3 files changed, 180 insertions, 19 deletions

diff --git a/crates/libeditor/src/scope/mod_scope.rs b/crates/libeditor/src/scope/mod_scope.rs
index aa8dd93a7..25faee3b8 100644
--- a/crates/libeditor/src/scope/mod_scope.rs
+++ b/crates/libeditor/src/scope/mod_scope.rs
@@ -6,21 +6,38 @@ pub struct ModuleScope {
     entries: Vec<Entry>,
 }
 
+pub struct Entry {
+    node: SyntaxNode,
+    kind: EntryKind,
+}
+
+enum EntryKind {
+    Item, Import,
+}
+
 impl ModuleScope {
     pub fn new(m: ast::Root) -> ModuleScope {
-        let entries = m.items().filter_map(|item| {
-            match item {
+        let mut entries = Vec::new();
+        for item in m.items() {
+            let entry = match item {
                 ast::ModuleItem::StructDef(item) => Entry::new(item),
                 ast::ModuleItem::EnumDef(item) => Entry::new(item),
                 ast::ModuleItem::FnDef(item) => Entry::new(item),
                 ast::ModuleItem::ConstDef(item) => Entry::new(item),
                 ast::ModuleItem::StaticDef(item) => Entry::new(item),
                 ast::ModuleItem::TraitDef(item) => Entry::new(item),
+                ast::ModuleItem::Module(item) => Entry::new(item),
+                ast::ModuleItem::UseItem(item) => {
+                    if let Some(tree) = item.use_tree() {
+                        collect_imports(tree, &mut entries);
+                    }
+                    continue;
+                },
                 ast::ModuleItem::ExternCrateItem(_) |
-                ast::ModuleItem::ImplItem(_) |
-                ast::ModuleItem::UseItem(_) => None
-            }
-        }).collect();
+                ast::ModuleItem::ImplItem(_) => continue,
+            };
+            entries.extend(entry)
+        }
 
         ModuleScope { entries }
     }
@@ -30,20 +47,63 @@ impl ModuleScope {
     }
 }
 
-pub struct Entry {
-    name: SyntaxNode,
-}
-
 impl Entry {
     fn new<'a>(item: impl ast::NameOwner<'a>) -> Option<Entry> {
         let name = item.name()?;
-        Some(Entry { name: name.syntax().owned() })
+        Some(Entry { node: name.syntax().owned(), kind: EntryKind::Item })
+    }
+    fn new_import(path: ast::Path) -> Option<Entry> {
+        let name_ref = path.segment()?.name_ref()?;
+        Some(Entry { node: name_ref.syntax().owned(), kind: EntryKind::Import })
     }
     pub fn name(&self) -> SmolStr {
-        self.ast().text()
+        match self.kind {
+            EntryKind::Item =>
+                ast::Name::cast(self.node.borrowed()).unwrap()
+                    .text(),
+            EntryKind::Import =>
+                ast::NameRef::cast(self.node.borrowed()).unwrap()
+                    .text(),
+        }
     }
-    fn ast(&self) -> ast::Name {
-        ast::Name::cast(self.name.borrowed()).unwrap()
+}
+
+fn collect_imports(tree: ast::UseTree, acc: &mut Vec<Entry>) {
+    if let Some(use_tree_list) = tree.use_tree_list() {
+        return use_tree_list.use_trees().for_each(|it| collect_imports(it, acc));
+    }
+    if let Some(path) = tree.path() {
+        acc.extend(Entry::new_import(path));
     }
 }
 
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use libsyntax2::File;
+
+    fn do_check(code: &str, expected: &[&str]) {
+        let file = File::parse(&code);
+        let scope = ModuleScope::new(file.ast());
+        let actual = scope.entries
+            .iter()
+            .map(|it| it.name())
+            .collect::<Vec<_>>();
+        assert_eq!(expected, actual.as_slice());
+    }
+
+    #[test]
+    fn test_module_scope() {
+        do_check("
+            struct Foo;
+            enum Bar {}
+            mod baz {}
+            fn quux() {}
+            use x::{
+                y::z,
+                t,
+            };
+        ", &["Foo", "Bar", "baz", "quux", "z", "t"])
+    }
+}
diff --git a/crates/libsyntax2/src/ast/generated.rs b/crates/libsyntax2/src/ast/generated.rs
index c2a22c8fc..1bb3b11d1 100644
--- a/crates/libsyntax2/src/ast/generated.rs
+++ b/crates/libsyntax2/src/ast/generated.rs
@@ -977,6 +977,7 @@ pub enum ModuleItem<'a> {
     ExternCrateItem(ExternCrateItem<'a>),
     ConstDef(ConstDef<'a>),
     StaticDef(StaticDef<'a>),
+    Module(Module<'a>),
 }
 
 impl<'a> AstNode<'a> for ModuleItem<'a> {
@@ -991,6 +992,7 @@ impl<'a> AstNode<'a> for ModuleItem<'a> {
             EXTERN_CRATE_ITEM => Some(ModuleItem::ExternCrateItem(ExternCrateItem { syntax })),
             CONST_DEF => Some(ModuleItem::ConstDef(ConstDef { syntax })),
             STATIC_DEF => Some(ModuleItem::StaticDef(StaticDef { syntax })),
+            MODULE => Some(ModuleItem::Module(Module { syntax })),
             _ => None,
         }
     }
@@ -1005,6 +1007,7 @@ impl<'a> AstNode<'a> for ModuleItem<'a> {
             ModuleItem::ExternCrateItem(inner) => inner.syntax(),
             ModuleItem::ConstDef(inner) => inner.syntax(),
             ModuleItem::StaticDef(inner) => inner.syntax(),
+            ModuleItem::Module(inner) => inner.syntax(),
         }
     }
 }
@@ -1294,7 +1297,11 @@ impl<'a> AstNode<'a> for Path<'a> {
     fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
 }
 
