5 files changed, 68 insertions, 46 deletions

diff --git a/crates/libeditor/src/completion.rs b/crates/libeditor/src/completion.rs
index c25b4c217..52df6fd10 100644
--- a/crates/libeditor/src/completion.rs
+++ b/crates/libeditor/src/completion.rs
@@ -2,7 +2,7 @@ use std::collections::{HashSet, HashMap};
 
 use libsyntax2::{
     File, TextUnit, AstNode, SyntaxNodeRef, SyntaxKind::*,
-    ast::{self, LoopBodyOwner},
+    ast::{self, LoopBodyOwner, ModuleItemOwner},
     algo::{
         ancestors,
         visit::{visitor, Visitor, visitor_ctx, VisitorCtx},
@@ -58,22 +58,34 @@ fn complete_name_ref(file: &File, name_ref: ast::NameRef, acc: &mut Vec<Completi
     if !is_node::<ast::Path>(name_ref.syntax()) {
         return;
     }
-    if let Some(fn_def) = ancestors(name_ref.syntax()).filter_map(ast::FnDef::cast).next() {
-        complete_expr_keywords(&file, fn_def, name_ref, acc);
-        let scopes = FnScopes::new(fn_def);
-        complete_fn(name_ref, &scopes, acc);
-    }
-    if let Some(root) = ancestors(name_ref.syntax()).filter_map(ast::Root::cast).next() {
-        let scope = ModuleScope::new(root);
-        acc.extend(
-            scope.entries().iter()
-                .filter(|entry| entry.syntax() != name_ref.syntax())
-                .map(|entry| CompletionItem {
-                    label: entry.name().to_string(),
-                    lookup: None,
-                    snippet: None,
-                })
-        );
+    let mut visited_fn = false;
+    for node in ancestors(name_ref.syntax()) {
+        if let Some(items) = visitor()
+            .visit::<ast::Root, _>(|it| Some(it.items()))
+            .visit::<ast::Module, _>(|it| Some(it.item_list()?.items()))
+            .accept(node) {
+            if let Some(items) = items {
+                let scope = ModuleScope::new(items);
+                acc.extend(
+                    scope.entries().iter()
+                        .filter(|entry| entry.syntax() != name_ref.syntax())
+                        .map(|entry| CompletionItem {
+                            label: entry.name().to_string(),
+                            lookup: None,
+                            snippet: None,
+                        })
+                );
+            }
+            break;
+
+        } else if !visited_fn {
+            if let Some(fn_def) = ast::FnDef::cast(node) {
+                visited_fn = true;
+                complete_expr_keywords(&file, fn_def, name_ref, acc);
+                let scopes = FnScopes::new(fn_def);
+                complete_fn(name_ref, &scopes, acc);
+            }
+        }
     }
 }
 
@@ -300,6 +312,18 @@ mod tests {
     }
 
     #[test]
+    fn test_completion_mod_scope_nested() {
+        check_scope_completion(r"
+            struct Foo;
+            mod m {
+                struct Bar;
+                fn quux() { <|> }
+            }
+            ", r#"[CompletionItem { label: "Bar", lookup: None, snippet: None },
+                   CompletionItem { label: "quux", lookup: None, snippet: None }]"#);
+    }
+
+    #[test]
     fn test_complete_type() {
         check_scope_completion(r"
             struct Foo;
diff --git a/crates/libeditor/src/scope/mod_scope.rs b/crates/libeditor/src/scope/mod_scope.rs
index 67baa8678..0ec56a206 100644
--- a/crates/libeditor/src/scope/mod_scope.rs
+++ b/crates/libeditor/src/scope/mod_scope.rs
@@ -1,5 +1,6 @@
 use libsyntax2::{
-    AstNode, SyntaxNode, SyntaxNodeRef, SmolStr, ast
+    AstNode, SyntaxNode, SyntaxNodeRef, SmolStr,
+    ast::{self, AstChildren},
 };
 
 pub struct ModuleScope {
@@ -16,9 +17,9 @@ enum EntryKind {
 }
 
 impl ModuleScope {
-    pub fn new(m: ast::Root) -> ModuleScope {
+    pub fn new(items: AstChildren<ast::ModuleItem>) -> ModuleScope {
         let mut entries = Vec::new();
-        for item in m.items() {
+        for item in items {
             let entry = match item {
                 ast::ModuleItem::StructDef(item) => Entry::new(item),
                 ast::ModuleItem::EnumDef(item) => Entry::new(item),
@@ -85,11 +86,11 @@ fn collect_imports(tree: ast::UseTree, acc: &mut Vec<Entry>) {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use libsyntax2::File;
+    use libsyntax2::{File, ast::ModuleItemOwner};
 
     fn do_check(code: &str, expected: &[&str]) {
         let file = File::parse(&code);
-        let scope = ModuleScope::new(file.ast());
+        let scope = ModuleScope::new(file.ast().items());
         let actual = scope.entries
             .iter()
             .map(|it| it.name())
diff --git a/crates/libsyntax2/src/ast/generated.rs b/crates/libsyntax2/src/ast/generated.rs
index a239f0630..c945c094a 100644
--- a/crates/libsyntax2/src/ast/generated.rs
+++ b/crates/libsyntax2/src/ast/generated.rs
@@ -699,11 +699,8 @@ impl<'a> AstNode<'a> for ItemList<'a> {
 }
 
 impl<'a> ast::FnDefOwner<'a> for ItemList<'a> {}
-impl<'a> ItemList<'a> {
-    pub fn items(self) -> impl Iterator<Item = ModuleItem<'a>> + 'a {
-        super::children(self)
-    }
-}
+impl<'a> ast::ModuleItemOwner<'a> for ItemList<'a> {}
+impl<'a> ItemList<'a> {}
 
 // Label
 #[derive(Debug, Clone, Copy)]
@@ -979,7 +976,6 @@ impl<'a> AstNode<'a> for Module<'a> {
 
 impl<'a> ast::NameOwner<'a> for Module<'a> {}
 impl<'a> ast::AttrsOwner<'a> for Module<'a> {}
-impl<'a> ast::FnDefOwner<'a> for Module<'a> {}
 impl<'a> Module<'a> {pub fn item_list(self) -> Option<ItemList<'a>> {
         super::child_opt(self)
     }
@@ -1616,12 +1612,9 @@ impl<'a> AstNode<'a> for Root<'a> {
     fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
 }
 
+impl<'a> ast::ModuleItemOwner<'a> for Root<'a> {}
 impl<'a> ast::FnDefOwner<'a> for Root<'a> {}
 impl<'a> Root<'a> {
-    pub fn items(self) -> impl Iterator<Item = ModuleItem<'a>> + 'a {
-        super::children(self)
-    }
-
     pub fn modules(self) -> impl Iterator<Item = Module<'a>> + 'a {
         super::children(self)
     }
diff --git a/crates/libsyntax2/src/ast/mod.rs b/crates/libsyntax2/src/ast/mod.rs
index 0b6868547..a6da82957 100644
--- a/crates/libsyntax2/src/ast/mod.rs
+++ b/crates/libsyntax2/src/ast/mod.rs
@@ -36,7 +36,13 @@ pub trait ArgListOwner<'a>: AstNode<'a> {
 }
 
 pub trait FnDefOwner<'a>: AstNode<'a> {
-    fn functions(self) -> AstNodeChildren<'a, FnDef<'a>> {
+    fn functions(self) -> AstChildren<'a, FnDef<'a>> {
+        children(self)
+    }
+}
+
+pub trait ModuleItemOwner<'a>: AstNode<'a> {
+    fn items(self) -> AstChildren<'a, ModuleItem<'a>> {
         children(self)
     }
 }
@@ -52,7 +58,7 @@ pub trait TypeParamsOwner<'a>: AstNode<'a> {
 }
 
 pub trait AttrsOwner<'a>: AstNode<'a> {
-    fn attrs(self) -> AstNodeChildren<'a, Attr<'a>> {
+    fn attrs(self) -> AstChildren<'a, Attr<'a>> {
         children(self)
     }
 }
@@ -158,7 +164,7 @@ impl<'a> IfExpr<'a> {
     pub fn else_branch(self) -> Option<Block<'a>> {
         self.blocks().nth(1)
     }
-    fn blocks(self) -> AstNodeChildren<'a, Block<'a>> {
+    fn blocks(self) -> AstChildren<'a, Block<'a>> {
         children(self)
     }
 }
@@ -167,27 +173,27 @@ fn child_opt<'a, P: AstNode<'a>, C: AstNode<'a>>(parent: P) -> Option<C> {
     children(parent).next()
 }
 
-fn children<'a, P: AstNode<'a>, C: AstNode<'a>>(parent: P) -> AstNodeChildren<'a, C> {
-    AstNodeChildren::new(parent.syntax())
+fn children<'a, P: AstNode<'a>, C: AstNode<'a>>(parent: P) -> AstChildren<'a, C> {
+    AstChildren::new(parent.syntax())
 }
 
 
 #[derive(Debug)]
-pub struct AstNodeChildren<'a, N> {
+pub struct AstChildren<'a, N> {
     inner: SyntaxNodeChildren<RefRoot<'a>>,
     ph: PhantomData<N>,
 }
 
-impl<'a, N> AstNodeChildren<'a, N> {
+impl<'a, N> AstChildren<'a, N> {
     fn new(parent: SyntaxNodeRef<'a>) -> Self {
-        AstNodeChildren {
+        AstChildren {
             inner: parent.children(),
             ph: PhantomData,
         }
     }
 }
 
-impl<'a, N: AstNode<'a>> Iterator for AstNodeChildren<'a, N> {
+impl<'a, N: AstNode<'a>> Iterator for AstChildren<'a, N> {
     type Item = N;
     fn next(&mut self) -> Option<N> {
         loop {
diff --git a/crates/libsyntax2/src/grammar.ron b/crates/libsyntax2/src/grammar.ron
index 6ed658daa..77ae4c7db 100644
--- a/crates/libsyntax2/src/grammar.ron
+++ b/crates/libsyntax2/src/grammar.ron
@@ -238,9 +238,8 @@ Grammar(
     ],
     ast: {
         "Root": (
-            traits: [ "FnDefOwner" ],
+            traits: [ "ModuleItemOwner", "FnDefOwner" ],
             collections: [
-                ["items", "ModuleItem"],
                 ["modules", "Module"],
             ]
         ),
@@ -271,12 +270,11 @@ Grammar(
         ] ),
         "TraitDef": ( traits: ["NameOwner", "AttrsOwner"] ),
         "Module": (
-            traits: ["NameOwner", "AttrsOwner", "FnDefOwner" ],
+            traits: ["NameOwner", "AttrsOwner" ],
             options: [ "ItemList" ]
         ),
         "ItemList": (
-            traits: [ "FnDefOwner" ],
-            collections: [ ["items", "ModuleItem"] ]
+            traits: [ "FnDefOwner", "ModuleItemOwner" ],
         ),
         "ConstDef": ( traits: [
             "NameOwner",