Added support for a "fixed" directive

It lets you specify a fixed cost for a duration of a ledger file, for
example:

  fixed ecu $2

  2008/01/01 income
      assets:bank:checking  1 ecu
      income:salary

  end fixed

This is equivalent to:

  2008/01/01 income
      assets:bank:checking  1 ecu {=$2}
      income:salary

4 files changed, 75 insertions, 21 deletions

diff --git a/src/pool.cc b/src/pool.cc
index 00f4a3da..70f4eed6 100644
--- a/src/pool.cc
+++ b/src/pool.cc
@@ -286,7 +286,8 @@ commodity_pool_t::exchange(const amount_t&	       amount,
   return breakdown;
 }
 
-optional<price_point_t> commodity_pool_t::parse_price_directive(char * line)
+optional<std::pair<commodity_t *, price_point_t> >
+commodity_pool_t::parse_price_directive(char * line, bool do_not_add_price)
 {
   char * date_field_ptr = line;
   char * time_field_ptr = next_element(date_field_ptr);
@@ -295,6 +296,7 @@ optional<price_point_t> commodity_pool_t::parse_price_directive(char * line)
 
   char *     symbol_and_price;
   datetime_t datetime;
+  string     symbol;
 
   if (std::isdigit(time_field_ptr[0])) {
     symbol_and_price = next_element(time_field_ptr);
@@ -307,12 +309,13 @@ optional<price_point_t> commodity_pool_t::parse_price_directive(char * line)
     datetime = datetime_t(parse_date(date_field));
   }
   else {
-    symbol_and_price = date_field_ptr;
+    symbol = date_field_ptr;
+    symbol_and_price = time_field_ptr;
     datetime = CURRENT_TIME();
   }
 
-  string symbol;
-  commodity_t::parse_symbol(symbol_and_price, symbol);
+  if (symbol.empty())
+    commodity_t::parse_symbol(symbol_and_price, symbol);
 
   price_point_t point;
   point.when = datetime;
@@ -323,9 +326,10 @@ optional<price_point_t> commodity_pool_t::parse_price_directive(char * line)
   if (commodity_t * commodity = find_or_create(symbol)) {
     DEBUG("commodity.download", "Adding price for " << symbol << ": "
 	  << point.when << " " << point.price);
-    commodity->add_price(point.when, point.price, true);
+    if (! do_not_add_price)
+      commodity->add_price(point.when, point.price, true);
     commodity->add_flags(COMMODITY_KNOWN);
-    return point;
+    return std::pair<commodity_t *, price_point_t>(commodity, point);
   }
 
   return none;
diff --git a/src/pool.h b/src/pool.h
index 85de73a9..995ab23c 100644
--- a/src/pool.h
+++ b/src/pool.h
@@ -123,7 +123,8 @@ public:
 
   // Parse commodity prices from a textual representation
 
-  optional<price_point_t> parse_price_directive(char * line);
+  optional<std::pair<commodity_t *, price_point_t> >
+  parse_price_directive(char * line, bool do_not_add_price = false);
 
   commodity_t *
   parse_price_expression(const std::string&          str,
diff --git a/src/quotes.cc b/src/quotes.cc
index ffe2142a..f892e93f 100644
--- a/src/quotes.cc
+++ b/src/quotes.cc
@@ -75,7 +75,7 @@ commodity_quote_from_script(commodity_t& commodity,
     if (char * p = std::strchr(buf, '\n')) *p = '\0';
     DEBUG("commodity.download", "downloaded quote: " << buf);
 
-    if (optional<price_point_t> point =
+    if (optional<std::pair<commodity_t *, price_point_t> > point =
 	commodity_pool_t::current_pool->parse_price_directive(buf)) {
       if (commodity_pool_t::current_pool->price_db) {
 #if defined(__GNUG__) && __GNUG__ < 3
@@ -86,12 +86,12 @@ commodity_quote_from_script(commodity_t& commodity,
 			  std::ios_base::out | std::ios_base::app);
 #endif
 	database << "P "
-		 << format_datetime(point->when, FMT_WRITTEN)
+		 << format_datetime(point->second.when, FMT_WRITTEN)
 		 << " " << commodity.symbol()
-		 << " " << point->price
+		 << " " << point->second.price
 		 << std::endl;
       }
-      return point;
+      return point->second;
     }
   } else {
     DEBUG("commodity.download",
diff --git a/src/textual.cc b/src/textual.cc
index 0eaa5869..cf670cae 100644
--- a/src/textual.cc
+++ b/src/textual.cc
@@ -54,7 +54,8 @@ namespace {
     static const std::size_t MAX_LINE = 1024;
 
   public:
-    typedef variant<account_t *, string> state_t;
+    typedef std::pair<commodity_t *, amount_t>	       fixed_rate_t;
+    typedef variant<account_t *, string, fixed_rate_t> state_t;
 
     std::list<state_t>& state_stack;
 
