8 files changed, 224 insertions, 161 deletions

diff --git a/crates/ra_analysis/src/completion.rs b/crates/ra_analysis/src/completion.rs
index 6667c06e7..7c3476e5c 100644
--- a/crates/ra_analysis/src/completion.rs
+++ b/crates/ra_analysis/src/completion.rs
@@ -11,10 +11,10 @@ use rustc_hash::{FxHashMap, FxHashSet};
 use crate::{
     db::{self, SyntaxDatabase},
     descriptors::function::FnScopes,
-    descriptors::module::{ModuleId, ModuleScope, ModuleTree},
+    descriptors::module::{ModuleId, ModuleScope, ModuleTree, ModuleSource},
     descriptors::DescriptorDatabase,
     input::FilesDatabase,
-    Cancelable, FileId,
+    Cancelable, FilePosition,
 };
 
 #[derive(Debug)]
@@ -29,21 +29,21 @@ pub struct CompletionItem {
 
 pub(crate) fn resolve_based_completion(
     db: &db::RootDatabase,
-    file_id: FileId,
-    offset: TextUnit,
+    position: FilePosition,
 ) -> Cancelable<Option<Vec<CompletionItem>>> {
-    let source_root_id = db.file_source_root(file_id);
-    let file = db.file_syntax(file_id);
+    let source_root_id = db.file_source_root(position.file_id);
+    let file = db.file_syntax(position.file_id);
     let module_tree = db.module_tree(source_root_id)?;
-    let module_id = match module_tree.any_module_for_file(file_id) {
+    let module_id = match module_tree.any_module_for_source(ModuleSource::File(position.file_id)) {
         None => return Ok(None),
         Some(it) => it,
     };
     let file = {
-        let edit = AtomEdit::insert(offset, "intellijRulezz".to_string());
+        let edit = AtomEdit::insert(position.offset, "intellijRulezz".to_string());
         file.reparse(&edit)
     };
-    let target_module_id = match find_target_module(&module_tree, module_id, &file, offset) {
+    let target_module_id = match find_target_module(&module_tree, module_id, &file, position.offset)
+    {
         None => return Ok(None),
         Some(it) => it,
     };
@@ -99,18 +99,17 @@ fn crate_path(name_ref: ast::NameRef) -> Option<Vec<ast::NameRef>> {
 
 pub(crate) fn scope_completion(
     db: &db::RootDatabase,
-    file_id: FileId,
-    offset: TextUnit,
+    position: FilePosition,
 ) -> Option<Vec<CompletionItem>> {
-    let original_file = db.file_syntax(file_id);
+    let original_file = db.file_syntax(position.file_id);
     // Insert a fake ident to get a valid parse tree
     let file = {
-        let edit = AtomEdit::insert(offset, "intellijRulezz".to_string());
+        let edit = AtomEdit::insert(position.offset, "intellijRulezz".to_string());
         original_file.reparse(&edit)
     };
     let mut has_completions = false;
     let mut res = Vec::new();
-    if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(file.syntax(), offset) {
+    if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(file.syntax(), position.offset) {
         has_completions = true;
         complete_name_ref(&file, name_ref, &mut res);
         // special case, `trait T { fn foo(i_am_a_name_ref) {} }`
@@ -129,7 +128,7 @@ pub(crate) fn scope_completion(
             _ => (),
         }
     }
-    if let Some(name) = find_node_at_offset::<ast::Name>(file.syntax(), offset) {
+    if let Some(name) = find_node_at_offset::<ast::Name>(file.syntax(), position.offset) {
         if is_node::<ast::Param>(name.syntax()) {
             has_completions = true;
             param_completions(name.syntax(), &mut res);
@@ -383,7 +382,7 @@ mod tests {
 
     fn check_scope_completion(code: &str, expected_completions: &str) {
         let (analysis, position) = single_file_with_position(code);
-        let completions = scope_completion(&analysis.imp.db, position.file_id, position.offset)
+        let completions = scope_completion(&analysis.imp.db, position)
             .unwrap()
             .into_iter()
             .filter(|c| c.snippet.is_none())
@@ -393,7 +392,7 @@ mod tests {
 
