rustdoc: Add a sorting pass

src/rustdoc/rustdoc.rc

@@ -29,3 +29,4 @@ mod unindent_pass;
 mod trim_pass;
 mod astsrv;
 mod demo;
+mod sort_pass;

src/rustdoc/sort_pass.rs

@@ -0,0 +1,69 @@
+#[doc = "A general sorting pass"];
+
+import std::sort;
+
+export item_lteq, mk_pass;
+
+type item_lteq = fn~(doc::itemtag, doc::itemtag) -> bool;
+
+fn mk_pass(lteq: item_lteq) -> pass {
+    fn~(srv: astsrv::srv, doc: doc::cratedoc) -> doc::cratedoc {
+        run(srv, doc, lteq)
+    }
+}
+
+fn run(
+    _srv: astsrv::srv,
+    doc: doc::cratedoc,
+    lteq: item_lteq
+) -> doc::cratedoc {
+    let fold = fold::fold({
+        fold_mod: fold_mod
+        with *fold::default_seq_fold(lteq)
+    });
+    fold.fold_crate(fold, doc)
+}
+
+fn fold_mod(
+    fold: fold::fold<item_lteq>,
+    doc: doc::moddoc
+) -> doc::moddoc {
+    let doc = fold::default_seq_fold_mod(fold, doc);
+    ~{
+        items: sort::merge_sort(fold.ctxt, doc.items)
+        with *doc
+    }
+}
+
+#[test]
+fn test() {
+    fn name_lteq(item1: doc::itemtag, item2: doc::itemtag) -> bool {
+        str::lteq(item1.name(), item2.name())
+    }
+
+    let source = "mod z { mod y { } fn x() { } } mod w { }";
+    let srv = astsrv::mk_srv_from_str(source);
+    let doc = extract::from_srv(srv, "");
+    let doc = mk_pass(name_lteq)(srv, doc);
+    assert doc.topmod.mods()[0].name == "w";
+    assert doc.topmod.mods()[1].items[0].name() == "x";
+    assert doc.topmod.mods()[1].items[1].name() == "y";
+    assert doc.topmod.mods()[1].name == "z";
+}
+
+#[test]
+fn should_be_stable() {
+    fn always_eq(_item1: doc::itemtag, _item2: doc::itemtag) -> bool {
+        true
+    }
+
+    let source = "mod a { mod b { } } mod c { mod d { } }";
+    let srv = astsrv::mk_srv_from_str(source);
+    let doc = extract::from_srv(srv, "");
+    let doc = mk_pass(always_eq)(srv, doc);
+    assert doc.topmod.mods()[0].items[0].name() == "b";
+    assert doc.topmod.mods()[1].items[0].name() == "d";
+    let doc = mk_pass(always_eq)(srv, doc);
+    assert doc.topmod.mods()[0].items[0].name() == "b";
+    assert doc.topmod.mods()[1].items[0].name() == "d";
+}