checkin for extending javascript types

lib/compile/common.js

@@ -29,7 +29,10 @@ var createFunction = function (body, defined, scope, scopeNames, definedNames) {
 
 var createDefined = (function () {
 
-    var _createDefined = function (action, defined, scope) {
+    var _createDefined = function (options, defined, scope) {
+        var action = options.properties
+            ,proto, base;
+        //
         if (isString(action)) {
             var declares = [];
             extd(defined).keys().forEach(function (i) {
@@ -57,7 +60,14 @@ var createDefined = (function () {
                 }
             }
         };
-        var proto = ret.prototype;
+        if (options.extend) {
+            base = defined[options.extend];
+            proto = Object.create(base.prototype);
+            ret.prototype = proto;
+        }
+        else {
+            proto = ret.prototype;
+        }
         for (var i in action) {
             proto[i] = action[i];
         }
@@ -66,7 +76,7 @@ var createDefined = (function () {
     };
 
     return function (options, defined, scope) {
-        return _createDefined(options.properties, defined, scope);
+        return _createDefined(options, defined, scope);
     };
 })();
 

lib/compile/transpile.js

@@ -7,26 +7,47 @@ var extd = require("../extended"),
     constraintMatcher = require("../constraintMatcher"),
     parser = require("../parser");
 
-function definedToJs(options) {
+function definedToJs(options, extend) {
     /*jshint evil:true*/
     options = isString(options) ? new Function("return " + options + ";")() : options;
-    var ret = ["(function(){"], value;
-
+    var ret = ["(function(flow){"], value;
+    
     if (options.hasOwnProperty("constructor") && "function" === typeof options.constructor) {
         ret.push("var Defined = " + options.constructor.toString() + ";");
     } else {
         ret.push("var Defined = function(opts){ for(var i in opts){if(opts.hasOwnProperty(i)){this[i] = opts[i];}}};");
     }
-    ret.push("var proto = Defined.prototype;");
+    if (extend) {
+        ret.push("var proto = Object.create(flow.getDefined('" + extend + "').prototype); proto.constructor = Defined; Defined.prototype = proto;");
+    }
+    else {
+        ret.push("var proto = Defined.prototype;");
+    }
+
     for (var key in options) {
-        if (options.hasOwnProperty(key)) {
+        var str;
+        if (options.hasOwnProperty(key) && key !== 'constructor') {
             value = options[key];
-            ret.push("proto." + key + " = " + (extd.isFunction(value) ? value.toString() : extd.format("%j", value)) + ";");
+            str = ("proto." + key + " = ");
+            if (extd.isFunction(value)) {
+                str += value.toString();
+            }
+            else {
+                if (value instanceof Array) {
+                    str += JSON.stringify(value);
+                }
+                else {
+                    str += extd.format("%j", value);
+                }
+                str += ";"
+            }
+            ret.push(str);
         }
     }
     ret.push("return Defined;");
-    ret.push("}())");
-    return ret.join("");
+    ret.push("}(this))");
+    var sJoin =  ret.join("");
+    return sJoin;
 
 }
 
@@ -148,7 +169,7 @@ exports.transpile = function (flowObj, options) {
     ret.push(extd(flowObj.define || []).map(function (defined) {
         var name = defined.name;
         defined[name] = {};
-        return ["var", name, "= defined." + name, "= this.addDefined('" + name + "',", definedToJs(defined.properties) + ");"].join(" ");
+        return ["var", name, "= defined." + name, "= this.addDefined('" + name + "',", definedToJs(defined.properties, defined.extend) + ");"].join(" ");
     }).value().join("\n"));
     ret.push(extd(flowObj.scope || []).map(function (s) {
         var name = s.name;