-impl<'a> Path<'a> {}
+impl<'a> Path<'a> {
+    pub fn segment(self) -> Option<PathSegment<'a>> {
+        super::child_opt(self)
+    }
+}
 
 // PathExpr
 #[derive(Debug, Clone, Copy)]
@@ -1332,6 +1339,28 @@ impl<'a> AstNode<'a> for PathPat<'a> {
 
 impl<'a> PathPat<'a> {}
 
+// PathSegment
+#[derive(Debug, Clone, Copy)]
+pub struct PathSegment<'a> {
+    syntax: SyntaxNodeRef<'a>,
+}
+
+impl<'a> AstNode<'a> for PathSegment<'a> {
+    fn cast(syntax: SyntaxNodeRef<'a>) -> Option<Self> {
+        match syntax.kind() {
+            PATH_SEGMENT => Some(PathSegment { syntax }),
+            _ => None,
+        }
+    }
+    fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
+}
+
+impl<'a> PathSegment<'a> {
+    pub fn name_ref(self) -> Option<NameRef<'a>> {
+        super::child_opt(self)
+    }
+}
+
 // PathType
 #[derive(Debug, Clone, Copy)]
 pub struct PathType<'a> {
@@ -1989,7 +2018,59 @@ impl<'a> AstNode<'a> for UseItem<'a> {
     fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
 }
 
-impl<'a> UseItem<'a> {}
+impl<'a> UseItem<'a> {
+    pub fn use_tree(self) -> Option<UseTree<'a>> {
+        super::child_opt(self)
+    }
+}
+
+// UseTree
+#[derive(Debug, Clone, Copy)]
+pub struct UseTree<'a> {
+    syntax: SyntaxNodeRef<'a>,
+}
+
+impl<'a> AstNode<'a> for UseTree<'a> {
+    fn cast(syntax: SyntaxNodeRef<'a>) -> Option<Self> {
+        match syntax.kind() {
+            USE_TREE => Some(UseTree { syntax }),
+            _ => None,
+        }
+    }
+    fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
+}
+
+impl<'a> UseTree<'a> {
+    pub fn path(self) -> Option<Path<'a>> {
+        super::child_opt(self)
+    }
+
+    pub fn use_tree_list(self) -> Option<UseTreeList<'a>> {
+        super::child_opt(self)
+    }
+}
+
+// UseTreeList
+#[derive(Debug, Clone, Copy)]
+pub struct UseTreeList<'a> {
+    syntax: SyntaxNodeRef<'a>,
+}
+
+impl<'a> AstNode<'a> for UseTreeList<'a> {
+    fn cast(syntax: SyntaxNodeRef<'a>) -> Option<Self> {
+        match syntax.kind() {
+            USE_TREE_LIST => Some(UseTreeList { syntax }),
+            _ => None,
+        }
+    }
+    fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
+}
+
+impl<'a> UseTreeList<'a> {
+    pub fn use_trees(self) -> impl Iterator<Item = UseTree<'a>> + 'a {
+        super::children(self)
+    }
+}
 
 // WhereClause
 #[derive(Debug, Clone, Copy)]
diff --git a/crates/libsyntax2/src/grammar.ron b/crates/libsyntax2/src/grammar.ron
index 0bb40f5ab..8267c2854 100644
--- a/crates/libsyntax2/src/grammar.ron
+++ b/crates/libsyntax2/src/grammar.ron
@@ -337,7 +337,7 @@ Grammar(
         ),
         "ModuleItem": (
             enum: ["StructDef", "EnumDef", "FnDef", "TraitDef", "ImplItem",
-                   "UseItem", "ExternCrateItem", "ConstDef", "StaticDef" ]
+                   "UseItem", "ExternCrateItem", "ConstDef", "StaticDef", "Module" ]
         ),
 
         "TupleExpr": (),
@@ -507,13 +507,33 @@ Grammar(
         "Param": (
             options: [["pat", "Pat"]],
         ),
-        "UseItem": (),
+        "UseItem": (
+            options: [["use_tree", "UseTree"]]
+        ),
+        "UseTree": (
+            options: [
+                ["path", "Path"],
+                ["use_tree_list", "UseTreeList"],
+            ]
+        ),
+        "UseTreeList": (
+            collections: [["use_trees", "UseTree"]]
+        ),
         "ExternCrateItem": (),
         "ArgList": (
             collections: [
                 ["args", "Expr"]
             ]
         ),
-        "Path": (),
+        "Path": (
+            options: [
+                ["segment", "PathSegment"]
+            ]
+        ),
+        "PathSegment": (
+            options: [
+                ["name_ref", "NameRef"]
+            ]
+        ),
     },
 )