Refactoring, rename isNil to isNull.

git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@1428206 13f79535-47bb-0310-9956-ffa450edef68

43 files changed, 414 insertions, 414 deletions

diff --git a/sca-cpp/trunk/modules/atom/atom.hpp b/sca-cpp/trunk/modules/atom/atom.hpp
index 259769e2cb..b6f2788b1e 100644
--- a/sca-cpp/trunk/modules/atom/atom.hpp
+++ b/sca-cpp/trunk/modules/atom/atom.hpp
@@ -46,22 +46,22 @@ const value entry("entry");
  */
 const list<value> entryElementValues(const list<value>& e) {
     const list<value> lt = elementChildren("title", e);
-    const list<value> t = nilListValue + element + value("title") + (isNil(lt)? value(emptyString) : elementValue(car(lt)));
+    const list<value> t = nilListValue + element + value("title") + (isNull(lt)? value(emptyString) : elementValue(car(lt)));
 
     const list<value> li = elementChildren("id", e);
-    const list<value> i = nilListValue + element + value("id") + (isNil(li)? value(emptyString) : elementValue(car(li)));
+    const list<value> i = nilListValue + element + value("id") + (isNull(li)? value(emptyString) : elementValue(car(li)));
 
     const list<value> la = elementChildren("author", e);
-    const list<value> lan = isNil(la)? nilListValue : elementChildren("name", car(la));
-    const list<value> lae = isNil(la)? nilListValue : elementChildren("email", car(la));
-    const list<value> laa = isNil(lan)? lae : lan;
-    const list<value> a = isNil(laa)? nilListValue : mklist<value>(nilListValue + element + value("author") + elementValue(car(laa)));
+    const list<value> lan = isNull(la)? nilListValue : elementChildren("name", car(la));
+    const list<value> lae = isNull(la)? nilListValue : elementChildren("email", car(la));
+    const list<value> laa = isNull(lan)? lae : lan;
+    const list<value> a = isNull(laa)? nilListValue : mklist<value>(nilListValue + element + value("author") + elementValue(car(laa)));
 
     const list<value> lu = elementChildren("updated", e);
-    const list<value> u = isNil(lu)? nilListValue : mklist<value>(nilListValue + element + value("updated") + elementValue(car(lu)));
+    const list<value> u = isNull(lu)? nilListValue : mklist<value>(nilListValue + element + value("updated") + elementValue(car(lu)));
 
     const list<value> lc = elementChildren("content", e);
-    const list<value> c = isNil(lc)? nilListValue : isAttribute(elementValue(car(lc)))? nilListValue :
+    const list<value> c = isNull(lc)? nilListValue : isAttribute(elementValue(car(lc)))? nilListValue :
         mklist<value>(nilListValue + element + value("content") + elementValue(car(lc)));
 
     return append<value>(append<value>(append<value>(nilListValue + element + entry + value(t) + value(i), a), u), c);
@@ -71,7 +71,7 @@ const list<value> entryElementValues(const list<value>& e) {
  * Convert a list of elements to a list of element values representing ATOM entries.
  */
 const list<value> entriesElementValues(const list<value>& e) {
-    if (isNil(e))
+    if (isNull(e))
         return e;
     return cons<value>(entryElementValues(car(e)), entriesElementValues(cdr(e)));
 }
@@ -99,7 +99,7 @@ const bool isATOMEntry(const list<string>& ls) {
  */
 const failable<list<value> > readATOMEntry(const list<string>& ilist) {
     const list<value> e = content(xml::readElements(ilist));
-    if (isNil(e))
+    if (isNull(e))
         return mkfailure<list<value> >("Empty entry");
     return mklist<value>(entryElementValues(car(e)));
 }
@@ -109,7 +109,7 @@ const failable<list<value> > readATOMEntry(const list<string>& ilist) {
  */
 const failable<list<value> > readATOMFeed(const list<string>& ilist) {
     const list<value> f = content(xml::readElements(ilist));
-    if (isNil(f))
+    if (isNull(f))
         return mkfailure<list<value> >("Empty feed");
     const list<value> t = elementChildren("title", car(f));
     const list<value> i = elementChildren("id", car(f));
@@ -136,18 +136,18 @@ const list<value> entryElement(const list<value>& l) {
     const value title = elementChild("title", l);
     const value id = elementChild("id", l);
     const value author = elementChild("author", l);
-    const bool email = isNil(author)? false : contains(elementValue(author), "@");
+    const bool email = isNull(author)? false : contains(elementValue(author), "@");
     const value updated = elementChild("updated", l);
     const value content = elementChild("content", l);
-    const bool text = isNil(content)? false : elementHasValue(content);
+    const bool text = isNull(content)? false : elementHasValue(content);
     return nilListValue
         + element + entry + (nilListValue + attribute + "xmlns" + "http://www.w3.org/2005/Atom")
         + (nilListValue + element + "title" + (nilListValue + attribute + "type" + "text") + elementValue(title))
         + (nilListValue + element + "id" + elementValue(id))
-        + (isNil(author)? nilListValue : (nilListValue + element + "author" +
+        + (isNull(author)? nilListValue : (nilListValue + element + "author" +
             (email? (nilListValue + element + "email" + elementValue(author)) : (nilListValue + element + "name" + elementValue(author)))))
-        + (isNil(updated)? nilListValue : (nilListValue + element + "updated" + elementValue(updated)))
-        + (isNil(content)?
+        + (isNull(updated)? nilListValue : (nilListValue + element + "updated" + elementValue(updated)))
+        + (isNull(content)?
             nilListValue :
             append<value>(nilListValue + element + "content" + (nilListValue + attribute + "type" + (text? "text" : "application/xml")),
                 text? mklist<value>(elementValue(content)) : contentElementChildren(content)))
@@ -158,7 +158,7 @@ const list<value> entryElement(const list<value>& l) {
  * Convert a list of element values representing ATOM entries to a list of elements.
  */
 const list<value> entriesElements(const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons<value>(entryElement(car(l)), entriesElements(cdr(l)));
 }
@@ -167,7 +167,7 @@ const list<value> entriesElements(const list<value>& l) {
  * Convert a list of element values representing an ATOM entry to an ATOM entry.
  */
 template<typename R> const failable<R> writeATOMEntry(const lambda<const R(const string&, const R)>& reduce, const R& initial, const list<value>& ll) {
-    const list<value> l = isNil(ll)? ll : (list<value>)car(ll);
+    const list<value> l = isNull(ll)? ll : (list<value>)car(ll);
     return xml::writeElements<R>(reduce, initial, mklist<value>(entryElement(l)));
 }
 
@@ -182,11 +182,11 @@ const failable<list<string> > writeATOMEntry(const list<value>& l) {
  * Convert a list of element values representing an ATOM feed to an ATOM feed.
  */
 template<typename R> const failable<R> writeATOMFeed(const lambda<const R(const string&, const R)>& reduce, const R& initial, const list<value>& ll) {
-    const list<value> l = isNil(ll)? ll : (list<value>)car(ll);
+    const list<value> l = isNull(ll)? ll : (list<value>)car(ll);
     const list<value> lt = elementChildren("title", l);
-    const value t = isNil(lt)? value(emptyString) : elementValue(car(lt));
+    const value t = isNull(lt)? value(emptyString) : elementValue(car(lt));
     const list<value> li = elementChildren("id", l);
-    const value i = isNil(li)? value(emptyString) : elementValue(car(li));
+    const value i = isNull(li)? value(emptyString) : elementValue(car(li));
     const list<value> f = nilListValue
         + element + feed + (nilListValue + attribute + "xmlns" + "http://www.w3.org/2005/Atom")
         + (nilListValue + element + "title" + (nilListValue + attribute + "type" + "text") + t)
@@ -194,11 +194,11 @@ template<typename R> const failable<R> writeATOMFeed(const lambda<const R(const
 
     // Write ATOM entries
     const list<value> le = elementChildren(entry, l);
-    if (isNil(le))
+    if (isNull(le))
         return xml::writeElements<R>(reduce, initial, mklist<value>(f));
 
     // Write a single ATOM entry element with a list of values
-    if (!isNil(le) && !isNil(car(le)) && isList(car<value>(caddr<value>(car(le))))) {
+    if (!isNull(le) && !isNull(car(le)) && isList(car<value>(caddr<value>(car(le))))) {
         const list<value> fe = append(f, entriesElements(caddr<value>(car(le))));
         return xml::writeElements<R>(reduce, initial, mklist<value>(fe));
     }
diff --git a/sca-cpp/trunk/modules/http/http.hpp b/sca-cpp/trunk/modules/http/http.hpp
index cd0eb6c04b..04b0d4e490 100644
--- a/sca-cpp/trunk/modules/http/http.hpp
+++ b/sca-cpp/trunk/modules/http/http.hpp
@@ -367,7 +367,7 @@ public:
  */
 size_t readCallback(void *ptr, size_t size, size_t nmemb, void *data) {
     CURLReadContext& rcx = *(CURLReadContext*)data;
-    if (isNil((const list<string>)rcx.ilist))
+    if (isNull((const list<string>)rcx.ilist))
         return 0;
     const list<string> f(fragment(rcx.ilist, size * nmemb));
     const string s = car(f);
@@ -403,7 +403,7 @@ template<typename R> size_t writeCallback(void *ptr, size_t size, size_t nmemb,
  * a reduce function used to process the response.
  */
 curl_slist* headers(curl_slist* const cl, const list<string>& h) {
-    if (isNil(h))
+    if (isNull(h))
         return cl;
     return headers(curl_slist_append(cl, c_str(string(car(h)))), cdr(h));
 }
@@ -508,7 +508,7 @@ const failable<value> evalExpr(const value& expr, const string& url, const CURLS
  * Find and return a header.
  */
 const maybe<string> header(const char* const prefix, const list<string>& h) {
-    if (isNil(h))
+    if (isNull(h))
         return maybe<string>();
     const string s = car(h);
     if (find(s, prefix) != 0)
@@ -676,7 +676,7 @@ const failable<list<list<string> > > contentRequest(const value& c, unused const
 
     // Write in the format requested by the client, if any
     const list<value> fmt = assoc<value>("format", nilListValue);
-    if (!isNil(fmt)) {
+    if (!isNull(fmt)) {
         if (cadr(fmt) == "scheme")
             return writeRequest(scheme::writeValue(c), "text/x-scheme; charset=utf-8");
         if (cadr(fmt) == "json")
@@ -692,26 +692,26 @@ const failable<list<list<string> > > contentRequest(const value& c, unused const
     }
 
     // Write an empty list as a JSON value
-    if (isNil((list<value>)c)) {
+    if (isNull((list<value>)c)) {
         debug(nilListValue, "http::contentRequest::empty");
         return writeRequest(json::writeValue(c), "application/json; charset=utf-8");
     }
 
     // Write content-type / content-list pair
-    if (isString(car<value>(c)) && !isNil(cdr<value>(c)) && isList(cadr<value>(c)))
+    if (isString(car<value>(c)) && !isNull(cdr<value>(c)) && isList(cadr<value>(c)))
         return writeRequest(convertValues<string>(cadr<value>(c)), car<value>(c));
 
     // Write an assoc value as a JSON value
-    if (isSymbol(car<value>(c)) && !isNil(cdr<value>(c))) {
+    if (isSymbol(car<value>(c)) && !isNull(cdr<value>(c))) {
         debug(c, "http::contentRequest::assoc");
         return writeRequest(json::writeValue(c), "application/json; charset=utf-8");
     }
 
     // Write an ATOM feed or entry
     const list<value> e = valuesToElements(c);
-    if (isList(car<value>(e)) && !isNil(car<value>(e))) {
+    if (isList(car<value>(e)) && !isNull(car<value>(e))) {
         const list<value> el = car<value>(e);
-        if (isSymbol(car<value>(el)) && car<value>(el) == element && !isNil(cdr<value>(el)) && isSymbol(cadr<value>(el)) && elementHasChildren(el) && !elementHasValue(el)) {
+        if (isSymbol(car<value>(el)) && car<value>(el) == element && !isNull(cdr<value>(el)) && isSymbol(cadr<value>(el)) && elementHasChildren(el) && !elementHasValue(el)) {
             if (cadr<value>(el) == atom::feed)
                 return writeRequest(atom::writeATOMFeed(e), "application/atom+xml; charset=utf-8");
             if (cadr<value>(el) == atom::entry)
@@ -943,14 +943,14 @@ const failable<size_t> recv(char* const c, const size_t l, const CURLSession& cs
  * Converts a list of key value pairs to a query string.
  */
 ostringstream& queryString(const list<value>& args, ostringstream& os) {
-    if (isNil(args))
+    if (isNull(args))
         return os;
     const list<value> arg = car(args);
     debug(arg, "http::queryString::arg");
-    if (isNil(arg) || isNil(cdr(arg)))
+    if (isNull(arg) || isNull(cdr(arg)))
         return queryString(cdr(args), os);
     os << car(arg) << "=" << c_str(cadr(arg));
-    if (!isNil(cdr(args)))
+    if (!isNull(cdr(args)))
         os << "&";
     return queryString(cdr(args), os);
 }
diff --git a/sca-cpp/trunk/modules/http/httpd.hpp b/sca-cpp/trunk/modules/http/httpd.hpp
index 255f0aa31b..bf06ed5d91 100644
--- a/sca-cpp/trunk/modules/http/httpd.hpp
+++ b/sca-cpp/trunk/modules/http/httpd.hpp
@@ -260,7 +260,7 @@ const string cookie(const request_rec* const r) {
  * Return the remaining part of a uri after the given path (aka the path info.)
  */
 const list<value> pathInfo(const list<value>& uri, const list<value>& path) {
-    if (isNil(path))
+    if (isNull(path))
         return uri;
     return pathInfo(cdr(uri), cdr(path));
 }
@@ -347,14 +347,14 @@ const list<value> unescapeArgs(const list<value>& args) {
 const value queryArg(const string& s) {
     debug(s, "httpd::queryArg::string");
     const list<string> t = tokenize("=", s);
-    if (isNil(cdr(t)))
+    if (isNull(cdr(t)))
         return mklist<value>(c_str(car(t)), emptyString);
     return mklist<value>(c_str(car(t)), cadr(t));
 }
 
 const string fixupQueryArgs(const string& a) {
     const list<string> t = tokenize("?", a);
-    if (isNil(t) || isNil(cdr(t)))
+    if (isNull(t) || isNull(cdr(t)))
         return a;
     return join("&", t);
 }
@@ -376,7 +376,7 @@ const list<value> queryArgs(const request_rec* const r) {
  * Converts the args received in a POST to a list of key value pairs.
  */
 const list<value> postArgs(const list<value>& a) {
-    if (isNil(a))
+    if (isNull(a))
         return nilListValue;
     const list<value> l = car(a);
     return cons<value>(l, postArgs(cdr(a)));
diff --git a/sca-cpp/trunk/modules/http/mod-openauth.cpp b/sca-cpp/trunk/modules/http/mod-openauth.cpp
index 1b70f27744..3adc488301 100644
--- a/sca-cpp/trunk/modules/http/mod-openauth.cpp
+++ b/sca-cpp/trunk/modules/http/mod-openauth.cpp
@@ -127,7 +127,7 @@ static apr_status_t (*ap_session_set_fn)(request_rec * r, session_rec * z, const
  * Run the authnz hooks to authenticate a request.
  */
 const failable<int> checkAuthnzProviders(const string& user, const string& pw, request_rec* const r, const list<AuthnProviderConf>& apcs) {
-    if(isNil(apcs))
+    if(isNull(apcs))
         return mkfailure<int>("Authentication failure for: " + user, HTTP_UNAUTHORIZED);
     const AuthnProviderConf apc = car<AuthnProviderConf>(apcs);
     if(apc.provider == NULL || !apc.provider->check_password)
@@ -145,7 +145,7 @@ const failable<int> checkAuthnz(const string& user, const string& pw, request_re
     if(substr(user, 0, 1) == "/" && pw == "password")
         return mkfailure<int>(string("Encountered FakeBasicAuth spoof: ") + user, HTTP_UNAUTHORIZED);
 
-    if(isNil((const list<AuthnProviderConf>)dc.apcs)) {
+    if(isNull((const list<AuthnProviderConf>)dc.apcs)) {
         const authn_provider* provider = (const authn_provider*)ap_lookup_provider(AUTHN_PROVIDER_GROUP, AUTHN_DEFAULT_PROVIDER, AUTHN_PROVIDER_VERSION);
         return checkAuthnzProviders(user, pw, r, mklist<AuthnProviderConf>(AuthnProviderConf(AUTHN_DEFAULT_PROVIDER, provider)));
     }
@@ -181,10 +181,10 @@ const failable<value> userInfoFromCookie(const value& sid, const string& realm,
     const list<value> info = httpd::queryArgs(sid);
     debug(info, "modopenauth::userInfoFromCookie::info");
     const list<value> user = assoc<value>(realm + "-user", info);
-    if(isNil(user))
+    if(isNull(user))
         return userInfoFromSession(realm, r);
     const list<value> pw = assoc<value>(realm + "-pw", info);
-    if(isNil(pw))
+    if(isNull(pw))
         return mkfailure<value>("Couldn't retrieve password", HTTP_UNAUTHORIZED);
     return value(mklist<value>(mklist<value>("realm", realm), mklist<value>("id", cadr(user)), mklist<value>("password", cadr(pw))));
 }
@@ -217,12 +217,12 @@ const failable<int> authenticated(const list<value>& info, request_rec* const r)
 
     // Store user info in the request
     const list<value> realm = assoc<value>("realm", info);
-    if(isNil(realm) || isNil(cdr(realm)))
+    if(isNull(realm) || isNull(cdr(realm)))
         return mkfailure<int>("Couldn't retrieve realm", HTTP_UNAUTHORIZED);
     apr_table_set(r->subprocess_env, apr_pstrdup(r->pool, "REALM"), apr_pstrdup(r->pool, c_str(cadr(realm))));
 
     const list<value> id = assoc<value>("id", info);
-    if(isNil(id) || isNil(cdr(id)))
+    if(isNull(id) || isNull(cdr(id)))
         return mkfailure<int>("Couldn't retrieve user id", HTTP_UNAUTHORIZED);
     r->user = apr_pstrdup(r->pool, c_str(cadr(id)));
 
@@ -313,7 +313,7 @@ static int checkAuthn(request_rec* const r) {
     }
 
     // Decline if the request is for another authentication provider
-    if(!isNil(assoc<value>("openid_identifier", args)))
+    if(!isNull(assoc<value>("openid_identifier", args)))
         return DECLINED;
 