lib/parser/nools/tokens.js

@@ -222,12 +222,17 @@ var topLevelTokens = {
         var name = src.match(/^([a-zA-Z_$][0-9a-zA-Z_$]*)/);
         if (name) {
             src = src.replace(name[0], "").replace(/^\s*|\s*$/g, "");
+            var extend = src.match(/^extends\s+([a-zA-Z_$][0-9a-zA-Z_$]*)/);
+            if (extend) {
+                src = src.replace(extend[0], "").replace(/^\s*|\s*$/g, "");
+                extend = extend[1];
+            }
             if (utils.findNextToken(src) === "{") {
                 name = name[1];
                 var body = utils.getTokensBetween(src, "{", "}", true).join("");
                 src = src.replace(body, "");
                 //should
-                context.define.push({name: name, properties: "(" + body + ")"});
+                context.define.push({ name: name, extend: extend, properties: "(" + body + ")" });
                 return src;
             } else {
                 throw new Error("unexpected token : expected : '{' found : '" + utils.findNextToken(src) + "'");

readme.md

@@ -315,6 +315,20 @@ session.modify(m);
 
 **Note** `modify` is typically used during the execution of the rules.
 
+# Type Declaration 'extends'
+Defined types in the DSL no support 'extends' keyword for inheritance.
+
+Any type present in the flow can be extended. Base types must be defined before extended types.
+
+```
+define EncodedMessage extends Message {
+	encoding: 'sha1'
+	,constructor: function(message, encoding) {
+		Message.call(this, message);   // call superclass manually
+		this.encoding = encoding
+	}
+}
+
 <a name="get-facts"></a>
 ### Retrieving Facts
 

test/flow.dsl.test.js

@@ -593,4 +593,27 @@ it.describe("Flow dsl", function (it) {
             });
         });
     });
+
+    it.describe("extended Fact types", function (it) {
+        var Person, Student, LongTermStudent, Count, session1Fired = {}, session1;
+        var flow = nools.compile(resolve(__dirname, "./rules/extends.nools"), {
+            name: 'extendsTest'
+        });
+        Person = flow.getDefined('Person');
+        Student = flow.getDefined('Student');
+        LongTermStudent = flow.getDefined('LongTermStudent');
+        //
+        session1 = flow.getSession(new Person('Bob'), new Student('Sue', 'harvard'), new LongTermStudent('Jim', 'princeton', 1)).on('fire', function (name) {
+            session1Fired[name] = session1Fired[name] || { cnt: 0 };
+            session1Fired[name].cnt++;
+        });
+        //
+        it.should(" fire rule(s) correctly according to type. each rule matching a single type ", function (next) {
+            return session1.match().then(function () {
+                assert(session1Fired['PersonTest'].cnt === 3);
+                assert(session1Fired['StudentTest'].cnt === 2);
+                assert(session1Fired['LongTermStudentTest'].cnt === 1);
+            })
+        });
+    });
 });

test/noolsParser.test.js

@@ -14,6 +14,7 @@ it.describe("nools dsl parser", function (it) {
                 define: [
                     {
                         name: "Test",
+						extend: null,
                         properties: "({myProp : 'value'})"
                     }
                 ],
@@ -28,6 +29,7 @@ it.describe("nools dsl parser", function (it) {
                 define: [
                     {
                         name: "Test",
+						extend: null,
                         properties: "({myFunc : function(){}})"
                     }
                 ],
@@ -183,6 +185,7 @@ it.describe("nools dsl parser", function (it) {
                     "define": [
                         {
                             "name": "Count",
+							extend: null,
                             "properties": "({     constructor: function(){         this.called = 0;     } })"
                         }
                     ],

test/rules/extends.nools

@@ -0,0 +1,46 @@
+
+define Person {
+    constructor: function(name){
+        this.name = name;
+    }
+}
+
+define Student extends Person {
+	constructor: function(name, school) {
+		Person.call(this, name);
+		this.school = school;
+	}
+}
+
+define LongTermStudent extends Student {
+	constructor: function(name, school, years) {
+		Student.call(this, name, school);
+		this.years = years;
+	}
+}
+
+
+rule PersonTest {
+    when {
+        p: Person;
+    }
+    then {
+    }
+}
+
+rule StudentTest {
+    when {
+        s: Student;
+    }
+    then {
+    }
+}
+
+
+rule LongTermStudentTest {
+    when {
+        s: LongTermStudent;
+    }
+    then {
+    }
+}