node: add lookupPrefix method (NOT TESTED)

Signed-off-by: Francis Bouvier <francis.bouvier@gmail.com>

src/dom/node.zig

@@ -175,6 +175,11 @@ pub const Node = struct {
         return parser.nodeIsSameNode(self, other);
     }
 
+    pub fn _lookupPrefix(self: *parser.Node, namespace: ?[]const u8) ?[]const u8 {
+        // TODO: other is not an optional parameter, but can be null.
+        return parser.nodeLookupPrefix(self, namespace);
+    }
+
     pub fn _normalize(self: *parser.Node) void {
         return parser.nodeNormalize(self);
     }

src/netsurf.zig

@@ -383,6 +383,21 @@ pub fn nodeIsSameNode(node: *Node, other: *Node) bool {
     return res;
 }
 
+pub fn nodeLookupPrefix(node: *Node, namespace: ?[]const u8) ?[]const u8 {
+    if (namespace == null) {
+        return null;
+    }
+    if (std.mem.eql(u8, namespace.?, "")) {
+        return null;
+    }
+    var s: ?*String = undefined;
+    _ = nodeVtable(node).dom_node_lookup_prefix.?(node, stringFromData(namespace.?), &s);
+    if (s == null) {
+        return null;
+    }
+    return stringToData(s.?);
+}
+
 pub fn nodeNormalize(node: *Node) void {
     _ = nodeVtable(node).dom_node_normalize.?(node);
 }