unmaintained/modules/js/eval.hpp - tuscany-sca-cpp - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  *   http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  * KIND, either express or implied.  See the License for the
  * specific language governing permissions and limitations
  * under the License.
  */

 /* $Rev$ $Date$ */

 #ifndef tuscany_js_hpp
 #define tuscany_js_hpp

 /**
  * Javascript evaluation functions.
  */

 #define XP_UNIX
 #ifdef WANT_MAINTAINER_WARNINGS
 #pragma GCC diagnostic ignored "-Wunused-parameter"
 #pragma GCC diagnostic ignored "-Wsign-compare"
 #pragma GCC diagnostic ignored "-Wredundant-decls"
 #endif
 #include "jsapi.h"
 #ifdef WANT_MAINTAINER_WARNINGS
 #pragma GCC diagnostic warning "-Wunused-parameter"
 #pragma GCC diagnostic warning "-Wsign-compare"
 #pragma GCC diagnostic warning "-Wredundant-decls"
 #endif
 #include "string.hpp"
 #include "list.hpp"
 #include "value.hpp"
 #include "element.hpp"
 #include "monad.hpp"
 #include "parallel.hpp"

 namespace tuscany {
 namespace js {

 /**
  * Report Javascript errors.
  */
 void reportError(unused ::JSContext *cx, const char *message, JSErrorReport *report) {
     cfailure << (const char*)(report->filename? report->filename : "<no filename>") << ":"
             << (int)report->lineno << ":" << message << endl;
 }

 /**
  * Encapsulates a JavaScript runtime. Shared by multiple threads in
  * a process.
  */
 class JSRuntime {
 public:
     JSRuntime() {
         // Create JS runtime
         debug("js::jsruntime");
         pthread_mutex_init(&mutex, NULL);
 #ifdef WANT_THREADS
         rt = JS_NewRuntime(32L * 1024L * 1024L);
 #else
         rt = JS_NewRuntime(8L * 1024L * 1024L);
 #endif
         if(rt == NULL)
             cleanup();
     }

     operator ::JSRuntime*() const {
         return rt;
     }

     ~JSRuntime() {
         debug("js::~jsruntime");
     }

     bool lock() {
         //pthread_mutex_lock(&mutex);
         return true;
     }

     bool unlock() {
         //pthread_mutex_unlock(&mutex);
         return true;
     }

 private:
     bool cleanup() {
         if(rt != NULL) {
             JS_DestroyRuntime(rt);
             rt = NULL;
         }
         JS_ShutDown();
         return true;
     }

     pthread_mutex_t mutex;
     ::JSRuntime* rt;
 } jsRuntime;

 JSClass jsGlobalClass = { "global", JSCLASS_GLOBAL_FLAGS,
     JS_PropertyStub, JS_PropertyStub,
     JS_PropertyStub, JS_StrictPropertyStub,
     JS_EnumerateStub, JS_ResolveStub,
     JS_ConvertStub, JS_FinalizeStub,
     JSCLASS_NO_OPTIONAL_MEMBERS };

 /**
  * Represents a JavaScript context. Maintains one context per thread.
  */
 #ifdef WANT_THREADS
 perthread_ptr<JSContext> jsContext;
 #else
 ::JSContext* jsContext = NULL;
 #endif

 class JSContext {
 public:
     JSContext() {
         debug("js::jscontext");
         jsRuntime.lock();

         // Create JS context if necessary
         if (jsContext != NULL) {
             cx = jsContext;
             debug(cx, "js::jscontext::beginRequest::cx");
             JS_SetContextThread(cx);
             JS_BeginRequest(cx);
             return;
         }

         debug("js::jscontext::newcontext");
         cx = JS_NewContext(jsRuntime, 8192);
         if(cx == NULL) {
             jsRuntime.unlock();
             return;
         }
         debug(cx, "js::jscontext::beginRequest::cx");
         JS_SetContextThread(cx);
         JS_BeginRequest(cx);

         JS_SetOptions(cx, JSOPTION_VAROBJFIX /*| JSOPTION_JIT | JSOPTION_METHODJIT*/);
         JS_SetVersion(cx, JSVERSION_LATEST);
         JS_SetErrorReporter(cx, reportError);
         JS_SetGCZeal(cx, 0);

