Added new command: "pricemap [DATE]"

This outputs the pricing relationship of commodities in your data file,
as of DATE (optional), using the DOT language.  If you have graphviz
installed, it can be viewed quite simply using:

  ledger pricemap | dotty -

Each relationship in the graph shows the conversion factor to exchange
one commodity for another, and the date at which this factor was
determined.

1 files changed, 72 insertions, 0 deletions

diff --git a/src/pool.cc b/src/pool.cc
index 6b422351..ad97a9c6 100644
--- a/src/pool.cc
+++ b/src/pool.cc
@@ -364,4 +364,76 @@ commodity_pool_t::parse_price_expression(const std::string&          str,
   return NULL;
 }
 
+void commodity_pool_t::print_pricemap(std::ostream&		  out,
+				      const keep_details_t&       keep,
+				      const optional<datetime_t>& moment)
+{
+  typedef std::map<commodity_t *, commodity_t *> comm_map_t;
+
+  comm_map_t comm_map;
+
+  foreach (const commodities_map::value_type& comm_pair, commodities) {
+    commodity_t * comm(&comm_pair.second->strip_annotations(keep));
+    comm_map.insert(comm_map_t::value_type(comm, NULL));
+  }
+
+  out << "digraph commodities {\n";
+
+  foreach (const comm_map_t::value_type& comm_pair, comm_map) {
+    commodity_t * comm(comm_pair.first);
+    if (comm->has_flags(COMMODITY_BUILTIN))
+      continue;
+
+    out << "    ";
+    if (commodity_t::symbol_needs_quotes(comm->symbol()))
+      out << comm->symbol() << ";\n";
+    else
+      out << "\"" << comm->symbol() << "\";\n";
+
+    if (! comm->has_flags(COMMODITY_NOMARKET) &&
+	(! commodity_pool_t::current_pool->default_commodity ||
+	 comm != commodity_pool_t::current_pool->default_commodity)) {
+      if (optional<commodity_t::varied_history_t&> vhist =
+	  comm->varied_history()) {
+	foreach (const commodity_t::history_by_commodity_map::value_type& pair,
+		 vhist->histories) {
+	  datetime_t most_recent;
+	  amount_t   most_recent_amt;
+	  foreach (const commodity_t::history_map::value_type& inner_pair,
+		   pair.second.prices) {
+	    if ((most_recent.is_not_a_date_time() ||
+		 inner_pair.first > most_recent) &&
+		(! moment || inner_pair.first <= moment)) {
+	      most_recent     = inner_pair.first;
+	      most_recent_amt = inner_pair.second;
+	    }
+	  }
+
+	  if (! most_recent.is_not_a_date_time()) {
+	    out << "    ";
+	    if (commodity_t::symbol_needs_quotes(comm->symbol()))
+	      out << comm->symbol();
+	    else
+	      out << "\"" << comm->symbol() << "\"";
+
+	    out << " -> ";
+
+	    if (commodity_t::symbol_needs_quotes(pair.first->symbol()))
+	      out << pair.first->symbol();
+	    else
+	      out << "\"" << pair.first->symbol() << "\"";
+
+	    out << " [label=\""
+		<< most_recent_amt.number() << "\\n"
+		<< format_date(most_recent.date(), FMT_WRITTEN)
+		<< "\" fontcolor=\"#008e28\"];\n";
+	  }
+	}
+      }
+    }
+  }
+
+  out << "}\n";
+}
+
 } // namespace ledger