1 files changed, 56 insertions, 3 deletions

diff --git a/project2/variables.cpp b/project2/variables.cpp
index 09ea36e..c6a65f1 100644
--- a/project2/variables.cpp
+++ b/project2/variables.cpp
@@ -8,6 +8,9 @@
 #include <boost/tokenizer.hpp>
 #include <boost/foreach.hpp>
 #include <boost/algorithm/string/predicate.hpp>
+#include <boost/lexical_cast.hpp>
+#include <boost/function.hpp>
+#include <boost/bind.hpp>
 
 class VariableLiteral : public VariableImpl {
 	public:
@@ -19,6 +22,7 @@ class VariableLiteral : public VariableImpl {
 class VariableImplDyn : public VariableImpl {
 	public:
 		VariableImplDyn(const Glib::ustring & src) : VariableImpl(src), cacheValid(false) { }
+		VariableImplDyn(const Glib::ustring & src, boost::optional<Glib::ustring> def) : VariableImpl(src, def), cacheValid(false) { }
 		virtual const Glib::ustring & value() const = 0;
 
 	protected:
@@ -94,6 +98,15 @@ class VariableParent : public VariableImplDyn, public RowUser {
 			depth(src.length() - source.length()),
 			dep(d)
 		{
+			bind();
+		}
+		VariableParent(const Glib::ustring & name, unsigned int d) :
+			VariableImplDyn(name, NULL),
+			row(NULL),
+			depth(d),
+			dep(NULL)
+		{
+			bind();
 		}
 		~VariableParent()
 		{
@@ -120,7 +133,7 @@ class VariableParent : public VariableImplDyn, public RowUser {
 							row->use(dep);
 						}
 					}
-					cache = row->getCurrentValue(name);
+					getValue(cache, row);
 				}
 				catch (PerRowValues::ParentOutOfRange) {
 					if (!defaultValue) {
@@ -143,9 +156,31 @@ class VariableParent : public VariableImplDyn, public RowUser {
 			cacheValid = false;
 		}
 	protected:
+		static void assignHelper(Glib::ustring & dest, const Glib::ustring & src) {
+			dest = src;
+		}
+		void bind()
+		{
+			if (name[0] == '!') {
+				if (name == "!rownum") {
+					getValue = boost::bind(&assignHelper, _1,
+							boost::bind(&boost::lexical_cast<Glib::ustring, unsigned int>,
+								boost::bind(&PerRowValues::getRowNum, _2)));
+				}
+				else {
+					throw PerRowValues::FieldDoesNotExist();
+				}
+			}
+			else {
+				typedef const Glib::ustring & (PerRowValues::*gCV)(const Glib::ustring &) const;
+				getValue = boost::bind(&assignHelper, _1,
+						boost::bind((gCV)&PerRowValues::getCurrentValue, _2, name));
+			}
+		}
 		mutable const PerRowValues * row;
 		const size_t depth;
 		const RowUser * dep;
+		boost::function2<void, Glib::ustring &, const PerRowValues *> getValue;
 };
 
 class VariableParse : public VariableImplDyn, public RowUser {
@@ -190,16 +225,21 @@ Variable::Variable(const Glib::ustring & s) :
 {
 }
 
-Variable::Variable(xmlpp::Attribute * a) :
+Variable::Variable(const xmlpp::Attribute * a) :
 	var(create(a->get_value()))
 {
 }
 
-Variable::Variable(xmlpp::Element * e) :
+Variable::Variable(const xmlpp::Element * e) :
 	var(create(e->get_child_text()->get_content()))
 {
 }
 
+Variable::Variable(VariableImpl * v) :
+	var(v)
+{
+}
+
 Variable::VariableImplPtr
 Variable::create(const Glib::ustring & s, RowUser * dep)
 {
@@ -224,6 +264,19 @@ Variable::create(const Glib::ustring & s, RowUser * dep)
 	}
 }
 
+Variable
+Variable::makeParent(const Glib::ustring & n, unsigned int d)
+{
+	return Variable(new VariableParent(n, d));
+}
+
+VariableImpl::VariableImpl(const Glib::ustring & src, boost::optional<Glib::ustring> def) :
+	source(src),
+	name(src),
+	defaultValue(def)
+{
+}
+
 VariableImpl::VariableImpl(const Glib::ustring & src) :
 	source(src)
 {