Turn script values inside out to avoid throwing internally

4 files changed, 20 insertions, 21 deletions

diff --git a/project2/common/scripts.cpp b/project2/common/scripts.cpp
index 4e9f18b..997f558 100644
--- a/project2/common/scripts.cpp
+++ b/project2/common/scripts.cpp
@@ -20,24 +20,21 @@ ScriptNode::variable(const Glib::ustring & n, const VariableType & def) const
 VariableType
 ScriptNode::value(const Glib::ustring & n, const VariableType & def) const
 {
-	try {
-		return value(n);
-	}
-	catch (const ValueNotFound &) {
-		return def;
+	VariableType r;
+	if (applyValue(n, r)) {
+		return r;
 	}
+	return def;
 }
 
-bool
-ScriptNode::applyValue(const Glib::ustring & n, VariableType & target) const
+VariableType
+ScriptNode::value(const Glib::ustring & n) const
 {
-	try {
-		target = value(n);
-		return true;
-	}
-	catch (const ValueNotFound &) {
-		return false;
+	VariableType r;
+	if (applyValue(n, r)) {
+		return r;
 	}
+	throw ValueNotFound(n);
 }
 
 void
diff --git a/project2/common/scripts.h b/project2/common/scripts.h
index b7fdec9..405056e 100644
--- a/project2/common/scripts.h
+++ b/project2/common/scripts.h
@@ -38,11 +38,11 @@ class ScriptNode : public IntrusivePtrBase {
 		virtual ScriptNodes childrenIn(const Glib::ustring & sub) const = 0;
 		
 		virtual bool valueExists(const Glib::ustring & name) const = 0;
-		bool applyValue(const Glib::ustring & name, VariableType & target) const;
+		virtual bool applyValue(const Glib::ustring & name, VariableType & target) const = 0;
 		virtual VariableImpl * variable(const boost::optional<Glib::ustring> & defaultSource = boost::optional<Glib::ustring>()) const = 0;
 		virtual VariableImpl * variable(const Glib::ustring & name) const = 0;
 		VariableImpl * variable(const Glib::ustring & name, const VariableType & def) const;
-		virtual VariableType value(const Glib::ustring & name) const = 0;
+		VariableType value(const Glib::ustring & name) const;
 		VariableType value(const Glib::ustring & name, const VariableType & def) const;
 		virtual void composeWithCallbacks(const LiteralCallback &, const NodeCallback &) const = 0;
 
diff --git a/project2/xml/xmlScriptParser.cpp b/project2/xml/xmlScriptParser.cpp
index 5091f31..af69566 100644
--- a/project2/xml/xmlScriptParser.cpp
+++ b/project2/xml/xmlScriptParser.cpp
@@ -194,11 +194,12 @@ XmlScriptNode::variable(const boost::optional<Glib::ustring> & defaultSource) co
 	}
 }
 
-VariableType
-XmlScriptNode::value(const Glib::ustring & n) const
+bool
+XmlScriptNode::applyValue(const Glib::ustring & n, VariableType & val) const
 {
 	if (const xmlpp::Attribute * a = element->get_attribute(n)) {
-		return a->get_value();
+		val = a->get_value();
+		return true;
 	}
 	const xmlpp::Element::NodeList cs = element->get_children(n);
 	if (cs.size() == 1) {
@@ -210,10 +211,11 @@ XmlScriptNode::value(const Glib::ustring & n) const
 			else {
 				v = new VariableLiteral(new XmlScriptNode(c, script));
 			}
-			return v->value();
+			val = v->value();
+			return false;
 		}
 	}
-	throw ValueNotFound(n);
+	return false;
 }
 
 void
diff --git a/project2/xml/xmlScriptParser.h b/project2/xml/xmlScriptParser.h
index 2d2d5db..9862f49 100644
--- a/project2/xml/xmlScriptParser.h
+++ b/project2/xml/xmlScriptParser.h
@@ -24,7 +24,7 @@ class XmlScriptNode : public ScriptNode {
 		bool valueExists(const Glib::ustring&) const;
 		VariableImpl * variable(const boost::optional<Glib::ustring> & defaultSource) const;
 		VariableImpl * variable(const Glib::ustring&) const;
-		VariableType value(const Glib::ustring&) const;
+		bool applyValue(const Glib::ustring & name, VariableType & target) const;
 		void composeWithCallbacks(const ScriptNode::LiteralCallback&, const ScriptNode::NodeCallback&) const;
 
 	private: