Add xml.Node __repr__(), __str__()

base/src/xml.act

@@ -23,6 +23,30 @@ n.text and c.tail for all children of n.
     def encode(self) -> str:
         NotImplemented
 
+    def __str__(self):
+        return self.encode()
+
+    def __repr__(self):
+        # Build the arguments to xml.Node() and skip arguments where our value
+        # equals the default. We do this with appending to a string because that
+        # does not leak the *mut* effect, unlike appending to a list.
+        args = repr(self.tag)
+        if len(self.nsdefs) != 0:
+            args += ", nsdefs={repr(self.nsdefs)}"
+        if self.prefix is not None:
+            args += ", prefix={repr(self.prefix)}"
+        if len(self.attributes) != 0:
+            args += ", attributes={repr(self.attributes)}"
+        if len(self.children) != 0:
+            args += ", children={repr(self.children)}"
+        if self.text is not None:
+            args += ", text={repr(self.text)}"
+        if self.tail is not None:
+            args += ", tail={repr(self.tail)}"
+
+        return "xml.Node({args})"
+
+
 class XmlParseError(ValueError):
     """Exception raised for XML parsing errors
 

base/src/xml.ext.c

@@ -69,13 +69,14 @@ static unsigned char* copy_with_xml_escape(unsigned char *dst, B_str src, int es
 }
 
 // Helper function to collect text from consecutive TEXT and CDATA nodes
-// Returns the combined string and updates the node pointer to the first non-text node
+// Returns the combined string (or NULL if there is no text/CDATA content) and
+// updates the node pointer to the first non-text node
 // Note: cur_ptr is passed by reference (pointer to pointer) so we can update the caller's pointer
 //       to skip past all consumed text/CDATA nodes
 static B_str collect_text_cdata_nodes(xmlNodePtr *cur_ptr) {
     xmlNodePtr cur = *cur_ptr;
     if (!cur || (cur->type != XML_TEXT_NODE && cur->type != XML_CDATA_SECTION_NODE)) {
-        return to$str("");
+        return NULL;
     }
 
     // Count total length of combined text and CDATA nodes
@@ -106,7 +107,7 @@ static B_str collect_text_cdata_nodes(xmlNodePtr *cur_ptr) {
     }
 
     *cur_ptr = cur;
-    return to$str("");
+    return NULL;
 }
 
 xmlQ_Node $NodePtr2Node(xmlNodePtr node) {

test/stdlib_tests/src/test_xml.act

@@ -178,3 +178,8 @@ def _test_xml_namespace_attributes_undefined():
     testing.assertEqual(child_attr.1, 'child', "Undefined namespace: child attribute value not preserved")
     e = xml.encode(d)
     testing.assertEqual(e, test_xml, "Undefined namespace: roundtrip failed")
+
+def _test_xml_repr():
+    test_xml = """<data xmlns="http://default"><a xmlns:ns="http://foo" ns:operation="remove"><ns:b ns:type="element">text</ns:b></a></data>"""
+    d = xml.decode(test_xml)
+    testing.assertEqual(repr(d), "xml.Node(tag='data', nsdefs=[(None, 'http://default')], children=[xml.Node(tag='a', nsdefs=[('ns', 'http://foo')], attributes=[('ns:operation', 'remove')], children=[xml.Node(tag='b', prefix='ns', attributes=[('ns:type', 'element')], text='text')])])")