Filters

- Implemented Command::filter_shortcut to detect when a filter begins
  with "status:pending" and skip the loading/parsing of completed.data.
- Removed obsolete att.t.cpp tests.
- Removed diagnostics from TDB2::TDB2 that were causing a segfault.
  I suppose there is no std::cout available during global ctors?

src/commands/Command.cpp

@@ -297,7 +297,6 @@ void Command::filter (std::vector <Task>& output)
   if (f.size ())
   {
     const std::vector <Task>& pending = context.tdb2.pending.get_tasks ();
-    const std::vector <Task>& completed = context.tdb2.completed.get_tasks (); // TODO Optional
 
     Expression e (f);
 
@@ -307,9 +306,15 @@ void Command::filter (std::vector <Task>& output)
       if (e.eval (*task))
         output.push_back (*task);
 
-    for (task = completed.begin (); task != completed.end (); ++task)
-      if (e.eval (*task))
-        output.push_back (*task);
+    if (! filter_shortcut (f))
+    {
+      const std::vector <Task>& completed = context.tdb2.completed.get_tasks (); // TODO Optional
+      for (task = completed.begin (); task != completed.end (); ++task)
+        if (e.eval (*task))
+          output.push_back (*task);
+    }
+    else
+      context.debug ("Command::filter skipping completed.data");
   }
   else
   {
@@ -325,6 +330,31 @@ void Command::filter (std::vector <Task>& output)
   }
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// If the filter contains the restriction "status:pending", as the first filter
+// term, then completed.data does not need to be loaded.
+bool Command::filter_shortcut (const Arguments& filter)
+{
+/**/
+  if (filter.size () >= 3)
+  {
+    std::cout << "# filter[0] " << filter[0]._first << "\n"
+              << "# filter[1] " << filter[1]._first << "\n"
+              << "# filter[2] " << filter[2]._first << "\n";
+  }
+/**/
+
+  // Postfix: <status> <"pending"> <=>
+  //                 0           1   2
+  if (filter.size ()                    >= 3                 &&
+      filter[0]._first                  == "status"          &&
+      filter[1]._first.find ("pending") != std::string::npos &&
+      filter[2]._first                  == "=")
+    return true;
+
+  return false;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Apply the modifications in arguments to the task.
 void Command::modify_task_description_replace (Task& task, Arguments& arguments)

src/commands/Command.h

@@ -55,6 +55,7 @@ public:
 protected:
   void filter (std::vector <Task>&, std::vector <Task>&);
   void filter (std::vector <Task>&);
+  bool filter_shortcut (const Arguments&);
 
   void modify_task_description_replace (Task&, Arguments&);
   void modify_task_description_prepend (Task&, Arguments&);