* `nix-instantiate --{eval|parse}-only --xml': print an XML

  representation instead of an ATerm.
* Indent XML output.

1 files changed, 15 insertions, 2 deletions

diff --git a/src/libutil/xml-writer.cc b/src/libutil/xml-writer.cc
index e5f0d9455e40..cd37dff5608f 100644
--- a/src/libutil/xml-writer.cc
+++ b/src/libutil/xml-writer.cc
@@ -3,8 +3,8 @@
 #include "xml-writer.hh"
 
 
-XMLWriter::XMLWriter(ostream & output)
-    : output(output)
+XMLWriter::XMLWriter(bool indent, ostream & output)
+    : output(output), indent(indent)
 {
     output << "<?xml version='1.0' encoding='utf-8'?>\n";
     closed = false;
@@ -25,13 +25,22 @@ void XMLWriter::close()
 }
 
 
+void XMLWriter::indent_(unsigned int depth)
+{
+    if (!indent) return;
+    output << string(depth * 2, ' ');
+}
+
+
 void XMLWriter::openElement(const string & name,
     const XMLAttrs & attrs)
 {
     assert(!closed);
+    indent_(pendingElems.size());
     output << "<" << name;
     writeAttrs(attrs);
     output << ">";
+    if (indent) output << "\n";
     pendingElems.push_back(name);
 }
 
@@ -39,7 +48,9 @@ void XMLWriter::openElement(const string & name,
 void XMLWriter::closeElement()
 {
     assert(!pendingElems.empty());
+    indent_(pendingElems.size() - 1);
     output << "</" << pendingElems.back() << ">";
+    if (indent) output << "\n";
     pendingElems.pop_back();
     if (pendingElems.empty()) closed = true;
 }
@@ -49,9 +60,11 @@ void XMLWriter::writeEmptyElement(const string & name,
     const XMLAttrs & attrs)
 {
     assert(!closed);
+    indent_(pendingElems.size());
     output << "<" << name;
     writeAttrs(attrs);
     output << " />";
+    if (indent) output << "\n";
 }