     // Redirect to the login page, unless we have a session id from another module
diff --git a/sca-cpp/trunk/modules/http/openauth.hpp b/sca-cpp/trunk/modules/http/openauth.hpp
index 1c49c4254c..70c6f658ad 100644
--- a/sca-cpp/trunk/modules/http/openauth.hpp
+++ b/sca-cpp/trunk/modules/http/openauth.hpp
@@ -49,13 +49,13 @@ const char* const cookieName(const char* const cs) {
 }
 
 const maybe<string> sessionID(const list<string>& c, const string& key) {
-    if (isNil(c))
+    if (isNull(c))
         return maybe<string>();
     const string cn = cookieName(c_str(car(c)));
     const size_t i = find(cn, "=");
     if (i < length(cn)) {
         const list<string> kv = mklist<string>(substr(cn, 0, i), substr(cn, i+1));
-        if (!isNil(kv) && !isNil(cdr(kv))) {
+        if (!isNull(kv) && !isNull(cdr(kv))) {
             if (car(kv) == key)
                 return cadr(kv);
         }
@@ -92,10 +92,10 @@ const string cookie(const string& key, const string& sid, const string& domain)
  * Redirect to the configured login page.
  */
 const failable<int> login(const string& page, const value& ref, const value& attempt, request_rec* const r) {
-    const list<value> rarg = ref == string("/")? nilListValue : mklist<value>(mklist<value>("openauth_referrer", httpd::escape(httpd::url(isNil(ref)? r->uri : ref, r))));
-    const list<value> aarg = isNil(attempt)? nilListValue : mklist<value>(mklist<value>("openauth_attempt", attempt));
+    const list<value> rarg = ref == string("/")? nilListValue : mklist<value>(mklist<value>("openauth_referrer", httpd::escape(httpd::url(isNull(ref)? r->uri : ref, r))));
+    const list<value> aarg = isNull(attempt)? nilListValue : mklist<value>(mklist<value>("openauth_attempt", attempt));
     const list<value> largs = append(rarg, aarg);
-    const string loc = isNil(largs)? httpd::url(page, r) : httpd::url(page, r) + string("?") + http::queryString(largs);
+    const string loc = isNull(largs)? httpd::url(page, r) : httpd::url(page, r) + string("?") + http::queryString(largs);
     debug(loc, "openauth::login::uri");
     return httpd::externalRedirect(loc, r);
 }
diff --git a/sca-cpp/trunk/modules/java/driver.hpp b/sca-cpp/trunk/modules/java/driver.hpp
index 4ffc84f4db..a8d162249c 100644
--- a/sca-cpp/trunk/modules/java/driver.hpp
+++ b/sca-cpp/trunk/modules/java/driver.hpp
@@ -38,7 +38,7 @@ namespace java {
 const value evalDriverLoop(const JavaRuntime& jr, const JavaClass jc, istream& in, ostream& out) {
     scheme::promptForInput(scheme::evalInputPrompt, out);
     const value input = content(scheme::readValue(in));
-    if (isNil(input))
+    if (isNull(input))
         return input;
     const failable<value> output = evalClass(jr, input, jc);
     scheme::announceOutput(scheme::evalOutputPrompt, out);
diff --git a/sca-cpp/trunk/modules/java/eval.hpp b/sca-cpp/trunk/modules/java/eval.hpp
index 2c76b764fa..407e3d2a59 100644
--- a/sca-cpp/trunk/modules/java/eval.hpp
+++ b/sca-cpp/trunk/modules/java/eval.hpp
@@ -132,7 +132,7 @@ public:
         h.invokerLambda = h.env->GetFieldID(h.invokerClass, "lambda", "J");
         h.iterableUtilClass = h.env->FindClass("org/apache/tuscany/IterableUtil");
         h.iterableValueOf = h.env->GetStaticMethodID(h.iterableUtilClass, "list", "([Ljava/lang/Object;)Ljava/lang/Iterable;");
-        h.iterableIsNil = h.env->GetStaticMethodID(h.iterableUtilClass, "isNil", "(Ljava/lang/Object;)Z");
+        h.iterableIsNil = h.env->GetStaticMethodID(h.iterableUtilClass, "isNull", "(Ljava/lang/Object;)Z");
         h.iterableCar = h.env->GetStaticMethodID(h.iterableUtilClass, "car", "(Ljava/lang/Object;)Ljava/lang/Object;");
         h.iterableCdr = h.env->GetStaticMethodID(h.iterableUtilClass, "cdr", "(Ljava/lang/Object;)Ljava/lang/Iterable;");
         h.uuidClass = h.env->FindClass("org/apache/tuscany/UUIDUtil");
@@ -257,7 +257,7 @@ public:
     }
 
     const value operator()(const list<value>& expr) const {
-        if (isNil(expr))
+        if (isNull(expr))
             return func(expr);
         const value& op(car(expr));
         if (op == "equals")
@@ -331,7 +331,7 @@ const jobject mkJavaLambda(const JavaRuntime& jr, unused const value& iface, con
  * Convert a list of values to a Java jobjectArray.
  */
 const jobjectArray valuesToJarrayHelper(const JavaRuntime& jr, jobjectArray a, const list<value>& v, const int i) {
-    if (isNil(v))
+    if (isNull(v))
         return a;
     jr.h.env->SetObjectArrayElement(a, i, valueToJobject(jr, nilValue, car(v)));
     return valuesToJarrayHelper(jr, a, cdr(v), i + 1);
@@ -375,7 +375,7 @@ const jobject valueToJobject(const JavaRuntime& jr, const value& jtype, const va
  * Convert a list of values to an array of jvalues.
  */
 const jvalue* valuesToJvaluesHelper(const JavaRuntime& jr, jvalue* const a, const list<value>& types, const list<value>& v) {
-    if (isNil(v))
+    if (isNull(v))
         return a;
     a->l = valueToJobject(jr, car(types), car(v));
     return valuesToJvaluesHelper(jr, a + 1, cdr(types), cdr(v));
@@ -542,7 +542,7 @@ const failable<value> evalClass(const JavaRuntime& jr, const value& expr, const
 
     // Lookup the Java function named as the expression operand
     const list<value> func = assoc<value>(car<value>(expr), jc.m);
-    if (isNil(func)) {
+    if (isNull(func)) {
 
         // The start, stop, and restart functions are optional
         const value fn = car<value>(expr);
diff --git a/sca-cpp/trunk/modules/java/org/apache/tuscany/IterableUtil.java b/sca-cpp/trunk/modules/java/org/apache/tuscany/IterableUtil.java
index 2366d79af6..58bb18cf72 100644
--- a/sca-cpp/trunk/modules/java/org/apache/tuscany/IterableUtil.java
+++ b/sca-cpp/trunk/modules/java/org/apache/tuscany/IterableUtil.java
@@ -61,9 +61,9 @@ public class IterableUtil {
     /**
      * Return true if a list is nil (empty).
      */
-    public static boolean isNil(final Object l) {
+    public static boolean isNull(final Object l) {
         if(l instanceof BasicIterable<?>)
-            return ((BasicIterable<?>)l).isNil();
+            return ((BasicIterable<?>)l).isNull();
         if(l instanceof Collection<?>)
             return ((Collection<?>)l).isEmpty();
         return !((Iterable<?>)l).iterator().hasNext();
@@ -144,7 +144,7 @@ public class IterableUtil {
      */
     @SuppressWarnings("unchecked")
     public static <T> Iterable<T> append(final Object a, final Object b) {
-        if (isNil(a))
+        if (isNull(a))
             return (Iterable<T>)b;
         return cons(car(a), append(cdr(a), b));
     }
@@ -153,7 +153,7 @@ public class IterableUtil {
      * Return the first pair matching a key from a list of key value pairs.
      */
     public static <T> Iterable<T> assoc(final Object k, final Object l) {
-        if(isNil(l))
+        if(isNull(l))
             return list();
         if(k.equals(car(car(l))))
             return car(l);
@@ -168,11 +168,11 @@ public class IterableUtil {
 
         abstract Iterable<T> cdr();
 
-        abstract Boolean isNil();
+        abstract Boolean isNull();
 
         @Override
         public int size() {
-            return this.isNil()? 0 : 1 + ((List<T>)this.cdr()).size();
+            return this.isNull()? 0 : 1 + ((List<T>)this.cdr()).size();
         }
 
         @Override
@@ -194,7 +194,7 @@ public class IterableUtil {
         }
 
         @Override
-        Boolean isNil() {
+        Boolean isNull() {
             return this.a.length - this.start == 0;
         }
 
@@ -243,7 +243,7 @@ public class IterableUtil {
         }
 
         @Override
-        Boolean isNil() {
+        Boolean isNull() {
             return this.l.size() - this.start == 0;
         }
 
@@ -292,7 +292,7 @@ public class IterableUtil {
         }
 
         @Override
-        Boolean isNil() {
+        Boolean isNull() {
             return false;
         }
 
@@ -365,12 +365,12 @@ public class IterableUtil {
             assert jl.get(2) == Integer.valueOf(2);
 
             final Iterable<Object> n = list();
-            assert isNil(n);
+            assert isNull(n);
             assert n.toString().equals("[]");
 
             final Iterable<Object> cn = cons(0, n);
-            assert !isNil(cn);
-            assert isNil(cdr(cn));
+            assert !isNull(cn);
+            assert isNull(cdr(cn));
             assert cn.toString().equals("[0]");
 
             final Iterable<Object> al = new ArrayList<Object>(Arrays.asList(1, 2, 3));
diff --git a/sca-cpp/trunk/modules/java/test/ServerImpl.java b/sca-cpp/trunk/modules/java/test/ServerImpl.java
index 4499681f78..8a6f0e95c9 100644
--- a/sca-cpp/trunk/modules/java/test/ServerImpl.java
+++ b/sca-cpp/trunk/modules/java/test/ServerImpl.java
@@ -28,7 +28,7 @@ public class ServerImpl {
     }
 
     public Iterable<?> get(final Iterable<String> id) {
-        if (isNil(id))
+        if (isNull(id))
             return list(list("'feed", list("'title", "Sample Feed"), list("'id", "123456789"), list("'entry", list(
                     list(list("'title", "Item"), list("'id", "111"),
                         list("'content", list("'item", list("'name", "Apple"), list("'currencyCode", "USD"), list("'currencySymbol", "$"), list("'price", 2.99)))),
diff --git a/sca-cpp/trunk/modules/js/htdocs/atomutil.js b/sca-cpp/trunk/modules/js/htdocs/atomutil.js
index 3d4e9d08d2..4b57b36fb4 100644
--- a/sca-cpp/trunk/modules/js/htdocs/atomutil.js
+++ b/sca-cpp/trunk/modules/js/htdocs/atomutil.js
@@ -27,22 +27,22 @@ var atom = {};
  */
 atom.entryElementValues = function(e) {
     var lt = filter(selector(mklist(element, "'title")), e);
-    var t = mklist(element, "'title", isNil(lt)? '' : elementValue(car(lt)));
+    var t = mklist(element, "'title", isNull(lt)? '' : elementValue(car(lt)));
 
     var li = filter(selector(mklist(element, "'id")), e);
-    var i = mklist(element, "'id", isNil(li)? '' : elementValue(car(li)));
+    var i = mklist(element, "'id", isNull(li)? '' : elementValue(car(li)));
 
     var la = filter(selector(mklist(element, "'author")), e);
-    var lan = isNil(la)? mklist() : filter(selector(mklist(element, "'name")), car(la));
-    var lae = isNil(la)? mklist() : filter(selector(mklist(element, "'email")), car(la));
-    var laa = isNil(lan)? lae : lan;
-    var a = isNil(laa)? mklist() : mklist(mklist(element, "'author", elementValue(car(laa))));
+    var lan = isNull(la)? mklist() : filter(selector(mklist(element, "'name")), car(la));
+    var lae = isNull(la)? mklist() : filter(selector(mklist(element, "'email")), car(la));
+    var laa = isNull(lan)? lae : lan;
+    var a = isNull(laa)? mklist() : mklist(mklist(element, "'author", elementValue(car(laa))));
 
     var lu = filter(selector(mklist(element, "'updated")), e);
-    var u = isNil(lu)? mklist() : mklist(mklist(element, "'updated", elementValue(car(lu))));
+    var u = isNull(lu)? mklist() : mklist(mklist(element, "'updated", elementValue(car(lu))));
 
     var lc = filter(selector(mklist(element, "'content")), e);
-    var c = isNil(lc)? mklist() : isAttribute(elementValue(car(lc)))? mklist() : mklist(mklist(element, "'content", elementValue(car(lc))));
+    var c = isNull(lc)? mklist() : isAttribute(elementValue(car(lc)))? mklist() : mklist(mklist(element, "'content", elementValue(car(lc))));
 
     return append(append(append(mklist(element, "'entry", t, i), a), u), c);
 };
@@ -51,7 +51,7 @@ atom.entryElementValues = function(e) {
  * Convert a list of elements to a list of values representing ATOM entries.
  */
 atom.entriesElementValues = function(e) {
-    if (isNil(e))
+    if (isNull(e))
         return e;
     return cons(atom.entryElementValues(car(e)), atom.entriesElementValues(cdr(e)));
 };
@@ -70,7 +70,7 @@ atom.isATOMEntry = function(l) {
  */
 atom.readATOMEntryDocument = function(doc) {
     var e = readXMLDocument(doc);
-    if (isNil(e))
+    if (isNull(e))
         return mklist();
     return mklist(atom.entryElementValues(car(e)));
 };
@@ -96,7 +96,7 @@ atom.isATOMFeed = function(l) {
  */
 atom.readATOMFeedDocument = function(doc) {
     var f = readXMLDocument(doc);
-    if (isNil(f))
+    if (isNull(f))
         return mklist();
     var t = filter(selector(mklist(element, "'title")), car(f));
     var i = filter(selector(mklist(element, "'id")), car(f));
@@ -120,17 +120,17 @@ atom.entryElement = function(l) {
     var title = elementValue(namedElementChild("'title", l));
     var id = elementValue(namedElementChild("'id", l));
     var author = namedElementChild("'author", l);
-    var email = isNil(author)? false : (elementValue(author).indexOf('@') != -1);
+    var email = isNull(author)? false : (elementValue(author).indexOf('@') != -1);
     var updated = namedElementChild("'updated", l);
     var content = namedElementChild("'content", l);
-    var text = isNil(content)? false : elementHasValue(content);
+    var text = isNull(content)? false : elementHasValue(content);
     return append(append(append(append(
             mklist(element, "'entry", mklist(attribute, "'xmlns", "http://www.w3.org/2005/Atom"),
                 mklist(element, "'title", mklist(attribute, "'type", "text"), title), mklist(element, "'id", id)),
-                isNil(author)? mklist() : mklist(mklist(element, "'author",
+                isNull(author)? mklist() : mklist(mklist(element, "'author",
                     (email? mklist(element, "'email", elementValue(author)) : mklist(element, "'name", elementValue(author)))))),
-                isNil(updated)? mklist() : mklist(mklist(element, "'updated", elementValue(updated)))),
-                isNil(content)? mklist() :
+                isNull(updated)? mklist() : mklist(mklist(element, "'updated", elementValue(updated)))),
+                isNull(content)? mklist() :
                     mklist(append(mklist(element, "'content", mklist(attribute, "'type", text? "text" : "application/xml")),
                         text? mklist(elementValue(content)) : elementChildren(content)))),
                 mklist(mklist(element, "'link", mklist(attribute, "'href", id))));
@@ -140,7 +140,7 @@ atom.entryElement = function(l) {
  * Convert a list of values representing ATOM entries to a list of elements.
  */
 atom.entriesElements = function(l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons(atom.entryElement(car(l)), atom.entriesElements(cdr(l)));
 };
@@ -149,7 +149,7 @@ atom.entriesElements = function(l) {
  * Convert a list of values representing an ATOM entry to an ATOM entry.
  */
 atom.writeATOMEntry = function(ll) {
-    var l = isNil(ll)? ll : car(ll);
+    var l = isNull(ll)? ll : car(ll);
     return writeXML(mklist(atom.entryElement(l)), true);
 };
 
@@ -157,22 +157,22 @@ atom.writeATOMEntry = function(ll) {
  * Convert a list of values representing an ATOM feed to an ATOM feed.
  */
 atom.writeATOMFeed = function(ll) {
-    var l = isNil(ll)? ll : car(ll);
+    var l = isNull(ll)? ll : car(ll);
     var lt = filter(selector(mklist(element, "'title")), l);
-    var t = isNil(lt)? '' : elementValue(car(lt));
+    var t = isNull(lt)? '' : elementValue(car(lt));
     var li = filter(selector(mklist(element, "'id")), l);
-    var i = isNil(li)? '' : elementValue(car(li));
+    var i = isNull(li)? '' : elementValue(car(li));
     var f = mklist(element, "'feed", mklist(attribute, "'xmlns", "http://www.w3.org/2005/Atom"),
             mklist(element, "'title", mklist(attribute, "'type", "text"), car(l)),
             mklist(element, "'id", cadr(l)));
 
     // Write ATOM entries
     var le = filter(selector(mklist(element, "'entry")), l);
-    if (isNil(le))
+    if (isNull(le))
         return writeXML(mklist(f), true);
 
     // Write a single ATOM entry element with a list of values
-    if (!isNil(le) && !isNil(car(le)) && isList(car(caddr(car(le))))) {
+    if (!isNull(le) && !isNull(car(le)) && isList(car(caddr(car(le))))) {
         var fe = append(f, atom.entriesElements(caddr(car(le))));
         return writeXML(mklist(fe), true);
     }
diff --git a/sca-cpp/trunk/modules/js/htdocs/elemutil.js b/sca-cpp/trunk/modules/js/htdocs/elemutil.js
index 37d641f7b3..62050f5953 100644
--- a/sca-cpp/trunk/modules/js/htdocs/elemutil.js
+++ b/sca-cpp/trunk/modules/js/htdocs/elemutil.js
@@ -29,14 +29,14 @@ var atsign = "'@"
  * Return true if a value is an element.
  */
 function isElement(v) {
-    return (!(!isList(v) || isNil(v) || car(v) != element));
+    return (!(!isList(v) || isNull(v) || car(v) != element));
 }
 
 /**
  * Return true if a value is an attribute.
  */
 function isAttribute(v) {
-    return (!(!isList(v) || isNil(v) || car(v) != attribute));
+    return (!(!isList(v) || isNull(v) || car(v) != attribute));
 }
 
 /**
@@ -58,7 +58,7 @@ elementName = cadr;
  * Return true if an element has children.
  */
 function elementHasChildren(l) {
-    return !isNil(cddr(l));
+    return !isNull(cddr(l));
 }
 
 /**
@@ -73,7 +73,7 @@ function elementHasValue(l) {
     var r = reverse(l);
     if (isSymbol(car(r)))
         return false;
-    return (!(isList(car(r)) && !isNil(car(r)) && isSymbol(car(car(r)))))
+    return (!(isList(car(r)) && !isNull(car(r)) && isSymbol(car(car(r)))))
 }
 