         // Create global JS object
         global = JS_NewCompartmentAndGlobalObject(cx, &jsGlobalClass, NULL);
         if(global == NULL) {
             JS_DestroyContext(cx);
             cleanup();
             return;
         }
         JS_SetGlobalObject(cx, global);

         // Populate global object with the standard globals, like Object and Array
         if(!JS_InitStandardClasses(cx, global)) {
             JS_DestroyContext(cx);
             cleanup();
             return;
         }

         jsContext = cx;
     }

     ~JSContext() {
         debug("js::~jscontext");
         cleanup();
     }

     operator ::JSContext*() const {
         return cx;
     }

     JSObject* getGlobal() const {
         return global;
     }

 private:
     bool cleanup() {
         if(cx != NULL) {
             if (cx != jsContext) {
                 debug(cx, "js::jscontext::endrequest::cx");
                 JS_EndRequest(cx);
                 JS_ClearContextThread(cx);
                 debug(cx, "js::jscontext::destroycontext::cx");
                 JS_DestroyContext(cx);
                 jsContext = NULL;
             } else {
                 //debug(cx, "js::jscontext::maybegc::cx");
                 //JS_MaybeGC(cx);
                 debug(cx, "js::jscontext::endrequest::cx");
                 JS_EndRequest(cx);
                 JS_ClearContextThread(cx);
             }
             cx = NULL;
         }
         jsRuntime.unlock();
         return true;
     }

     ::JSContext* cx;
     JSObject* global;
 };

 /**
  * Returns true if a list represents a JS array.
  */
 const bool isJSArray(const list<value>& l) {
     if(isNil(l))
         return true;
     const value v = car(l);
     if (isSymbol(v))
         return false;
     if(isList(v)) {
         if(!isNil((list<value>)v) && isSymbol(car<value>(v)))
             return false;
     }
     return true;
 }

 /**
  * Converts JS properties to values.
  */
 const list<value> jsPropertiesToValues(const list<value>& propertiesSoFar, JSObject* o, JSObject* i, const js::JSContext& cx) {

     const value jsValToValue(const jsval& jsv, const js::JSContext& cx);

     jsid id;
     if(!JS_NextProperty(cx, i, &id))
         return propertiesSoFar;
     jsval idv;
     JS_IdToValue(cx, id, &idv);
     if (idv == JSVAL_VOID)
         return propertiesSoFar;

     jsval jsv;
     if(!JS_GetPropertyById(cx, o, id, &jsv))
         return propertiesSoFar;
     const value val = jsValToValue(jsv, cx);

     if(JSVAL_IS_STRING(idv)) {
         char* cname = JS_EncodeString(cx, JSVAL_TO_STRING(idv));
         const string name = cname;
         JS_free(cx, cname);
         if (isNil(val) && !isList(val))
             return jsPropertiesToValues(cons<value> (mklist<value> (element, c_str(name), val), propertiesSoFar), o, i, cx);
             //return jsPropertiesToValues(propertiesSoFar, o, i, cx);
         if (substr(name, 0, 1) == atsign)
             return jsPropertiesToValues(cons<value>(mklist<value>(attribute, c_str(substr(name, 1)), val), propertiesSoFar), o, i, cx);
         if (isList(val) && !isJSArray(val))
             return jsPropertiesToValues(cons<value>(cons<value>(element, cons<value>(c_str(name), list<value>(val))), propertiesSoFar), o, i, cx);
         return jsPropertiesToValues(cons<value> (mklist<value> (element, c_str(name), val), propertiesSoFar), o, i, cx);
     }
     return jsPropertiesToValues(cons(val, propertiesSoFar), o, i, cx);
 }