     fn check_snippet_completion(code: &str, expected_completions: &str) {
         let (analysis, position) = single_file_with_position(code);
-        let completions = scope_completion(&analysis.imp.db, position.file_id, position.offset)
+        let completions = scope_completion(&analysis.imp.db, position)
             .unwrap()
             .into_iter()
             .filter(|c| c.snippet.is_some())
diff --git a/crates/ra_analysis/src/descriptors/mod.rs b/crates/ra_analysis/src/descriptors/mod.rs
index eaeef54c1..56bde3849 100644
--- a/crates/ra_analysis/src/descriptors/mod.rs
+++ b/crates/ra_analysis/src/descriptors/mod.rs
@@ -5,16 +5,16 @@ use std::sync::Arc;
 
 use ra_syntax::{
     ast::{self, AstNode, FnDefNode},
-    SmolStr, TextRange,
+    TextRange,
 };
 
 use crate::{
     db::SyntaxDatabase,
     descriptors::function::{resolve_local_name, FnId, FnScopes},
-    descriptors::module::{ModuleId, ModuleScope, ModuleTree},
+    descriptors::module::{ModuleId, ModuleScope, ModuleTree, ModuleSource},
     input::SourceRootId,
     syntax_ptr::LocalSyntaxPtr,
-    Cancelable, FileId,
+    Cancelable,
 };
 
 salsa::query_group! {
@@ -23,7 +23,7 @@ salsa::query_group! {
             type ModuleTreeQuery;
             use fn module::imp::module_tree;
         }
-        fn submodules(file_id: FileId) -> Cancelable<Arc<Vec<SmolStr>>> {
+        fn submodules(source: ModuleSource) -> Cancelable<Arc<Vec<module::imp::Submodule>>> {
             type SubmodulesQuery;
             use fn module::imp::submodules;
         }
diff --git a/crates/ra_analysis/src/descriptors/module/imp.rs b/crates/ra_analysis/src/descriptors/module/imp.rs
index 3a010ecf5..b3b1f1f21 100644
--- a/crates/ra_analysis/src/descriptors/module/imp.rs
+++ b/crates/ra_analysis/src/descriptors/module/imp.rs
@@ -19,25 +19,66 @@ use super::{
     ModuleTree, Problem,
 };
 
+#[derive(Clone, Hash, PartialEq, Eq, Debug)]
+pub(crate) enum Submodule {
+    Declaration(SmolStr),
+    Definition(SmolStr, ModuleSource),
+}
+
+impl Submodule {
+    fn name(&self) -> &SmolStr {
+        match self {
+            Submodule::Declaration(name) => name,
+            Submodule::Definition(name, _) => name,
+        }
+    }
+}
+
 pub(crate) fn submodules(
     db: &impl DescriptorDatabase,
-    file_id: FileId,
-) -> Cancelable<Arc<Vec<SmolStr>>> {
+    source: ModuleSource,
+) -> Cancelable<Arc<Vec<Submodule>>> {
     db::check_canceled(db)?;
-    let file = db.file_syntax(file_id);
-    let root = file.ast();
-    let submodules = modules(root).map(|(name, _)| name).collect();
-    Ok(Arc::new(submodules))
+    let file_id = source.file_id();
+    let submodules = match source.resolve(db) {
+        ModuleSourceNode::Root(it) => collect_submodules(file_id, it.ast()),
+        ModuleSourceNode::Inline(it) => it
+            .ast()
+            .item_list()
+            .map(|it| collect_submodules(file_id, it))
+            .unwrap_or_else(Vec::new),
+    };
+    return Ok(Arc::new(submodules));
+
+    fn collect_submodules<'a>(
+        file_id: FileId,
+        root: impl ast::ModuleItemOwner<'a>,
+    ) -> Vec<Submodule> {
+        modules(root)
+            .map(|(name, m)| {
+                if m.has_semi() {
+                    Submodule::Declaration(name)
+                } else {
+                    let src = ModuleSource::new_inline(file_id, m);
+                    Submodule::Definition(name, src)
+                }
+            })
+            .collect()
+    }
 }
 
