balances and values can now be iterated, to get at the component amounts

amounts.py

@@ -16,3 +16,10 @@ z = Value ("$1000.45")
 
 z += Value(x)
 print z
+
+bal = Balance (x)
+bal += Amount ("100.8 DM")
+
+print "balance:", bal
+for amt in bal:
+    print "  amount:", amt

balance.cc

@@ -92,6 +92,38 @@ void balance_t::write(std::ostream& out,
 using namespace boost::python;
 using namespace ledger;
 
+unsigned int balance_len(balance_t& bal)
+{
+  return bal.amounts.size();
+}
+
+amount_t balance_getitem(balance_t& bal, int i)
+{
+  std::size_t len = bal.amounts.size();
+
+  if (abs(i) >= len) {
+    PyErr_SetString(PyExc_IndexError, "Index out of range");
+    throw_error_already_set();
+  }
+
+  int x = i < 0 ? len + i : i;
+  amounts_map::iterator elem = bal.amounts.begin();
+  while (--x >= 0)
+    elem++;
+
+  return (*elem).second;
+}
+
+unsigned int balance_pair_len(balance_pair_t& bal_pair)
+{
+  return balance_len(bal_pair.quantity);
+}
+
+amount_t balance_pair_getitem(balance_pair_t& bal_pair, int i)
+{
+  return balance_getitem(bal_pair.quantity, i);
+}
+
 void export_balance()
 {
   class_< balance_t > ("Balance")
@@ -134,9 +166,10 @@ void export_balance()
     .def(! self)
 
     .def(abs(self))
-#if 0
-    .def(str(self))
-#endif
+    .def(self_ns::str(self))
+
+    .def("__len__", balance_len)
+    .def("__getitem__", balance_getitem)
 
     .def("negate", &balance_t::negate)
     .def("amount", &balance_t::amount)
@@ -200,9 +233,10 @@ void export_balance()
     .def(! self)
 
     .def(abs(self))
-#if 0
-    .def(str(self))
-#endif
+    .def(self_ns::str(self))
+
+    .def("__len__", balance_pair_len)
+    .def("__getitem__", balance_pair_getitem)
 
     .def("negate", &balance_pair_t::negate)
     .def("amount", &balance_pair_t::amount)

balance.h

@@ -391,6 +391,7 @@ inline balance_t abs(const balance_t& bal) {
 
 inline std::ostream& operator<<(std::ostream& out, const balance_t& bal) {
   bal.write(out, 12);
+  return out;
 }
 
 
@@ -762,6 +763,7 @@ inline balance_pair_t abs(const balance_pair_t& bal_pair) {
 inline std::ostream& operator<<(std::ostream& out,
 				const balance_pair_t& bal_pair) {
   bal_pair.quantity.write(out, 12);
+  return out;
 }
 
 } // namespace ledger

value.cc

@@ -550,6 +550,62 @@ value_t value_t::cost() const
 using namespace boost::python;
 using namespace ledger;
 
+unsigned int balance_len(balance_t& bal);
+amount_t     balance_getitem(balance_t& bal, int i);
+unsigned int balance_pair_len(balance_pair_t& bal_pair);
+amount_t     balance_pair_getitem(balance_pair_t& bal_pair, int i);
+
+unsigned int value_len(value_t& value)
+{
+  switch (value.type) {
+  case value_t::BOOLEAN:
+  case value_t::INTEGER:
+  case value_t::AMOUNT:
+    return 1;
+
+  case value_t::BALANCE:
+    return balance_len(*((balance_t *) value.data));
+
+  case value_t::BALANCE_PAIR:
+    return balance_pair_len(*((balance_pair_t *) value.data));
+
+  default:
+    assert(0);
+    break;
+  }
+  assert(0);
+  return 0;
+}
+
+amount_t value_getitem(value_t& value, int i)
+{
+  std::size_t len = value_len(value);
+
+  if (abs(i) >= len) {
+    PyErr_SetString(PyExc_IndexError, "Index out of range");
+    throw_error_already_set();
+  }
+
+  switch (value.type) {
+  case value_t::BOOLEAN:
+  case value_t::INTEGER:
+  case value_t::AMOUNT:
+    return value;
+
+  case value_t::BALANCE:
+    return balance_getitem(*((balance_t *) value.data), i);
+
+  case value_t::BALANCE_PAIR:
+    return balance_pair_getitem(*((balance_pair_t *) value.data), i);
+
+  default:
+    assert(0);
+    break;
+  }
+  assert(0);
+  return 0;
+}
+
 void export_value()
 {
   class_< value_t > ("Value")
@@ -627,6 +683,9 @@ void export_value()
     .def(abs(self))
     .def(self_ns::str(self))
 
+    .def("__len__", value_len)
+    .def("__getitem__", value_getitem)
+
     .def("cast", &value_t::cast)
     .def("negate", &value_t::negate)
     .def("cost", &value_t::cost)