From 42becb9e4150d2afca781b2d67fbaeb03a62c374 Mon Sep 17 00:00:00 2001
From: Paul Beckingham <paul@beckingham.net>
Date: Sat, 2 Jul 2011 11:47:39 -0400
Subject: [PATCH] Expressions/Arguments

- Converted the arguments parsed from a pair (token/modified-category)
  to a triple (token/type/category)
---
 src/Arguments.cpp        | 291 ++++++++++++++++++++-------------------
 src/Arguments.h          |  48 ++++++-
 src/DOM.cpp              |   2 +-
 src/Expression.cpp       | 236 +++++++++++++++----------------
 src/commands/CmdExec.cpp |   6 +-
 src/commands/Command.cpp |  22 +--
 6 files changed, 327 insertions(+), 278 deletions(-)

diff --git a/src/Arguments.cpp b/src/Arguments.cpp
index 5807d9c4f..9118a4d46 100644
--- a/src/Arguments.cpp
+++ b/src/Arguments.cpp
@@ -158,10 +158,10 @@ void Arguments::capture (int argc, const char** argv)
     {
       std::vector <std::string>::iterator part;
       for (part = parts.begin (); part != parts.end (); ++part)
-        this->push_back (std::make_pair (*part, ""));
+        this->push_back (Triple (*part, "?", ""));
     }
     else
-      this->push_back (std::make_pair (argv[i], ""));
+      this->push_back (Triple (argv[i], "?", ""));
   }
 
   categorize ();
@@ -176,10 +176,10 @@ void Arguments::capture (const std::string& arg)
   {
     std::vector <std::string>::iterator part;
     for (part = parts.begin (); part != parts.end (); ++part)
-      this->push_back (std::make_pair (*part, ""));
+      this->push_back (Triple (*part, "?", ""));
   }
   else
-    this->push_back (std::make_pair (arg, ""));
+    this->push_back (Triple (arg, "?", ""));
 
   categorize ();
 }
@@ -189,24 +189,24 @@ void Arguments::capture (const std::string& arg)
 void Arguments::capture_first (const std::string& arg)
 {
   // Break the new argument into parts that comprise a series.
-  std::vector <std::pair <std::string, std::string> > series;
+  std::vector <Triple> series;
 
   std::vector <std::string> parts;
   if (is_multipart (arg, parts))
   {
     std::vector <std::string>::iterator part;
     for (part = parts.begin (); part != parts.end (); ++part)
-      series.push_back (std::make_pair (*part, ""));
+      series.push_back (Triple (*part, "?", ""));
   }
   else
-    series.push_back (std::make_pair (arg, ""));
+    series.push_back (Triple (arg, "?", ""));
 
   // Locate an appropriate place to insert the series.  This would be
   // immediately after the program and command arguments.
-  std::vector <std::pair <std::string, std::string> >::iterator position;
+  std::vector <Triple>::iterator position;
   for (position = this->begin (); position != this->end (); ++position)
-    if (position->second != "program" &&
-        position->second != "command")
+    if (position->_third != "program" &&
+        position->_third != "command")
       break;
 
   this->insert (position, series.begin (), series.end ());
@@ -238,7 +238,7 @@ void Arguments::append_stdin ()
       if (arg == "--")
         break;
 
-      this->push_back (std::make_pair (arg, ""));
+      this->push_back (Triple (arg, "?", ""));
       something_happened = true;
     }
   }
@@ -269,150 +269,150 @@ void Arguments::categorize ()
 
   // Now categorize every argument.
   std::string ignored;
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = this->begin (); arg != this->end (); ++arg)
   {
     if (!terminated)
     {
       // Nothing after -- is to be interpreted in any way.
-      if (arg->first == "--")
+      if (arg->_first == "--")
       {
         terminated = true;
         found_non_sequence = true;
         if (found_sequence)
           found_something_after_sequence = true;
 
-        arg->second = "terminator";
+        arg->_third = "terminator";
       }
 
       // program
       else if (arg == this->begin ())
       {
-        arg->second = "program";  // TODO Is this a problem for expressions that do not contain a program name?
+        arg->_third = "program";  // TODO Is this a problem for expressions that do not contain a program name?
       }
 
       // command
       else if (!found_command &&
-               is_command (keywords, arg->first))
+               is_command (keywords, arg->_first))
       {
         found_command = true;
         found_non_sequence = true;
         if (found_sequence)
           found_something_after_sequence = true;
 
-        arg->second = "command";
+        arg->_third = "command";
       }
 
       // rc:<file>
       // Note: This doesn't break a sequence chain.
-      else if (arg->first.substr (0, 3) == "rc:")
+      else if (arg->_first.substr (0, 3) == "rc:")
       {
-        arg->second = "rc";
+        arg->_third = "rc";
       }
 
       // rc.<name>:<value>
       // Note: This doesn't break a sequence chain.
-      else if (arg->first.substr (0, 3) == "rc.")
+      else if (arg->_first.substr (0, 3) == "rc.")
       {
-        arg->second = "override";
+        arg->_third = "override";
       }
 
       // <id>[-<id>][,...]
-      else if (is_id (arg->first))
+      else if (is_id (arg->_first))
       {
         if (!found_something_after_sequence)
         {
           found_sequence = true;
-          arg->second = "id";
+          arg->_third = "id";
         }
         else
         {
-          arg->second = "word";
+          arg->_third = "word";
         }
       }
 
       // <uuid>[,...]
-      else if (is_uuid (arg->first))
+      else if (is_uuid (arg->_first))
       {
         if (!found_something_after_sequence)
         {
           found_sequence = true;
-          arg->second = "uuid";
+          arg->_third = "uuid";
         }
         else
         {
-          arg->second = "word";
+          arg->_third = "word";
         }
       }
 
       // [+-]tag
-      else if (is_tag (arg->first))
+      else if (is_tag (arg->_first))
       {
         found_non_sequence = true;
         if (found_sequence)
           found_something_after_sequence = true;
 
-        arg->second = "tag";
+        arg->_third = "tag";
       }
 
       // <name>.<modifier>:<value>
-      else if (is_attmod (arg->first))
+      else if (is_attmod (arg->_first))
       {
         found_non_sequence = true;
         if (found_sequence)
           found_something_after_sequence = true;
 