-pub(crate) fn modules(root: ast::Root<'_>) -> impl Iterator<Item = (SmolStr, ast::Module<'_>)> {
-    root.modules().filter_map(|module| {
-        let name = module.name()?.text();
-        if !module.has_semi() {
-            return None;
-        }
-        Some((name, module))
-    })
+pub(crate) fn modules<'a>(
+    root: impl ast::ModuleItemOwner<'a>,
+) -> impl Iterator<Item = (SmolStr, ast::Module<'a>)> {
+    root.items()
+        .filter_map(|item| match item {
+            ast::ModuleItem::Module(m) => Some(m),
+            _ => None,
+        })
+        .filter_map(|module| {
+            let name = module.name()?.text();
+            Some((name, module))
+        })
 }
 
 pub(crate) fn module_scope(
@@ -66,11 +107,6 @@ pub(crate) fn module_tree(
     Ok(Arc::new(res))
 }
 
-#[derive(Clone, Hash, PartialEq, Eq, Debug)]
-pub struct Submodule {
-    pub name: SmolStr,
-}
-
 fn create_module_tree<'a>(
     db: &impl DescriptorDatabase,
     source_root: SourceRootId,
@@ -85,7 +121,8 @@ fn create_module_tree<'a>(
 
     let source_root = db.source_root(source_root);
     for &file_id in source_root.files.iter() {
-        if visited.contains(&file_id) {
+        let source = ModuleSource::File(file_id);
+        if visited.contains(&source) {
             continue; // TODO: use explicit crate_roots here
         }
         assert!(!roots.contains_key(&file_id));
@@ -96,7 +133,7 @@ fn create_module_tree<'a>(
             &mut visited,
             &mut roots,
             None,
-            file_id,
+            source,
         )?;
         roots.insert(file_id, module_id);
     }
@@ -107,36 +144,63 @@ fn build_subtree(
     db: &impl DescriptorDatabase,
     source_root: &SourceRoot,
     tree: &mut ModuleTree,
-    visited: &mut FxHashSet<FileId>,
+    visited: &mut FxHashSet<ModuleSource>,
     roots: &mut FxHashMap<FileId, ModuleId>,
     parent: Option<LinkId>,
-    file_id: FileId,
+    source: ModuleSource,
 ) -> Cancelable<ModuleId> {
-    visited.insert(file_id);
+    visited.insert(source);
     let id = tree.push_mod(ModuleData {
-        source: ModuleSource::File(file_id),
+        source,
         parent,
         children: Vec::new(),
     });
-    for name in db.submodules(file_id)?.iter() {
-        let (points_to, problem) = resolve_submodule(file_id, name, &source_root.file_resolver);
+    for sub in db.submodules(source)?.iter() {
         let link = tree.push_link(LinkData {
-            name: name.clone(),
+            name: sub.name().clone(),
             owner: id,
             points_to: Vec::new(),
             problem: None,
         });
 
-        let points_to = points_to
-            .into_iter()
-            .map(|file_id| match roots.remove(&file_id) {
-                Some(module_id) => {
-                    tree.module_mut(module_id).parent = Some(link);
-                    Ok(module_id)
-                }
-                None => build_subtree(db, source_root, tree, visited, roots, Some(link), file_id),
-            })
-            .collect::<Cancelable<Vec<_>>>()?;
+        let (points_to, problem) = match sub {
+            Submodule::Declaration(name) => {
+                let (points_to, problem) =
+                    resolve_submodule(source, &name, &source_root.file_resolver);
+                let points_to = points_to
+                    .into_iter()
+                    .map(|file_id| match roots.remove(&file_id) {
+                        Some(module_id) => {
+                            tree.module_mut(module_id).parent = Some(link);
+                            Ok(module_id)
+                        }
+                        None => build_subtree(
+                            db,
+                            source_root,
+                            tree,
+                            visited,
+                            roots,
+                            Some(link),
+                            ModuleSource::File(file_id),
+                        ),
+                    })
+                    .collect::<Cancelable<Vec<_>>>()?;
+                (points_to, problem)
+            }
+            Submodule::Definition(_name, submodule_source) => {
+                let points_to = build_subtree(
+                    db,
+                    source_root,
+                    tree,
+                    visited,
+                    roots,
+                    Some(link),
+                    *submodule_source,
+                )?;
+                (vec![points_to], None)
+            }
+        };
+
         tree.link_mut(link).points_to = points_to;
         tree.link_mut(link).problem = problem;
     }
@@ -144,10 +208,17 @@ fn build_subtree(
 }
 
