diff --git a/src/gfx/generated_image.cpp b/src/gfx/generated_image.cpp
index 16dc9fbf..ecbe77e7 100644
--- a/src/gfx/generated_image.cpp
+++ b/src/gfx/generated_image.cpp
@@ -374,7 +374,7 @@ Image BuiltInImage::generate(const Options& opt) const {
 	// TODO : use opt.width and opt.height?
 	Image img = load_resource_image(name);
 	if (!img.Ok()) {
-		throw ScriptError(_("There is no build in image '") + name + _("'"));
+		throw ScriptError(_("There is no built in image '") + name + _("'"));
 	}
 	return img;
 }
diff --git a/src/script/context.cpp b/src/script/context.cpp
index 1296d191..bac67cbf 100644
--- a/src/script/context.cpp
+++ b/src/script/context.cpp
@@ -12,8 +12,6 @@
 #include <util/error.hpp>
 #include <iostream>
 
-DECLARE_TYPEOF_COLLECTION(pair<Variable COMMA ScriptValueP>);
-
 // ----------------------------------------------------------------------------- : Context
 
 Context::Context()
@@ -290,41 +288,6 @@ class ScriptCompose : public ScriptValue {
 	ScriptValueP a,b;
 };
 
-// ----------------------------------------------------------------------------- : Closures
-
-/// A closure around a function
-class ScriptClosure : public ScriptValue {
-  public:
-	ScriptClosure(ScriptValueP fun) : fun(fun) {}
-	
-	/// Add a binding
-	void bind(Variable v, const ScriptValueP& value) {
-		bindings.push_back(make_pair(v,value));
-	}
-	/// Apply the bindings
-	void applyBindings(Context& ctx) const {
-		FOR_EACH_CONST(b, bindings) {
-			if (ctx.getVariableScope(b.first) != 0) {
-				ctx.setVariable(b.first, b.second);
-			}
-		}
-	}
-	
-	virtual ScriptType type() const { return SCRIPT_FUNCTION; }
-	virtual String typeName() const { return _("function closure"); }
-	virtual ScriptValueP eval(Context& ctx) const {
-		applyBindings(ctx);
-		return fun->eval(ctx);
-	}
-	virtual ScriptValueP dependencies(Context& ctx, const Dependency& dep) const {
-		applyBindings(ctx);
-		return fun->dependencies(ctx, dep);
-	}
-  private:
-	ScriptValueP                         fun;
-	vector<pair<Variable,ScriptValueP> > bindings;
-};
-
 // ----------------------------------------------------------------------------- : Simple instructions : binary
 
 // operator on ints
@@ -459,11 +422,14 @@ void Context::makeObject(size_t n) {
 void Context::makeClosure(size_t n, const Instruction*& instr) {
 	intrusive_ptr<ScriptClosure> closure(new ScriptClosure(stack[stack.size() - n - 1]));
 	for (size_t j = 0 ; j < n ; ++j) {
-		closure->bind((Variable)instr[n - j - 1].data, stack.back());
+		closure->addBinding((Variable)instr[n - j - 1].data, stack.back());
 		stack.pop_back();
 	}
 	// skip arguments
 	instr += n;
-	// set value
-	stack.back() = closure;
+	// set value, try to simplify
+	stack.back() = closure->simplify();
+	if (!stack.back()) {
+		stack.back() = closure;
+	}
 }
diff --git a/src/script/functions/basic.cpp b/src/script/functions/basic.cpp
index fec66ef1..6608a76d 100644
--- a/src/script/functions/basic.cpp
+++ b/src/script/functions/basic.cpp
@@ -611,9 +611,18 @@ ScriptValueP match_rule(Context& ctx) {
 SCRIPT_FUNCTION(match_rule) {
 	return match_rule(ctx);
 }
-SCRIPT_FUNCTION(match) {
+SCRIPT_FUNCTION_WITH_SIMPLIFY(match) {
 	return match_rule(ctx)->eval(ctx);
 }
+SCRIPT_FUNCTION_SIMPLIFY_CLOSURE(match) {
+	ScriptValueP match = closure.getBinding(SCRIPT_VAR_match);
+	if (match) {
+		intrusive_ptr<ScriptMatchRule> ret(new ScriptMatchRule);
+		from_script(match, ret->regex);
+		return ret;
+	}
+	return ScriptValueP();
+}
 
 // ----------------------------------------------------------------------------- : Rules : sort text
 
diff --git a/src/script/functions/functions.hpp b/src/script/functions/functions.hpp
index 4983c680..660cc1c2 100644
--- a/src/script/functions/functions.hpp
+++ b/src/script/functions/functions.hpp
@@ -26,7 +26,7 @@ void init_script_editor_functions(Context& ctx);
 void init_script_export_functions(Context& ctx);
 void init_script_english_functions(Context& ctx);
 