-        arg->second = "attmod";
+        arg->_third = "attmod";
       }
 
       // <name>:<value>
-      else if (is_attr (arg->first))
+      else if (is_attr (arg->_first))
       {
         found_non_sequence = true;
         if (found_sequence)
           found_something_after_sequence = true;
 
-        arg->second = "attr";
+        arg->_third = "attr";
       }
 
       // /<from>/<to>/[g]
-      else if (is_subst (arg->first))
+      else if (is_subst (arg->_first))
       {
         found_non_sequence = true;
         if (found_sequence)
           found_something_after_sequence = true;
 
-        arg->second = "subst";
+        arg->_third = "subst";
       }
 
       // /pattern/
-      else if (enable_patterns && is_pattern (arg->first))
+      else if (enable_patterns && is_pattern (arg->_first))
       {
         found_non_sequence = true;
         if (found_sequence)
           found_something_after_sequence = true;
 
-        arg->second = "pattern";
+        arg->_third = "pattern";
       }
 
       // <operator>
-      else if (is_operator (arg->first))
+      else if (is_operator (arg->_first))
       {
         found_non_sequence = true;
         if (found_sequence)
           found_something_after_sequence = true;
 
-        arg->second = "op";
+        arg->_third = "op";
       }
 
       // <expression>
-      else if (enable_expressions && is_expression (arg->first))
+      else if (enable_expressions && is_expression (arg->_first))
       {
         found_non_sequence = true;
         if (found_sequence)
           found_something_after_sequence = true;
 
-        arg->second = "exp";
+        arg->_third = "exp";
       }
 
       // If the type is not known, it is treated as a generic word.
@@ -422,7 +422,7 @@ void Arguments::categorize ()
         if (found_sequence)
           found_something_after_sequence = true;
 
-        arg->second = "word";
+        arg->_third = "word";
       }
     }
 
@@ -433,7 +433,7 @@ void Arguments::categorize ()
       if (found_sequence)
         found_something_after_sequence = true;
 
-      arg->second = "word";
+      arg->_third = "word";
     }
   }
 }
@@ -444,12 +444,12 @@ void Arguments::rc_override (
   File& rc)
 {
   // Is there an override for rc:<file>?
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = this->begin (); arg != this->end (); ++arg)
   {
-    if (arg->second == "rc")
+    if (arg->_third == "rc")
     {
-      rc = File (arg->first.substr (3));
+      rc = File (arg->_first.substr (3));
       home = rc;
 
       std::string::size_type last_slash = rc.data.rfind ("/");
@@ -474,15 +474,15 @@ void Arguments::get_data_location (std::string& data)
     data = location;
 
   // Are there any overrides for data.location?
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = this->begin (); arg != this->end (); ++arg)
   {
-    if (arg->second == "override")
+    if (arg->_third == "override")
     {
-      if (arg->first.substr (0, 16) == "rc.data.location" &&
-          arg->first[16] == ':')
+      if (arg->_first.substr (0, 16) == "rc.data.location" &&
+          arg->_first[16] == ':')
       {
-        data = arg->first.substr (17);
+        data = arg->_first.substr (17);
         context.header ("Using alternate data.location " + data);
       }
     }
@@ -497,14 +497,14 @@ void Arguments::get_data_location (std::string& data)
 // leaving only the plain args.
 void Arguments::apply_overrides ()
 {
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = this->begin (); arg != this->end (); ++arg)
   {
-    if (arg->second == "override")
+    if (arg->_third == "override")
     {
       std::string name;
       std::string value;
-      Nibbler n (arg->first);
+      Nibbler n (arg->_first);
       if (n.getLiteral ("rc.")   &&  // rc.
           n.getUntil (':', name) &&  //    xxx
           n.skip (':'))              //       :
@@ -515,7 +515,7 @@ void Arguments::apply_overrides ()
         context.footnote ("Configuration override rc." + name + ":" + value);
       }
       else
-        context.footnote ("Problem with override: " + arg->first);
+        context.footnote ("Problem with override: " + arg->_first);
     }
   }
 }
@@ -528,22 +528,22 @@ void Arguments::resolve_aliases ()
   std::vector <std::string> expanded;
   bool something = false;
 
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = this->begin (); arg != this->end (); ++arg)
   {
     std::map <std::string, std::string>::iterator match =
-      context.aliases.find (arg->first);
+      context.aliases.find (arg->_first);
 
     if (match != context.aliases.end ())
     {
       context.debug (std::string ("Arguments::resolve_aliases '")
-                     + arg->first
+                     + arg->_first
                      + "' --> '"
-                     + context.aliases[arg->first]
+                     + context.aliases[arg->_first]
                      + "'");
 
       std::vector <std::string> words;
-      splitq (words, context.aliases[arg->first], ' ');
+      splitq (words, context.aliases[arg->_first], ' ');
 
       std::vector <std::string>::iterator word;
       for (word = words.begin (); word != words.end (); ++word)
@@ -552,7 +552,7 @@ void Arguments::resolve_aliases ()
       something = true;
     }
     else
-      expanded.push_back (arg->first);
+      expanded.push_back (arg->_first);
   }
 
   // Only overwrite if something happened.
@@ -561,7 +561,7 @@ void Arguments::resolve_aliases ()
     this->clear ();
     std::vector <std::string>::iterator e;
     for (e = expanded.begin (); e != expanded.end (); ++e)
-      this->push_back (std::make_pair (*e, ""));
+      this->push_back (Triple (*e, "?", ""));
 
     categorize ();
   }
@@ -574,18 +574,18 @@ void Arguments::inject_defaults ()
   bool found_sequence = false;
   bool found_other    = false;
 
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = this->begin (); arg != this->end (); ++arg)
   {
-    if (arg->second == "command")
+    if (arg->_third == "command")
       found_command = true;
 
-    else if (arg->second == "id")
+    else if (arg->_third == "id")
       found_sequence = true;
 
-    else if (arg->second != "program"  &&
-             arg->second != "override" &&
-             arg->second != "rc")
+    else if (arg->_third != "program"  &&
+             arg->_third != "override" &&
+             arg->_third != "rc")
       found_other = true;
   }
 