 /**
@@ -89,7 +89,7 @@ function elementValue(l) {
 function elementToValueIsList(v) {
     if (!isList(v))
         return false;
-    return isNil(v) || !isSymbol(car(v));
+    return isNull(v) || !isSymbol(car(v));
 }
 
 function elementToValue(t) {
@@ -112,11 +112,11 @@ function elementToValue(t) {
  * Convert a list of elements to a list of values.
  */
 function elementToValueIsSymbol(v) {
-    return (!(!isList(v)) || isNil(v) || !isSymbol(car(v)));
+    return (!(!isList(v)) || isNull(v) || !isSymbol(car(v)));
 }
 
 function elementToValueGroupValues(v, l) {
-    if (isNil(l) || !elementToValueIsSymbol(v) || !elementToValueIsSymbol(car(l)))
+    if (isNull(l) || !elementToValueIsSymbol(v) || !elementToValueIsSymbol(car(l)))
         return cons(v, l);
     if (car(car(l)) != car(v))
         return cons(v, l);
@@ -129,7 +129,7 @@ function elementToValueGroupValues(v, l) {
 }
 
 function elementsToValues(e) {
-    if (isNil(e))
+    if (isNull(e))
         return e;
     return elementToValueGroupValues(elementToValue(car(e)), elementsToValues(cdr(e)));
 }
@@ -138,15 +138,15 @@ function elementsToValues(e) {
  * Convert a value to an element.
  */
 function valueToElement(t) {
-    if (isList(t) && !isNil(t) && isSymbol(car(t))) {
+    if (isList(t) && !isNull(t) && isSymbol(car(t))) {
         var n = car(t);
-        var v = isNil(cdr(t))? mklist() : cadr(t);
+        var v = isNull(cdr(t))? mklist() : cadr(t);
         if (!isList(v)) {
             if (n.substring(0, 2) == atsign)
                 return mklist(attribute, "'" + n.substring(2), v);
             return mklist(element, n, v);
         }
-        if (isNil(v) || !isSymbol(car(v)))
+        if (isNull(v) || !isSymbol(car(v)))
             return cons(element, cons(n, mklist(valuesToElements(v))));
         return cons(element, cons(n, valuesToElements(cdr(t))));
     }
@@ -159,7 +159,7 @@ function valueToElement(t) {
  * Convert a list of values to a list of elements.
  */
 function valuesToElements(l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons(valueToElement(car(l)), valuesToElements(cdr(l)));
 }
@@ -169,9 +169,9 @@ function valuesToElements(l) {
  */
 function selector(s) {
     function evalSelect(s, v) {
-        if (isNil(s))
+        if (isNull(s))
             return true;
-        if (isNil(v))
+        if (isNull(v))
             return false;
         if (car(s) != car(v))
             return false;
@@ -187,7 +187,7 @@ function selector(s) {
 function namedAttribute(name, l) {
     return memo(l, name, function() {
         var f = filter(function(v) { return isAttribute(v) && attributeName(v) == name; }, l);
-        if (isNil(f))
+        if (isNull(f))
             return null;
         return car(f);
     });
@@ -217,7 +217,7 @@ function namedElementChildren(name, l) {
  */
 function namedElementChild(name, l) {
     var f = namedElementChildren(name, l);
-    if (isNil(f))
+    if (isNull(f))
         return null;
     return car(f);
 }
diff --git a/sca-cpp/trunk/modules/js/htdocs/jsonutil.js b/sca-cpp/trunk/modules/js/htdocs/jsonutil.js
index 8aa291bc89..9960a5d82f 100644
--- a/sca-cpp/trunk/modules/js/htdocs/jsonutil.js
+++ b/sca-cpp/trunk/modules/js/htdocs/jsonutil.js
@@ -41,13 +41,13 @@ json.Exception.prototype.toString = function() {
  * Return true if a list represents a JS array.
  */
 json.isJSArray = function(l) {
-    if (isNil(l))
+    if (isNull(l))
         return true;
     var v = car(l);
     if (isSymbol(v))
         return false;
     if (isList(v))
-        if (!isNil(v) && isSymbol(car(v)))
+        if (!isNull(v) && isSymbol(car(v)))
             return false;
     return true;
 };
@@ -56,7 +56,7 @@ json.isJSArray = function(l) {
  * Converts JSON properties to values.
  */
 json.jsPropertiesToValues = function(propertiesSoFar, o, i) {
-    if (isNil(i))
+    if (isNull(i))
         return propertiesSoFar;
     var p = car(i);
     var jsv = o[p];
@@ -92,7 +92,7 @@ json.jsValToValue = function(jsv) {
  * Return true if a list of strings contains a JSON document.
  */
 json.isJSON = function(l) {
-    if (isNil(l))
+    if (isNull(l))
         return false;
     var s = car(l).slice(0, 1);
     return s == "[" || s == "{";
@@ -112,7 +112,7 @@ json.readJSON = function(l) {
  * Convert a list of values to JSON array elements.
  */
 json.valuesToJSElements = function(a, l, i) {
-    if (isNil(l))
+    if (isNull(l))
         return a;
     var pv = json.valueToJSVal(car(l));
     a[i] = pv
@@ -134,7 +134,7 @@ json.valueToJSVal = function(v) {
  * Convert a list of values to JSON properties.
  */
 json.valuesToJSProperties = function(o, l) {
-    if (isNil(l))
+    if (isNull(l))
         return o;
     var token = car(l);
     if (isTaggedList(token, attribute)) {
diff --git a/sca-cpp/trunk/modules/js/htdocs/scdl.js b/sca-cpp/trunk/modules/js/htdocs/scdl.js
index 50dab53e7c..fd0e08035f 100644
--- a/sca-cpp/trunk/modules/js/htdocs/scdl.js
+++ b/sca-cpp/trunk/modules/js/htdocs/scdl.js
@@ -27,7 +27,7 @@ var scdl = {};
  */
 scdl.composite = function(l) {
     var cs = namedElementChildren("'composite", l);
-    if (isNil(cs))
+    if (isNull(cs))
         return cs;
     return car(cs);
 };
@@ -37,7 +37,7 @@ scdl.composite = function(l) {
  */
 scdl.components = function(l) {
     var cs = namedElementChildren("'composite", l);
-    if (isNil(cs))
+    if (isNull(cs))
         return cs;
     return namedElementChildren("'component", car(cs));
 };
@@ -47,7 +47,7 @@ scdl.components = function(l) {
  */
 scdl.promotions = function(l) {
     var cs = namedElementChildren("'composite", l);
-    if (isNil(cs))
+    if (isNull(cs))
         return cs;
     return namedElementChildren("'service", car(cs));
 };
@@ -57,7 +57,7 @@ scdl.promotions = function(l) {
  */
 scdl.promote = function(l) {
     var puri = namedAttributeValue("'promote", l);
-    if (isNil(puri))
+    if (isNull(puri))
         return puri;
     return car(tokens(puri));
 };
@@ -74,7 +74,7 @@ scdl.name = function(l) {
  */
 scdl.documentation = function(l) {
     var d = namedElementChildren("'documentation", l);
-    if (isNil(d))
+    if (isNull(d))
         return null;
     if (!elementHasValue(car(d)))
         return null;
@@ -126,7 +126,7 @@ scdl.implementation = function(l) {
     }
 
     var n = filter(filterImplementation, l);
-    if (isNil(n))
+    if (isNull(n))
         return null;
     return car(n);
 };
@@ -204,21 +204,21 @@ scdl.bindingType = function(l) {
 scdl.target = function(l) {
     function targetURI() {
         function bindingsTarget(l) {
-            if (isNil(l))
+            if (isNull(l))
                 return null;
             var u = scdl.uri(car(l));
-            if (!isNil(u))
+            if (!isNull(u))
                 return u;
             return bindingsTarget(cdr(l));
         }
     
         var t = namedAttributeValue("'target", l);
-        if (!isNil(t))
+        if (!isNull(t))
             return t;
         return bindingsTarget(scdl.bindings(l));
     }
     var turi = targetURI();
-    if (isNil(turi))
+    if (isNull(turi))
         return turi;
     return car(tokens(turi));
 };
@@ -243,7 +243,7 @@ scdl.propertyValue = function(l) {
  * Convert a list of elements to a name -> element assoc list.
  */
 scdl.nameToElementAssoc = function(l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons(mklist(scdl.name(car(l)), car(l)), scdl.nameToElementAssoc(cdr(l)));
 };
diff --git a/sca-cpp/trunk/modules/js/htdocs/ui.js b/sca-cpp/trunk/modules/js/htdocs/ui.js
index 0c80b92bcf..3aa9e1052a 100644
--- a/sca-cpp/trunk/modules/js/htdocs/ui.js
+++ b/sca-cpp/trunk/modules/js/htdocs/ui.js
@@ -31,7 +31,7 @@ ui.elementByID = function(node, id) {
         return null;
     for (var i in node.childNodes) {
         var child = node.childNodes[i];
-        if (isNil(child))
+        if (isNull(child))
             continue;
         if (child.id == id)
             return child;
@@ -275,7 +275,7 @@ ui.msieVersion = function() {
  */
 ui.asyncFrame = null;
 ui.async = function(f) {
-    if (isNil(ui.asyncFrame))
+    if (isNull(ui.asyncFrame))
         // Use requestAnimationFrame when available, fallback to setTimeout
         ui.asyncFrame = window.requestAnimationFrame || window.webkitRequestAnimationFrame ||
             window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
@@ -293,7 +293,7 @@ ui.delay = function(f, t) {
     var id =  window.setTimeout(function() {
         delete ui.delayed[id];
         return f();
-    }, isNil(t)? 16 : t);
+    }, isNull(t)? 16 : t);
     ui.delayed[id] = id;
     return id;
 };
@@ -311,12 +311,12 @@ ui.cancelDelay = function(id) {
  */
 ui.animationFrame = null;
 ui.animation = function(f) {
-    if (isNil(ui.animationFrame))
+    if (isNull(ui.animationFrame))
         // Use requestAnimationFrame when available, fallback to setInterval
         ui.animationFrame = window.requestAnimationFrame || window.webkitRequestAnimationFrame ||
             window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
             function(f) {
-                if (!('interval' in f) || isNil(f.interval)) {
+                if (!('interval' in f) || isNull(f.interval)) {
                     // First call, setup the interval
                     f.interval = window.setInterval(function animation() {
                         f.clearInterval = true;
@@ -370,7 +370,7 @@ ui.onload = function() {
     } else {
         // Style scroll bars
         var h = document.getElementsByTagName('html');
-        if (!isNil(h))
+        if (!isNull(h))
             h[0].className = h[0].className? h[0].classname + ' flatscrollbars' : 'flatscrollbars';
     }
 
@@ -393,7 +393,7 @@ ui.onload = function() {
 ui.onorientationchange = function(e) {
 
     // Adjust filler height
-    if (!isNil(ui.filler))
+    if (!isNull(ui.filler))
         ui.filler.style.height = ui.pixpos(window.orientation == 0? screen.height : screen.width);
 
     // Scroll to hide the address bar
@@ -524,7 +524,7 @@ ui.datatable = function(l) {
     }
 
     function rows(l, i) {
-        if (isNil(l))
+        if (isNull(l))
             return '';
         var e = car(l);
 
@@ -564,7 +564,7 @@ ui.datatable = function(l) {
 ui.datalist = function(l) {
 
     function rows(l, i) {
-        if (isNil(l))
+        if (isNull(l))
             return '';
         var e = car(l);
 
diff --git a/sca-cpp/trunk/modules/js/htdocs/util.js b/sca-cpp/trunk/modules/js/htdocs/util.js
index 1cf086c60e..a8fec3994d 100644
--- a/sca-cpp/trunk/modules/js/htdocs/util.js
+++ b/sca-cpp/trunk/modules/js/htdocs/util.js
@@ -81,7 +81,7 @@ function range(a, b) {
     return l;
 }
 
-function isNil(v) {
+function isNull(v) {
     return (v == null || typeof v == 'undefined' || (v.constructor == Array && v.length == 0));
 }
 
@@ -98,7 +98,7 @@ function isList(v) {
 }
 
 function isTaggedList(v, t) {
-    return (isList(v) && !isNil(v) && car(v) == t);
+    return (isList(v) && !isNull(v) && car(v) == t);
 }
 
 var emptylist = new Array();
@@ -120,7 +120,7 @@ function length(l) {
  * Scheme-like associations.
  */
 function assoc(k, l) {
-    if (isNil(l))
+    if (isNull(l))
         return emptylist;
     var n = l.length;
     for(var i = 0; i < n; i++) {
@@ -134,7 +134,7 @@ function assoc(k, l) {
  * Map, filter and reduce functions.
  */
 function map(f, l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     var n = l.length;
     var a = new Array();
@@ -145,7 +145,7 @@ function map(f, l) {
 }
 
 function filter(f, l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     var n = l.length;
     var a = new Array();
@@ -157,7 +157,7 @@ function filter(f, l) {
 }
 
 function reduce(f, i, l) {
-    if (isNil(l))
+    if (isNull(l))
         return i;
     return reduce(f, f(i, car(l)), cdr(l));
 }
@@ -223,7 +223,7 @@ function isIE() {
  * External build configuration.
  */
 var config;
-if (isNil(config))
+if (isNull(config))
     config = {};
 
 /**
@@ -245,7 +245,7 @@ function assert(exp) {
  * Write a list of strings.
  */
 function writeStrings(l) {
-    if (isNil(l))
+    if (isNull(l))
         return '';
     var s = '';
     var n = l.length;
@@ -268,14 +268,14 @@ function writeValue(v) {
     }
 
     function writeList(l) {
-        if (isNil(l))
+        if (isNull(l))
             return '';
         return ' ' + writeValue(car(l)) + writeList(cdr(l));
     }
 
     if (!isList(v))
         return writePrimitive(v);
-    if (isNil(v))
+    if (isNull(v))
         return '()';
     return '(' + writeValue(car(v)) + writeList(cdr(v)) + ')';
 }
@@ -403,7 +403,7 @@ function domainname(host) {
     if (s != -1)
         return domainname(host.substring(0, s));
     var h = reverse(host.split('.'));
-    var d = (!isNil(cddr(h)) && caddr(h) == 'www')? mklist(car(h), cadr(h), caddr(h)) : mklist(car(h), cadr(h));
+    var d = (!isNull(cddr(h)) && caddr(h) == 'www')? mklist(car(h), cadr(h), caddr(h)) : mklist(car(h), cadr(h));
     return reverse(d).join('.');
 }
 
@@ -536,7 +536,7 @@ function setcaddr(l, v) {
  * Append the elements of a list to a list.
  */
 function setappend(a, b) {
-    if (isNil(b))
+    if (isNull(b))
         return a;
     a.push(car(b));
     return setappend(a, cdr(b));
diff --git a/sca-cpp/trunk/modules/js/htdocs/xmlutil.js b/sca-cpp/trunk/modules/js/htdocs/xmlutil.js
index 4d943cce75..29240dff9c 100644
--- a/sca-cpp/trunk/modules/js/htdocs/xmlutil.js
+++ b/sca-cpp/trunk/modules/js/htdocs/xmlutil.js
@@ -26,7 +26,7 @@
  */
 function nodeList(n) {
     var l = new Array();
-    if (isNil(n))
+    if (isNull(n))
         return l;
     for (var i = 0; i < n.length; i++)
         l[i] = n[i];
@@ -37,7 +37,7 @@ function nodeList(n) {
  * Append a list of nodes to a parent node.
  */
 function appendNodes(nodes, p) {
-    if (isNil(nodes))
+    if (isNull(nodes))
         return p;
     p.appendChild(car(nodes));
     return appendNodes(cdr(nodes), p);
@@ -71,7 +71,7 @@ function childText(e) {
  * Read a list of XML attributes.
  */
 function readAttributes(p, a) {
-    if (isNil(a))
+    if (isNull(a))
         return a;
     var x = car(a);
     return cons(mklist(attribute, "'" + x.nodeName, x.nodeValue), readAttributes(p, cdr(a)));
@@ -83,7 +83,7 @@ function readAttributes(p, a) {
 function readElement(e, childf) {
     var l = append(append(mklist(element, "'" + e.nodeName), readAttributes(e, childf(e))), readElements(childElements(e), childf));
     var t = childText(e);
-    if (isNil(t))
+    if (isNull(t))
         return l;
     return append(l, mklist(car(t).nodeValue));
 }
@@ -92,7 +92,7 @@ function readElement(e, childf) {
  * Read a list of XML elements.
  */
 function readElements(l, childf) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons(readElement(car(l), childf), readElements(cdr(l), childf));
 }
@@ -101,7 +101,7 @@ function readElements(l, childf) {
  * Return true if a list of strings contains an XML document.
  */
 function isXML(l) {
-    if (isNil(l))
+    if (isNull(l))
         return false;
     return car(l).substring(0, 5) == '<?xml';
 }
@@ -120,7 +120,7 @@ function parseXML(l) {
  */
 function readXMLDocument(doc) {
     var root = childElements(doc);
-    if (isNil(root))
+    if (isNull(root))
         return mklist();
     return mklist(readElement(car(root), childAttributes));
 }
@@ -133,7 +133,7 @@ function readXHTMLElement(xhtml) {
     function ieChildAttributes(e) {
         var a = filter(function(n) {
             // Filter out empty and internal DOM attributes
-            if (n.nodeType != 2 || isNil(n.nodeValue) || n.nodeValue == '')
+            if (n.nodeType != 2 || isNull(n.nodeValue) || n.nodeValue == '')
                 return false;
             if (n.nodeName == 'contentEditable' || n.nodeName == 'maxLength' || n.nodeName == 'loop' || n.nodeName == 'start')
                 return false;
@@ -174,13 +174,13 @@ function writeXMLDocument(doc) {
  * Write a list of XML element and attribute tokens.
  */
 function expandElementValues(n, l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons(cons(element, cons(n, car(l))), expandElementValues(n, cdr(l)));
 }
 
 function writeList(l, node, doc) {
-    if (isNil(l))
+    if (isNull(l))
         return node;
 
     var token = car(l);
@@ -196,7 +196,7 @@ function writeList(l, node, doc) {
 
         function mkelem(tok, doc) {
             function xmlns(l) {
-                if (isNil(l))
+                if (isNull(l))
                     return null;
                 var t = car(l);
                 if (isTaggedList(t, attribute)) {
diff --git a/sca-cpp/trunk/modules/json/json.hpp b/sca-cpp/trunk/modules/json/json.hpp
index 497624070b..caef19b835 100644
--- a/sca-cpp/trunk/modules/json/json.hpp
+++ b/sca-cpp/trunk/modules/json/json.hpp
@@ -58,13 +58,13 @@ public:
  * Returns true if a list represents a JS array.
  */
 inline const bool isJSArray(const list<value>& l) {
-    if(isNil(l))
+    if(isNull(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)))
+        if(!isNull((list<value>)v) && isSymbol(car<value>(v)))
             return false;
     }
     return true;
@@ -94,7 +94,7 @@ inline const list<value> jsPropertiesToValues(const list<value>& propertiesSoFar
     const char* const name = json_object_iter_key(i);
     json_t* const jsv = json_object_iter_value(i);
     const value val = jsValToValue(jsv);
-    if (isNil(val) && !isList(val))
+    if (isNull(val) && !isList(val))
         return jsPropertiesToValues(cons<value> (mklist<value> (element, c_str(name), val), propertiesSoFar), o, json_object_iter_next(o, i));
     if (substr(name, 0, 1) == atsign)
         return jsPropertiesToValues(cons<value>(mklist<value>(attribute, c_str(substr(name, 1)), val), propertiesSoFar), o, json_object_iter_next(o, i));
@@ -148,7 +148,7 @@ const value jsValToValue(json_t* const jsv) {
  */
 inline json_t* const valuesToJSElements(json_t* const a, const list<value>& l) {
     json_t* const valueToJSVal(const value& val);
-    if (isNil(l))
+    if (isNull(l))
         return a;
     json_t* const v = valueToJSVal(car(l));
     json_array_append(a, v);
@@ -199,7 +199,7 @@ inline json_t* const valueToJSVal(const value& val) {
  * Converts a list of values to JS properties.
  */
 inline json_t* const valuesToJSProperties(json_t* const o, const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return o;
 