-/// Initialize all build in functions for a context
+/// Initialize all built in functions for a context
 inline void init_script_functions(Context& ctx) {
 	init_script_basic_functions(ctx);
 	init_script_image_functions(ctx);
diff --git a/src/script/functions/util.hpp b/src/script/functions/util.hpp
index 4abddb30..6f453f8c 100644
--- a/src/script/functions/util.hpp
+++ b/src/script/functions/util.hpp
@@ -42,20 +42,27 @@
 		SCRIPT_FUNCTION_AUX(name, virtual ScriptValueP dependencies(Context&, const Dependency&) const;)
 
 #define SCRIPT_FUNCTION_DEPENDENCIES(name)								\
-		ScriptValueP ScriptBuildin_##name::dependencies(Context& ctx, const Dependency& dep) const
+		ScriptValueP ScriptBuiltIn_##name::dependencies(Context& ctx, const Dependency& dep) const
+
+/// Macro to declare a new script function with custom closure simplification
+#define SCRIPT_FUNCTION_WITH_SIMPLIFY(name)								\
+		SCRIPT_FUNCTION_AUX(name, virtual ScriptValueP simplifyClosure(ScriptClosure&) const;)
+
+#define SCRIPT_FUNCTION_SIMPLIFY_CLOSURE(name)							\
+		ScriptValueP ScriptBuiltIn_##name::simplifyClosure(ScriptClosure& closure) const
 
 // helper for SCRIPT_FUNCTION and SCRIPT_FUNCTION_DEP
 #define SCRIPT_FUNCTION_AUX(name,dep)									\
-		class ScriptBuildin_##name : public ScriptValue {				\
+		class ScriptBuiltIn_##name : public ScriptValue {				\
 			dep															\
 			virtual  ScriptType type() const							\
 				{ return SCRIPT_FUNCTION; }								\
 			virtual String typeName() const								\
-				{ return _("build in function '") _(#name) _("'"); }	\
+				{ return _("built-in function '") _(#name) _("'"); }	\
 			virtual ScriptValueP eval(Context&) const;					\
 		};																\
-		ScriptValueP script_##name(new ScriptBuildin_##name);			\
-		ScriptValueP ScriptBuildin_##name::eval(Context& ctx) const
+		ScriptValueP script_##name(new ScriptBuiltIn_##name);			\
+		ScriptValueP ScriptBuiltIn_##name::eval(Context& ctx) const
 
 /// Return a value from a SCRIPT_FUNCTION
 #define SCRIPT_RETURN(value) return to_script(value)
diff --git a/src/script/to_value.hpp b/src/script/to_value.hpp
index b8e20944..f5607d1d 100644
--- a/src/script/to_value.hpp
+++ b/src/script/to_value.hpp
@@ -10,6 +10,7 @@
 // ----------------------------------------------------------------------------- : Includes
 
 #include <script/value.hpp>
+#include <script/script.hpp>
 #include <util/reflect.hpp>
 #include <util/error.hpp>
 #include <util/io/get_member.hpp>
@@ -290,6 +291,36 @@ class ScriptObject : public ScriptValue {
 	}
 };
 
+// ----------------------------------------------------------------------------- : Default arguments / closure
+
+/// A wrapper around a function that gives default arguments
+class ScriptClosure : public ScriptValue {
+  public:
+	ScriptClosure(ScriptValueP fun) : fun(fun) {}
+	
+	virtual ScriptType type() const;
+	virtual String typeName() const;
+	virtual ScriptValueP eval(Context& ctx) const;
+	virtual ScriptValueP dependencies(Context& ctx, const Dependency& dep) const;
+	
+	/// Add a binding
+	void addBinding(Variable v, const ScriptValueP& value);
+	/// Is there a binding for the given variable? If so, retrieve it
+	ScriptValueP getBinding(Variable v) const;
+	
+	/// Try to simplify this closure, returns a value if successful
+	ScriptValueP simplify();
+	
+	/// The wrapped function
+	ScriptValueP                          fun;
+	/// The default argument bindings
+	vector<pair<Variable,ScriptValueP> >  bindings;
+	
+  private:
+	/// Apply the bindings in a context
+	void applyBindings(Context& ctx) const;
+};
+
 // ----------------------------------------------------------------------------- : Creating
 
 /// Convert a value to a script value
@@ -329,5 +360,7 @@ template <> inline bool         from_script<bool>        (const ScriptValueP& va
 template <> inline Color        from_script<Color>       (const ScriptValueP& value) { return (AColor)*value; }
 template <> inline AColor       from_script<AColor>      (const ScriptValueP& value) { return *value; }
 