@@ -611,7 +611,7 @@ void Arguments::inject_defaults ()
     else if (found_sequence)
     {
       context.header (STRING_ASSUME_INFO);
-      push_back (std::make_pair ("information", "command"));
+      push_back (Triple ("information", "?", "command"));
     }
   }
 }
@@ -620,9 +620,9 @@ void Arguments::inject_defaults ()
 std::vector <std::string> Arguments::list ()
 {
   std::vector <std::string> all;
-  std::vector <std::pair <std::string, std::string> >::iterator i;
-  for (i = this->begin (); i != this->end (); ++i)
-    all.push_back (i->first);
+  std::vector <Triple>::iterator arg;
+  for (arg = this->begin (); arg != this->end (); ++arg)
+    all.push_back (arg->_first);
 
   return all;
 }
@@ -642,13 +642,13 @@ std::string Arguments::combine ()
 {
   std::string combined;
 
-  std::vector <std::pair <std::string, std::string> >::iterator i;
-  for (i = this->begin (); i != this->end (); ++i)
+  std::vector <Triple>::iterator arg;
+  for (arg = this->begin (); arg != this->end (); ++arg)
   {
-    if (i != this->begin ())
+    if (arg != this->begin ())
       combined += " ";
 
-    combined += i->first;
+    combined += arg->_first;
   }
 
   return combined;
@@ -657,12 +657,12 @@ std::string Arguments::combine ()
 ////////////////////////////////////////////////////////////////////////////////
 bool Arguments::find_command (std::string& command)
 {
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = this->begin (); arg != this->end (); ++arg)
   {
-    if (arg->second == "command")
+    if (arg->_third == "command")
     {
-      command = arg->first;
+      command = arg->_first;
       return true;
     }
   }
@@ -673,10 +673,10 @@ bool Arguments::find_command (std::string& command)
 ////////////////////////////////////////////////////////////////////////////////
 std::string Arguments::find_limit ()
 {
-  std::vector <std::pair <std::string, std::string> >::reverse_iterator arg;
+  std::vector <Triple>::reverse_iterator arg;
   for (arg = this->rbegin (); arg != this->rend (); ++arg)
-    if (arg->first.find ("limit:") != std::string::npos)
-      return arg->first.substr (6);
+    if (arg->_first.find ("limit:") != std::string::npos)
+      return arg->_first.substr (6);
 
   return "";
 }
@@ -1222,8 +1222,8 @@ bool Arguments::extract_pattern (const std::string& input, std::string& pattern)
 //
 // The sequence is "1 2".
 //
-// The first number found in the command line is assumed to be a sequence.  If
-// there are two sequences, only the first is recognized, for example:
+// The _first number found in the command line is assumed to be a sequence.  If
+// there are two sequences, only the _first is recognized, for example:
 //
 //    1,2 three 4,5
 //
@@ -1340,39 +1340,39 @@ Arguments Arguments::extract_read_only_filter ()
 {
   Arguments filter;
 
-  std::vector <std::pair <std::string, std::string> >::iterator i;
-  for (i = this->begin (); i != this->end (); ++i)
+  std::vector <Triple>::iterator arg;
+  for (arg = this->begin (); arg != this->end (); ++arg)
   {
     // Excluded.
-    if (i->second == "program"  ||
-        i->second == "command"  ||
-        i->second == "rc"       ||
-        i->second == "override")
+    if (arg->_third == "program"  ||
+        arg->_third == "command"  ||
+        arg->_third == "rc"       ||
+        arg->_third == "override")
     {
       ;
     }
 
     // Included.
-    else if (i->second == "tag"       ||
-             i->second == "pattern"   ||
-             i->second == "attr"      ||
-             i->second == "attmod"    ||
-             i->second == "id"        ||
-             i->second == "uuid"      ||
-             i->second == "op"        ||
-             i->second == "exp"       ||
-             i->second == "word")
+    else if (arg->_third == "tag"       ||
+             arg->_third == "pattern"   ||
+             arg->_third == "attr"      ||
+             arg->_third == "attmod"    ||
+             arg->_third == "id"        ||
+             arg->_third == "uuid"      ||
+             arg->_third == "op"        ||
+             arg->_third == "exp"       ||
+             arg->_third == "word")
     {
       // "limit" is special - it is recognized but not included in filters.
-      if (i->first.find ("limit:") == std::string::npos)
-        filter.push_back (*i);
+      if (arg->_first.find ("limit:") == std::string::npos)
+        filter.push_back (*arg);
     }
 
     // Error.
     else
     {
       // substitution
-      throw std::string ("A substitution '") + i->first + "' is not allowed "
+      throw std::string ("A substitution '") + arg->_first + "' is not allowed "
             "in a read-only command filter.";
     }
   }
@@ -1385,35 +1385,35 @@ Arguments Arguments::extract_write_filter ()
 {
   Arguments filter;
 
-  std::vector <std::pair <std::string, std::string> >::iterator i;
-  for (i = this->begin (); i != this->end (); ++i)
+  std::vector <Triple>::iterator arg;
+  for (arg = this->begin (); arg != this->end (); ++arg)
   {
     // Only use args prior to command.
-    if (i->second == "command")
+    if (arg->_third == "command")
       break;
 
     // Excluded.
-    else if (i->second == "program"  ||
-             i->second == "rc"       ||
-             i->second == "override")
+    else if (arg->_third == "program"  ||
+             arg->_third == "rc"       ||
+             arg->_third == "override")
     {
       ;
     }
 
     // Included.
-    else if (i->second == "tag"       ||
-             i->second == "pattern"   ||
-             i->second == "attr"      ||
-             i->second == "attmod"    ||
-             i->second == "id"        ||
-             i->second == "uuid"      ||
-             i->second == "op"        ||
-             i->second == "exp"       ||
-             i->second == "word")
+    else if (arg->_third == "tag"       ||
+             arg->_third == "pattern"   ||
+             arg->_third == "attr"      ||
+             arg->_third == "attmod"    ||
+             arg->_third == "id"        ||
+             arg->_third == "uuid"      ||
+             arg->_third == "op"        ||
+             arg->_third == "exp"       ||
+             arg->_third == "word")
     {
       // "limit" is special - it is recognized but not included in filters.
-      if (i->first.find ("limit:") == std::string::npos)
-        filter.push_back (*i);
+      if (arg->_first.find ("limit:") == std::string::npos)
+        filter.push_back (*arg);
     }
 
     // Error.
@@ -1421,7 +1421,7 @@ Arguments Arguments::extract_write_filter ()
     {
       // substitution
       throw std::string ("A substitutions '")
-            + i->first
+            + arg->_first
             + "' is not allowed in a read-only command filter.";
     }
   }
@@ -1435,11 +1435,11 @@ Arguments Arguments::extract_modifications ()
   Arguments modifications;
 
   bool seen_command = false;
-  std::vector <std::pair <std::string, std::string> >::iterator i;
-  for (i = this->begin (); i != this->end (); ++i)
+  std::vector <Triple>::iterator arg;
+  for (arg = this->begin (); arg != this->end (); ++arg)
   {
     // Only use args after command.
-    if (i->second == "command")
+    if (arg->_third == "command")
     {
       seen_command = true;
     }
@@ -1447,46 +1447,46 @@ Arguments Arguments::extract_modifications ()
     else if (seen_command)
     {
       // Excluded.
-      if (i->second == "program"  ||
-          i->second == "rc"       ||
-          i->second == "override")
+      if (arg->_third == "program"  ||
+          arg->_third == "rc"       ||
+          arg->_third == "override")
       {
       }
 
       // Included.
-      else if (i->second == "tag"   ||
-               i->second == "attr"  ||
-               i->second == "subst" ||
-               i->second == "op"    ||
-               i->second == "word")
+      else if (arg->_third == "tag"   ||
+               arg->_third == "attr"  ||
+               arg->_third == "subst" ||
+               arg->_third == "op"    ||
+               arg->_third == "word")
       {
         // "limit" is special - it is recognized but not included in filters.
-        if (i->first.find ("limit:") == std::string::npos)
-          modifications.push_back (*i);
+        if (arg->_first.find ("limit:") == std::string::npos)
+          modifications.push_back (*arg);
       }
 
       // Error.
       else
       {
-        if (i->second == "pattern")
+        if (arg->_third == "pattern")
           throw std::string ("A pattern '")
-                + i->first
+                + arg->_first
                 + "' is not allowed when modifiying a task.";
 
-        else if (i->second == "attmod")
+        else if (arg->_third == "attmod")
           throw std::string ("An attribute modifier '")
-                + i->first
+                + arg->_first
                 + "' is not allowed when modifiying a task.";
 
-        else if (i->second == "exp")
+        else if (arg->_third == "exp")
           throw std::string ("An expression '")
-                + i->first
+                + arg->_first
                 + "' is not allowed when modifiying a task.";
 
-        else if (i->second == "id")
+        else if (arg->_third == "id")
           throw std::string ("A task id cannot be modified.");
 
-        else if (i->second == "uuid")
+        else if (arg->_third == "uuid")
           throw std::string ("A task uuid cannot be modified.");
       }
     }
@@ -1545,11 +1545,13 @@ void Arguments::dump (const std::string& label)
 
   view.addRow ();
   view.addRow ();
+  view.addRow ();
 
   for (unsigned int i = 0; i < this->size (); ++i)
   {
-    std::string arg      = (*this)[i].first;
-    std::string category = (*this)[i].second;
+    std::string arg      = (*this)[i]._first;
+    std::string expanded = (*this)[i]._second;
+    std::string category = (*this)[i]._third;
 
     Color c;
     if (color_map[category].nontrivial ())
@@ -1558,7 +1560,8 @@ void Arguments::dump (const std::string& label)
       c = color_map["none"];
 
     view.set (0, i, arg,      c);
-    view.set (1, i, category, c);
+    view.set (1, i, expanded, c);
+    view.set (2, i, category, c);
   }
 
   out << view.render ();
diff --git a/src/Arguments.h b/src/Arguments.h
index cefbe4b3d..985394e6b 100644
--- a/src/Arguments.h
+++ b/src/Arguments.h
@@ -34,7 +34,53 @@
 
 #define ARGUMENTS_SEQUENCE_MAX_RANGE 1000
 
-class Arguments : public std::vector <std::pair <std::string, std::string> >
+class Triple
+{
+public:
+  Triple (
+    const std::string& one,
+    const std::string& two,
+    const std::string& three)
+  : _first (one)
+  , _second (two)
+  , _third (three)
+  {
+  }
+
+  Triple (const Triple& other)
+  {
+    _first  = other._first;
+    _second = other._second;
+    _third  = other._third;
+  }
+
+  Triple& operator= (const Triple& other)
+  {
+    if (this != &other)
+    {
+      _first  = other._first;
+      _second = other._second;
+      _third  = other._third;
+    }
+
+    return *this;
+  }
+
+  bool operator== (const Triple& other) const
+  {
+    return _first  == other._first  &&
+           _second == other._second &&
+           _third  == other._third;
+  }
+
+public:
+  std::string _first;
+  std::string _second;
+  std::string _third;
+};
+
+//class Arguments : public std::vector <std::pair <std::string, std::string> >
+class Arguments : public std::vector <Triple>
 {
 public:
   Arguments ();
diff --git a/src/DOM.cpp b/src/DOM.cpp
index 04ee4e3ff..1b603ddf7 100644
--- a/src/DOM.cpp
+++ b/src/DOM.cpp
@@ -98,7 +98,7 @@ const std::string DOM::get (const std::string& name)
            name.substr (0, 8) == "context.")
   {
     if (name == "context.program")
-      return /*_cache[name] =*/ context.args[0].first;
+      return /*_cache[name] =*/ context.args[0]._first;
 
     else if (name == "context.args")
     {
diff --git a/src/Expression.cpp b/src/Expression.cpp
index 17ca29027..2f3053727 100644
--- a/src/Expression.cpp
+++ b/src/Expression.cpp
@@ -81,15 +81,15 @@ bool Expression::eval (Task& task)
 
   // TODO Build an on-demand regex cache.
 