     // Write an attribute
@@ -235,7 +235,7 @@ inline json_t* const valuesToJSProperties(json_t* const o, const list<value>& l)
  * Return true if a list of strings contains a JSON document.
  */
 inline const bool isJSON(const list<string>& ls) {
-    if (isNil(ls))
+    if (isNull(ls))
         return false;
     const string s = substr(car(ls), 0, 1);
     return s == "[" || s == "{";
@@ -390,7 +390,7 @@ inline const string funcName(const string& f) {
  * of key value pairs.
  */
 inline const list<value> queryParams(const list<value>& a) {
-    if (isNil(a))
+    if (isNull(a))
         return nilListValue;
     const list<value> p = car(a);
     if (car(p) == value("id") || car(p) == value("method"))
diff --git a/sca-cpp/trunk/modules/oauth/mod-oauth1.cpp b/sca-cpp/trunk/modules/oauth/mod-oauth1.cpp
index a7238804f8..b1786d1098 100644
--- a/sca-cpp/trunk/modules/oauth/mod-oauth1.cpp
+++ b/sca-cpp/trunk/modules/oauth/mod-oauth1.cpp
@@ -104,7 +104,7 @@ public:
  * Run the authnz hooks to authenticate a request.
  */
 const failable<int> checkAuthnzProviders(const string& user, request_rec* const r, const list<AuthnProviderConf>& apcs) {
-    if (isNil(apcs))
+    if (isNull(apcs))
         return mkfailure<int>("Authentication failure for: " + user, HTTP_UNAUTHORIZED);
     const AuthnProviderConf apc = car<AuthnProviderConf>(apcs);
     if (apc.provider == NULL || !apc.provider->check_password)
@@ -122,7 +122,7 @@ const failable<int> checkAuthnz(const string& user, request_rec* const r, const
     if (substr(user, 0, 1) == "/")
         return mkfailure<int>(string("Encountered FakeBasicAuth spoof: ") + user, HTTP_UNAUTHORIZED);
 
-    if (isNil(apcs)) {
+    if (isNull(apcs)) {
         const authn_provider* provider = (const authn_provider*)ap_lookup_provider(AUTHN_PROVIDER_GROUP, AUTHN_DEFAULT_PROVIDER, AUTHN_PROVIDER_VERSION);
         return checkAuthnzProviders(user, r, mklist<AuthnProviderConf>(AuthnProviderConf(AUTHN_DEFAULT_PROVIDER, provider)));
     }
@@ -142,11 +142,11 @@ const failable<value> userInfo(const value& sid, const memcache::MemCached& mc)
 const failable<int> authenticated(const list<value>& userinfo, const bool check, request_rec* const r, const list<value>& scopeattrs, const list<AuthnProviderConf>& apcs) {
     debug(userinfo, "modoauth2::authenticated::userinfo");
 
-    if (isNil(scopeattrs)) {
+    if (isNull(scopeattrs)) {
 
         // Store user id in an environment variable
         const list<value> id = assoc<value>("id", userinfo);
-        if (isNil(id) || isNil(cdr(id)))
+        if (isNull(id) || isNull(cdr(id)))
             return mkfailure<int>("Couldn't retrieve user id", HTTP_UNAUTHORIZED);
         apr_table_set(r->subprocess_env, "OAUTH2_ID", apr_pstrdup(r->pool, c_str(cadr(id))));
 
@@ -164,7 +164,7 @@ const failable<int> authenticated(const list<value>& userinfo, const bool check,
     // Store each configured OAuth scope attribute in an environment variable
     const list<value> a = car(scopeattrs);
     const list<value> v = assoc<value>(cadr(a), userinfo);
-    if (!isNil(v) && !isNil(cdr(v))) {
+    if (!isNull(v) && !isNull(cdr(v))) {
 
         // Map the REMOTE_USER attribute to the request user field
         if (string(car(a)) == "REMOTE_USER")
@@ -192,7 +192,7 @@ const string header(const string& qs, const string& redir, const string& verif)
         << "oauth_consumer_key=\"" << string(cadr(assoc<value>("oauth_consumer_key", args))) << "\", ";
 
     const list<value> atok = assoc<value>("oauth_token", args);
-    if (!isNil(atok) && !isNil(cdr(atok)))
+    if (!isNull(atok) && !isNull(cdr(atok)))
         hdr << "oauth_token=\"" << string(cadr(atok)) << "\", ";
 
     if (length(verif) != 0)
@@ -223,22 +223,22 @@ const list<string> sign(const string& verb, const string& uri, const list<value>
 const failable<int> authorize(const list<value>& args, request_rec* const r, const list<value>& appkeys, const memcache::MemCached& mc) {
     // Extract authorize, access_token, client ID and info URIs
     const list<value> ref = assoc<value>("openauth_referrer", args);
-    if (isNil(ref) || isNil(cdr(ref)))
+    if (isNull(ref) || isNull(cdr(ref)))
         return mkfailure<int>("Missing openauth_referrer parameter");
     const list<value> req = assoc<value>("oauth1_request_token", args);
-    if (isNil(req) || isNil(cdr(req)))
+    if (isNull(req) || isNull(cdr(req)))
         return mkfailure<int>("Missing oauth1_request_token parameter");
     const list<value> auth = assoc<value>("oauth1_authorize", args);
-    if (isNil(auth) || isNil(cdr(auth)))
+    if (isNull(auth) || isNull(cdr(auth)))
         return mkfailure<int>("Missing oauth1_authorize parameter");
     const list<value> tok = assoc<value>("oauth1_access_token", args);
-    if (isNil(tok) || isNil(cdr(tok)))
+    if (isNull(tok) || isNull(cdr(tok)))
         return mkfailure<int>("Missing oauth1_access_token parameter");
     const list<value> cid = assoc<value>("oauth1_client_id", args);
-    if (isNil(cid) || isNil(cdr(cid)))
+    if (isNull(cid) || isNull(cdr(cid)))
         return mkfailure<int>("Missing oauth1_client_id parameter");
     const list<value> info = assoc<value>("oauth1_info", args);
-    if (isNil(info) || isNil(cdr(info)))
+    if (isNull(info) || isNull(cdr(info)))
         return mkfailure<int>("Missing oauth1_info parameter");
 
     // Build the redirect URI
@@ -248,7 +248,7 @@ const failable<int> authorize(const list<value>& args, request_rec* const r, con
 
     // Lookup client app configuration
     const list<value> app = assoc<value>(cadr(cid), appkeys);
-    if (isNil(app) || isNil(cdr(app)))
+    if (isNull(app) || isNull(cdr(app)))
         return mkfailure<int>(string("client id not found: ") + (string)cadr(cid));
     list<value> appkey = cadr(app);
 
@@ -271,13 +271,13 @@ const failable<int> authorize(const list<value>& args, request_rec* const r, con
 
     // Retrieve the request token
     const list<value> conf = assoc<value>("oauth_callback_confirmed", resargs);
-    if (isNil(conf) || isNil(cdr(conf)) || cadr(conf) != "true")
+    if (isNull(conf) || isNull(cdr(conf)) || cadr(conf) != "true")
         return mkfailure<int>("Couldn't confirm oauth_callback");
     const list<value> tv = assoc<value>("oauth_token", resargs);
-    if (isNil(tv) || isNil(cdr(tv)))
+    if (isNull(tv) || isNull(cdr(tv)))
         return mkfailure<int>("Couldn't retrieve oauth_token");
     const list<value> sv = assoc<value>("oauth_token_secret", resargs);
-    if (isNil(sv) || isNil(cdr(sv)))
+    if (isNull(sv) || isNull(cdr(sv)))
         return mkfailure<int>("Couldn't retrieve oauth_token_secret");
 
     // Store the request token in memcached
@@ -301,12 +301,12 @@ const failable<list<value> > profileUserInfo(const value& cid, const string& inf
     if (b == "[") {
         // Twitter JSON profile
         const list<value> infov(content(json::readValue(mklist<string>(info))));
-        if (isNil(infov))
+        if (isNull(infov))
             return mkfailure<list<value> >("Couldn't retrieve user info");
         debug(infov, "modoauth1::access_token::info");
         const list<value> uv = assoc<value>("user", car(infov));
         debug(uv, "modoauth1::access_token::userInfo");
-        if (isNil(uv) || isNil(cdr(uv)))
+        if (isNull(uv) || isNull(cdr(uv)))
             return mkfailure<list<value> >("Couldn't retrieve user info");
         const list<value> iv = cdr(uv);
         return cons<value>(mklist<value>("realm", cid), iv);
@@ -314,12 +314,12 @@ const failable<list<value> > profileUserInfo(const value& cid, const string& inf
     if (b == "{") {
         // Foursquare JSON profile
         const list<value> infov(content(json::readValue(mklist<string>(info))));
-        if (isNil(infov))
+        if (isNull(infov))
             return mkfailure<list<value> >("Couldn't retrieve user info");
         debug(infov, "modoauth1::access_token::info");
         const list<value> uv = assoc<value>("user", infov);
         debug(uv, "modoauth1::access_token::userInfo");
-        if (isNil(uv) || isNil(cdr(uv)))
+        if (isNull(uv) || isNull(cdr(uv)))
             return mkfailure<list<value> >("Couldn't retrieve user info");
         const list<value> iv = cdr(uv);
         return cons<value>(mklist<value>("realm", cid), iv);
@@ -327,12 +327,12 @@ const failable<list<value> > profileUserInfo(const value& cid, const string& inf
     if (b == "<") {
         // XML profile
         const list<value> infov = elementsToValues(content(xml::readElements(mklist<string>(info))));
-        if (isNil(infov))
+        if (isNull(infov))
             return mkfailure<list<value> >("Couldn't retrieve user info");
         debug(infov, "modoauth1::access_token::info");
         const list<value> pv = car(infov);
         debug(pv, "modoauth1::access_token::userInfo");
-        if (isNil(pv) || isNil(cdr(pv)))
+        if (isNull(pv) || isNull(cdr(pv)))
             return mkfailure<list<value> >("Couldn't retrieve user info");
         const list<value> iv = cdr(pv);
         return cons<value>(mklist<value>("realm", cid), iv);
@@ -347,27 +347,27 @@ const failable<int> accessToken(const list<value>& args, request_rec* r, const l
 
     // Extract access_token URI, client ID and verification code
     const list<value> ref = assoc<value>("openauth_referrer", args);
-    if (isNil(ref) || isNil(cdr(ref)))
+    if (isNull(ref) || isNull(cdr(ref)))
         return mkfailure<int>("Missing openauth_referrer parameter");
     const list<value> tok = assoc<value>("oauth1_access_token", args);
-    if (isNil(tok) || isNil(cdr(tok)))
+    if (isNull(tok) || isNull(cdr(tok)))
         return mkfailure<int>("Missing oauth1_access_token parameter");
     const list<value> cid = assoc<value>("oauth1_client_id", args);
-    if (isNil(cid) || isNil(cdr(cid)))
+    if (isNull(cid) || isNull(cdr(cid)))
         return mkfailure<int>("Missing oauth1_client_id parameter");
     const list<value> info = assoc<value>("oauth1_info", args);
-    if (isNil(info) || isNil(cdr(info)))
+    if (isNull(info) || isNull(cdr(info)))
         return mkfailure<int>("Missing oauth1_info parameter");
     const list<value> tv = assoc<value>("oauth_token", args);
-    if (isNil(tv) || isNil(cdr(tv)))
+    if (isNull(tv) || isNull(cdr(tv)))
         return mkfailure<int>("Missing oauth_token parameter");
     const list<value> vv = assoc<value>("oauth_verifier", args);
-    if (isNil(vv) || isNil(cdr(vv)))
+    if (isNull(vv) || isNull(cdr(vv)))
         return mkfailure<int>("Missing oauth_verifier parameter");
 
     // Lookup client app configuration
     const list<value> app = assoc<value>(cadr(cid), appkeys);
-    if (isNil(app) || isNil(cdr(app)))
+    if (isNull(app) || isNull(cdr(app)))
         return mkfailure<int>(string("client id not found: ") + (string)cadr(cid));
     const list<value> appkey = cadr(app);
 
@@ -395,10 +395,10 @@ const failable<int> accessToken(const list<value>& args, request_rec* r, const l
 
     // Retrieve the access token
     const list<value> atv = assoc<value>("oauth_token", tokresargs);
-    if (isNil(atv) || isNil(cdr(atv)))
+    if (isNull(atv) || isNull(cdr(atv)))
         return mkfailure<int>("Couldn't retrieve oauth_token");
     const list<value> asv = assoc<value>("oauth_token_secret", tokresargs);
-    if (isNil(asv) || isNil(cdr(asv)))
+    if (isNull(asv) || isNull(cdr(asv)))
         return mkfailure<int>("Couldn't retrieve oauth_token_secret");
     debug(atv, "modoauth1::access_token::token");
 
@@ -498,7 +498,7 @@ static int checkAuthn(request_rec *r) {
         hasContent(openauth::sessionID(r, "TuscanyOpenAuth")) ||
         hasContent(openauth::sessionID(r, "TuscanyOAuth2")))
         return DECLINED;
-    if ((substr(string(r->uri), 0, 8) == "/oauth2/") || !isNil(assoc<value>("openid_identifier", args)))
+    if ((substr(string(r->uri), 0, 8) == "/oauth2/") || !isNull(assoc<value>("openid_identifier", args)))
         return DECLINED;
 
     r->ap_auth_type = const_cast<char*>(atype);
@@ -515,9 +515,9 @@ int postConfigMerge(const ServerConf& mainsc, server_rec* const s) {
     debug(httpd::serverName(s), "modoauth1::postConfigMerge::serverName");
 
     // Merge configuration from main server
-    if (isNil((list<value>)sc.appkeys))
+    if (isNull((list<value>)sc.appkeys))
         sc.appkeys = mainsc.appkeys;
-    if (isNil((list<string>)sc.mcaddrs))
+    if (isNull((list<string>)sc.mcaddrs))
         sc.mcaddrs = mainsc.mcaddrs;
     sc.mc = mainsc.mc;
     sc.cs = mainsc.cs;
@@ -549,7 +549,7 @@ void childInit(apr_pool_t* const p, server_rec* const s) {
     ServerConf& sc = *psc;
 
     // Connect to Memcached
-    if (isNil((list<string>)sc.mcaddrs))
+    if (isNull((list<string>)sc.mcaddrs))
         sc.mc = *(new (gc_new<memcache::MemCached>()) memcache::MemCached("localhost", 11211));
     else
         sc.mc = *(new (gc_new<memcache::MemCached>()) memcache::MemCached(sc.mcaddrs));
diff --git a/sca-cpp/trunk/modules/oauth/mod-oauth2.cpp b/sca-cpp/trunk/modules/oauth/mod-oauth2.cpp
index 5bc212a681..0a4405ce2e 100644
--- a/sca-cpp/trunk/modules/oauth/mod-oauth2.cpp
+++ b/sca-cpp/trunk/modules/oauth/mod-oauth2.cpp
@@ -98,7 +98,7 @@ public:
  * Run the authnz hooks to authenticate a request.
  */
 const failable<int> checkAuthnzProviders(const string& user, request_rec* const r, const list<AuthnProviderConf>& apcs) {
-    if (isNil(apcs))
+    if (isNull(apcs))
         return mkfailure<int>("Authentication failure for: " + user, HTTP_UNAUTHORIZED);
     const AuthnProviderConf apc = car<AuthnProviderConf>(apcs);
     if (apc.provider == NULL || !apc.provider->check_password)
@@ -116,7 +116,7 @@ const failable<int> checkAuthnz(const string& user, request_rec* const r, const
     if (substr(user, 0, 1) == "/")
         return mkfailure<int>(string("Encountered FakeBasicAuth spoof: ") + user, HTTP_UNAUTHORIZED);
 
-    if (isNil(apcs)) {
+    if (isNull(apcs)) {
         const authn_provider* provider = (const authn_provider*)ap_lookup_provider(AUTHN_PROVIDER_GROUP, AUTHN_DEFAULT_PROVIDER, AUTHN_PROVIDER_VERSION);
         return checkAuthnzProviders(user, r, mklist<AuthnProviderConf>(AuthnProviderConf(AUTHN_DEFAULT_PROVIDER, provider)));
     }
@@ -136,11 +136,11 @@ const failable<value> userInfo(const value& sid, const memcache::MemCached& mc)
 const failable<int> authenticated(const list<value>& userinfo, const bool check, request_rec* const r, const list<value>& scopeattrs, const list<AuthnProviderConf>& apcs) {
     debug(userinfo, "modoauth2::authenticated::userinfo");
 
-    if (isNil(scopeattrs)) {
+    if (isNull(scopeattrs)) {
 
         // Store user id in an environment variable
         const list<value> id = assoc<value>("id", userinfo);
-        if (isNil(id) || isNil(cdr(id)))
+        if (isNull(id) || isNull(cdr(id)))
             return mkfailure<int>("Couldn't retrieve user id", HTTP_UNAUTHORIZED);
         apr_table_set(r->subprocess_env, "OAUTH2_ID", apr_pstrdup(r->pool, c_str(cadr(id))));
 
@@ -158,7 +158,7 @@ const failable<int> authenticated(const list<value>& userinfo, const bool check,
     // Store each configured OAuth scope attribute in an environment variable
     const list<value> a = car(scopeattrs);
     const list<value> v = assoc<value>(cadr(a), userinfo);
-    if (!isNil(v) && !isNil(cdr(v))) {
+    if (!isNull(v) && !isNull(cdr(v))) {
 
         // Map the REMOTE_USER attribute to the request user field
         if (string(car(a)) == "REMOTE_USER")
@@ -175,22 +175,22 @@ const failable<int> authenticated(const list<value>& userinfo, const bool check,
 const failable<int> authorize(const list<value>& args, request_rec* const r, const list<value>& appkeys) {
     // Extract authorize, access_token, client ID and info URIs
     const list<value> ref = assoc<value>("openauth_referrer", args);
-    if (isNil(ref) || isNil(cdr(ref)))
+    if (isNull(ref) || isNull(cdr(ref)))
         return mkfailure<int>("Missing openauth_referrer parameter");
     const list<value> auth = assoc<value>("oauth2_authorize", args);
-    if (isNil(auth) || isNil(cdr(auth)))
+    if (isNull(auth) || isNull(cdr(auth)))
         return mkfailure<int>("Missing oauth2_authorize parameter");
     const list<value> tok = assoc<value>("oauth2_access_token", args);
-    if (isNil(tok) || isNil(cdr(tok)))
+    if (isNull(tok) || isNull(cdr(tok)))
         return mkfailure<int>("Missing oauth2_access_token parameter");
     const list<value> cid = assoc<value>("oauth2_client_id", args);
-    if (isNil(cid) || isNil(cdr(cid)))
+    if (isNull(cid) || isNull(cdr(cid)))
         return mkfailure<int>("Missing oauth2_client_id parameter");
     const list<value> info = assoc<value>("oauth2_info", args);
-    if (isNil(info) || isNil(cdr(info)))
+    if (isNull(info) || isNull(cdr(info)))
         return mkfailure<int>("Missing oauth2_info parameter");
     const list<value> scope = assoc<value>("oauth2_scope", args);
-    if (isNil(scope) || isNil(cdr(scope)))
+    if (isNull(scope) || isNull(cdr(scope)))
         return mkfailure<int>("Missing oauth2_scope parameter");
     const list<value> display = assoc<value>("oauth2_display", args);
 
@@ -205,12 +205,12 @@ const failable<int> authorize(const list<value>& args, request_rec* const r, con
 
     // Lookup client app configuration
     const list<value> app = assoc<value>(cadr(cid), appkeys);
-    if (isNil(app) || isNil(cdr(app)))
+    if (isNull(app) || isNull(cdr(app)))
         return mkfailure<int>(string("client id not found: ") + (string)cadr(cid));
     list<value> appkey = cadr(app);
 
     // Redirect to the authorize URI
-    const list<value> adisplay = (isNil(display) || isNil(cdr(display)))? nilListValue : mklist<value>("display", cadr(display));
+    const list<value> adisplay = (isNull(display) || isNull(cdr(display)))? nilListValue : mklist<value>("display", cadr(display));
     const list<value> aargs = mklist<value>(mklist<value>("response_type", "code"), mklist<value>("client_id", car(appkey)), mklist<value>("scope", cadr(scope)), adisplay, mklist<value>("redirect_uri", httpd::escape(redir)), mklist<value>("state", httpd::escape(state)));
     const string uri = httpd::unescape(cadr(auth)) + string("?") + http::queryString(aargs);
     debug(uri, "modoauth2::authorize::uri");
@@ -233,28 +233,28 @@ const failable<int> accessToken(const list<value>& args, request_rec* r, const l
 
     // Extract access_token URI, client ID and authorization code parameters
     const list<value> state = assoc<value>("state", args);
-    if (isNil(state) || isNil(cdr(state)))
+    if (isNull(state) || isNull(cdr(state)))
         return mkfailure<int>("Missing state parameter");
     const list<value>& stargs = httpd::queryArgs(httpd::unescape(cadr(state)));
     const list<value> ref = assoc<value>("openauth_referrer", stargs);
-    if (isNil(ref) || isNil(cdr(ref)))
+    if (isNull(ref) || isNull(cdr(ref)))
         return mkfailure<int>("Missing openauth_referrer parameter");
     const list<value> tok = assoc<value>("oauth2_access_token", stargs);
-    if (isNil(tok) || isNil(cdr(tok)))
+    if (isNull(tok) || isNull(cdr(tok)))
         return mkfailure<int>("Missing oauth2_access_token parameter");
     const list<value> cid = assoc<value>("oauth2_client_id", stargs);
-    if (isNil(cid) || isNil(cdr(cid)))
+    if (isNull(cid) || isNull(cdr(cid)))
         return mkfailure<int>("Missing oauth2_client_id parameter");
     const list<value> info = assoc<value>("oauth2_info", stargs);
-    if (isNil(info) || isNil(cdr(info)))
+    if (isNull(info) || isNull(cdr(info)))
         return mkfailure<int>("Missing oauth2_info parameter");
     const list<value> code = assoc<value>("code", args);
-    if (isNil(code) || isNil(cdr(code)))
+    if (isNull(code) || isNull(cdr(code)))
         return mkfailure<int>("Missing code parameter");
 
     // Lookup client app configuration
     const list<value> app = assoc<value>(cadr(cid), appkeys);
-    if (isNil(app) || isNil(cdr(app)))
+    if (isNull(app) || isNull(cdr(app)))
         return mkfailure<int>(string("client id not found: ") + (string)cadr(cid));
     list<value> appkey = cadr(app);
 
@@ -274,12 +274,12 @@ const failable<int> accessToken(const list<value>& args, request_rec* r, const l
         return mkfailure<int>(ftr);
     const value tr = content(ftr);
     debug(tr, "modoauth2::access_token::response");
-    if (!isList(tr) || isNil(tr))
+    if (!isList(tr) || isNull(tr))
         return mkfailure<int>("Empty access token");
     const list<value> tv = isString(car<value>(tr)) ?
         assoc<value>("access_token", httpd::queryArgs(join("", convertValues<string>(cadr<value>(tr))))) :
         assoc<value>("access_token", tr);
-    if (isNil(tv) || isNil(cdr(tv)))
+    if (isNull(tv) || isNull(cdr(tv)))
         return mkfailure<int>("Couldn't retrieve access_token");
     debug(tv, "modoauth2::access_token::token");
 
@@ -373,7 +373,7 @@ static int checkAuthn(request_rec *r) {
         hasContent(openauth::sessionID(r, "TuscanyOpenAuth")) ||
         hasContent(openauth::sessionID(r, "TuscanyOAuth1")))
         return DECLINED;
-    if ((substr(string(r->uri), 0, 8) == "/oauth1/") || !isNil(assoc<value>("openid_identifier", args)))
+    if ((substr(string(r->uri), 0, 8) == "/oauth1/") || !isNull(assoc<value>("openid_identifier", args)))
         return DECLINED;
 
     r->ap_auth_type = const_cast<char*>(atype);
@@ -390,9 +390,9 @@ int postConfigMerge(const ServerConf& mainsc, server_rec* const s) {
     debug(httpd::serverName(s), "modoauth2::postConfigMerge::serverName");
 
     // Merge configuration from main server
-    if (isNil((list<value>)sc.appkeys))
+    if (isNull((list<value>)sc.appkeys))
         sc.appkeys = mainsc.appkeys;
-    if (isNil((list<string>)sc.mcaddrs))
+    if (isNull((list<string>)sc.mcaddrs))
         sc.mcaddrs = mainsc.mcaddrs;
     sc.mc = mainsc.mc;
     sc.cs = mainsc.cs;
@@ -424,7 +424,7 @@ void childInit(apr_pool_t* const p, server_rec* const s) {
     ServerConf& sc = *psc;
 
     // Connect to Memcached
-    if (isNil((list<string>)sc.mcaddrs))
+    if (isNull((list<string>)sc.mcaddrs))
         sc.mc = *(new (gc_new<memcache::MemCached>()) memcache::MemCached("localhost", 11211));
     else
         sc.mc = *(new (gc_new<memcache::MemCached>()) memcache::MemCached(sc.mcaddrs));
diff --git a/sca-cpp/trunk/modules/opencl/driver.hpp b/sca-cpp/trunk/modules/opencl/driver.hpp
index c45bcf6ee4..f60e9c1dd3 100644
--- a/sca-cpp/trunk/modules/opencl/driver.hpp
+++ b/sca-cpp/trunk/modules/opencl/driver.hpp
@@ -38,7 +38,7 @@ namespace opencl {
 const value evalDriverLoop(const OpenCLProgram& clprog, istream& in, ostream& out, const OpenCLContext& cl) {
     scheme::promptForInput(scheme::evalInputPrompt, out);
     const value input = content(scheme::readValue(in));
-    if (isNil(input))
+    if (isNull(input))
         return input;
     const failable<value> output = evalKernel(createKernel(input, clprog), input, 1, value::String, 512, cl);
     scheme::announceOutput(scheme::evalOutputPrompt, out);
diff --git a/sca-cpp/trunk/modules/opencl/eval.hpp b/sca-cpp/trunk/modules/opencl/eval.hpp
index f842ba783d..e910d427bc 100644
--- a/sca-cpp/trunk/modules/opencl/eval.hpp
+++ b/sca-cpp/trunk/modules/opencl/eval.hpp
@@ -412,7 +412,7 @@ const failable<OpenCLBuffer> readOnlyBuffer(const size_t size, const void* const
  * Fill an array of write events for a given list of buffers.
  */
 const cl_uint writeBufferEvents(const list<OpenCLBuffer>& buf, cl_event* const evt) {
-    if (isNil(buf))
+    if (isNull(buf))
         return 0;
     const cl_event e = car(buf).evt;
     if (e == 0)
@@ -486,7 +486,7 @@ const failable<OpenCLBuffer> valueToKernelArg(const value& v, const cl_uint i, c
  * Convert a list of values to kernel args.
  */
 const failable<list<OpenCLBuffer>> valuesToKernelArgsListHelper(const list<value>& v, const cl_uint i, const OpenCLKernel& kernel, const OpenCLContext& cl, const cl_command_queue cq) {
-    if (isNil(v))
+    if (isNull(v))
         return list<OpenCLBuffer>();
     const failable<OpenCLBuffer> a = valueToKernelArg(car(v), i, kernel, cl, cq);
     if (!hasContent(a))
diff --git a/sca-cpp/trunk/modules/python/driver.hpp b/sca-cpp/trunk/modules/python/driver.hpp
index 41daed32c3..3b02302c65 100644
--- a/sca-cpp/trunk/modules/python/driver.hpp
+++ b/sca-cpp/trunk/modules/python/driver.hpp
@@ -38,7 +38,7 @@ namespace python {
 const value evalDriverLoop(PyObject* const script, istream& in, ostream& out, PythonRuntime& py) {
     scheme::promptForInput(scheme::evalInputPrompt, out);
     const value input = content(scheme::readValue(in));
-    if (isNil(input))
+    if (isNull(input))
         return input;
     const failable<value> output = evalScript(input, script, py);
     scheme::announceOutput(scheme::evalOutputPrompt, out);
diff --git a/sca-cpp/trunk/modules/python/eval.hpp b/sca-cpp/trunk/modules/python/eval.hpp
index 3f9c6c20a2..3728cdb7bb 100644
--- a/sca-cpp/trunk/modules/python/eval.hpp
+++ b/sca-cpp/trunk/modules/python/eval.hpp
@@ -483,7 +483,7 @@ PyObject* const mkPyLambda(const lvvlambda& l, PythonRuntime* const py) {
  * Convert a list of values to a python list.
  */
 PyObject* const valuesToPyListHelper(PyObject* const l, const list<value>& v, PythonRuntime* const py) {
-    if (isNil(v))
+    if (isNull(v))
         return l;
     PyObject* const pyv = valueToPyObject(car(v), py);
     PyList_Append(l, pyv);
diff --git a/sca-cpp/trunk/modules/python/python-test.cpp b/sca-cpp/trunk/modules/python/python-test.cpp
index 44a72f8f88..65b18c9b1b 100644
--- a/sca-cpp/trunk/modules/python/python-test.cpp
+++ b/sca-cpp/trunk/modules/python/python-test.cpp
@@ -197,7 +197,7 @@ const list<future<bool> > submitEvals(worker& w, const int max, const int i, PyO
 }
 
 const bool checkEvalResults(const list<future<bool> > r) {
-    if (isNil(r))
+    if (isNull(r))
         return true;
     assert(car(r) == true);
     return checkEvalResults(cdr(r));
diff --git a/sca-cpp/trunk/modules/rss/rss.hpp b/sca-cpp/trunk/modules/rss/rss.hpp
index 348d50e8f3..e8edc0dcb1 100644
--- a/sca-cpp/trunk/modules/rss/rss.hpp
+++ b/sca-cpp/trunk/modules/rss/rss.hpp
@@ -46,14 +46,14 @@ const value entry("entry");
  */
 const list<value> entryElementValues(const list<value>& e) {
     const list<value> lt = elementChildren("title", e);
-    const value t = isNil(lt)? value(emptyString) : elementValue(car(lt));
+    const value t = isNull(lt)? value(emptyString) : elementValue(car(lt));
     const list<value> li = elementChildren("link", e);
-    const value i = isNil(li)? value(emptyString) : elementValue(car(li));
+    const value i = isNull(li)? value(emptyString) : elementValue(car(li));
     const list<value> ld = elementChildren("description", e);
     return append<value>(nilListValue + element + entry 
                 + value(nilListValue + element + value("title") + t)
                 + value(nilListValue + element + value("id") + i),
-                isNil(ld)? nilListValue : isAttribute(elementValue(car(ld)))? nilListValue :
+                isNull(ld)? nilListValue : isAttribute(elementValue(car(ld)))? nilListValue :
                     mklist<value>(value(nilListValue + element + value("content") + elementValue(car(ld)))));
 }
 
@@ -61,7 +61,7 @@ const list<value> entryElementValues(const list<value>& e) {
  * Convert a list of elements to a list of element values representing ATOM entries.
  */
 const list<value> entriesElementValues(const list<value>& e) {
-    if (isNil(e))
+    if (isNull(e))
         return e;
     return cons<value>(entryElementValues(car(e)), entriesElementValues(cdr(e)));
 }
@@ -80,7 +80,7 @@ const bool isRSSFeed(const list<string>& ls) {
  */
 const failable<list<value> > readRSSEntry(const list<string>& ilist) {
     const list<value> e = content(xml::readElements(ilist));
-    if (isNil(e))
+    if (isNull(e))
         return mkfailure<list<value> >("Empty entry");
     return mklist<value>(entryElementValues(car(e)));
 }
@@ -90,7 +90,7 @@ const failable<list<value> > readRSSEntry(const list<string>& ilist) {
  */
 const failable<list<value> > readRSSFeed(const list<string>& ilist) {
     const list<value> f = content(xml::readElements(ilist));
-    if (isNil(f))
+    if (isNull(f))
         return mkfailure<list<value> >("Empty feed");
     const list<value> c = elementChildren("channel", car(f));
     const list<value> t = elementChildren("title", car(c));
@@ -109,12 +109,12 @@ const list<value> entryElement(const list<value>& l) {
     const value title = elementValue(elementChild("title", l));
     const value id = elementValue(elementChild("id", l));
     const value content = elementChild("content", l);
-    const bool text = isNil(content)? false : elementHasValue(content);
+    const bool text = isNull(content)? false : elementHasValue(content);
     return append<value>(nilListValue
         + element + "item"
         + (nilListValue + element + "title" + title)
         + (nilListValue + element + "link" + id),
-        isNil(content)?
+        isNull(content)?
             nilListValue :
             mklist<value>(append<value>(nilListValue + element + "description",
                 text? mklist<value>(elementValue(content)) : elementChildren(content))));
@@ -124,7 +124,7 @@ const list<value> entryElement(const list<value>& l) {
  * Convert a list of values representing RSS entries to a list of elements.
  */
 const list<value> entriesElements(const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons<value>(entryElement(car(l)), entriesElements(cdr(l)));
 }
@@ -134,7 +134,7 @@ const list<value> entriesElements(const list<value>& l) {
  * The first two values in the list are the entry id and title.
  */
 template<typename R> const failable<R> writeRSSEntry(const lambda<const R(const string&, const R)>& reduce, const R& initial, const list<value>& ll) {
-    const list<value> l = isNil(ll)? ll : (list<value>)car(ll);
+    const list<value> l = isNull(ll)? ll : (list<value>)car(ll);
     return xml::writeElements<R>(reduce, initial, mklist<value>(entryElement(l)));
 }
 
@@ -150,11 +150,11 @@ const failable<list<string> > writeRSSEntry(const list<value>& l) {
  * The first two values in the list are the feed id and title.
  */
 template<typename R> const failable<R> writeRSSFeed(const lambda<const R(const string&, const R)>& reduce, const R& initial, const list<value>& ll) {
-    const list<value> l = isNil(ll)? ll : (list<value>)car(ll);
+    const list<value> l = isNull(ll)? ll : (list<value>)car(ll);
     const list<value> lt = elementChildren("title", l);
-    const value t = isNil(lt)? value(emptyString) : elementValue(car(lt));
+    const value t = isNull(lt)? value(emptyString) : elementValue(car(lt));
     const list<value> li = elementChildren("id", l);
-    const value i = isNil(li)? value(emptyString) : elementValue(car(li));
+    const value i = isNull(li)? value(emptyString) : elementValue(car(li));
     const list<value> c = nilListValue
         + (nilListValue + element + "title" + t)
         + (nilListValue + element + "link" + i)
@@ -162,7 +162,7 @@ template<typename R> const failable<R> writeRSSFeed(const lambda<const R(const s
 
     // Write RSS entries
     const list<value> le = elementChildren(entry, l);
-    if (isNil(le)) {
+    if (isNull(le)) {
         const list<value> fe = nilListValue
             + element + "rss" + (nilListValue + attribute + "version" + "2.0")
             + append(nilListValue + element + "channel", c);
@@ -170,7 +170,7 @@ template<typename R> const failable<R> writeRSSFeed(const lambda<const R(const s
     }
 
     // Write a single RSS entry element with a list of values
-    if (!isNil(le) && !isNil(car(le)) && isList(car<value>(caddr<value>(car(le))))) {
+    if (!isNull(le) && !isNull(car(le)) && isList(car<value>(caddr<value>(car(le))))) {
         const list<value> ce = append(c, entriesElements(caddr<value>(car(le))));
         const list<value> fe = nilListValue
             + element + "rss" + (nilListValue + attribute + "version" + "2.0")
diff --git a/sca-cpp/trunk/modules/scdl/scdl.hpp b/sca-cpp/trunk/modules/scdl/scdl.hpp
index 35a717d478..98afbe604c 100644
--- a/sca-cpp/trunk/modules/scdl/scdl.hpp
+++ b/sca-cpp/trunk/modules/scdl/scdl.hpp
@@ -40,7 +40,7 @@ namespace scdl {
  */
 const list<value> components(const value& l) {
     const list<value> cs = elementChildren("composite", l);
-    if (isNil(cs))
+    if (isNull(cs))
         return cs;
     return elementChildren("component", car(cs));
 }
@@ -50,7 +50,7 @@ const list<value> components(const value& l) {
  */
 const list<value> promotions(const value& l) {
     const list<value> cs = elementChildren("composite", l);
-    if (isNil(cs))
+    if (isNull(cs))
         return cs;
     return elementChildren("service", car(cs));
 }
@@ -73,7 +73,7 @@ const value name(const value& l) {
  * Convert a list of elements to a name -> element assoc list.
  */
 const list<value> nameToElementAssoc(const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     const value e(car(l));
     return cons<value>(mklist<value>(name(e), e), nameToElementAssoc(cdr(l)));
@@ -87,7 +87,7 @@ const value named(const value& n, const value& l) {
         return name(v) == n;
     };
     const list<value> c = filter<value>(filterName, l);
-    if (isNil(c))
+    if (isNull(c))
         return nilValue;
     return car(c);
 }
@@ -100,7 +100,7 @@ const value implementation(const value& l) {
         return isElement(v) && contains(string(cadr<value>(v)), "implementation.");
     };
     const list<value> n = filter<value>(filterImplementation, l);
-    if (isNil(n))
+    if (isNull(n))
         return nilValue;
     return car(n);
 }
@@ -148,17 +148,17 @@ const list<value> bindings(const value& l) {
  * Returns the target of a reference.
  */
 const value bindingsTarget(const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return nilValue;
     const value u = uri(car(l));
-    if (!isNil(u))
+    if (!isNull(u))
         return u;
     return bindingsTarget(cdr(l));
 }
 
 const value target(const value& l) {
     const value target = attributeValue("target", l);
-    if (!isNil(target))
+    if (!isNull(target))
         return target;
     return bindingsTarget(bindings(l));
 }
@@ -167,7 +167,7 @@ const value target(const value& l) {
  * Convert a list of references to a reference name -> target assoc list.
  */
 const list<value> referenceToTargetAssoc(const list<value>& r) {
-    if (isNil(r))
+    if (isNull(r))
         return r;
     const value ref(car(r));
     return cons<value>(mklist<value>(scdl::name(ref), scdl::target(ref)), referenceToTargetAssoc(cdr(r)));
diff --git a/sca-cpp/trunk/modules/scheme/driver.hpp b/sca-cpp/trunk/modules/scheme/driver.hpp
index c94af7bbf7..015348c9e1 100644
--- a/sca-cpp/trunk/modules/scheme/driver.hpp
+++ b/sca-cpp/trunk/modules/scheme/driver.hpp
@@ -56,7 +56,7 @@ const bool userPrint(const value val, ostream& out) {
 const value evalDriverLoop(istream& in, ostream& out, Env& env) {
     promptForInput(evalInputPrompt, out);
     const value input = content(readValue(in));
-    if (isNil(input))
+    if (isNull(input))
         return input;
     const value output = evalExpr(input, env);
     announceOutput(evalOutputPrompt, out);
diff --git a/sca-cpp/trunk/modules/scheme/environment.hpp b/sca-cpp/trunk/modules/scheme/environment.hpp
index 1a295c74f4..ee82bc0401 100644
--- a/sca-cpp/trunk/modules/scheme/environment.hpp
+++ b/sca-cpp/trunk/modules/scheme/environment.hpp
@@ -81,16 +81,16 @@ const bool isDotVariable(const value& var) {
 }
 
 const Frame makeBinding(const Frame& frameSoFar, const list<value>& variables, const list<value> values) {
-    if (isNil(variables)) {
-        if (!isNil(values))
+    if (isNull(variables)) {
+        if (!isNull(values))
             logStream() << "Too many arguments supplied " << values << endl;
         return frameSoFar;
     }
     if (isDotVariable(car(variables)))
         return makeBinding(frameSoFar, cdr(variables), mklist<value>(values));
 
-    if (isNil(values)) {
-        if (!isNil(variables))
+    if (isNull(values)) {
+        if (!isNull(variables))
             logStream() << "Too few arguments supplied " << variables << endl;
         return frameSoFar;
     }
@@ -118,7 +118,7 @@ const value definitionVariable(const value& exp) {
 const value definitionValue(const value& exp) {
     const list<value> exps(exp);
     if(isSymbol(car(cdr(exps)))) {
-        if (isNil(cdr(cdr(exps))))
+        if (isNull(cdr(cdr(exps))))
             return nilValue;
         return car(cdr(cdr(exps)));
     }
@@ -158,7 +158,7 @@ const Env setupEnvironment() {
 const value lookupEnvLoop(const value& var, const Env& env);
 
 const value lookupEnvScan(const value& var, const list<value>& vars, const list<value>& vals, const Env& env) {
-    if(isNil(vars))
+    if(isNull(vars))
         return lookupEnvLoop(var, enclosingEnvironment(env));
     if(var == car(vars))
         return car(vals);
diff --git a/sca-cpp/trunk/modules/scheme/eval.hpp b/sca-cpp/trunk/modules/scheme/eval.hpp
index 5074471931..17150a7b48 100644
--- a/sca-cpp/trunk/modules/scheme/eval.hpp
+++ b/sca-cpp/trunk/modules/scheme/eval.hpp
@@ -87,7 +87,7 @@ const list<value> operands(const value& exp) {
 }
 
 const list<value> listOfValues(const list<value> exps, Env& env) {
-    if(isNil(exps))
+    if(isNull(exps))
         return list<value> ();
     return cons(evalExpr(car(exps), env), listOfValues(cdr(exps), env));
 }
@@ -117,7 +117,7 @@ const Env procedureEnvironment(const value& exp) {
 }
 
 const bool isLastExp(const list<value>& seq) {
-    return isNil(cdr(seq));
+    return isNull(cdr(seq));
 }
 
 const value firstExp(const list<value>& seq) {
@@ -151,7 +151,7 @@ const value applyProcedure(const value& procedure, list<value>& arguments) {
 }
 
 const value sequenceToExp(const list<value> exps) {
-    if(isNil(exps))
+    if(isNull(exps))
         return exps;
     if(isLastExp(exps))
         return firstExp(exps);
@@ -179,7 +179,7 @@ const value ifConsequent(const value& exp) {
 }
 
 const value ifAlternative(const value& exp) {
-    if(!isNil(cdr(cdr(cdr((list<value> )exp)))))
+    if(!isNull(cdr(cdr(cdr((list<value> )exp)))))
         return car(cdr(cdr(cdr((list<value> )exp))));
     return false;
 }
@@ -201,12 +201,12 @@ const value makeIf(value predicate, value consequent, value alternative) {
 }
 
 const value expandClauses(const list<value>& clauses) {
-    if(isNil(clauses))
+    if(isNull(clauses))
         return false;
     const value first = car(clauses);
     const list<value> rest = cdr(clauses);
     if(isCondElseClause(first)) {
-        if(isNil(rest))
+        if(isNull(rest))
             return sequenceToExp(condActions(first));
         logStream() << "else clause isn't last " << clauses << endl;
         return nilValue;
@@ -259,7 +259,7 @@ const value evalExpr(const value& exp, Env& env) {
 }
 
 const list<value> quotedParameters(const list<value>& p) {
-    if (isNil(p))
+    if (isNull(p))
         return p;
     return cons<value>(mklist<value>(quoteSymbol, car(p)), quotedParameters(cdr(p)));
 }
@@ -268,7 +268,7 @@ const list<value> quotedParameters(const list<value>& p) {
  * Evaluate an expression against a script provided as a list of values.
  */
 const value evalScriptLoop(const value& expr, const list<value>& script, scheme::Env& env) {
-    if (isNil(script))
+    if (isNull(script))
         return scheme::evalExpr(expr, env);
     scheme::evalExpr(car(script), env);
     return evalScriptLoop(expr, cdr(script), env);
diff --git a/sca-cpp/trunk/modules/scheme/io.hpp b/sca-cpp/trunk/modules/scheme/io.hpp
index 02f6923c86..c7177b54ae 100644
--- a/sca-cpp/trunk/modules/scheme/io.hpp
+++ b/sca-cpp/trunk/modules/scheme/io.hpp
@@ -231,7 +231,7 @@ inline const failable<list<string> > writeValue(const value& val) {
 
 inline const value readScript(istream& in) {
     const value val = content(readValue(in));
-    if (isNil(val))
+    if (isNull(val))
         return nilListValue;
     return cons(val, (list<value>)readScript(in));
 }
diff --git a/sca-cpp/trunk/modules/scheme/primitive.hpp b/sca-cpp/trunk/modules/scheme/primitive.hpp
index 4815e9a497..da0056d6da 100644
--- a/sca-cpp/trunk/modules/scheme/primitive.hpp
+++ b/sca-cpp/trunk/modules/scheme/primitive.hpp
@@ -118,10 +118,10 @@ inline const value treeSelectAssocProc(const list<value>& args) {
 
 inline const value nullProc(const list<value>& args) {
     const value v(car(args));
-    if (isNil(v))
+    if (isNull(v))
         return true;
     if (isList(v))
-        return isNil(list<value>(v));
+        return isNull(list<value>(v));
     return false;
 }
 
@@ -138,13 +138,13 @@ inline const value lesserProc(const list<value>& args) {
 }
 
 inline const value addProc(const list<value>& args) {
-    if (isNil(cdr(args)))
+    if (isNull(cdr(args)))
         return (double)car(args);
     return (double)car(args) + (double)cadr(args);
 }
 
 inline const value subProc(const list<value>& args) {
-    if (isNil(cdr(args)))
+    if (isNull(cdr(args)))
         return (double)0 - (double)car(args);
     return (double)car(args) - (double)cadr(args);
 }
@@ -162,7 +162,7 @@ inline const value sqrtProc(const list<value>& args) {
 }
 
 inline const value displayProc(const list<value>& args) {
-    if (isNil(args)) {
+    if (isNull(args)) {
         displayStream() << endl;
         return true;
     }
@@ -171,7 +171,7 @@ inline const value displayProc(const list<value>& args) {
 }
 
 inline const value logProc(const list<value>& args) {
-    if (isNil(args)) {
+    if (isNull(args)) {
         logStream() << endl;
         return true;
     }
@@ -225,7 +225,7 @@ inline const bool isPrimitiveProcedure(const value& proc) {
 }
 
 inline const bool isSelfEvaluating(const value& exp) {
-    if(isNil(exp))
+    if(isNull(exp))
         return true;
     if(isNumber(exp))
         return true;
diff --git a/sca-cpp/trunk/modules/server/client-test.hpp b/sca-cpp/trunk/modules/server/client-test.hpp
index 29da9e4798..562fe9c68e 100644
--- a/sca-cpp/trunk/modules/server/client-test.hpp
+++ b/sca-cpp/trunk/modules/server/client-test.hpp
@@ -190,7 +190,7 @@ const list<future<bool> > startPost(worker& w, const int threads, const blambda&
 }
 
 const bool checkPost(const list<future<bool> >& r) {
-    if (isNil(r))
+    if (isNull(r))
         return true;
     assert(car(r) == true);
     return checkPost(cdr(r));
@@ -244,7 +244,7 @@ const list<pid_t> startPost(const int procs, const blambda& l) {
 }
 
 const bool checkPost(const list<pid_t>& r) {
-    if (isNil(r))
+    if (isNull(r))
         return true;
     int status;
     waitpid(car(r), &status, 0);
diff --git a/sca-cpp/trunk/modules/server/mod-cpp.hpp b/sca-cpp/trunk/modules/server/mod-cpp.hpp
index 1321466383..54742306b0 100644
--- a/sca-cpp/trunk/modules/server/mod-cpp.hpp
+++ b/sca-cpp/trunk/modules/server/mod-cpp.hpp
@@ -46,7 +46,7 @@ namespace modcpp {
  * Apply a C++ component implementation function.
  */
 const list<value> failableResult(const value& func, const list<value>& v) {
-    if (isNil(cdr(v)))
+    if (isNull(cdr(v)))
         return v;
 
     // Report a failure with an empty reason as 'function not supported'
@@ -69,7 +69,7 @@ const failable<lvvlambda > evalImplementation(const string& path, const value& i
     // Configure the implementation's lambda function
     const value ipath(attributeValue("path", impl));
     const value iname(attributeValue("library", impl));
-    const string fpath(isNil(ipath)? path + (string)iname : path + (string)ipath + "/" + (string)iname);
+    const string fpath(isNull(ipath)? path + (string)iname : path + (string)ipath + "/" + (string)iname);
     const lib ilib(*(new (gc_new<lib>()) lib(fpath + dynlibExt)));
     const failable<lvvlambda > fappl(dynlambda<const value(const list<value>&)>("apply", ilib));
     if (!hasContent(fappl))
diff --git a/sca-cpp/trunk/modules/server/mod-eval.hpp b/sca-cpp/trunk/modules/server/mod-eval.hpp
index 5a8a15bf43..204459e127 100644
--- a/sca-cpp/trunk/modules/server/mod-eval.hpp
+++ b/sca-cpp/trunk/modules/server/mod-eval.hpp
@@ -161,9 +161,9 @@ static APR_OPTIONAL_FN_TYPE(ap_authn_cache_store) *authnCacheStore = NULL;
  * failable monad.
  */
 const failable<value> failableResult(const list<value>& v) {
-    if (isNil(cdr(v)))
+    if (isNull(cdr(v)))
         return car(v);
-    return mkfailure<value>(string(cadr(v)), isNil(cddr(v))? -1 : (int)caddr(v), false);
+    return mkfailure<value>(string(cadr(v)), isNull(cddr(v))? -1 : (int)caddr(v), false);
 }
 
 /**
@@ -207,7 +207,7 @@ public:
 
         // Lookup the component implementation
         const list<value> impl(rbtreeAssoc<value>(cname, (list<value>)impls));
-        if (isNil(impl))
+        if (isNull(impl))
             return mkfailure<value>(string("Couldn't find component implementation: ") + (string)cname);
 
         // Call its lambda function
@@ -225,7 +225,7 @@ public:
         debug(params, "modeval::implProxy::input");
 
         // If the reference was 'wiredByImpl' use the first param as target
-        if (isNil(name)) {
+        if (isNull(name)) {
             const value uri = cadr(params);
             const list<value> aparams = cons<value>(car(params), cddr(params));
             debug(uri, "modeval::implProxy::wiredByImpl::uri");
@@ -313,7 +313,7 @@ const value mkrefProxy(const value& ref, const gc_mutable_ref<list<value> >& imp
     // Use an HTTP proxy or an internal proxy to the component implementation
     if (wbyimpl)
         return mkimplProxy(nilValue, impls, sslc, timeout);
-    if (isNil(target))
+    if (isNull(target))
         return mkunwiredProxy(scdl::name(ref));
     if (http::isAbsolute(target))
         return mkhttpProxy(target, timeout);
@@ -321,7 +321,7 @@ const value mkrefProxy(const value& ref, const gc_mutable_ref<list<value> >& imp
 }
 
 const list<value> refProxies(const list<value>& refs, const gc_mutable_ref<list<value> >& impls, const SSLConf& sslc, const int timeout) {
-    if (isNil(refs))
+    if (isNull(refs))
         return refs;
     return cons(mkrefProxy(car(refs), impls, sslc, timeout), refProxies(cdr(refs), impls, sslc, timeout));
 }
@@ -352,7 +352,7 @@ const lvvlambda mkappPropProxy(const value& v) {
         if (currentRequest == NULL)
             return v;
         const RequestConf& reqc = httpd::requestConf<RequestConf>(currentRequest, &mod_tuscany_eval);
-        const value a = isNil((const list<value>)reqc.vpath)? v : car((const list<value>)reqc.vpath);
+        const value a = isNull((const list<value>)reqc.vpath)? v : car((const list<value>)reqc.vpath);
         debug(a, "modeval::appPropProxy::value");
         return a;
     };
@@ -463,7 +463,7 @@ const value mkpropProxy(const value& prop) {
 }
 
 const list<value> propProxies(const list<value>& props) {
-    if (isNil(props))
+    if (isNull(props))
         return props;
     return cons(mkpropProxy(car(props)), propProxies(cdr(props)));
 }
@@ -505,7 +505,7 @@ const value evalComponent(const string& contribPath, const value& comp, const gc
  * Return a list of component-name + configured-implementation pairs.
  */
 const list<value> componentToImplementationAssoc(const list<value>& c, const string& contribPath, const gc_mutable_ref<list<value> >& impls, const lvvlambda& lifecycle, const SSLConf& sslc, const int timeout) {
-    if (isNil(c))
+    if (isNull(c))
         return c;
     return cons<value>(mklist<value>(scdl::name(car(c)),
                 evalComponent(contribPath, car(c), impls, lifecycle, sslc, timeout)),
@@ -531,11 +531,11 @@ const failable<list<value> > getComponents(const lvvlambda& contributor, const s
         return mkfailure<list<value> >(val);
     debug(content(val), "modeval::getComponents::val");
     const list<value> valc = assoc<value>(value("content"), cdr<value>(car<value>(content(val))));
-    if (isNil(valc))
+    if (isNull(valc))
         return mkfailure<list<value> >(string("Could not get composite: ") + name);
     const list<value> comp = assoc<value>(value("composite"), cdr<value>(valc));
     debug(comp, "modeval::getComponents::comp");
-    if (isNil(comp))
+    if (isNull(comp))
         return mkfailure<list<value> >(string("Could not get composite: ") + name);
     const failable<list<string> > x = xml::writeElements(car<value>(valuesToElements(mklist<value>(mklist<value>(comp)))));
     if (!hasContent(x))
@@ -548,7 +548,7 @@ const failable<list<value> > getComponents(const lvvlambda& contributor, const s
  * Return the functions returned by the component implementations.
  */
 const failable<list<value> > applyLifecycleExpr(const list<value>& impls, const list<value>& expr) {
-    if (isNil(impls))
+    if (isNull(impls))
         return nilListValue;
 
     // Evaluate lifecycle expression against a component implementation lambda
@@ -559,7 +559,7 @@ const failable<list<value> > applyLifecycleExpr(const list<value>& impls, const
     const lvvlambda rl = content(r);
 
     // Use the returned lambda function, if any, from now on
-    const lvvlambda al = isNil(rl)? l : rl;
+    const lvvlambda al = isNull(rl)? l : rl;
 
     // Continue with the rest of the list
     const failable<list<value> > nr = applyLifecycleExpr(cdr(impls), expr);
@@ -577,7 +577,7 @@ const list<value> componentReferenceToTargetTree(const value& c) {
 }
 
 const list<value> componentReferenceToTargetAssoc(const list<value>& c) {
-    if (isNil(c))
+    if (isNull(c))
         return c;
     return cons<value>(componentReferenceToTargetTree(car(c)), componentReferenceToTargetAssoc(cdr(c)));
 }
@@ -591,26 +591,26 @@ const list<value> defaultBindingURI(const string& cn, const string& sn) {
 }
 
 const list<value> bindingToComponentAssoc(const string& cn, const string& sn, const list<value>& b) {
-    if (isNil(b))
+    if (isNull(b))
         return b;
     const value uri(scdl::uri(car(b)));
-    if (isNil(uri))
+    if (isNull(uri))
         return cons<value>(mklist<value>(defaultBindingURI(cn, sn), cn), bindingToComponentAssoc(cn, sn, cdr(b)));
     return cons<value>(mklist<value>(pathValues(c_str(string(uri))), cn), bindingToComponentAssoc(cn, sn, cdr(b)));
 }
 
 const list<value> serviceToComponentAssoc(const string& cn, const list<value>& s) {
-    if (isNil(s))
+    if (isNull(s))
         return s;
     const string sn(scdl::name(car(s)));
     const list<value> btoc(bindingToComponentAssoc(cn, sn, scdl::bindings(car(s))));
-    if (isNil(btoc))
+    if (isNull(btoc))
         return cons<value>(mklist<value>(defaultBindingURI(cn, sn), cn), serviceToComponentAssoc(cn, cdr(s)));
     return append<value>(btoc, serviceToComponentAssoc(cn, cdr(s)));
 }
 
 const list<value> uriToComponentAssoc(const list<value>& c) {
-    if (isNil(c))
+    if (isNull(c))
         return c;
     return append<value>(serviceToComponentAssoc(scdl::name(car(c)), scdl::services(car(c))), uriToComponentAssoc(cdr(c)));
 }
@@ -625,7 +625,7 @@ const failable<Composite> confComponents(const string& contribPath, const string
     debug(vhost, "modeval::confComponents::vhost");
     debug(impls, "modeval::confComponents::impls");
 
-    const failable<list<value> > fcomps = isNil(contributor)?
+    const failable<list<value> > fcomps = isNull(contributor)?
         readComponents(scdl::resourcePath(length(vhost) != 0? contribPath + vhost + "/" : contribPath, composName)) :
         getComponents(contributor, vhost);
     if (!hasContent(fcomps))
@@ -641,7 +641,7 @@ const failable<Composite> confComponents(const string& contribPath, const string
     debug(flatten(svcs), "modeval::confComponents::svcs");
 
     const list<value> cimpls = mkbrbtree(sort(componentToImplementationAssoc(comps,
-                    isNil(contributor)? length(vhost) != 0? contribPath + vhost + "/" : contribPath : contribPath,
+                    isNull(contributor)? length(vhost) != 0? contribPath + vhost + "/" : contribPath : contribPath,
                     impls, lifecycle, sslc, timeout)));
     debug(flatten(cimpls), "modeval::confComponents::impls");
 
@@ -701,7 +701,7 @@ const failable<int> get(const list<value>& rpath, request_rec* const r, const lv
     const list<value> ma = assoc(value("method"), args);
 