+void from_script(const ScriptValueP& value, wxRegEx& out);
+
 // ----------------------------------------------------------------------------- : EOF
 #endif
diff --git a/src/script/value.cpp b/src/script/value.cpp
index fb75f12f..20893ec6 100644
--- a/src/script/value.cpp
+++ b/src/script/value.cpp
@@ -9,9 +9,12 @@
 #include <util/prec.hpp>
 #include <script/value.hpp>
 #include <script/to_value.hpp>
+#include <script/context.hpp>
 #include <util/error.hpp>
 #include <boost/pool/singleton_pool.hpp>
 
+DECLARE_TYPEOF_COLLECTION(pair<Variable COMMA ScriptValueP>);
+
 // ----------------------------------------------------------------------------- : ScriptValue
 // Base cases
 
@@ -29,6 +32,8 @@ CompareWhat  ScriptValue::compareAs(String& compare_str, void const*& compare_pt
 	return COMPARE_AS_STRING;
 }
 
+ScriptValueP ScriptValue::simplifyClosure(ScriptClosure&) const { return ScriptValueP(); }
+
 ScriptValueP ScriptValue::dependencyMember(const String& name, const Dependency&) const { return dependency_dummy; }
 ScriptValueP ScriptValue::dependencies(Context&,               const Dependency&) const { return dependency_dummy; }
 
@@ -357,3 +362,50 @@ ScriptValueP ScriptConcatCollection::getMember(const String& name) const {
 ScriptValueP ScriptConcatCollection::makeIterator(const ScriptValueP& thisP) const {
 	return new_intrusive2<ScriptConcatCollectionIterator>(a->makeIterator(a), b->makeIterator(b));
 }
+
+// ----------------------------------------------------------------------------- : Default arguments / closure
+
+ScriptType ScriptClosure::type() const {
+	return SCRIPT_FUNCTION;
+}
+String ScriptClosure::typeName() const {
+	return fun->typeName() + _(" closure");
+}
+
+void ScriptClosure::addBinding(Variable v, const ScriptValueP& value) {
+	bindings.push_back(make_pair(v,value));
+}
+ScriptValueP ScriptClosure::getBinding(Variable v) const {
+	FOR_EACH_CONST(b, bindings) {
+		if (b.first == v) return b.second;
+	}
+	return ScriptValueP();
+}
+
+ScriptValueP ScriptClosure::simplify() {
+	return fun->simplifyClosure(*this);
+}
+
+ScriptValueP ScriptClosure::eval(Context& ctx) const {
+	applyBindings(ctx);
+	return fun->eval(ctx);
+}
+ScriptValueP ScriptClosure::dependencies(Context& ctx, const Dependency& dep) const {
+	applyBindings(ctx);
+	return fun->dependencies(ctx, dep);
+}
+void ScriptClosure::applyBindings(Context& ctx) const {
+	FOR_EACH_CONST(b, bindings) {
+		if (ctx.getVariableScope(b.first) != 0) {
+			ctx.setVariable(b.first, b.second);
+		}
+	}
+}
+
+// ----------------------------------------------------------------------------- : Destructing
+
+void from_script(const ScriptValueP& value, wxRegEx& regex) {
+	if (!regex.Compile(*value, wxRE_ADVANCED)) {
+		throw ScriptError(_ERROR_2_("can't convert", value->typeName(), _TYPE_("regex")));
+	}
+}
diff --git a/src/script/value.hpp b/src/script/value.hpp
index 17c63cc4..8582f021 100644
--- a/src/script/value.hpp
+++ b/src/script/value.hpp
@@ -13,6 +13,7 @@
 #include <gfx/color.hpp>
 class Context;
 class Dependency;
+class ScriptClosure;
 
 // ----------------------------------------------------------------------------- : ScriptValue
 
@@ -80,6 +81,11 @@ class ScriptValue : public IntrusivePtrBaseWithDelete {
 	/// Mark the scripts that this function depends on
 	/** Return value is an abstract version of the return value of eval */
 	virtual ScriptValueP dependencies(Context&, const Dependency&) const;
+	/// Simplify/optimize a default argument closure of this function.
+	/** Should return a simplification of the closure or null to keep the closure.
+	 *  Alternatively, the closure may be modified in place.
+	 */
+	virtual ScriptValueP simplifyClosure(ScriptClosure&) const;
 	
 	/// Return an iterator for the current collection, an iterator is a value that has next()
 	/** thisP can be used to prevent destruction of the collection */
diff --git a/src/util/prec.hpp b/src/util/prec.hpp
index facf909c..bed1c39a 100644
--- a/src/util/prec.hpp
+++ b/src/util/prec.hpp
@@ -28,6 +28,7 @@
 #include <wx/wx.h>
 #include <wx/image.h>
 #include <wx/datetime.h>
+#include <wx/regex.h>
 
 // Std headers
 #include <vector>