-  std::vector <std::pair <std::string, std::string> >::const_iterator arg;
+  std::vector <Triple>::const_iterator arg;
   for (arg = _args.begin (); arg != _args.end (); ++arg)
   {
-    if (arg->second == "op")
+    if (arg->_third == "op")
     {
-//      std::cout << "# operator " << arg->first << "\n";
+//      std::cout << "# operator " << arg->_first << "\n";
 
       // Handle the unary operator first.
-      if (arg->first == "!")
+      if (arg->_first == "!")
       {
         // Are there sufficient arguments?
         if (value_stack.size () < 1)
@@ -119,7 +119,7 @@ bool Expression::eval (Task& task)
 
       // Are there sufficient arguments?
       if (value_stack.size () < 2)
-        throw std::string ("Error: Insufficient operands for '") + arg->first + "' operator.";
+        throw std::string ("Error: Insufficient operands for '") + arg->_first + "' operator.";
 
       // rvalue (string, rx, int, number, dom ...).
       Variant right (value_stack.back ());
@@ -144,7 +144,7 @@ bool Expression::eval (Task& task)
 //      std::cout << "# left raw=" << left._raw << " type=" << left._type << " value=" << left._string << "\n";
 
       // Now the binary operators.
-      if (arg->first == "and")
+      if (arg->_first == "and")
       {
 //        std::cout << "#   " << left.dump () << " and " << right.dump () << "\n";
         bool result = (left && right);
@@ -155,7 +155,7 @@ bool Expression::eval (Task& task)
         value_stack.push_back (left);
       }
 
-      else if (arg->first == "xor")
+      else if (arg->_first == "xor")
       {
 //        std::cout << "#   " << left.dump () << " xor " << right.dump () << "\n";
         bool left_bool  = left.boolean ();
@@ -168,7 +168,7 @@ bool Expression::eval (Task& task)
         value_stack.push_back (left);
       }
 
-      else if (arg->first == "or")
+      else if (arg->_first == "or")
       {
 //        std::cout << "#   " << left.dump () << " or " << right.dump () << "\n";
         bool result = (left || right);
@@ -179,7 +179,7 @@ bool Expression::eval (Task& task)
         value_stack.push_back (left);
       }
 
-      else if (arg->first == "<=")
+      else if (arg->_first == "<=")
       {
 //        std::cout << "#   " << left.dump () << " <= " << right.dump () << "\n";
         bool result = false;
@@ -202,7 +202,7 @@ bool Expression::eval (Task& task)
         value_stack.push_back (left);
       }
 
-      else if (arg->first == ">=")
+      else if (arg->_first == ">=")
       {
 //        std::cout << "#   " << left.dump () << " >= " << right.dump () << "\n";
         bool result = false;
@@ -225,7 +225,7 @@ bool Expression::eval (Task& task)
         value_stack.push_back (left);
       }
 
-      else if (arg->first == "!~")
+      else if (arg->_first == "!~")
       {
 //        std::cout << "#   " << left.dump () << " !~ " << right.dump () << "\n";
         bool case_sensitive = context.config.getBoolean ("search.case.sensitive");
@@ -246,7 +246,7 @@ bool Expression::eval (Task& task)
         value_stack.push_back (left);
       }
 
-      else if (arg->first == "!=")
+      else if (arg->_first == "!=")
       {
 //        std::cout << "#   " << left.dump () << " != " << right.dump () << "\n";
         bool result = (left != right);
@@ -257,7 +257,7 @@ bool Expression::eval (Task& task)
         value_stack.push_back (left);
       }
 
-      else if (arg->first == "=")
+      else if (arg->_first == "=")
       {
 //        std::cout << "#   " << left.dump () << " = " << right.dump () << "\n";
         bool result = false;
@@ -280,7 +280,7 @@ bool Expression::eval (Task& task)
         value_stack.push_back (left);
       }
 
-      else if (arg->first == ">")
+      else if (arg->_first == ">")
       {
 //        std::cout << "#   " << left.dump () << " > " << right.dump () << "\n";
         bool result = false;
@@ -302,7 +302,7 @@ bool Expression::eval (Task& task)
         value_stack.push_back (left);
       }
 
-      else if (arg->first == "~")
+      else if (arg->_first == "~")
       {
 //        std::cout << "#   " << left.dump () << " ~ " << right.dump () << "\n";
         bool case_sensitive = context.config.getBoolean ("search.case.sensitive");
@@ -323,31 +323,31 @@ bool Expression::eval (Task& task)
         value_stack.push_back (left);
       }
 
-      else if (arg->first == "*")
+      else if (arg->_first == "*")
       {
         left = left * right;
         value_stack.push_back (left);
       }
 
-      else if (arg->first == "/")
+      else if (arg->_first == "/")
       {
         left = left / right;
         value_stack.push_back (left);
       }
 
-      else if (arg->first == "+")
+      else if (arg->_first == "+")
       {
         left = left + right;
         value_stack.push_back (left);
       }
 
-      else if (arg->first == "-")
+      else if (arg->_first == "-")
       {
         left = left - right;
         value_stack.push_back (left);
       }
 
-      else if (arg->first == "<")
+      else if (arg->_first == "<")
       {
 //        std::cout << "#   " << left.dump () << " < " << right.dump () << "\n";
         bool result = false;
@@ -370,14 +370,14 @@ bool Expression::eval (Task& task)
       }
 
       else
-        throw std::string ("Unsupported operator '") + arg->first + "'.";
+        throw std::string ("Unsupported operator '") + arg->_first + "'.";
     }
 
     // It's not an operator, it's either and lvalue or some form of rvalue.
     else
     {
       Variant operand;
-      create_variant (operand, arg->first, arg->second);
+      create_variant (operand, arg->_first, arg->_third);
       value_stack.push_back (operand);
     }
   }
@@ -464,14 +464,14 @@ void Expression::expand_sequence ()
   // Extract all the components of a sequence.
   std::vector <int> ids;
   std::vector <std::string> uuids;
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = _args.begin (); arg != _args.end (); ++arg)
   {
-    if (arg->second == "id")
-      Arguments::extract_id (arg->first, ids);
+    if (arg->_third == "id")
+      Arguments::extract_id (arg->_first, ids);
 
-    else if (arg->second == "uuid")
-      Arguments::extract_uuid (arg->first, uuids);
+    else if (arg->_third == "uuid")
+      Arguments::extract_uuid (arg->_first, uuids);
   }
 
