineStart);
+                if(lineEnd == -1) {
+                    lineEnd = text.length - 1;
+                }
+            }
+            var line = text.substring(lineStart, lineEnd + 1);
+
+            if(lineHash.hasOwnProperty ? lineHash.hasOwnProperty(line) : (lineHash[line] !== undefined)) {
+				chars += String.fromCharCode(lineHash[line]);
+            } else {
+                if (lineArrayLength == maxLines) {
+                  line = text.substring(lineStart);
+                  lineEnd = text.length;
+                }
+                chars += String.fromCharCode(lineArrayLength);
+                lineHash[line] = lineArrayLength;
+                lineArray[lineArrayLength++] = line;
+            }
+            lineStart = lineEnd + 1;
+        }
+        return chars;
+    }
+    var maxLines = 40000;
+    var chars1 = diff_linesToPartsMunge_(text1,mode);
+    maxLines = 65535;
+    var chars2 = diff_linesToPartsMunge_(text2,mode);
+    return {chars1: chars1, chars2: chars2, lineArray: lineArray};
+};
+
+exports.makepatches = function(source,operator,options) {
+	var dmpObject = new dmp.diff_match_patch(),
+		suffix = operator.suffix || "",
+		result = [];
+		
+		source(function(tiddler,title) {
+			var diffs, patches;
+			if(suffix === "lines" || suffix === "words") {
+				diffs = diffLineWordMode(title,operator.operand,suffix);
+				patches = dmpObject.patch_make(title,diffs);
+			} else {
+				patches = dmpObject.patch_make(title,operator.operand);
+			}
+			Array.prototype.push.apply(result,[dmpObject.patch_toText(patches)]);
+		});
+
+	return result;
+};
 
 exports.applypatches = makeStringBinaryOperator(
 	function(a,b) {
@@ -218,4 +291,4 @@ exports.charcode = function(source,operator,options) {
 	return [chars.join("")];
 };
 
-})();
+})();
\ No newline at end of file