Named filter run prefixes (#4915)

* First pass at refactoring filter code to support named filter run prefixes

* Remove filter prefix for now

* renamed module type and filter run prefixes

* Moved inline handling for no filter run prefix to 'or' filter run prefix.

* Added error handling for undefined filter run prefixes

core/language/en-GB/Misc.multids

@@ -26,6 +26,7 @@ Error/Caption: Error
 Error/EditConflict: File changed on server
 Error/Filter: Filter error
 Error/FilterSyntax: Syntax error in filter expression
+Error/FilterRunPrefix: Filter Error: Unknown prefix for filter run
 Error/IsFilterOperator: Filter Error: Unknown operand for the 'is' filter operator
 Error/FormatFilterOperator: Filter Error: Unknown suffix for the 'format' filter operator
 Error/LoadingPluginLibrary: Error loading plugin library

core/modules/filterrunprefixes/all.js

@@ -0,0 +1,25 @@
+/*\
+title: $:/core/modules/filterrunprefixes/all.js
+type: application/javascript
+module-type: filterrunprefix
+
+Union of sets without de-duplication.
+Equivalent to = filter run prefix.
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+/*
+Export our filter prefix function
+*/
+exports.all = function(operationSubFunction) {
+	return function(results,source,widget) {
+		Array.prototype.push.apply(results,operationSubFunction(source,widget));
+	};
+};
+
+})();

core/modules/filterrunprefixes/and.js

@@ -0,0 +1,28 @@
+/*\
+title: $:/core/modules/filterrunprefixes/and.js
+type: application/javascript
+module-type: filterrunprefix
+
+Intersection of sets.
+Equivalent to + filter run prefix.
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+/*
+Export our filter prefix function
+*/
+exports.and = function(operationSubFunction) {
+	return function(results,source,widget) {
+		// This replaces all the elements of the array, but keeps the actual array so that references to it are preserved
+		source = $tw.wiki.makeTiddlerIterator(results);
+		results.splice(0,results.length);
+		$tw.utils.pushTop(results,operationSubFunction(source,widget));
+	};
+};
+
+})();

core/modules/filterrunprefixes/else.js

@@ -0,0 +1,27 @@
+/*\
+title: $:/core/modules/filterrunprefixes/else.js
+type: application/javascript
+module-type: filterrunprefix
+
+Equivalent to ~ filter run prefix.
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+/*
+Export our filter prefix function
+*/
+exports.else = function(operationSubFunction) {
+	return function(results,source,widget) {
+		if(results.length === 0) {
+			// Main result so far is empty
+			$tw.utils.pushTop(results,operationSubFunction(source,widget));
+		}
+	};
+};
+
+})();

core/modules/filterrunprefixes/except.js

@@ -0,0 +1,25 @@
+/*\
+title: $:/core/modules/filterrunprefixes/except.js
+type: application/javascript
+module-type: filterrunprefix
+
+Difference of sets.
+Equivalent to - filter run prefix.
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+/*
+Export our filter prefix function
+*/
+exports.except = function(operationSubFunction) {
+	return function(results,source,widget) {
+		$tw.utils.removeArrayEntries(results,operationSubFunction(source,widget));
+	};
+};
+
+})();

core/modules/filterrunprefixes/or.js

@@ -0,0 +1,24 @@
+/*\
+title: $:/core/modules/filterrunprefixes/or.js
+type: application/javascript
+module-type: filterrunprefix
+
+Equivalent to a filter run with no prefix.
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+/*
+Export our filter prefix function
+*/
+exports.or = function(operationSubFunction) {
+	return function(results,source,widget) {
+		$tw.utils.pushTop(results,operationSubFunction(source,widget));
+	};
+};
+
+})();