   // If there is no sequence, we're done.
@@ -508,20 +508,20 @@ void Expression::expand_sequence ()
   // Copy everything up to the first id/uuid.
   for (arg = _args.begin (); arg != _args.end (); ++arg)
   {
-    if (arg->second == "id" || arg->second == "uuid")
+    if (arg->_third == "id" || arg->_third == "uuid")
       break;
 
     temp.push_back (*arg);
   }
 
   // Now insert the new sequence expression.
-  temp.push_back (std::make_pair (sequence.str (), "exp"));
+  temp.push_back (Triple (sequence.str (), "?", "exp"));
 
   // Now copy everything after the last id/uuid.
   bool found_id = false;
   for (arg = _args.begin (); arg != _args.end (); ++arg)
   {
-    if (arg->second == "id" || arg->second == "uuid")
+    if (arg->_third == "id" || arg->_third == "uuid")
       found_id = true;
 
     else if (found_id)
@@ -553,47 +553,47 @@ void Expression::expand_tokens ()
   time_t t;
 
   // Look at all args.
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = _args.begin (); arg != _args.end (); ++arg)
   {
-    if (arg->second == "exp")
+    if (arg->_third == "exp")
     {
       // Nibble each arg token by token.
-      Nibbler n (arg->first);
+      Nibbler n (arg->_first);
 
       while (! n.depleted ())
       {
         if (n.getQuoted ('"', s, true) ||
             n.getQuoted ('\'', s, true))
-          temp.push_back (std::make_pair (s, "string"));
+          temp.push_back (Triple (s, "?", "string"));
 
         else if (n.getQuoted ('/', s, true))
-          temp.push_back (std::make_pair (s, "pattern"));
+          temp.push_back (Triple (s, "?", "pattern"));
 
         else if (n.getOneOf (operators, s))
-          temp.push_back (std::make_pair (s, "op"));
+          temp.push_back (Triple (s, "?", "op"));
 
         else if (n.getDOM (s))
-          temp.push_back (std::make_pair (s, "lvalue"));
+          temp.push_back (Triple (s, "?", "lvalue"));
 
         else if (n.getNumber (d))
-          temp.push_back (std::make_pair (format (d), "number"));
+          temp.push_back (Triple (format (d), "?", "number"));
 
         else if (n.getInt (i))
-          temp.push_back (std::make_pair (format (i), "int"));
+          temp.push_back (Triple (format (i), "?", "int"));
 
         else if (n.getDateISO (t))
-          temp.push_back (std::make_pair (Date (t).toISO (), "date"));
+          temp.push_back (Triple (Date (t).toISO (), "?", "date"));
 
         else if (n.getDate (date_format, t))
-          temp.push_back (std::make_pair (Date (t).toString (date_format), "date"));
+          temp.push_back (Triple (Date (t).toString (date_format), "?", "date"));
 
         else
         {
           if (! n.getUntilWS (s))
             n.getUntilEOS (s);
 
-          temp.push_back (std::make_pair (s, "?"));
+          temp.push_back (Triple (s, "?", "?"));
         }
 
         n.skipWS ();
@@ -622,20 +622,20 @@ void Expression::implicit_and ()
   bool delta = false;
 
   std::string previous = "op";
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = _args.begin (); arg != _args.end (); ++arg)
   {
     // Old-style filters need 'and' conjunctions.
     if (previous    != "op" &&
-        arg->second != "op")
+        arg->_third != "op")
     {
-      temp.push_back (std::make_pair ("and", "op"));
+      temp.push_back (Triple ("and", "?", "op"));
       delta = true;
     }
 
     // Now insert the adjacent non-operator.
     temp.push_back (*arg);
-    previous = arg->second;
+    previous = arg->_third;
   }
 
   if (delta)
@@ -654,18 +654,18 @@ void Expression::expand_tag ()
   Arguments temp;
   bool delta = false;
 
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = _args.begin (); arg != _args.end (); ++arg)
   {
-    if (arg->second == "tag")
+    if (arg->_third == "tag")
     {
       char type;
       std::string value;
-      Arguments::extract_tag (arg->first, type, value);
+      Arguments::extract_tag (arg->_first, type, value);
 
-      temp.push_back (std::make_pair ("tags", "lvalue"));
-      temp.push_back (std::make_pair (type == '+' ? "~" : "!~", "op"));
-      temp.push_back (std::make_pair (value, "string"));
+      temp.push_back (Triple ("tags", "?", "lvalue"));
+      temp.push_back (Triple (type == '+' ? "~" : "!~", "?", "op"));
+      temp.push_back (Triple (value, "?", "string"));
       delta = true;
     }
     else
@@ -687,17 +687,17 @@ void Expression::expand_pattern ()
   Arguments temp;
   bool delta = false;
 
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = _args.begin (); arg != _args.end (); ++arg)
   {
-    if (arg->second == "pattern")
+    if (arg->_third == "pattern")
     {
       std::string value;
-      Arguments::extract_pattern (arg->first, value);
+      Arguments::extract_pattern (arg->_first, value);
 
-      temp.push_back (std::make_pair ("description", "lvalue"));
-      temp.push_back (std::make_pair ("~", "op"));
-      temp.push_back (std::make_pair (value, "rx"));
+      temp.push_back (Triple ("description", "?", "lvalue"));
+      temp.push_back (Triple ("~", "?", "op"));
+      temp.push_back (Triple (value, "?", "rx"));
       delta = true;
     }
     else
@@ -719,24 +719,24 @@ void Expression::expand_attr ()
   Arguments temp;
   bool delta = false;
 
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = _args.begin (); arg != _args.end (); ++arg)
   {
-    if (arg->second == "attr")
+    if (arg->_third == "attr")
     {
       // TODO Canonicalize 'name'.
       std::string name;
       std::string value;
-      Arguments::extract_attr (arg->first, name, value);
+      Arguments::extract_attr (arg->_first, name, value);
       Arguments::is_attribute (name, name);
 
       // Always quote the value, so that empty values, or values containing spaces
       // are preserved.
       value = "\"" + value + "\"";
 
