diff --git a/src/rustdoc/extract.rs b/src/rustdoc/extract.rs
new file mode 100644
index 000000000000..9e95faea231f
--- /dev/null
+++ b/src/rustdoc/extract.rs
@@ -0,0 +1,22 @@
+#[doc = "Converting the Rust AST to the rustdoc document model"];
+
+import rustc::syntax::ast;
+
+#[doc = "Converts the Rust AST to the rustdoc document model"]
+fn extract(crate: @ast::crate) -> doc::cratedoc {
+    {
+        mods: []
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    #[test]
+    fn extract_empty_crate() {
+        let source = ""; // empty crate
+        let ast = parse::from_str(source);
+        let doc = extract(ast);
+        assert doc.mods == [];
+    }
+}
\ No newline at end of file
diff --git a/src/rustdoc/rustdoc.rc b/src/rustdoc/rustdoc.rc
index 3f482740852e..1c80b1f5a058 100644
--- a/src/rustdoc/rustdoc.rc
+++ b/src/rustdoc/rustdoc.rc
@@ -8,5 +8,6 @@
 #[crate_type = "bin"];
 
 mod parse;
+mod extract;
 mod doc;
 mod gen;
\ No newline at end of file