Initial Commit

core/modules/filters/strings.js

@@ -74,6 +74,32 @@ exports.join = makeStringReducingOperator(
 	},null
 );
 
+var dmp = require("$:/core/modules/utils/diff-match-patch/diff_match_patch.js");
+
+exports.levenshtein = makeStringBinaryOperator(
+	function(a,b) {
+		var dmpObject = new dmp.diff_match_patch(),
+			diffs = dmpObject.diff_main(a,b);
+		return [dmpObject.diff_levenshtein(diffs) + ""];
+	}
+);
+
+exports.makepatches = makeStringBinaryOperator(
+	function(a,b) {
+		var dmpObject = new dmp.diff_match_patch(),
+			patches = dmpObject.patch_make(a,b);
+		return [dmpObject.patch_toText(patches)];
+	}
+);
+
+exports.applypatches = makeStringBinaryOperator(
+	function(a,b) {
+		var dmpObject = new dmp.diff_match_patch(),
+			patches = dmpObject.patch_fromText(b);
+		return [dmpObject.patch_apply(patches,a)[0]];
+	}
+);
+
 function makeStringBinaryOperator(fnCalc) {
 	return function(source,operator,options) {
 		var result = [];

editions/test/tiddlers/tests/data/filters/DiffMergePatch1.tid

@@ -0,0 +1,28 @@
+title: Filters/DiffMergePatch1
+description: Tests for diff-merge-patch derived operators
+type: text/vnd.tiddlywiki-multiple
+tags: [[$:/tags/wiki-test-spec]]
+
+title: Output
+
+\whitespace trim
+\define text1()
+the cat sat on the mat
+\end
+
+\define text2()
+the hat saw in every category
+\end
+
+<$text text={{{ [<text1>makepatches<text2>] }}}/>
++
+title: ExpectedResult
+
+<p>@@ -1,22 +1,29 @@
+ the 
+-c
++h
+ at sa
+-t on the mat
++w in every category
+</p>

editions/test/tiddlers/tests/data/filters/DiffMergePatch2.tid

@@ -0,0 +1,25 @@
+title: Filters/DiffMergePatch2
+description: Tests for diff-merge-patch derived operators
+type: text/vnd.tiddlywiki-multiple
+tags: [[$:/tags/wiki-test-spec]]
+
+title: Output
+
+\whitespace trim
+\define text1()
+the cat sat on the mat
+\end
+
+\define text2()
+the hat saw in every category
+\end
+
+<$let patches={{{ [<text1>makepatches<text2>] }}}>
+
+<$text text={{{ [<text1>applypatches<patches>] }}}/>
+
+</$let>
++
+title: ExpectedResult
+
+the hat saw in every category

editions/test/tiddlers/tests/test-filters.js

@@ -1071,6 +1071,20 @@ Tests the filtering mechanism.
 			expect(wiki.filterTiddlers("[charcode[9],[10]]").join(" ")).toBe(String.fromCharCode(9) + String.fromCharCode(10));
 			expect(wiki.filterTiddlers("[charcode[]]").join(" ")).toBe("");
 		});
+		
+		it("should handle the levenshtein operator", function() {
+			expect(wiki.filterTiddlers("[[apple]levenshtein[apple]]").join(" ")).toBe("0");
+			expect(wiki.filterTiddlers("[[apple]levenshtein[banana]]").join(" ")).toBe("9");
+			expect(wiki.filterTiddlers("[[representation]levenshtein[misreprehensionisation]]").join(" ")).toBe("10");
+			expect(wiki.filterTiddlers("[[the cat sat on the mat]levenshtein[the hat saw in every category]]").join(" ")).toBe("13");
+		});
+		
+		it("should handle the makepatches operator", function() {
+			expect(wiki.filterTiddlers("[[apple]makepatches[apple]]").join(" ")).toBe("");
+			expect(wiki.filterTiddlers("[[apple]makepatches[banana]]").join(" ")).toBe("@@ -1,5 +1,6 @@\n-apple\n+banana\n");
+			expect(wiki.filterTiddlers("[[representation]makepatches[misreprehensionisation]]").join(" ")).toBe("@@ -1,13 +1,21 @@\n+mis\n repre\n-sent\n+hensionis\n atio\n");
+			expect(wiki.filterTiddlers("[[the cat sat on the mat]makepatches[the hat saw in every category]]").join(" ")).toBe("@@ -1,22 +1,29 @@\n the \n-c\n+h\n at sa\n-t on the mat\n+w in every category\n");
+		});
 	
 		it("should parse filter variable parameters", function(){
 		  expect($tw.utils.parseFilterVariable("currentTiddler")).toEqual(