Added a truncated() method for amounts and values

When an amount is truncated, it drops all of the extra precision and
becomes exactly the value would have seen were it printed.

4 files changed, 37 insertions, 0 deletions

diff --git a/src/amount.h b/src/amount.h
index b6ca6d16..90f1359c 100644
--- a/src/amount.h
+++ b/src/amount.h
@@ -322,6 +322,12 @@ public:
       @see set_keep_precision */
   amount_t rounded() const;
 
+  /** Yields an amount which has lost all of its extra precision, beyond what
+      the display precision of the commodity would have printed. */
+  amount_t truncated() const {
+    return amount_t(to_string());
+  }
+
   /** Yields an amount whose display precision is never truncated, even
       though its commodity normally displays only rounded values. */
   amount_t unrounded() const;
diff --git a/src/balance.h b/src/balance.h
index a9684796..f8e4f25c 100644
--- a/src/balance.h
+++ b/src/balance.h
@@ -318,6 +318,13 @@ public:
     return temp;
   }
 
+  balance_t truncated() const {
+    balance_t temp;
+    foreach (const amounts_map::value_type& pair, amounts)
+      temp += pair.second.truncated();
+    return temp;
+  }
+
   balance_t unrounded() const {
     balance_t temp;
     foreach (const amounts_map::value_type& pair, amounts)
diff --git a/src/value.cc b/src/value.cc
index 94bcfb20..75d09441 100644
--- a/src/value.cc
+++ b/src/value.cc
@@ -1296,6 +1296,29 @@ value_t value_t::rounded() const
   return NULL_VALUE;
 }
 
+value_t value_t::truncated() const
+{
+  switch (type()) {
+  case INTEGER:
+    return *this;
+  case AMOUNT:
+    return as_amount().truncated();
+  case BALANCE:
+    return as_balance().truncated();
+  case SEQUENCE: {
+    value_t temp;
+    foreach (const value_t& value, as_sequence())
+      temp.push_back(value.truncated());
+    return temp;
+  }
+  default:
+    break;
+  }
+
+  throw_(value_error, _("Cannot truncate %1") << label());
+  return NULL_VALUE;
+}
+
 value_t value_t::unrounded() const
 {
   switch (type()) {
diff --git a/src/value.h b/src/value.h
index 85e4a714..4d019450 100644
--- a/src/value.h
+++ b/src/value.h
@@ -410,6 +410,7 @@ public:
   value_t abs() const;
 
   value_t rounded() const;
+  value_t truncated() const;
   value_t unrounded() const;
 
   value_t reduced() const {