-      temp.push_back (std::make_pair (name, "lvalue"));
-      temp.push_back (std::make_pair ("=", "op"));
-      temp.push_back (std::make_pair (value, "rvalue"));
+      temp.push_back (Triple (name, "?", "lvalue"));
+      temp.push_back (Triple ("=", "?", "op"));
+      temp.push_back (Triple (value, "?", "rvalue"));
       delta = true;
     }
     else
@@ -758,16 +758,16 @@ void Expression::expand_attmod ()
   Arguments temp;
   bool delta = false;
 
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = _args.begin (); arg != _args.end (); ++arg)
   {
-    if (arg->second == "attmod")
+    if (arg->_third == "attmod")
     {
       std::string name;
       std::string mod;
       std::string value;
       std::string sense;
-      Arguments::extract_attmod (arg->first, name, mod, value, sense);
+      Arguments::extract_attmod (arg->_first, name, mod, value, sense);
       Arguments::is_attribute (name, name);
       Arguments::is_modifier (mod);
 
@@ -778,75 +778,75 @@ void Expression::expand_attmod ()
 
       if (mod == "before" || mod == "under" || mod == "below")
       {
-        temp.push_back (std::make_pair (name, "lvalue"));
-        temp.push_back (std::make_pair ("<", "op"));
-        temp.push_back (std::make_pair (value, "rvalue"));
+        temp.push_back (Triple (name, "?", "lvalue"));
+        temp.push_back (Triple ("<", "?", "op"));
+        temp.push_back (Triple (value, "?", "rvalue"));
       }
       else if (mod == "after" || mod == "over" || mod == "above")
       {
-        temp.push_back (std::make_pair (name, "lvalue"));
-        temp.push_back (std::make_pair (">", "op"));
-        temp.push_back (std::make_pair (value, "rvalue"));
+        temp.push_back (Triple (name, "?", "lvalue"));
+        temp.push_back (Triple (">", "?", "op"));
+        temp.push_back (Triple (value, "?", "rvalue"));
       }
       else if (mod == "none")
       {
-        temp.push_back (std::make_pair (name, "lvalue"));
-        temp.push_back (std::make_pair ("==", "op"));
-        temp.push_back (std::make_pair ("\"\"", "string"));
+        temp.push_back (Triple (name, "?", "lvalue"));
+        temp.push_back (Triple ("==", "?", "op"));
+        temp.push_back (Triple ("\"\"", "?", "string"));
       }
       else if (mod == "any")
       {
-        temp.push_back (std::make_pair (name, "lvalue"));
-        temp.push_back (std::make_pair ("!=", "op"));
-        temp.push_back (std::make_pair ("\"\"", "string"));
+        temp.push_back (Triple (name, "?", "lvalue"));
+        temp.push_back (Triple ("!=", "?", "op"));
+        temp.push_back (Triple ("\"\"", "?", "string"));
       }
       else if (mod == "is" || mod == "equals")
       {
-        temp.push_back (std::make_pair (name, "lvalue"));
-        temp.push_back (std::make_pair ("=", "op"));
-        temp.push_back (std::make_pair (value, "rvalue"));
+        temp.push_back (Triple (name, "?", "lvalue"));
+        temp.push_back (Triple ("=", "?", "op"));
+        temp.push_back (Triple (value, "?", "rvalue"));
       }
       else if (mod == "isnt" || mod == "not")
       {
-        temp.push_back (std::make_pair (name, "lvalue"));
-        temp.push_back (std::make_pair ("!=", "op"));
-        temp.push_back (std::make_pair (value, "rvalue"));
+        temp.push_back (Triple (name, "?", "lvalue"));
+        temp.push_back (Triple ("!=", "?", "op"));
+        temp.push_back (Triple (value, "?", "rvalue"));
       }
       else if (mod == "has" || mod == "contains")
       {
-        temp.push_back (std::make_pair (name, "lvalue"));
-        temp.push_back (std::make_pair ("~", "op"));
-        temp.push_back (std::make_pair (value, "rvalue"));
+        temp.push_back (Triple (name, "?", "lvalue"));
+        temp.push_back (Triple ("~", "?", "op"));
+        temp.push_back (Triple (value, "?", "rvalue"));
       }
       else if (mod == "hasnt")
       {
-        temp.push_back (std::make_pair (name, "lvalue"));
-        temp.push_back (std::make_pair ("!~", "op"));
-        temp.push_back (std::make_pair (value, "rvalue"));
+        temp.push_back (Triple (name, "?", "lvalue"));
+        temp.push_back (Triple ("!~", "?", "op"));
+        temp.push_back (Triple (value, "?", "rvalue"));
       }
       else if (mod == "startswith" || mod == "left")
       {
-        temp.push_back (std::make_pair (name, "lvalue"));
-        temp.push_back (std::make_pair ("~", "op"));
-        temp.push_back (std::make_pair ("^" + raw_value, "rx"));
+        temp.push_back (Triple (name, "?", "lvalue"));
+        temp.push_back (Triple ("~", "?", "op"));
+        temp.push_back (Triple ("^" + raw_value, "?", "rx"));
       }
       else if (mod == "endswith" || mod == "right")
       {
-        temp.push_back (std::make_pair (name, "lvalue"));
-        temp.push_back (std::make_pair ("~", "op"));
-        temp.push_back (std::make_pair (raw_value + "$", "rx"));
+        temp.push_back (Triple (name, "?", "lvalue"));
+        temp.push_back (Triple ("~", "?", "op"));
+        temp.push_back (Triple (raw_value + "$", "?", "rx"));
       }
       else if (mod == "word")
       {
-        temp.push_back (std::make_pair (name, "lvalue"));
-        temp.push_back (std::make_pair ("~", "op"));
-        temp.push_back (std::make_pair ("\\b" + raw_value + "\\b", "rx"));
+        temp.push_back (Triple (name, "?", "lvalue"));
+        temp.push_back (Triple ("~", "?", "op"));
+        temp.push_back (Triple ("\\b" + raw_value + "\\b", "?", "rx"));
       }
       else if (mod == "noword")
       {
-        temp.push_back (std::make_pair (name, "lvalue"));
-        temp.push_back (std::make_pair ("!~", "op"));
-        temp.push_back (std::make_pair ("\\b" + raw_value + "\\b", "rx"));
+        temp.push_back (Triple (name, "?", "lvalue"));
+        temp.push_back (Triple ("!~", "?", "op"));
+        temp.push_back (Triple ("\\b" + raw_value + "\\b", "?", "rx"));
       }
       else
         throw std::string ("Error: unrecognized attribute modifier '") + mod + "'.";
@@ -872,14 +872,14 @@ void Expression::expand_word ()
   Arguments temp;
   bool delta = false;
 