 fn resolve_submodule(
-    file_id: FileId,
+    source: ModuleSource,
     name: &SmolStr,
     file_resolver: &FileResolverImp,
 ) -> (Vec<FileId>, Option<Problem>) {
+    let file_id = match source {
+        ModuleSource::File(it) => it,
+        ModuleSource::Inline(..) => {
+            // TODO
+            return (Vec::new(), None);
+        }
+    };
     let mod_name = file_resolver.file_stem(file_id);
     let is_dir_owner = mod_name == "mod" || mod_name == "lib" || mod_name == "main";
 
diff --git a/crates/ra_analysis/src/descriptors/module/mod.rs b/crates/ra_analysis/src/descriptors/module/mod.rs
index e22489fc1..3d799ba05 100644
--- a/crates/ra_analysis/src/descriptors/module/mod.rs
+++ b/crates/ra_analysis/src/descriptors/module/mod.rs
@@ -25,17 +25,17 @@ pub(crate) struct ModuleTree {
 }
 
 impl ModuleTree {
-    pub(crate) fn modules_for_file(&self, file_id: FileId) -> Vec<ModuleId> {
+    pub(crate) fn modules_for_source(&self, source: ModuleSource) -> Vec<ModuleId> {
         self.mods
             .iter()
             .enumerate()
-            .filter(|(_idx, it)| it.source.is_file(file_id))
+            .filter(|(_idx, it)| it.source == source)
             .map(|(idx, _)| ModuleId(idx as u32))
             .collect()
     }
 
-    pub(crate) fn any_module_for_file(&self, file_id: FileId) -> Option<ModuleId> {
-        self.modules_for_file(file_id).pop()
+    pub(crate) fn any_module_for_source(&self, source: ModuleSource) -> Option<ModuleId> {
+        self.modules_for_source(source).pop()
     }
 }
 
@@ -142,9 +142,7 @@ impl LinkId {
                     .1;
                 ast.into()
             }
-            ModuleSourceNode::Inline(..) => {
-                unimplemented!("https://github.com/rust-analyzer/rust-analyzer/issues/181")
-            }
+            ModuleSourceNode::Inline(it) => it,
         }
     }
 }
@@ -157,6 +155,12 @@ struct ModuleData {
 }
 
 impl ModuleSource {
+    pub(crate) fn new_inline(file_id: FileId, module: ast::Module) -> ModuleSource {
+        assert!(!module.has_semi());
+        let ptr = SyntaxPtr::new(file_id, module.syntax());
+        ModuleSource::Inline(ptr)
+    }
+
     pub(crate) fn as_file(self) -> Option<FileId> {
         match self {
             ModuleSource::File(f) => Some(f),
@@ -164,6 +168,13 @@ impl ModuleSource {
         }
     }
 
+    pub(crate) fn file_id(self) -> FileId {
+        match self {
+            ModuleSource::File(f) => f,
+            ModuleSource::Inline(ptr) => ptr.file_id(),
+        }
+    }
+
     fn resolve(self, db: &impl SyntaxDatabase) -> ModuleSourceNode {
         match self {
             ModuleSource::File(file_id) => {
@@ -178,10 +189,6 @@ impl ModuleSource {
             }
         }
     }
-
-    fn is_file(self, file_id: FileId) -> bool {
-        self.as_file() == Some(file_id)
-    }
 }
 