core/modules/filters.js

@@ -119,7 +119,7 @@ exports.parseFilter = function(filterString) {
 		p = 0, // Current position in the filter string
 		match;
 	var whitespaceRegExp = /(\s+)/mg,
-		operandRegExp = /((?:\+|\-|~|=)?)(?:(\[)|(?:"([^"]*)")|(?:'([^']*)')|([^\s\[\]]+))/mg;
+		operandRegExp = /((?:\+|\-|~|=|\:(\w+))?)(?:(\[)|(?:"([^"]*)")|(?:'([^']*)')|([^\s\[\]]+))/mg;
 	while(p < filterString.length) {
 		// Skip any whitespace
 		whitespaceRegExp.lastIndex = p;
@@ -140,16 +140,19 @@ exports.parseFilter = function(filterString) {
 			};
 			if(match[1]) {
 				operation.prefix = match[1];
-				p++;
+				p = p + operation.prefix.length;
+				if(match[2]) {
+					operation.namedPrefix = match[2];
+				}
 			}
-			if(match[2]) { // Opening square bracket
+			if(match[3]) { // Opening square bracket
 				p = parseFilterOperation(operation.operators,filterString,p);
 			} else {
 				p = match.index + match[0].length;
 			}
-			if(match[3] || match[4] || match[5]) { // Double quoted string, single quoted string or unquoted title
+			if(match[4] || match[5] || match[6]) { // Double quoted string, single quoted string or unquoted title
 				operation.operators.push(
-					{operator: "title", operand: match[3] || match[4] || match[5]}
+					{operator: "title", operand: match[4] || match[5] || match[6]}
 				);
 			}
 			results.push(operation);
@@ -166,6 +169,14 @@ exports.getFilterOperators = function() {
 	return this.filterOperators;
 };
 
+exports.getFilterRunPrefixes = function() {
+	if(!this.filterPrefixes) {
+		$tw.Wiki.prototype.filterRunPrefixes = {};
+		$tw.modules.applyMethods("filterrunprefix",this.filterRunPrefixes);
+	}
+	return this.filterRunPrefixes;
+}
+
 exports.filterTiddlers = function(filterString,widget,source) {
 	var fn = this.compileFilter(filterString);
 	return fn.call(this,source,widget);
@@ -241,35 +252,29 @@ exports.compileFilter = function(filterString) {
 				return resultArray;
 			}
 		};
+		var filterRunPrefixes = self.getFilterRunPrefixes();
 		// Wrap the operator functions in a wrapper function that depends on the prefix
 		operationFunctions.push((function() {
 			switch(operation.prefix || "") {
 				case "": // No prefix means that the operation is unioned into the result
-					return function(results,source,widget) {
+					return filterRunPrefixes["or"](operationSubFunction);
-						$tw.utils.pushTop(results,operationSubFunction(source,widget));
-					};
 				case "=": // The results of the operation are pushed into the result without deduplication
-					return function(results,source,widget) {
+					return filterRunPrefixes["all"](operationSubFunction);
-						Array.prototype.push.apply(results,operationSubFunction(source,widget));
-					};
 				case "-": // The results of this operation are removed from the main result
-					return function(results,source,widget) {
+					return filterRunPrefixes["except"](operationSubFunction);	
-						$tw.utils.removeArrayEntries(results,operationSubFunction(source,widget));
-					};
 				case "+": // This operation is applied to the main results so far
-					return function(results,source,widget) {
+					return filterRunPrefixes["and"](operationSubFunction);
-						// This replaces all the elements of the array, but keeps the actual array so that references to it are preserved
-						source = self.makeTiddlerIterator(results);
-						results.splice(0,results.length);
-						$tw.utils.pushTop(results,operationSubFunction(source,widget));
-					};
 				case "~": // This operation is unioned into the result only if the main result so far is empty
-					return function(results,source,widget) {
+					return filterRunPrefixes["else"](operationSubFunction);
-						if(results.length === 0) {
+				default: 
-							// Main result so far is empty
+					if(operation.namedPrefix && filterRunPrefixes[operation.namedPrefix]) {
-							$tw.utils.pushTop(results,operationSubFunction(source,widget));
+						return filterRunPrefixes[operation.namedPrefix](operationSubFunction);
-						}
+					} else {
-					};
+						return function(results,source,widget) {
+							results.splice(0,results.length);
+							results.push($tw.language.getString("Error/FilterRunPrefix"));
+						};
+					}
 			}
 		})());
 	});