Add new "order" filter operator

core/modules/filters/listops.js

@@ -12,6 +12,23 @@ Filter operators for manipulating the current selection list
 /*global $tw: false */
 "use strict";
 
+/*
+Order a list
+*/
+exports.order = function(source,operator,options) {
+	var results = [];
+	if(operator.operand.toLowerCase() === "reverse") {
+		source(function(tiddler,title) {
+			results.unshift(title);
+		});
+	} else {
+		source(function(tiddler,title) {
+			results.push(title);
+		});		
+	}
+	return results;
+};
+
 /*
 Reverse list
 */

editions/tw5.com/tiddlers/filters/order_Operator.tid

@@ -0,0 +1,15 @@
+caption: order
+created: 20161128185907280
+modified: 20161128191251557
+op-input: a [[selection of titles|Title Selection]]
+op-output: the input, with the order reversed if <<.field F>> is the special value `reverse`
+op-parameter: Either the string `reverse` or another value
+op-parameter-name: F
+op-purpose: selectively reverse the input list
+tags: [[Filter Operators]] [[Common Operators]] [[Field Operators]] [[Order Operators]]
+title: order Operator
+type: text/vnd.tiddlywiki
+
+Either reverses or preserves the order of the input list according to whether the parameter is the special value `reverse`.
+
+<<.operator-examples "order">>