 /**
  * Converts a JS val to a value.
  */
 const value jsValToValue(const jsval& jsv, const js::JSContext& cx) {
     switch(JS_TypeOfValue(cx, jsv)) {
     case JSTYPE_STRING: {
         char* cvalue = JS_EncodeString(cx, JSVAL_TO_STRING(jsv));
         const string svalue = string(cvalue);
         JS_free(cx, cvalue);
         return value(svalue);
     }
     case JSTYPE_BOOLEAN: {
         return value((bool)JSVAL_TO_BOOLEAN(jsv));
     }
     case JSTYPE_NUMBER: {
         double jsd;
         JS_ValueToNumber(cx, jsv, &jsd);
         return value((double)jsd);
     }
     case JSTYPE_OBJECT: {
         JSObject* o = JSVAL_TO_OBJECT(jsv);
         if (o == NULL)
             return value();
         JSObject* i = JS_NewPropertyIterator(cx, o);
         if(i == NULL)
             return value(list<value> ());
         const value pv = jsPropertiesToValues(list<value> (), o, i, cx);
         return pv;
     }
     default: {
         return value();
     }
     }
 }

 /**
  * Converts a list of values to JS array elements.
  */
 JSObject* valuesToJSElements(JSObject* a, const list<value>& l, int i, const js::JSContext& cx) {
     const jsval valueToJSVal(const value& val, const js::JSContext& cx);
     if (isNil(l))
         return a;
     jsval pv = valueToJSVal(car(l), cx);
     JS_SetElement(cx, a, i, &pv);
     return valuesToJSElements(a, cdr(l), ++i, cx);
 }

 /**
  * Converts a value to a JS val.
  */
 const jsval valueToJSVal(const value& val, const js::JSContext& cx) {
     JSObject* valuesToJSProperties(JSObject* o, const list<value>& l, const js::JSContext& cx);

     switch(type(val)) {
     case value::String: {
         return STRING_TO_JSVAL(JS_NewStringCopyZ(cx, c_str((string)val)));
     }
     case value::Symbol: {
         return STRING_TO_JSVAL(JS_NewStringCopyZ(cx, c_str((string)val)));
     }
     case value::Bool: {
         return BOOLEAN_TO_JSVAL((bool)val);
     }
     case value::Number: {
         jsval jsv = DOUBLE_TO_JSVAL((double)val);
         return jsv;
     }
     case value::List: {
         if (isJSArray(val)) {
             JSObject* array = JS_NewArrayObject(cx, 0, NULL);
             //debug(array, "js::valueToJSVal::new::array");
             return OBJECT_TO_JSVAL(valuesToJSElements(array, val, 0, cx));
         }
         JSObject* child = JS_NewObject(cx, NULL, NULL, NULL);
         //debug(child, "js::valueToJSVal::new::child");
         return OBJECT_TO_JSVAL(valuesToJSProperties(child, val, cx));
     }
     case value::Nil: {
         return JSVAL_NULL;
     }
     default: {
         return JSVAL_VOID;
     }
     }
 }

 /**
  * Converts a list of values to JS properties.
  */
 JSObject* valuesToJSProperties(JSObject* o, const list<value>& l, const js::JSContext& cx) {
     if (isNil(l))
         return o;

     // Write an attribute
     const value token(car(l));

     if (isTaggedList(token, attribute)) {
         jsval pv = valueToJSVal(attributeValue(token), cx);
         JS_SetProperty(cx, o, c_str(atsign + string(attributeName(token))), &pv);

     } else if (isTaggedList(token, element)) {

         // Write the value of an element
         if (elementHasValue(token)) {
             jsval pv = valueToJSVal(elementValue(token), cx);
             JS_SetProperty(cx, o, c_str(string(elementName(token))), &pv);

         } else {

             // Write a parent element
             JSObject* child = JS_NewObject(cx, NULL, NULL, NULL);
             //debug(child, "js::valuesToJSProperties::new::child");
             jsval pv = OBJECT_TO_JSVAL(child);
             JS_SetProperty(cx, o, c_str(string(elementName(token))), &pv);

             // Write its children
             valuesToJSProperties(child, elementChildren(token), cx);
         }
     }

     // Go on
     return valuesToJSProperties(o, cdr(l), cx);
 }

 /**
  * Evaluate a script provided as a string.
  */
 const failable<value> evalScript(const string& s) {
     js::JSContext cx;
     jsval rval;
     JSBool rc = JS_EvaluateScript(cx, cx.getGlobal(), c_str(s), (unsigned int)length(s), "eval.js", 1, &rval);
     if (rc != JS_TRUE) {
         return mkfailure<value>("Couldn't evaluate Javascript script.");
     }
     return jsValToValue(rval, cx);
 }

