1 files changed, 43 insertions, 0 deletions
diff --git a/servo/components/style/stylesheets/namespace_rule.rs b/servo/components/style/stylesheets/namespace_rule.rs
new file mode 100644
index 0000000000..ad980b70a8
--- /dev/null
+++ b/servo/components/style/stylesheets/namespace_rule.rs
@@ -0,0 +1,43 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+//! The `@namespace` at-rule.
+
+use crate::shared_lock::{SharedRwLockReadGuard, ToCssWithGuard};
+use crate::str::CssStringWriter;
+use crate::{Namespace, Prefix};
+use cssparser::SourceLocation;
+use std::fmt::{self, Write};
+use style_traits::{CssWriter, ToCss};
+
+/// A `@namespace` rule.
+#[derive(Clone, Debug, PartialEq, ToShmem)]
+#[allow(missing_docs)]
+pub struct NamespaceRule {
+    /// The namespace prefix, and `None` if it's the default Namespace
+    pub prefix: Option<Prefix>,
+    /// The actual namespace url.
+    pub url: Namespace,
+    /// The source location this rule was found at.
+    pub source_location: SourceLocation,
+}
+
+impl ToCssWithGuard for NamespaceRule {
+    // https://drafts.csswg.org/cssom/#serialize-a-css-rule CSSNamespaceRule
+    fn to_css(
+        &self,
+        _guard: &SharedRwLockReadGuard,
+        dest_str: &mut CssStringWriter,
+    ) -> fmt::Result {
+        let mut dest = CssWriter::new(dest_str);
+        dest.write_str("@namespace ")?;
+        if let Some(ref prefix) = self.prefix {
+            prefix.to_css(&mut dest)?;
+            dest.write_char(' ')?;
+        }
+        dest.write_str("url(")?;
+        self.url.to_string().to_css(&mut dest)?;
+        dest.write_str(");")
+    }
+}