     // Evaluate a JSON-RPC request and return a JSON result
-    if (!isNil(ia) && !isNil(ma)) {
+    if (!isNull(ia) && !isNull(ma)) {
 
         // Extract the request id, method and params
         const value id = cadr(ia);
@@ -725,13 +725,13 @@ const failable<int> get(const list<value>& rpath, request_rec* const r, const lv
     debug(c, "modeval::get::content");
 
     // Return a nil value as a not found status
-    if (!isList(c) && isNil(c))
+    if (!isList(c) && isNull(c))
         return HTTP_NOT_FOUND;
 
     // Write in the format requested by the client, if any
     const list<value> fmt = assoc<value>("format", args);
-    const value mtype = !isNil(fmt)? cadr(fmt) : acceptMediaType(r);
-    if (!isNil(mtype)) {
+    const value mtype = !isNull(fmt)? cadr(fmt) : acceptMediaType(r);
+    if (!isNull(mtype)) {
         if (mtype == "scheme")
             return httpd::writeResult(scheme::writeValue(c), "text/x-scheme; charset=utf-8", r);
         if (mtype == "json")
@@ -747,26 +747,26 @@ const failable<int> get(const list<value>& rpath, request_rec* const r, const lv
     }
 
     // Write an empty list as a JSON value
-    if (isNil((list<value>)c)) {
+    if (isNull((list<value>)c)) {
         debug(nilListValue, "modeval::get::empty");
         return httpd::writeResult(json::writeValue(c), "application/json; charset=utf-8", r);
     }
 
     // Write content-type / content-list pair
-    if (isString(car<value>(c)) && !isNil(cdr<value>(c)) && isList(cadr<value>(c)))
+    if (isString(car<value>(c)) && !isNull(cdr<value>(c)) && isList(cadr<value>(c)))
         return httpd::writeResult(convertValues<string>(cadr<value>(c)), car<value>(c), r);
 
     // Write an assoc value as a JSON value
-    if (isSymbol(car<value>(c)) && !isNil(cdr<value>(c))) {
+    if (isSymbol(car<value>(c)) && !isNull(cdr<value>(c))) {
         debug(c, "modeval::get::assoc");
         return httpd::writeResult(json::writeValue(c), "application/json; charset=utf-8", r);
     }
 
     // Write an ATOM feed or entry
     const list<value> e = valuesToElements(c);
-    if (isList(car<value>(e)) && !isNil(car<value>(e))) {
+    if (isList(car<value>(e)) && !isNull(car<value>(e))) {
         const list<value> el = car<value>(e);
-        if (isSymbol(car<value>(el)) && car<value>(el) == element && !isNil(cdr<value>(el)) && isSymbol(cadr<value>(el)) && elementHasChildren(el) && !elementHasValue(el)) {
+        if (isSymbol(car<value>(el)) && car<value>(el) == element && !isNull(cdr<value>(el)) && isSymbol(cadr<value>(el)) && elementHasChildren(el) && !elementHasValue(el)) {
             if (cadr<value>(el) == atom::feed)
                 return httpd::writeResult(atom::writeATOMFeed(e), "application/atom+xml; charset=utf-8", r);
             if (cadr<value>(el) == atom::entry)
@@ -829,7 +829,7 @@ const failable<int> post(const list<value>& rpath, request_rec* const r, const l
 
         // Report HTTP status code
         const value rval = content(val);
-        if (isNil(rval) || rval == falseValue)
+        if (isNull(rval) || rval == falseValue)
             return HTTP_NOT_FOUND;
         if (isNumber(rval))
             return (int)rval;
@@ -870,7 +870,7 @@ const failable<int> put(const list<value>& rpath, request_rec* const r, const lv
 
     // Report HTTP status
     const value rval = content(val);
-    if (isNil(rval) || rval == falseValue)
+    if (isNull(rval) || rval == falseValue)
         return HTTP_NOT_FOUND;
     if (isNumber(rval))
         return (int)rval;
@@ -898,7 +898,7 @@ const failable<int> patch(const list<value>& rpath, request_rec* const r, const
 
     // Report HTTP status
     const value rval = content(val);
-    if (isNil(rval) || rval == falseValue)
+    if (isNull(rval) || rval == falseValue)
         return HTTP_NOT_FOUND;
     if (isNumber(rval))
         return (int)rval;
@@ -918,7 +918,7 @@ const failable<int> del(const list<value>& rpath, request_rec* const r, const lv
 
     // Report HTTP status
     const value rval = content(val);
-    if (isNil(rval) || rval == falseValue)
+    if (isNull(rval) || rval == falseValue)
         return HTTP_NOT_FOUND;
     if (isNumber(rval))
         return (int)rval;
@@ -954,10 +954,10 @@ int translateComponent(request_rec* const r, const list<value>& rpath, const lis
     debug(flatten(impls), "modeval::translateComponent::impls");
 
     // Find the requested component
-    if (isNil(cdr(rpath)))
+    if (isNull(cdr(rpath)))
         return HTTP_NOT_FOUND;
     const list<value> impl(rbtreeAssoc(cadr(rpath), impls));
-    if (isNil(impl))
+    if (isNull(impl))
         return HTTP_NOT_FOUND;
     debug(impl, "modeval::translateComponent::impl");
 
@@ -973,16 +973,16 @@ int translateReference(request_rec* const r, const list<value>& rpath, const lis
     debug(flatten(refs), "modeval::translateReference::refs");
 
     // Find the requested component
-    if (isNil(cdr(rpath)))
+    if (isNull(cdr(rpath)))
         return HTTP_NOT_FOUND;
     const list<value> comp(rbtreeAssoc(cadr(rpath), refs));
-    if (isNil(comp))
+    if (isNull(comp))
         return HTTP_NOT_FOUND;
     debug(comp, "modeval::translateReference::comp");
 
     // Find the requested reference and target configuration
     const list<value> ref(rbtreeAssoc<value>(caddr(rpath), cadr(comp)));
-    if (isNil(ref))
+    if (isNull(ref))
         return HTTP_NOT_FOUND;
     debug(ref, "modeval::translateReference::ref");
 
@@ -1014,9 +1014,9 @@ int translateReference(request_rec* const r, const list<value>& rpath, const lis
  * Find a leaf matching a request path in a tree of URI paths.
  */
 const int matchPath(const list<value>& k, const list<value>& p) {
-    if (isNil(p))
+    if (isNull(p))
         return true;
-    if (isNil(k))
+    if (isNull(k))
         return false;
     if (car(k) != car(p))
         return false;
@@ -1024,7 +1024,7 @@ const int matchPath(const list<value>& k, const list<value>& p) {
 }
 
 const list<value> assocPath(const value& k, const list<value>& tree) {
-    if (isNil(tree))
+    if (isNull(tree))
         return tree;
     if (matchPath(k, car<value>(car(tree))))
         return car(tree);
@@ -1041,10 +1041,10 @@ int translateService(request_rec* const r, const list<value>& rpath, const list<
     debug(flatten(svcs), "modeval::translateService::svcs");
 
     // Find the requested component
-    if (isNil(rpath))
+    if (isNull(rpath))
         return HTTP_NOT_FOUND;
     const list<value> svc(assocPath(rpath, svcs));
-    if (isNil(svc))
+    if (isNull(svc))
         return DECLINED;
     debug(svc, "modeval::translateService::svc");
 
@@ -1061,7 +1061,7 @@ int translateService(request_rec* const r, const list<value>& rpath, const list<
 const int translateRequest(request_rec* const r, const list<value>& rpath, const list<value>& vpath, const list<value>& refs, const list<value>& svcs, const list<value>& impls) {
     debug(vpath, "modeval::translateRequest::vpath");
     debug(rpath, "modeval::translateRequest::rpath");
-    const string prefix = isNil(rpath)? emptyStringValue : car(rpath);
+    const string prefix = isNull(rpath)? emptyStringValue : car(rpath);
 
     // Translate a component request
     if ((prefix == string("components") || prefix == string("c")) && translateComponent(r, rpath, vpath, impls) == OK)
@@ -1076,7 +1076,7 @@ const int translateRequest(request_rec* const r, const list<value>& rpath, const
         return proceedToHandler(r, OK);
 
     // Attempt to map a request targeting the main host to an actual file
-    if (isNil(vpath)) {
+    if (isNull(vpath)) {
         const failable<request_rec*> fnr = httpd::internalSubRequest(r->uri, r);
         if (!hasContent(fnr))
             return rcode(fnr);
@@ -1095,7 +1095,7 @@ const int translateRequest(request_rec* const r, const list<value>& rpath, const
 
         // Make sure a document root request ends with a '/' using
         // an external redirect
-        if (isNil(rpath) && r->uri[strlen(r->uri) - 1] != '/') {
+        if (isNull(rpath) && r->uri[strlen(r->uri) - 1] != '/') {
             const string target = string(r->uri) + string("/") + (r->args != NULL? string("?") + string(r->args) : emptyString);
             debug(target, "modeval::translateRequest::location");
             return proceedToHandler(r, httpd::externalRedirect(target, r));
@@ -1128,7 +1128,7 @@ int translate(request_rec *r) {
     const list<value> rpath = pathValues(r->uri);
 
     // Let default handler handle a resource request
-    const string prefix = isNil(rpath)? emptyStringValue : car(rpath);
+    const string prefix = isNull(rpath)? emptyStringValue : car(rpath);
     if (prefix == string("vhosts") || prefix == string("v"))
         return DECLINED;
 
@@ -1137,7 +1137,7 @@ int translate(request_rec *r) {
 
     // If the request is targeting a virtual host, configure the components
     // in that virtual host
-    if (length(sc.vhostc.domain) != 0 && (length(sc.vhostc.contribPath) != 0 || !isNil(sc.vhostc.contributor)) && httpd::isVhostRequest(sc.server, sc.vhostc.domain, r)) {
+    if (length(sc.vhostc.domain) != 0 && (length(sc.vhostc.contribPath) != 0 || !isNull(sc.vhostc.contributor)) && httpd::isVhostRequest(sc.server, sc.vhostc.domain, r)) {
         const string vname = http::subDomain(httpd::hostName(r));
         const failable<Composite> fvcompos = confComponents(sc.vhostc.contribPath, sc.vhostc.composName, sc.vhostc.contributor, vname, reqc.impls, (value)sc.lifecycle, sc.sslc, sc.timeout);
         if (!hasContent(fvcompos))
@@ -1158,7 +1158,7 @@ int translate(request_rec *r) {
         return rc;
 
     // Attempt to map the first segment of the request path to a virtual host
-    if (length(prefix) != 0 && (length(sc.vhostc.contribPath) != 0 || !isNil(sc.vhostc.contributor))) {
+    if (length(prefix) != 0 && (length(sc.vhostc.contribPath) != 0 || !isNull(sc.vhostc.contributor))) {
         const string vname = prefix;
         const failable<Composite> fvcompos = confComponents(sc.vhostc.contribPath, sc.vhostc.composName, sc.vhostc.contributor, vname, reqc.impls, (value)sc.lifecycle, sc.sslc, sc.timeout);
         if (!hasContent(fvcompos))
@@ -1180,7 +1180,7 @@ const int handleRequest(const list<value>& rpath, request_rec* const r, const li
 
     // Get the component implementation lambda
     const list<value> impl(rbtreeAssoc<value>(cadr(rpath), impls));
-    if (isNil(impl)) {
+    if (isNull(impl)) {
         mkfailure<int>(string("Couldn't find component implementation: ") + (string)cadr(rpath));
         return HTTP_NOT_FOUND;
     }
@@ -1233,14 +1233,14 @@ int handler(request_rec* r) {
         debug(redir, "modeval::handler::internalredirect");
         return httpd::internalRedirect(redir, r);
     }
-    if (isNil((const list<value>)reqc.rpath))
+    if (isNull((const list<value>)reqc.rpath))
         return HTTP_NOT_FOUND;
 
     // Get the server configuration
     const ServerConf& sc = httpd::serverConf<ServerConf>(r, &mod_tuscany_eval);
 
     // Handle a request targeting a component in a virtual host
-    if (!isNil((const list<value>)reqc.vpath)) {
+    if (!isNull((const list<value>)reqc.vpath)) {
 
         // Start the components in the virtual host
         const failable<list<value> > fsimpls = startComponents(reqc.impls);
@@ -1280,7 +1280,7 @@ authn_status checkPassword(request_rec* r, const char* u, const char* p) {
 
     // Get the server configuration
     const ServerConf& sc = httpd::serverConf<ServerConf>(r, &mod_tuscany_eval);
-    if (isNil(sc.vhostc.authenticator)) {
+    if (isNull(sc.vhostc.authenticator)) {
         mkfailure<int>("SCA authenticator not configured");
         return AUTH_GENERAL_ERROR;
     }
@@ -1293,9 +1293,9 @@ authn_status checkPassword(request_rec* r, const char* u, const char* p) {
         return AUTH_USER_NOT_FOUND;
     }
     const value hval = content(val);
-    const list<value> hcontent = isList(hval) && !isNil(hval) && isList(car<value>(hval)) && !isNil(car<value>(hval))?  assoc<value>(value("content"), cdr<value>(car<value>(hval))) : nilListValue;
-    const list<value> hassoc = isNil(hcontent)? nilListValue : assoc<value>(value("hash"), cdr<value>(hcontent));
-    if (isNil(hassoc)) {
+    const list<value> hcontent = isList(hval) && !isNull(hval) && isList(car<value>(hval)) && !isNull(car<value>(hval))?  assoc<value>(value("content"), cdr<value>(car<value>(hval))) : nilListValue;
+    const list<value> hassoc = isNull(hcontent)? nilListValue : assoc<value>(value("hash"), cdr<value>(hcontent));
+    if (isNull(hassoc)) {
         mkfailure<int>(string("SCA authentication check user failed, hash not found: ") + user, -1, user != "admin");
         return AUTH_USER_NOT_FOUND;
     }
@@ -1330,10 +1330,10 @@ apr_status_t serverCleanup(void* v) {
     stopComponents(sc.compos.impls);
 
     // Call the module lifecycle function
-    if (isNil((value)sc.lifecycle))
+    if (isNull((value)sc.lifecycle))
         return APR_SUCCESS;
     const lvvlambda ll = (value)sc.lifecycle;
-    if (isNil(ll))
+    if (isNull(ll))
         return APR_SUCCESS;
 
     debug((value)sc.lifecycle, "modeval::serverCleanup::stop");
@@ -1449,7 +1449,7 @@ void childInit(apr_pool_t* p, server_rec* s) {
     // Get the vhost contributor component implementation lambda
     if (length(sc.vhostc.contributorName) != 0) {
         const list<value> impl(rbtreeAssoc<value>((string)sc.vhostc.contributorName, (const list<value>)sc.compos.impls));
-        if (isNil(impl)) {
+        if (isNull(impl)) {
             mkfailure<int>(string("Couldn't find contributor component implementation: ") + sc.vhostc.contributorName);
             failureExitChild();
         }
@@ -1459,7 +1459,7 @@ void childInit(apr_pool_t* p, server_rec* s) {
     // Get the vhost authenticator component implementation lambda
     if (length(sc.vhostc.authenticatorName) != 0) {
         const list<value> impl(rbtreeAssoc<value>((string)sc.vhostc.authenticatorName, (const list<value>)sc.compos.impls));
-        if (isNil(impl)) {
+        if (isNull(impl)) {
             mkfailure<int>(string("Couldn't find authenticator component implementation: ") + sc.vhostc.authenticatorName);
             failureExitChild();
         }
diff --git a/sca-cpp/trunk/modules/server/mod-scheme.hpp b/sca-cpp/trunk/modules/server/mod-scheme.hpp
index 36d91dc904..6a387a0991 100644
--- a/sca-cpp/trunk/modules/server/mod-scheme.hpp
+++ b/sca-cpp/trunk/modules/server/mod-scheme.hpp
@@ -43,7 +43,7 @@ namespace modscheme {
  * Convert proxy lambdas to evaluator primitive procedures.
  */
 const list<value> primitiveProcedures(const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons<value>(mklist<value>(scheme::primitiveSymbol, car(l)), primitiveProcedures(cdr(l)));
 }
@@ -58,7 +58,7 @@ const failable<lvvlambda > evalImplementation(const string& path, const value& i
     if (fail(is))
         return mkfailure<lvvlambda >(string("Could not read implementation: ") + fpath);
     const value script = scheme::readScript(is);
-    if (isNil(script))
+    if (isNull(script))
         return mkfailure<lvvlambda >(string("Could not read implementation: ") + fpath);
     const list<value> pxproc = scheme::quotedParameters(primitiveProcedures(px));
 
@@ -68,7 +68,7 @@ const failable<lvvlambda > evalImplementation(const string& path, const value& i
         debug(expr, "modeval::scheme::applyImplementation::input");
         scheme::Env env = scheme::setupEnvironment();
         const value res = scheme::evalScript(expr, script, env);
-        const value val = isNil(res)? mklist<value>(nilValue, string("Could not evaluate expression")) : mklist<value>(res);
+        const value val = isNull(res)? mklist<value>(nilValue, string("Could not evaluate expression")) : mklist<value>(res);
         debug(val, "modeval::scheme::applyImplementation::result");
         return val;
     };
diff --git a/sca-cpp/trunk/modules/wsgi/atomutil.py b/sca-cpp/trunk/modules/wsgi/atomutil.py
index 4b67ef216e..d65b26c41c 100644
--- a/sca-cpp/trunk/modules/wsgi/atomutil.py
+++ b/sca-cpp/trunk/modules/wsgi/atomutil.py
@@ -24,23 +24,23 @@ from xmlutil import *
 # Convert a list of elements to a list of values representing an ATOM entry
 def entryElementValues(e):
     lt = filter(selector((element, "'title")), e)
-    t = "" if isNil(lt) else elementValue(car(lt))
+    t = "" if isNull(lt) else elementValue(car(lt))
     li = filter(selector((element, "'id")), e)
-    i = "" if isNil(li) else elementValue(car(li))
+    i = "" if isNull(li) else elementValue(car(li))
     lc = filter(selector((element, "'content")), e)
     return append((element, "'entry", (element, "'title", t), (element, "'id", i)),
-            () if isNil(lc) else () if isAttribute(elementValue(car(lc))) else ((element, "'content", elementValue(car(lc))),))
+            () if isNull(lc) else () if isAttribute(elementValue(car(lc))) else ((element, "'content", elementValue(car(lc))),))
 
 # Convert a list of elements to a list of values representing ATOM entries
 def entriesElementValues(e):
-    if isNil(e):
+    if isNull(e):
         return e
     return cons(entryElementValues(car(e)), entriesElementValues(cdr(e)))
 
 # Convert a list of strings to a list of values representing an ATOM entry
 def readATOMEntry(l):
     e = readXML(l)
-    if isNil(e):
+    if isNull(e):
         return ()
     return (entryElementValues(car(e)),)
 