 }
 }

 #endif /* tuscany_js_hpp */
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*/

	/* $Rev$ $Date$ */

	#ifndef tuscany_js_hpp
	#define tuscany_js_hpp

	/**
	* Javascript evaluation functions.
	*/

	#define XP_UNIX
	#ifdef WANT_MAINTAINER_WARNINGS
	#pragma GCC diagnostic ignored "-Wunused-parameter"
	#pragma GCC diagnostic ignored "-Wsign-compare"
	#pragma GCC diagnostic ignored "-Wredundant-decls"
	#endif
	#include "jsapi.h"
	#ifdef WANT_MAINTAINER_WARNINGS
	#pragma GCC diagnostic warning "-Wunused-parameter"
	#pragma GCC diagnostic warning "-Wsign-compare"
	#pragma GCC diagnostic warning "-Wredundant-decls"
	#endif
	#include "string.hpp"
	#include "list.hpp"
	#include "value.hpp"
	#include "element.hpp"
	#include "monad.hpp"
	#include "parallel.hpp"

	namespace tuscany {
	namespace js {

	/**
	* Report Javascript errors.
	*/
	void reportError(unused ::JSContext cx, const char message, JSErrorReport *report) {
	cfailure << (const char*)(report->filename? report->filename : "<no filename>") << ":"
	<< (int)report->lineno << ":" << message << endl;
	}

	/**
	* Encapsulates a JavaScript runtime. Shared by multiple threads in
	* a process.
	*/
	class JSRuntime {
	public:
	JSRuntime() {
	// Create JS runtime
	debug("js::jsruntime");
	pthread_mutex_init(&mutex, NULL);
	#ifdef WANT_THREADS
	rt = JS_NewRuntime(32L * 1024L * 1024L);
	#else
	rt = JS_NewRuntime(8L * 1024L * 1024L);
	#endif
	if(rt == NULL)
	cleanup();
	}

	operator ::JSRuntime*() const {
	return rt;
	}

	~JSRuntime() {
	debug("js::~jsruntime");
	}

	bool lock() {
	//pthread_mutex_lock(&mutex);
	return true;
	}

	bool unlock() {
	//pthread_mutex_unlock(&mutex);
	return true;
	}

	private:
	bool cleanup() {
	if(rt != NULL) {
	JS_DestroyRuntime(rt);
	rt = NULL;
	}
	JS_ShutDown();
	return true;
	}

	pthread_mutex_t mutex;
	::JSRuntime* rt;
	} jsRuntime;

	JSClass jsGlobalClass = { "global", JSCLASS_GLOBAL_FLAGS,
	JS_PropertyStub, JS_PropertyStub,
	JS_PropertyStub, JS_StrictPropertyStub,
	JS_EnumerateStub, JS_ResolveStub,
	JS_ConvertStub, JS_FinalizeStub,
	JSCLASS_NO_OPTIONAL_MEMBERS };

	/**
	* Represents a JavaScript context. Maintains one context per thread.
	*/
	#ifdef WANT_THREADS
	perthread_ptr<JSContext> jsContext;
	#else
	::JSContext* jsContext = NULL;
	#endif

	class JSContext {
	public:
	JSContext() {
	debug("js::jscontext");
	jsRuntime.lock();

	// Create JS context if necessary
	if (jsContext != NULL) {
	cx = jsContext;
	debug(cx, "js::jscontext::beginRequest::cx");
	JS_SetContextThread(cx);
	JS_BeginRequest(cx);
	return;
	}

	debug("js::jscontext::newcontext");
	cx = JS_NewContext(jsRuntime, 8192);
	if(cx == NULL) {
	jsRuntime.unlock();
	return;
	}
	debug(cx, "js::jscontext::beginRequest::cx");
	JS_SetContextThread(cx);
	JS_BeginRequest(cx);

	JS_SetOptions(cx, JSOPTION_VAROBJFIX /\| JSOPTION_JIT \| JSOPTION_METHODJIT/);
	JS_SetVersion(cx, JSVERSION_LATEST);
	JS_SetErrorReporter(cx, reportError);
	JS_SetGCZeal(cx, 0);

