Add new "regexp" filter operator

Fixes #762

core/modules/filters/regexp.js

@@ -0,0 +1,68 @@
+/*\
+title: $:/core/modules/filters/regexp.js
+type: application/javascript
+module-type: filteroperator
+
+Filter operator for regexp matching
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+/*
+Export our filter function
+*/
+exports.regexp = function(source,operator,options) {
+	var results = [],
+		fieldname = (operator.suffix || "title").toLowerCase(),
+		regexpString, regexp, flags = "", match,
+		getFieldString = function(tiddler,title) {
+			if(tiddler) {
+				return tiddler.getFieldString(fieldname);
+			} else if(fieldname === "title") {
+				return title;
+			} else {
+				return null;
+			}
+		};
+	// Process flags and construct regexp
+	regexpString = operator.operand;
+	match = /^\(\?([gim]+)\)/.exec(regexpString);
+	if(match) {
+		flags = match[1];
+		regexpString = regexpString.substr(match[0].length);
+	} else {
+		match = /\(\?([gim]+)\)$/.exec(regexpString);
+		if(match) {
+			flags = match[1];
+			regexpString = regexpString.substr(0,regexpString.length - match[0].length);
+		}
+	}
+	regexp = new RegExp(regexpString,flags);
+	// Process the incoming tiddlers
+	if(operator.prefix === "!") {
+		source(function(tiddler,title) {
+			var text = getFieldString(tiddler,title);
+			if(text !== null) {
+				if(!regexp.exec(text)) {
+					results.push(title);
+				}
+			}
+		});
+	} else {
+		source(function(tiddler,title) {
+			var text = getFieldString(tiddler,title);
+			if(text !== null) {
+				if(!!regexp.exec(text)) {
+					results.push(title);
+				}
+			}
+		});
+	}
+	return results;
+};
+
+})();

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

@@ -97,6 +97,14 @@ describe("Filter tests", function() {
 		expect(wiki.filterTiddlers("[!is[system]!field:modifier[JoeBloggs]]").join(",")).toBe("Tiddler Three,a fourth tiddler,one");
 	});
 
+	it("should handle the regexp operator", function() {
+		expect(wiki.filterTiddlers("[regexp[id]]").join(",")).toBe("TiddlerOne,$:/TiddlerTwo,Tiddler Three,a fourth tiddler");
+		expect(wiki.filterTiddlers("[!regexp[id]]").join(",")).toBe("one");
+		expect(wiki.filterTiddlers("[regexp[Tid]]").join(",")).toBe("TiddlerOne,$:/TiddlerTwo,Tiddler Three");
+		expect(wiki.filterTiddlers("[regexp[(?i)Tid]]").join(",")).toBe("TiddlerOne,$:/TiddlerTwo,Tiddler Three,a fourth tiddler");
+		expect(wiki.filterTiddlers("[!regexp[Tid(?i)]]").join(",")).toBe("one");
+	});
+
 	it("should handle the field operator with a regular expression operand", function() {
 		expect(wiki.filterTiddlers("[modifier/JoeBloggs/]").join(",")).toBe("TiddlerOne");
 		expect(wiki.filterTiddlers("[modifier/Jo/]").join(",")).toBe("TiddlerOne,$:/TiddlerTwo,Tiddler Three,a fourth tiddler,one");

editions/tw5.com/tiddlers/dev/TiddlerFilter Formal Grammar.tid

@@ -1,5 +1,5 @@
 created: 20140210141217955
-modified: 20140725091312363
+modified: 20140909134102102
 tags: dev
 title: TiddlerFilter Formal Grammar
 type: text/vnd.tiddlywiki
@@ -34,15 +34,7 @@ Whitespace is matched with javascript "\s+", which matches space, tab, carriage
 
 ''<opt-operator-suffix>'' ::= ''<string>'' | ""
 
-''&lt;operand&gt;'' ::= "[" ''&lt;search-string&gt;'' "]" | "{" ''&lt;indirect-search-string&gt;'' "}" | "<" ''&lt;variable-name-string&gt;'' ">" | ''&lt;regex&gt;''
-
-''&lt;regex&gt;'' ::= "/" ''&lt;string&gt;'' "/" ''&lt;opt-regex-args&gt;''
-
-''&lt;opt-regex-args&gt;'' ::= "(" ''&lt;regex-args&gt;'' ")" | ""
-
-''&lt;regex-args&gt;'' ::= ''&lt;regex-arg&gt;'' | ''&lt;regex-arg&gt;'' ''&lt;regex-args&gt;''
-
-''&lt;regex-arg&gt;'' ::= "m" | "y" | "g" | "i"
+''&lt;operand&gt;'' ::= "[" ''&lt;search-string&gt;'' "]" | "{" ''&lt;indirect-search-string&gt;'' "}" | "<" ''&lt;variable-name-string&gt;'' ">"
 
 ''&lt;string&gt;'' ::= ''&lt;string-type-1&gt;'' | ''&lt;string-type-2&gt;'' | ...
 

editions/tw5.com/tiddlers/filters/FilterOperator regexp.tid

@@ -0,0 +1,21 @@
+created: 20140909134102102
+modified: 20140909134102102
+tags: filters
+title: FilterOperator: regexp
+type: text/vnd.tiddlywiki
+
+The ''regexp'' filter operator filters tiddlers that match a regular expression.
+
+Regular expressions are a way of encoding complex string matching criteria. The format is defined fully in [[this Mozilla reference|https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions]].
+
+The regexp filter operator takes a fieldname as the optional suffix (defaulting to `title`).
+
+The regular expression itself can start or end with an optional string to specify flags in the format `(?flags)` where flags can be "g", "m" or "i". Only the "i" flag is generally useful: it forces the match to be case-insensitive (ie upper and lower case letters are considered the same).
+
+For example:
+
+|!Filter String |!Description |
+|`[all[tiddlers]regexp[EggCup]]` |Selects all tiddlers that have the CamelCase string "EggCup" in their title |
+|`[all[tiddlers]regexp[eggcup(?i)]]` |Selects all tiddlers that have the string "eggcup" in their title (ignoring case) |
+|`[all[tiddlers]regexp:modified[eggcup(^2014)]]` |Selects all tiddlers that have the string "eggcup" in their title (ignoring case) |
+

editions/tw5.com/tiddlers/filters/Introduction to Filters.tid

@@ -1,5 +1,5 @@
 created: 20140410101941871
-modified: 20140725103229640
+modified: 20140909134102102
 tags: introduction
 title: Introduction to Filters
 type: text/vnd.tiddlywiki
@@ -77,14 +77,6 @@ If a filter operator is written with angle brackets around the operand then it i
 
 (Note that the `currentTiddler` variable is used to track the current tiddler).
 
-! Regular Expression Operands
-
-The "field" filter also accepts [[regular expressions|http://en.wikipedia.org/wiki/Regular_expression]] with the syntax `/regexp/(modifier)`. For example:
-
-* `[field:title/example/]`: searches for all tiddlers having "example" in their title
-* `[field:title/example$/]`: `$` is an "anchor" for the end of the text so that "example" has to be at the end of the title
-* `[field:text/summer|winter/(i)]`: Searches for tiddlers containing "summer" or "winter", ignoring case
-
 ! ORing Multiple Filter Operators
 
 You can use multiple filter operations at once. This example selects all tiddlers that are either tagged "introduction" or "demo":