1 files changed, 32 insertions, 6 deletions
diff --git a/libbuild2/functions-target-triplet.cxx b/libbuild2/functions-target-triplet.cxx
index ff9a15d..6e12c97 100644
--- a/libbuild2/functions-target-triplet.cxx
+++ b/libbuild2/functions-target-triplet.cxx
@@ -13,22 +13,48 @@ namespace build2
   {
     function_family f (m, "target_triplet");
 
-    f["string"] = [](target_triplet t) {return t.string ();};
-    f["representation"] = [](target_triplet t) {return t.representation ();};
+    // $string(<target-triplet>)
+    //
+    // Return the canonical (that is, without the `unknown` vendor component)
+    // target triplet string.
+    //
+
+    // Note that we must handle NULL values (relied upon by the parser
+    // to provide conversion semantics consistent with untyped values).
+    //
+    f["string"] += [](target_triplet* t)
+    {
+      return t != nullptr ? t->string () : string ();
+    };
+
+    // $representation(<target-triplet>)
+    //
+    // Return the complete target triplet string that always contains the
+    // vendor component.
+    //
+    f["representation"] += [](target_triplet t)
+    {
+      return t.representation ();
+    };
 
     // Target triplet-specific overloads from builtins.
     //
     function_family b (m, "builtin");
 
-    b[".concat"] = [](target_triplet l, string sr) {return l.string () + sr;};
-    b[".concat"] = [](string sl, target_triplet r) {return sl + r.string ();};
+    // Note that while we should normally handle NULL values (relied upon by
+    // the parser to provide concatenation semantics consistent with untyped
+    // values), the result will unlikely be what the user expected. So for now
+    // we keep it a bit tighter.
+    //
+    b[".concat"] += [](target_triplet l, string sr) {return l.string () + sr;};
+    b[".concat"] += [](string sl, target_triplet r) {return sl + r.string ();};
 
-    b[".concat"] = [](target_triplet l, names ur)
+    b[".concat"] += [](target_triplet l, names ur)
     {
       return l.string () + convert<string> (move (ur));
     };
 
-    b[".concat"] = [](names ul, target_triplet r)
+    b[".concat"] += [](names ul, target_triplet r)
     {
       return convert<string> (move (ul)) + r.string ();
     };