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = _args.begin (); arg != _args.end (); ++arg)
   {
-    if (arg->second == "word")
+    if (arg->_third == "word")
     {
-      temp.push_back (std::make_pair ("description", "lvalue"));
-      temp.push_back (std::make_pair ("~", "op"));
-      temp.push_back (std::make_pair ("\"" + arg->first + "\"", "rvalue"));
+      temp.push_back (Triple ("description", "?", "lvalue"));
+      temp.push_back (Triple ("~", "?", "op"));
+      temp.push_back (Triple ("\"" + arg->_first + "\"", "?", "rvalue"));
 
       delta = true;
     }
@@ -936,17 +936,17 @@ void Expression::postfix ()
   int precedence;
   char associativity;
 
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = _args.begin (); arg != _args.end (); ++arg)
   {
-    if (arg->first == "(")
+    if (arg->_first == "(")
     {
       op_stack.push_back (*arg);
     }
-    else if (arg->first == ")")
+    else if (arg->_first == ")")
     {
       while (op_stack.size () > 0 &&
-             op_stack.back ().first != "(")
+             op_stack.back ()._first != "(")
       {
         temp.push_back (op_stack.back ());
         op_stack.pop_back ();
@@ -961,13 +961,13 @@ void Expression::postfix ()
         throw std::string ("Mismatched parentheses in expression");
       }
     }
-    else if (Arguments::is_operator (arg->first, type, precedence, associativity))
+    else if (Arguments::is_operator (arg->_first, type, precedence, associativity))
     {
       char type2;
       int precedence2;
       char associativity2;
       while (op_stack.size () > 0 &&
-             Arguments::is_operator (op_stack.back ().first, type2, precedence2, associativity2) &&
+             Arguments::is_operator (op_stack.back ()._first, type2, precedence2, associativity2) &&
              ((associativity == 'l' && precedence <= precedence2) ||
               (associativity == 'r' && precedence <  precedence2)))
       {
@@ -985,8 +985,8 @@ void Expression::postfix ()
 
   while (op_stack.size () != 0)
   {
-    if (op_stack.back ().first == "(" ||
-        op_stack.back ().first == ")")
+    if (op_stack.back ()._first == "(" ||
+        op_stack.back ()._first == ")")
       throw std::string ("Mismatched parentheses in expression");
 
     temp.push_back (op_stack.back ());
@@ -1007,9 +1007,9 @@ void Expression::postfix ()
 //
 bool Expression::is_new_style ()
 {
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = _args.begin (); arg != _args.end (); ++arg)
-    if (Arguments::is_symbol_operator (arg->first))
+    if (Arguments::is_symbol_operator (arg->_first))
       return true;
 
   return false;
diff --git a/src/commands/CmdExec.cpp b/src/commands/CmdExec.cpp
index 9f55f3df4..5c872f1cf 100644
--- a/src/commands/CmdExec.cpp
+++ b/src/commands/CmdExec.cpp
@@ -48,12 +48,12 @@ CmdExec::CmdExec ()
 int CmdExec::execute (std::string& output)
 {
   std::string command_line;
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = context.args.begin (); arg != context.args.end (); ++arg)
   {
     if (arg != context.args.begin () &&
-        arg->first != "execute")
-      command_line += arg->first;
+        arg->_first != "execute")
+      command_line += arg->_first;
   }
 
   return system (command_line.c_str ());
diff --git a/src/commands/Command.cpp b/src/commands/Command.cpp
index df84f2784..ad111e53c 100644
--- a/src/commands/Command.cpp
+++ b/src/commands/Command.cpp
@@ -284,16 +284,16 @@ void Command::modify_task (Task& task, Arguments& arguments)
 {
   std::string description;
 
-  std::vector <std::pair <std::string, std::string> >::iterator arg;
+  std::vector <Triple>::iterator arg;
   for (arg = arguments.begin (); arg != arguments.end (); ++arg)
   {
     // Attributes are essentially name:value pairs, and correspond directly
     // to stored attributes.
-    if (arg->second == "attr")
+    if (arg->_third == "attr")
     {
       std::string name;
       std::string value;
-      Arguments::extract_attr (arg->first, name, value);
+      Arguments::extract_attr (arg->_first, name, value);
 
       // TODO All 'value's must be eval'd first.
 
@@ -324,11 +324,11 @@ void Command::modify_task (Task& task, Arguments& arguments)
     // Tags need special handling because they are essentially a vector stored
     // in a single string, therefore Task::{add,remove}Tag must be called as
     // appropriate.
-    else if (arg->second == "tag")
+    else if (arg->_third == "tag")
     {
       char type;
       std::string value;
-      Arguments::extract_tag (arg->first, type, value);
+      Arguments::extract_tag (arg->_first, type, value);
 
       if (type == '+')
         task.addTag (value);
@@ -337,29 +337,29 @@ void Command::modify_task (Task& task, Arguments& arguments)
     }
 
     // Words and operators are aggregated into a description.
-    else if (arg->second == "word" ||
-             arg->second == "op")
+    else if (arg->_third == "word" ||
+             arg->_third == "op")
     {
       if (description.length ())
         description += " ";
 
-      description += arg->first;
+      description += arg->_first;
     }
 
     // Substitutions.
-    else if (arg->second == "subst")
+    else if (arg->_third == "subst")
     {
       std::string from;
       std::string to;
       bool global;
-      Arguments::extract_subst (arg->first, from, to, global);
+      Arguments::extract_subst (arg->_first, from, to, global);
       task.substitute (from, to, global);
     }
 
     // Any additional argument types are indicative of a failure in
     // Arguments::extract_modifications.
     else
-      throw format (STRING_CMD_MOD_UNEXPECTED, arg->first);
+      throw format (STRING_CMD_MOD_UNEXPECTED, arg->_first);
   }
 
   // Only update description if one was specified.