 #[derive(Hash, Debug, PartialEq, Eq)]
diff --git a/crates/ra_analysis/src/imp.rs b/crates/ra_analysis/src/imp.rs
index 4f337d163..f2482559f 100644
--- a/crates/ra_analysis/src/imp.rs
+++ b/crates/ra_analysis/src/imp.rs
@@ -27,7 +27,7 @@ use crate::{
     input::{FilesDatabase, SourceRoot, SourceRootId, WORKSPACE},
     symbol_index::SymbolIndex,
     AnalysisChange, Cancelable, CrateGraph, CrateId, Diagnostic, FileId, FileResolver,
-    FileSystemEdit, Position, Query, SourceChange, SourceFileEdit,
+    FileSystemEdit, FilePosition, Query, SourceChange, SourceFileEdit,
 };
 
 #[derive(Clone, Debug)]
@@ -220,27 +220,29 @@ impl AnalysisImpl {
         let source_root = self.db.file_source_root(file_id);
         self.db.module_tree(source_root)
     }
-    pub fn parent_module(&self, file_id: FileId) -> Cancelable<Vec<(FileId, FileSymbol)>> {
-        let module_tree = self.module_tree(file_id)?;
+    pub fn parent_module(&self, position: FilePosition) -> Cancelable<Vec<(FileId, FileSymbol)>> {
+        let module_tree = self.module_tree(position.file_id)?;
+        let file = self.db.file_syntax(position.file_id);
+        let module_source = match find_node_at_offset::<ast::Module>(file.syntax(), position.offset)
+        {
+            Some(m) if !m.has_semi() => ModuleSource::new_inline(position.file_id, m),
+            _ => ModuleSource::File(position.file_id),
+        };
 
         let res = module_tree
-            .modules_for_file(file_id)
+            .modules_for_source(module_source)
             .into_iter()
             .filter_map(|module_id| {
                 let link = module_id.parent_link(&module_tree)?;
-                let file_id = match link.owner(&module_tree).source(&module_tree) {
-                    ModuleSource::File(file_id) => file_id,
-                    ModuleSource::Inline(..) => {
-                        //TODO: https://github.com/rust-analyzer/rust-analyzer/issues/181
-                        return None;
-                    }
-                };
+                let file_id = link.owner(&module_tree).source(&module_tree).file_id();
                 let decl = link.bind_source(&module_tree, &*self.db);
                 let decl = decl.ast();
 
+                let decl_name = decl.name().unwrap();
+
                 let sym = FileSymbol {
-                    name: decl.name().unwrap().text(),
-                    node_range: decl.syntax().range(),
+                    name: decl_name.text(),
+                    node_range: decl_name.syntax().range(),
                     kind: MODULE,
                 };
                 Some((file_id, sym))
@@ -252,7 +254,7 @@ impl AnalysisImpl {
         let module_tree = self.module_tree(file_id)?;
         let crate_graph = self.db.crate_graph();
         let res = module_tree
-            .modules_for_file(file_id)
+            .modules_for_source(ModuleSource::File(file_id))
             .into_iter()
             .map(|it| it.root(&module_tree))
             .filter_map(|it| it.source(&module_tree).as_file())
@@ -264,18 +266,14 @@ impl AnalysisImpl {
     pub fn crate_root(&self, crate_id: CrateId) -> FileId {
         self.db.crate_graph().crate_roots[&crate_id]
     }
-    pub fn completions(
-        &self,
-        file_id: FileId,
-        offset: TextUnit,
-    ) -> Cancelable<Option<Vec<CompletionItem>>> {
+    pub fn completions(&self, position: FilePosition) -> Cancelable<Option<Vec<CompletionItem>>> {
         let mut res = Vec::new();
         let mut has_completions = false;
-        if let Some(scope_based) = scope_completion(&self.db, file_id, offset) {
+        if let Some(scope_based) = scope_completion(&self.db, position) {
             res.extend(scope_based);
             has_completions = true;
         }
-        if let Some(scope_based) = resolve_based_completion(&self.db, file_id, offset)? {
+        if let Some(scope_based) = resolve_based_completion(&self.db, position)? {
             res.extend(scope_based);
             has_completions = true;
         }
@@ -284,18 +282,19 @@ impl AnalysisImpl {
     }
     pub fn approximately_resolve_symbol(
         &self,
-        file_id: FileId,
-        offset: TextUnit,
+        position: FilePosition,
     ) -> Cancelable<Vec<(FileId, FileSymbol)>> {
-        let module_tree = self.module_tree(file_id)?;
-        let file = self.db.file_syntax(file_id);
+        let module_tree = self.module_tree(position.file_id)?;
+        let file = self.db.file_syntax(position.file_id);
         let syntax = file.syntax();
-        if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(syntax, offset) {
+        if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(syntax, position.offset) {
             // First try to resolve the symbol locally
-            return if let Some((name, range)) = resolve_local_name(&self.db, file_id, name_ref) {
+            return if let Some((name, range)) =
+                resolve_local_name(&self.db, position.file_id, name_ref)
+            {
                 let mut vec = vec![];
                 vec.push((
-                    file_id,
+                    position.file_id,
                     FileSymbol {
                         name,
                         node_range: range,
@@ -308,10 +307,10 @@ impl AnalysisImpl {
                 self.index_resolve(name_ref)
             };
         }
-        if let Some(name) = find_node_at_offset::<ast::Name>(syntax, offset) {
+        if let Some(name) = find_node_at_offset::<ast::Name>(syntax, position.offset) {
             if let Some(module) = name.syntax().parent().and_then(ast::Module::cast) {
                 if module.has_semi() {
-                    let file_ids = self.resolve_module(&*module_tree, file_id, module);
+                    let file_ids = self.resolve_module(&*module_tree, position.file_id, module);
 