	// Create global JS object
	global = JS_NewCompartmentAndGlobalObject(cx, &jsGlobalClass, NULL);
	if(global == NULL) {
	JS_DestroyContext(cx);
	cleanup();
	return;
	}
	JS_SetGlobalObject(cx, global);

	// Populate global object with the standard globals, like Object and Array
	if(!JS_InitStandardClasses(cx, global)) {
	JS_DestroyContext(cx);
	cleanup();
	return;
	}

	jsContext = cx;
	}

	~JSContext() {
	debug("js::~jscontext");
	cleanup();
	}

	operator ::JSContext*() const {
	return cx;
	}

	JSObject* getGlobal() const {
	return global;
	}

	private:
	bool cleanup() {
	if(cx != NULL) {
	if (cx != jsContext) {
	debug(cx, "js::jscontext::endrequest::cx");
	JS_EndRequest(cx);
	JS_ClearContextThread(cx);
	debug(cx, "js::jscontext::destroycontext::cx");
	JS_DestroyContext(cx);
	jsContext = NULL;
	} else {
	//debug(cx, "js::jscontext::maybegc::cx");
	//JS_MaybeGC(cx);
	debug(cx, "js::jscontext::endrequest::cx");
	JS_EndRequest(cx);
	JS_ClearContextThread(cx);
	}
	cx = NULL;
	}
	jsRuntime.unlock();
	return true;
	}

	::JSContext* cx;
	JSObject* global;
	};

	/**
	* Returns true if a list represents a JS array.
	*/
	const bool isJSArray(const list<value>& l) {
	if(isNil(l))
	return true;
	const value v = car(l);
	if (isSymbol(v))
	return false;
	if(isList(v)) {
	if(!isNil((list<value>)v) && isSymbol(car<value>(v)))
	return false;
	}
	return true;
	}

	/**
	* Converts JS properties to values.
	*/
	const list<value> jsPropertiesToValues(const list<value>& propertiesSoFar, JSObject* o, JSObject* i, const js::JSContext& cx) {

	const value jsValToValue(const jsval& jsv, const js::JSContext& cx);

	jsid id;
	if(!JS_NextProperty(cx, i, &id))
	return propertiesSoFar;
	jsval idv;
	JS_IdToValue(cx, id, &idv);
	if (idv == JSVAL_VOID)
	return propertiesSoFar;

	jsval jsv;
	if(!JS_GetPropertyById(cx, o, id, &jsv))
	return propertiesSoFar;
	const value val = jsValToValue(jsv, cx);

	if(JSVAL_IS_STRING(idv)) {
	char* cname = JS_EncodeString(cx, JSVAL_TO_STRING(idv));
	const string name = cname;
	JS_free(cx, cname);
	if (isNil(val) && !isList(val))
	return jsPropertiesToValues(cons<value> (mklist<value> (element, c_str(name), val), propertiesSoFar), o, i, cx);
	//return jsPropertiesToValues(propertiesSoFar, o, i, cx);
	if (substr(name, 0, 1) == atsign)
	return jsPropertiesToValues(cons<value>(mklist<value>(attribute, c_str(substr(name, 1)), val), propertiesSoFar), o, i, cx);
	if (isList(val) && !isJSArray(val))
	return jsPropertiesToValues(cons<value>(cons<value>(element, cons<value>(c_str(name), list<value>(val))), propertiesSoFar), o, i, cx);
	return jsPropertiesToValues(cons<value> (mklist<value> (element, c_str(name), val), propertiesSoFar), o, i, cx);
	}
	return jsPropertiesToValues(cons(val, propertiesSoFar), o, i, cx);
	}

	/**
	* Converts a JS val to a value.
	*/
	const value jsValToValue(const jsval& jsv, const js::JSContext& cx) {
	switch(JS_TypeOfValue(cx, jsv)) {
	case JSTYPE_STRING: {
	char* cvalue = JS_EncodeString(cx, JSVAL_TO_STRING(jsv));
	const string svalue = string(cvalue);
	JS_free(cx, cvalue);
	return value(svalue);
	}
	case JSTYPE_BOOLEAN: {
	return value((bool)JSVAL_TO_BOOLEAN(jsv));
	}
	case JSTYPE_NUMBER: {
	double jsd;
	JS_ValueToNumber(cx, jsv, &jsd);
	return value((double)jsd);
	}
	case JSTYPE_OBJECT: {
	JSObject* o = JSVAL_TO_OBJECT(jsv);
	if (o == NULL)
	return value();
	JSObject* i = JS_NewPropertyIterator(cx, o);
	if(i == NULL)
	return value(list<value> ());
	const value pv = jsPropertiesToValues(list<value> (), o, i, cx);
	return pv;
	}
	default: {
	return value();
	}
	}
	}

