Merge pull request #401 from shlevy/external-value

Allow external code using libnixexpr to add types

1 files changed, 11 insertions, 0 deletions

diff --git a/src/libexpr/value-to-xml.cc b/src/libexpr/value-to-xml.cc
index 3934a83eec25..bbbb7039bf70 100644
--- a/src/libexpr/value-to-xml.cc
+++ b/src/libexpr/value-to-xml.cc
@@ -144,12 +144,23 @@ static void printValueAsXML(EvalState & state, bool strict, bool location,
             break;
         }
 
+        case tExternal:
+            v.external->printValueAsXML(state, strict, location, doc, context, drvsSeen);
+            break;
+
         default:
             doc.writeEmptyElement("unevaluated");
     }
 }
 
 
+void ExternalValueBase::printValueAsXML(EvalState & state, bool strict,
+    bool location, XMLWriter & doc, PathSet & context, PathSet & drvsSeen) const
+{
+    doc.writeEmptyElement("unevaluated");
+}
+
+
 void printValueAsXML(EvalState & state, bool strict, bool location,
     Value & v, std::ostream & out, PathSet & context)
 {