                     let res = file_ids
                         .into_iter()
@@ -336,16 +335,17 @@ impl AnalysisImpl {
         Ok(vec![])
     }
 
-    pub fn find_all_refs(&self, file_id: FileId, offset: TextUnit) -> Vec<(FileId, TextRange)> {
-        let file = self.db.file_syntax(file_id);
+    pub fn find_all_refs(&self, position: FilePosition) -> Vec<(FileId, TextRange)> {
+        let file = self.db.file_syntax(position.file_id);
         let syntax = file.syntax();
 
         // Find the binding associated with the offset
-        let maybe_binding = find_node_at_offset::<ast::BindPat>(syntax, offset).or_else(|| {
-            let name_ref = find_node_at_offset::<ast::NameRef>(syntax, offset)?;
-            let resolved = resolve_local_name(&self.db, file_id, name_ref)?;
-            find_node_at_offset::<ast::BindPat>(syntax, resolved.1.end())
-        });
+        let maybe_binding =
+            find_node_at_offset::<ast::BindPat>(syntax, position.offset).or_else(|| {
+                let name_ref = find_node_at_offset::<ast::NameRef>(syntax, position.offset)?;
+                let resolved = resolve_local_name(&self.db, position.file_id, name_ref)?;
+                find_node_at_offset::<ast::BindPat>(syntax, resolved.1.end())
+            });
 
         let binding = match maybe_binding {
             None => return Vec::new(),
@@ -354,11 +354,11 @@ impl AnalysisImpl {
 
         let decl = DeclarationDescriptor::new(binding);
 
-        let mut ret = vec![(file_id, decl.range)];
+        let mut ret = vec![(position.file_id, decl.range)];
         ret.extend(
             decl.find_all_refs()
                 .into_iter()
-                .map(|ref_desc| (file_id, ref_desc.range)),
+                .map(|ref_desc| (position.file_id, ref_desc.range)),
         );
 
         ret
@@ -376,7 +376,7 @@ impl AnalysisImpl {
                 fix: None,
             })
             .collect::<Vec<_>>();
-        if let Some(m) = module_tree.any_module_for_file(file_id) {
+        if let Some(m) = module_tree.any_module_for_source(ModuleSource::File(file_id)) {
             for (name_node, problem) in m.problems(&module_tree, &*self.db) {
                 let diag = match problem {
                     Problem::UnresolvedModule { candidate } => {
@@ -452,14 +452,13 @@ impl AnalysisImpl {
 
     pub fn resolve_callable(
         &self,
-        file_id: FileId,
-        offset: TextUnit,
+        position: FilePosition,
     ) -> Cancelable<Option<(FnDescriptor, Option<usize>)>> {
-        let file = self.db.file_syntax(file_id);
+        let file = self.db.file_syntax(position.file_id);
         let syntax = file.syntax();
 