	/**
	* Converts a list of values to JS array elements.
	*/
	JSObject* valuesToJSElements(JSObject* a, const list<value>& l, int i, const js::JSContext& cx) {
	const jsval valueToJSVal(const value& val, const js::JSContext& cx);
	if (isNil(l))
	return a;
	jsval pv = valueToJSVal(car(l), cx);
	JS_SetElement(cx, a, i, &pv);
	return valuesToJSElements(a, cdr(l), ++i, cx);
	}

	/**
	* Converts a value to a JS val.
	*/
	const jsval valueToJSVal(const value& val, const js::JSContext& cx) {
	JSObject* valuesToJSProperties(JSObject* o, const list<value>& l, const js::JSContext& cx);

	switch(type(val)) {
	case value::String: {
	return STRING_TO_JSVAL(JS_NewStringCopyZ(cx, c_str((string)val)));
	}
	case value::Symbol: {
	return STRING_TO_JSVAL(JS_NewStringCopyZ(cx, c_str((string)val)));
	}
	case value::Bool: {
	return BOOLEAN_TO_JSVAL((bool)val);
	}
	case value::Number: {
	jsval jsv = DOUBLE_TO_JSVAL((double)val);
	return jsv;
	}
	case value::List: {
	if (isJSArray(val)) {
	JSObject* array = JS_NewArrayObject(cx, 0, NULL);
	//debug(array, "js::valueToJSVal::new::array");
	return OBJECT_TO_JSVAL(valuesToJSElements(array, val, 0, cx));
	}
	JSObject* child = JS_NewObject(cx, NULL, NULL, NULL);
	//debug(child, "js::valueToJSVal::new::child");
	return OBJECT_TO_JSVAL(valuesToJSProperties(child, val, cx));
	}
	case value::Nil: {
	return JSVAL_NULL;
	}
	default: {
	return JSVAL_VOID;
	}
	}
	}

	/**
	* Converts a list of values to JS properties.
	*/
	JSObject* valuesToJSProperties(JSObject* o, const list<value>& l, const js::JSContext& cx) {
	if (isNil(l))
	return o;

	// Write an attribute
	const value token(car(l));

	if (isTaggedList(token, attribute)) {
	jsval pv = valueToJSVal(attributeValue(token), cx);
	JS_SetProperty(cx, o, c_str(atsign + string(attributeName(token))), &pv);

	} else if (isTaggedList(token, element)) {

	// Write the value of an element
	if (elementHasValue(token)) {
	jsval pv = valueToJSVal(elementValue(token), cx);
	JS_SetProperty(cx, o, c_str(string(elementName(token))), &pv);

	} else {

	// Write a parent element
	JSObject* child = JS_NewObject(cx, NULL, NULL, NULL);
	//debug(child, "js::valuesToJSProperties::new::child");
	jsval pv = OBJECT_TO_JSVAL(child);
	JS_SetProperty(cx, o, c_str(string(elementName(token))), &pv);

	// Write its children
	valuesToJSProperties(child, elementChildren(token), cx);
	}
	}

	// Go on
	return valuesToJSProperties(o, cdr(l), cx);
	}

	/**
	* Evaluate a script provided as a string.
	*/
	const failable<value> evalScript(const string& s) {
	js::JSContext cx;
	jsval rval;
	JSBool rc = JS_EvaluateScript(cx, cx.getGlobal(), c_str(s), (unsigned int)length(s), "eval.js", 1, &rval);
	if (rc != JS_TRUE) {
	return mkfailure<value>("Couldn't evaluate Javascript script.");
	}
	return jsValToValue(rval, cx);
	}

	}
	}

	#endif /* tuscany_js_hpp */