@@ -59,7 +59,7 @@ def isATOMEntry(l):
 # Convert a list of strings to a list of values representing an ATOM feed
 def readATOMFeed(l):
     f = readXML(l)
-    if isNil(f):
+    if isNull(f):
         return ()
     t = filter(selector((element, "'title")), car(f))
     i = filter(selector((element, "'id")), car(f))
@@ -73,44 +73,44 @@ def entryElement(l):
     title = elementValue(namedElementChild("'title", l))
     id = elementValue(namedElementChild("'id", l))
     content = namedElementChild("'content", l)
-    text = False if isNil(content) else elementHasValue(content)
+    text = False if isNull(content) else elementHasValue(content)
     return append(append(
             (element, "'entry", (attribute, "'xmlns", "http://www.w3.org/2005/Atom"),
              (element, "'title", (attribute, "'type", "text"), title),
              (element, "'id", id)),
-            () if isNil(content) else (append(
+            () if isNull(content) else (append(
                 (element, "'content", (attribute, "'type", "text" if text else "application/xml")), (elementValue(content),) if text else elementChildren(content)),)),
             ((element, "'link", (attribute, "'href", id)),))
 
 # Convert a list of values representing ATOM entries to a list of elements
 def entriesElements(l):
-    if isNil(l):
+    if isNull(l):
         return l
     return cons(entryElement(car(l)), entriesElements(cdr(l)))
 
 # Convert a list of values representing an ATOM entry to an ATOM entry
 def writeATOMEntry(ll):
-    l = ll if isNil(ll) else car(ll)
+    l = ll if isNull(ll) else car(ll)
     return writeXML((entryElement(l),), True)
 
 # Convert a list of values representing an ATOM feed to an ATOM feed
 def writeATOMFeed(ll):
-    l = ll if isNil(ll) else car(ll)
+    l = ll if isNull(ll) else car(ll)
     lt = filter(selector((element, "'title")), l)
-    t = '' if isNil(lt) else elementValue(car(lt))
+    t = '' if isNull(lt) else elementValue(car(lt))
     li = filter(selector((element, "'id")), l)
-    i = '' if isNil(li) else elementValue(car(li))
+    i = '' if isNull(li) else elementValue(car(li))
     f = (element, "'feed", (attribute, "'xmlns", "http://www.w3.org/2005/Atom"),
             (element, "'title", (attribute, "'type", "text"), t),
             (element, "'id", i))
 
     # Write ATOM entries
     le = filter(selector((element, "'entry")), l)
-    if isNil(le):
+    if isNull(le):
         return writeXML((f,), True)
 
     # Write a single ATOM entry element with a list of values
-    if not isNil(le) and not isNil(car(le)) and isList(car(caddr(car(le)))):
+    if not isNull(le) and not isNull(car(le)) and isList(car(caddr(car(le)))):
         fe = append(f, entriesElements(caddr(car(le))))
         return writeXML((fe,), True)
 
diff --git a/sca-cpp/trunk/modules/wsgi/composite.py b/sca-cpp/trunk/modules/wsgi/composite.py
index 77f2ecdb59..fbec66dc33 100755
--- a/sca-cpp/trunk/modules/wsgi/composite.py
+++ b/sca-cpp/trunk/modules/wsgi/composite.py
@@ -59,7 +59,7 @@ def requestIfNoneMatch(e):
 
 # Hash a list of strings into an MD5 signature
 def md5update(md, s):
-    if isNil(s):
+    if isNull(s):
         return md.hexdigest()
     md.update(car(s))
     return md5update(md, cdr(s))
@@ -113,7 +113,7 @@ def fileresult(e, r, ct, f):
 
 # Converts the args received in a POST to a list of key value pairs
 def postArgs(a):
-    if isNil(a):
+    if isNull(a):
         return ((),)
     l = car(a);
     return cons(l, postArgs(cdr(a)))
@@ -188,16 +188,16 @@ def application(e, r):
             return result(e, r, 200, (("Content-type", "application/json"),), writeJSON(()))
 
         # Write content-type / content-list pair
-        if isString(car(v)) and not isNil(cdr(v)) and isList(cadr(v)):
+        if isString(car(v)) and not isNull(cdr(v)) and isList(cadr(v)):
             return result(e, r, 200, (("Content-type", car(v)),), cadr(v))
         
         # Convert list of values to element values
         ve = valuesToElements(v)
 
         # Write an assoc result as a JSON value
-        if isList(car(ve)) and not isNil(car(ve)):
+        if isList(car(ve)) and not isNull(car(ve)):
             el = car(ve)
-            if isSymbol(car(el)) and car(el) == element and not isNil(cdr(el)) and isSymbol(cadr(el)):
+            if isSymbol(car(el)) and car(el) == element and not isNull(cdr(el)) and isSymbol(cadr(el)):
                 if cadr(el) == "'feed":
                     return result(e, r, 200, (("Content-type", "application/atom+xml"),), writeATOMFeed(ve))
                 if cadr(el) == "'entry":
@@ -224,7 +224,7 @@ def application(e, r):
         if contains(ct, "application/atom+xml"):
             ae = elementsToValues(readATOMEntry(requestBody(e)))
             v = comp("post", id, ae)
-            if isNil(v):
+            if isNull(v):
                 return failure(e, r, 500)
             return result(e, r, 201, (("Location", request_uri(e) + "/" + "/".join(v)),))
         return failure(e, r, 500)
diff --git a/sca-cpp/trunk/modules/wsgi/elemutil.py b/sca-cpp/trunk/modules/wsgi/elemutil.py
index 00b76c5c6e..bb176e7ffe 100644
--- a/sca-cpp/trunk/modules/wsgi/elemutil.py
+++ b/sca-cpp/trunk/modules/wsgi/elemutil.py
@@ -25,13 +25,13 @@ atsign = "'@"
 
 # Return true if a value is an element
 def isElement(v):
-    if not isList(v) or isNil(v) or v == None or car(v) != element:
+    if not isList(v) or isNull(v) or v == None or car(v) != element:
         return False
     return True
 
 # Return true if a value is an attribute
 def isAttribute(v):
-    if not isList(v) or isNil(v) or v == None or car(v) != attribute:
+    if not isList(v) or isNull(v) or v == None or car(v) != attribute:
         return False
     return True
 
@@ -49,7 +49,7 @@ def elementName(l):
 
 # Return true if an element has children
 def elementHasChildren(l):
-    return not isNil(cddr(l))
+    return not isNull(cddr(l))
 
 # Return the children of an element
 def elementChildren(l):
@@ -60,7 +60,7 @@ def elementHasValue(l):
     r = reverse(l)
     if isSymbol(car(r)):
         return False
-    if isList(car(r)) and not isNil(car(r)) and isSymbol(car(car(r))):
+    if isList(car(r)) and not isNull(car(r)) and isSymbol(car(car(r))):
         return False
     return True
 
@@ -72,7 +72,7 @@ def elementValue(l):
 def elementToValueIsList(v):
     if not isList(v):
         return False
-    return isNil(v) or not isSymbol(car(v))
+    return isNull(v) or not isSymbol(car(v))
 
 def elementToValue(t):
     if isTaggedList(t, attribute):
@@ -91,14 +91,14 @@ def elementToValue(t):
 def elementToValueIsSymbol(v):
     if not isList(v):
         return False
-    if (isNil(v)):
+    if (isNull(v)):
         return False
     if not isSymbol(car(v)):
         return False
     return True
 
 def elementToValueGroupValues(v, l):
-    if isNil(l) or not elementToValueIsSymbol(v) or not elementToValueIsSymbol(car(l)):
+    if isNull(l) or not elementToValueIsSymbol(v) or not elementToValueIsSymbol(car(l)):
         return cons(v, l)
     if car(car(l)) != car(v):
         return cons(v, l)
@@ -109,20 +109,20 @@ def elementToValueGroupValues(v, l):
     return elementToValueGroupValues(g, cdr(l))
 
 def elementsToValues(e):
-    if isNil(e):
+    if isNull(e):
         return e
     return elementToValueGroupValues(elementToValue(car(e)), elementsToValues(cdr(e)))
 
 # Convert a value to an element
 def valueToElement(t):
-    if isList(t) and not isNil(t) and isSymbol(car(t)):
+    if isList(t) and not isNull(t) and isSymbol(car(t)):
         n = car(t)
-        v = () if isNil(cdr(t)) else cadr(t)
+        v = () if isNull(cdr(t)) else cadr(t)
         if not isList(v):
             if n[0:2] == atsign:
                 return (attribute, "'" + n[2:], v)
             return (element, n, v)
-        if isNil(v) or not isSymbol(car(v)):
+        if isNull(v) or not isSymbol(car(v)):
             return cons(element, cons(n, (valuesToElements(v),)))
         return cons(element, cons(n, valuesToElements(cdr(t))))
     if not isList(t):
@@ -131,15 +131,15 @@ def valueToElement(t):
 
 # Convert a list of values to a list of elements
 def valuesToElements(l):
-    if isNil(l):
+    if isNull(l):
         return l
     return cons(valueToElement(car(l)), valuesToElements(cdr(l)))
 
 # Return a selector lambda function which can be used to filter elements
 def evalSelect(s, v):
-    if isNil(s):
+    if isNull(s):
         return True
-    if isNil(v):
+    if isNull(v):
         return False
     if car(s) != car(v):
         return False
@@ -151,7 +151,7 @@ def selector(s):
 # Return the value of the attribute with the given name
 def namedAttributeValue(name, l):
     f = filter(lambda v: isAttribute(v) and attributeName(v) == name, l)
-    if isNil(f):
+    if isNull(f):
         return None
     return caddr(car(f))
 
@@ -162,7 +162,7 @@ def namedElementChildren(name, l):
 # Return the child element with the given name
 def namedElementChild(name, l):
     f = namedElementChildren(name, l)
-    if isNil(f):
+    if isNull(f):
         return None
     return car(f)
 
diff --git a/sca-cpp/trunk/modules/wsgi/jsonutil.py b/sca-cpp/trunk/modules/wsgi/jsonutil.py
index 849b44405b..f284fd1a89 100644
--- a/sca-cpp/trunk/modules/wsgi/jsonutil.py
+++ b/sca-cpp/trunk/modules/wsgi/jsonutil.py
@@ -28,19 +28,19 @@ from elemutil import *
 
 # Return true if a list represents a JS array
 def isJSArray(l):
-    if isNil(l):
+    if isNull(l):
         return True
     v = car(l)
     if isSymbol(v):
         return False
     if isList(v):
-        if not isNil(v) and isSymbol(car(v)):
+        if not isNull(v) and isSymbol(car(v)):
             return False
     return True
 
 # Converts JSON properties to values
 def jsPropertiesToValues(propertiesSoFar, o, i):
-    if isNil(i):
+    if isNull(i):
         return propertiesSoFar
     p = car(i)
     jsv = o[p]
@@ -69,7 +69,7 @@ def jsValToValue(jsv):
 
 # Return true if a list of strings contains a JSON document
 def isJSON(l):
-    if isNil(l):
+    if isNull(l):
         return False
     s = car(l)[0:1]
     return s == "[" or s == "{"
@@ -83,7 +83,7 @@ def readJSON(l):
 
 # Convert a list of values to JSON array elements
 def valuesToJSElements(a, l, i):
-    if isNil(l):
+    if isNull(l):
         return a
     pv = valueToJSVal(car(l))
     a[i] = pv
@@ -99,7 +99,7 @@ def valueToJSVal(v):
 
 # Convert a list of values to JSON properties
 def valuesToJSProperties(o, l):
-    if isNil(l):
+    if isNull(l):
         return o
     token = car(l)
     if isTaggedList(token, attribute):
diff --git a/sca-cpp/trunk/modules/wsgi/rssutil.py b/sca-cpp/trunk/modules/wsgi/rssutil.py
index 984d71b690..c1b326c82d 100644
--- a/sca-cpp/trunk/modules/wsgi/rssutil.py
+++ b/sca-cpp/trunk/modules/wsgi/rssutil.py
@@ -24,22 +24,22 @@ from xmlutil import *
 # Convert a list of elements to a list of values representing an RSS entry
 def entryElementsToValues(e):
     lt = filter(selector((element, "'title")), e)
-    t = "" if isNil(lt) else elementValue(car(lt))
+    t = "" if isNull(lt) else elementValue(car(lt))
     li = filter(selector((element, "'link")), e)
-    i = "" if isNil(li) else elementValue(car(li))
+    i = "" if isNull(li) else elementValue(car(li))
     lc = filter(selector((element, "'description")), e)
     return (t, i, elementValue(car(lc)))
 
 # Convert a list of elements to a list of values representing RSS entries
 def entriesElementsToValues(e):
-    if isNil(e):
+    if isNull(e):
         return e
     return cons(entryElementsToValues(car(e)), entriesElementsToValues(cdr(e)))
 
 # Convert a list of strings to a list of values representing an RSS entry
 def readRSSEntry(l):
     e = readXML(l)
-    if isNil(e):
+    if isNull(e):
         return ()
     return entryElementsToValues(car(e))
 
@@ -57,19 +57,19 @@ def isRSSFeed(l):
 # Convert a list of strings to a list of values representing an RSS feed
 def readRSSFeed(l):
     f = readXML(l)
-    if isNil(f):
+    if isNull(f):
         return ()
     c = filter(selector((element, "'channel")), car(f))
     t = filter(selector((element, "'title")), car(c))
     i = filter(selector((element, "'link")), car(c))
     e = filter(selector((element, "'item")), car(c))
-    if isNil(e):
+    if isNull(e):
         return (elementValue(car(t)), elementValue(car(i)))
     return cons(elementValue(car(t)), cons(elementValue(car(i)), entriesElementsToValues(e)))
 
 # Convert an RSS feed containing elements to an RSS feed containing values
 def feedValuesLoop(e):
-    if (isNil(e)):
+    if (isNull(e)):
         return e
     return cons(entryValue(car(e)), feedValuesLoop(cdr(e)))
 
@@ -85,7 +85,7 @@ def entryElement(l):
 
 # Convert a list of values representing RSS entries to a list of elements
 def entriesElements(l):
-    if isNil(l):
+    if isNull(l):
         return l
     return cons(entryElement(car(l)), entriesElements(cdr(l)))
 
@@ -98,7 +98,7 @@ def writeRSSFeed(l):
     c = ((element, "'title", car(l)),
             (element, "'link", cadr(l)),
             (element, "'description", car(l)))
-    ce = c if isNil(cddr(l)) else append(c, entriesElements(cddr(l)))
+    ce = c if isNull(cddr(l)) else append(c, entriesElements(cddr(l)))
     fe = (element, "'rss", (attribute, "'version", "2.0"), append((element, "'channel"), ce))
     return writeXML((fe,), True)
 
@@ -108,7 +108,7 @@ def entryValuesToElements(v):
 
 # Convert an RSS feed containing values to an RSS feed containing elements
 def feedValuesToElementsLoop(v):
-    if isNil(v):
+    if isNull(v):
         return v
     return cons(entryValuesToElements(car(v)), feedValuesToElementsLoop(cdr(v)))
 
diff --git a/sca-cpp/trunk/modules/wsgi/util.py b/sca-cpp/trunk/modules/wsgi/util.py
index f630455901..97931c0c09 100644
--- a/sca-cpp/trunk/modules/wsgi/util.py
+++ b/sca-cpp/trunk/modules/wsgi/util.py
@@ -57,9 +57,9 @@ def reverse(l):
     r.reverse()
     return tuple(r)
 
-def isNil(l):
+def isNull(l):
     if isinstance(l, streampair):
-        return l.isNil()
+        return l.isNull()
     return l is None or l == ()
 
 def isSymbol(v):
@@ -76,7 +76,7 @@ def isList(v):
     return True
 
 def isTaggedList(v, t):
-    return isList(v) and not isNil(v) and car(v) == t
+    return isList(v) and not isNull(v) and car(v) == t
 
 
 # Scheme-like streams
@@ -88,7 +88,7 @@ class streampair(object):
     def __repr__(self):
         return repr(self[0:len(self)])
 
-    def isNil(self):
+    def isNull(self):
         return self.cdr == ()
 
     def __len__(self):
@@ -102,7 +102,7 @@ class streampair(object):
         return self.cdr()[i - 1]
 
     def __getslice__(self, i, j):
-        if isNil(self):
+        if isNull(self):
             return ()
         if i > 0:
             if j == maxint:
@@ -156,7 +156,7 @@ def curry(f, *args):
 
 # Convert a path represented as a list of values to a string
 def path(p):
-    if isNil(p):
+    if isNull(p):
         return ""
     return "/" + car(p) + path(cdr(p))
 
diff --git a/sca-cpp/trunk/modules/wsgi/xmlutil.py b/sca-cpp/trunk/modules/wsgi/xmlutil.py
index 83b1cf2f92..bc1a1b376a 100644
--- a/sca-cpp/trunk/modules/wsgi/xmlutil.py
+++ b/sca-cpp/trunk/modules/wsgi/xmlutil.py
@@ -46,7 +46,7 @@ def readElements(l):
 
 # Return true if a list of strings represents an XML document
 def isXML(l):
-    if isNil(l):
+    if isNull(l):
         return False
     if car(l)[0:5] != "<?xml":
         return False
@@ -86,12 +86,12 @@ def readXML(l):
 
 # Write a list of XML element and attribute tokens
 def expandElementValues(n, l):
-    if isNil(l):
+    if isNull(l):
         return l
     return cons(cons(element, cons(n, car(l))), expandElementValues(n, cdr(l)))
 
 def writeList(l, xml):
-    if isNil(l):
+    if isNull(l):
         return xml
     token = car(l)
     if isTaggedList(token, attribute):
diff --git a/sca-cpp/trunk/modules/xml/xml.hpp b/sca-cpp/trunk/modules/xml/xml.hpp
index 0a04d5f90a..70747e2157 100644
--- a/sca-cpp/trunk/modules/xml/xml.hpp
+++ b/sca-cpp/trunk/modules/xml/xml.hpp
@@ -192,7 +192,7 @@ inline const value readToken(XMLReader& reader) {
  */
 inline const list<value> readList(const list<value>& listSoFar, XMLReader& reader) {
     const value token = readToken(reader);
-    if(isNil(token) || endElement == token)
+    if(isNull(token) || endElement == token)
         return reverse(listSoFar);
     if(startElement == token)
         return readList(cons<value>(readList(mklist(element), reader), listSoFar), reader);
@@ -225,7 +225,7 @@ public:
  */
 inline int readCallback(void *context, char* buffer, int len) {
     XMLReadContext& rc = *(XMLReadContext*)context;
-    if (isNil((const list<string>)rc.ilist))
+    if (isNull((const list<string>)rc.ilist))
         return 0;
     const list<string> f(fragment(rc.ilist, len));
     const string s(car(f));
@@ -238,7 +238,7 @@ inline int readCallback(void *context, char* buffer, int len) {
  * Return true if a list of strings contains an XML document.
  */
 inline const bool isXML(const list<string>& ls) {
-    if (isNil(ls))
+    if (isNull(ls))
         return false;
     return substr(car(ls), 0, 5) == "<?xml";
 }
@@ -266,13 +266,13 @@ const char* const encoding = "UTF-8";
  * Write a list of XML element or attribute tokens.
  */
 inline const list<value> expandElementValues(const value& n, const list<value>& l) {
-    if (isNil(l))
+    if (isNull(l))
         return l;
     return cons<value>(value(cons<value>(element, cons<value>(n, isList(car(l))? (list<value>)car(l) : mklist(car(l))))), expandElementValues(n, cdr(l)));
 }
 
 inline const failable<bool> writeList(const list<value>& l, const xmlTextWriterPtr xml) {
-    if (isNil(l))
+    if (isNull(l))
         return true;
 
     // Write an attribute