@@ -99,6 +100,9 @@ namespace {
     bool front_is_string() {
       return state_stack.front().type() == typeid(string);
     }
+    bool front_is_fixed_rate() {
+      return state_stack.front().type() == typeid(fixed_rate_t);
+    }
 
     account_t * top_account() {
       foreach (state_t& state, state_stack)
@@ -135,6 +139,7 @@ namespace {
     void master_account_directive(char * line);
     void end_directive(char * line);
     void alias_directive(char * line);
+    void fixed_directive(char * line);
     void tag_directive(char * line);
     void define_directive(char * line);
     bool general_directive(char * line);
@@ -512,7 +517,7 @@ void instance_t::price_conversion_directive(char * line)
 
 void instance_t::price_xact_directive(char * line)
 {
-  optional<price_point_t> point =
+  optional<std::pair<commodity_t *, price_point_t> > point =
     commodity_pool_t::current_pool->parse_price_directive(skip_ws(line + 1));
   if (! point)
     throw parse_error(_("Pricing entry failed to parse"));
@@ -705,10 +710,13 @@ void instance_t::end_directive(char * kind)
 
   if ((name.empty() || name == "account") && ! front_is_account())
     throw_(std::runtime_error,
-	   _("'end account' directive does not match open tag directive"));
+	   _("'end account' directive does not match open directive"));
   else if (name == "tag" && ! front_is_string())
     throw_(std::runtime_error,
-	   _("'end tag' directive does not match open account directive"));
+	   _("'end tag' directive does not match open directive"));
+  else if (name == "fixed" && ! front_is_fixed_rate())
+    throw_(std::runtime_error,
+	   _("'end fixed' directive does not match open directive"));
 
   if (state_stack.size() <= 1)
     throw_(std::runtime_error,
@@ -738,6 +746,18 @@ void instance_t::alias_directive(char * line)
   }
 }
 
+void instance_t::fixed_directive(char * line)
+{
+  if (optional<std::pair<commodity_t *, price_point_t> > price_point = 
+      commodity_pool_t::current_pool->parse_price_directive(trim_ws(line),
+							    true)) {
+    state_stack.push_front(fixed_rate_t(price_point->first,
+					price_point->second.price));
+  } else {
+    throw_(std::runtime_error, _("Error in fixed directive"));
+  }
+}
+
 void instance_t::tag_directive(char * line)
 {
   string tag(trim_ws(line));
@@ -799,6 +819,13 @@ bool instance_t::general_directive(char * line)
     }
     break;
 
+  case 'f':
+    if (std::strcmp(p, "fixed") == 0) {
+      fixed_directive(arg);
+      return true;
+    }
+    break;
+
   case 'i':
     if (std::strcmp(p, "include") == 0) {
       include_directive(arg);
@@ -812,6 +839,13 @@ bool instance_t::general_directive(char * line)
       return true;
     }
     break;
+
+  case 'y':
+    if (std::strcmp(p, "year") == 0) {
+      year_directive(arg);
+      return true;
+    }
+    break;
   }
 
   if (expr_t::ptr_op_t op = lookup(symbol_t::DIRECTIVE, p)) {
@@ -935,13 +969,28 @@ post_t * instance_t::parse_post(char *		line,
 			post.get(), PARSE_NO_REDUCE | PARSE_SINGLE |
 			PARSE_NO_ASSIGN, defer_expr);
 
-    if (! post->amount.is_null() && honor_strict && strict &&
-	post->amount.has_commodity() &&
+    if (! post->amount.is_null() && post->amount.has_commodity()) {
+      if (honor_strict && strict && 
 	! post->amount.commodity().has_flags(COMMODITY_KNOWN)) {
-      if (post->_state == item_t::UNCLEARED)
-	warning_(_("\"%1\", line %2: Unknown commodity '%3'")
-		 << pathname << linenum << post->amount.commodity());
-      post->amount.commodity().add_flags(COMMODITY_KNOWN);
+	if (post->_state == item_t::UNCLEARED)
+	  warning_(_("\"%1\", line %2: Unknown commodity '%3'")
+		   << pathname << linenum << post->amount.commodity());
+	post->amount.commodity().add_flags(COMMODITY_KNOWN);
+      }
+
+      if (! post->amount.has_annotation()) {
+	foreach (state_t& state, state_stack) {
+	  if (state.type() == typeid(fixed_rate_t)) {
+	    fixed_rate_t& rate(boost::get<fixed_rate_t>(state));
+	    if (*rate.first == post->amount.commodity()) {
+	      annotation_t details(rate.second);
+	      details.add_flags(ANNOTATION_PRICE_FIXATED);
+	      post->amount.annotate(details);
+	      break;
+	    }
+	  }
+	}
+      }
     }
 
     DEBUG("textual.parse", "line " << linenum << ": "