Make name::pair char again

The plan is to represent scope/target-qualified variables as ':'-style pairs.

6 files changed, 38 insertions, 7 deletions

diff --git a/build2/file.cxx b/build2/file.cxx
index b735cab..e494f5a 100644
--- a/build2/file.cxx
+++ b/build2/file.cxx
@@ -594,6 +594,9 @@ namespace build2
             string n;
             if (i->pair)
             {
+              if (i->pair != '@')
+                fail << "unexpected pair style in variable subprojects";
+
               try
               {
                 n = convert<string> (move (*i));
diff --git a/build2/name b/build2/name
index d0a115f..68fe9c7 100644
--- a/build2/name
+++ b/build2/name
@@ -33,7 +33,8 @@ namespace build2
     dir_path dir;
     string type;
     string value;
-    bool pair = false; // True if first half of a pair.
+    char pair = '\0'; // Pair character if first half of a pair. Can be used
+                      // as bool.
 
     name () = default;
 
diff --git a/build2/name.cxx b/build2/name.cxx
index 296b4ec..f3e4c0f 100644
--- a/build2/name.cxx
+++ b/build2/name.cxx
@@ -49,7 +49,7 @@ namespace build2
       os << n;
 
       if (n.pair)
-        os << '@';
+        os << n.pair;
       else if (i != e)
         os << ' ';
     }
diff --git a/build2/name.ixx b/build2/name.ixx
index 21bd125..73dbb4a 100644
--- a/build2/name.ixx
+++ b/build2/name.ixx
@@ -37,6 +37,6 @@ namespace build2
     dir.clear ();
     type.clear ();
     value.clear ();
-    pair = false;
+    pair = '\0';
   }
 }
diff --git a/build2/parser.cxx b/build2/parser.cxx
index ce5b968..f7b17b2 100644
--- a/build2/parser.cxx
+++ b/build2/parser.cxx
@@ -991,6 +991,9 @@ namespace build2
 
       if (i->pair)
       {
+        if (i->pair != '@')
+          fail << "unexpected pair style in using directive";
+
         ++i;
         if (!i->simple ())
           fail (l) << "module version expected instead of " << *i;
@@ -1547,6 +1550,9 @@ namespace build2
 
         if (i->pair)
         {
+          if (i->pair != '=')
+            fail << "unexpected pair style in attributes";
+
           try
           {
             v = convert<string> (move (*++i));
@@ -2178,7 +2184,8 @@ namespace build2
         if (pair != 0)
           fail (t) << "nested pair on the right hand side of a pair";
 
-        // Catch '@@'. Maybe we can use for something later (e.g., escaping).
+        // Catch double pair separator ('@@'). Maybe we can use for something
+        // later (e.g., escaping).
         //
         if (!ns.empty () && ns.back ().pair)
           fail (t) << "double pair separator";
@@ -2197,7 +2204,7 @@ namespace build2
         else if (count > 1)
           fail (t) << "multiple names on the left hand side of a pair";
 
-        ns.back ().pair = true;
+        ns.back ().pair = lexer_->pair_separator ();
         tt = peek ();
 
         // If the next token is separated, then we have an empty RHS. Note
@@ -2527,6 +2534,9 @@ namespace build2
             dir_path src_base;
             if (i->pair)
             {
+              if (i->pair != '@')
+                fail << "unexpected pair style in buildspec";
+
               if (i->typed ())
                 fail (l) << "expected target src_base instead of " << *i;
 
diff --git a/build2/variable.txx b/build2/variable.txx
index 721e3c0..bd7a18b 100644
--- a/build2/variable.txx
+++ b/build2/variable.txx
@@ -138,7 +138,18 @@ namespace build2
     for (auto i (ns.begin ()); i != ns.end (); ++i)
     {
       name& n (*i);
-      name* r (n.pair ? &*++i : nullptr);
+      name* r (nullptr);
+
+      if (n.pair)
+      {
+        r = &*++i;
+
+        if (n.pair != '@')
+          fail << "unexpected pair style for "
+               << value_traits<T>::value_type.name << " value "
+               << "'" << n << "'" << n.pair << "'" << *r << "' "
+               << "in variable " << var.name;
+      }
 
       try
       {
@@ -279,6 +290,12 @@ namespace build2
 
       name& r (*++i); // Got to have the second half of the pair.
 
+      if (l.pair != '@')
+        fail << "unexpected pair style for "
+             << value_traits<map<K, V>>::value_type.name << " key-value "
+             << "'" << l << "'" << l.pair << "'" << r << "' "
+             << "in variable " << var.name;
+
       try
       {
         K k (value_traits<K>::convert (move (l), nullptr));
@@ -329,7 +346,7 @@ namespace build2
     for (const auto& p: vm)
     {
       s.push_back (value_traits<K>::reverse (p.first));
-      s.back ().pair = true;
+      s.back ().pair = '@';
       s.push_back (value_traits<V>::reverse (p.second));
     }