         // Find the calling expression and it's NameRef
-        let calling_node = match FnCallNode::with_node(syntax, offset) {
+        let calling_node = match FnCallNode::with_node(syntax, position.offset) {
             Some(node) => node,
             None => return Ok(None),
         };
@@ -494,7 +493,7 @@ impl AnalysisImpl {
                             if let Some(ref arg_list) = calling_node.arg_list() {
                                 let start = arg_list.syntax().range().start();
 
-                                let range_search = TextRange::from_to(start, offset);
+                                let range_search = TextRange::from_to(start, position.offset);
                                 let mut commas: usize = arg_list
                                     .syntax()
                                     .text()
@@ -539,7 +538,7 @@ impl AnalysisImpl {
             Some(name) => name.text(),
             None => return Vec::new(),
         };
-        let module_id = match module_tree.any_module_for_file(file_id) {
+        let module_id = match module_tree.any_module_for_source(ModuleSource::File(file_id)) {
             Some(id) => id,
             None => return Vec::new(),
         };
@@ -563,7 +562,7 @@ impl SourceChange {
             file_system_edits: vec![],
             cursor_position: edit
                 .cursor_position
-                .map(|offset| Position { offset, file_id }),
+                .map(|offset| FilePosition { offset, file_id }),
         }
     }
 }
diff --git a/crates/ra_analysis/src/lib.rs b/crates/ra_analysis/src/lib.rs
index 4e4c65f08..0ea9ebee7 100644
--- a/crates/ra_analysis/src/lib.rs
+++ b/crates/ra_analysis/src/lib.rs
@@ -119,18 +119,18 @@ impl AnalysisHost {
     }
 }
 
+#[derive(Clone, Copy, Debug)]
+pub struct FilePosition {
+    pub file_id: FileId,
+    pub offset: TextUnit,
+}
+
 #[derive(Debug)]
 pub struct SourceChange {
     pub label: String,
     pub source_file_edits: Vec<SourceFileEdit>,
     pub file_system_edits: Vec<FileSystemEdit>,
-    pub cursor_position: Option<Position>,
-}
-
-#[derive(Debug)]
-pub struct Position {
-    pub file_id: FileId,
-    pub offset: TextUnit,
+    pub cursor_position: Option<FilePosition>,
 }
 
 #[derive(Debug)]
@@ -224,18 +224,18 @@ impl Analysis {
         let file = self.imp.file_syntax(file_id);
         SourceChange::from_local_edit(file_id, "join lines", ra_editor::join_lines(&file, range))
     }
-    pub fn on_enter(&self, file_id: FileId, offset: TextUnit) -> Option<SourceChange> {
-        let file = self.imp.file_syntax(file_id);
-        let edit = ra_editor::on_enter(&file, offset)?;
-        let res = SourceChange::from_local_edit(file_id, "on enter", edit);
+    pub fn on_enter(&self, position: FilePosition) -> Option<SourceChange> {
+        let file = self.imp.file_syntax(position.file_id);
+        let edit = ra_editor::on_enter(&file, position.offset)?;
+        let res = SourceChange::from_local_edit(position.file_id, "on enter", edit);
         Some(res)
     }
-    pub fn on_eq_typed(&self, file_id: FileId, offset: TextUnit) -> Option<SourceChange> {
-        let file = self.imp.file_syntax(file_id);
+    pub fn on_eq_typed(&self, position: FilePosition) -> Option<SourceChange> {
+        let file = self.imp.file_syntax(position.file_id);
         Some(SourceChange::from_local_edit(
-            file_id,
+            position.file_id,
             "add semicolon",
-            ra_editor::on_eq_typed(&file, offset)?,
+            ra_editor::on_eq_typed(&file, position.offset)?,
         ))
     }
     pub fn file_structure(&self, file_id: FileId) -> Vec<StructureNode> {
@@ -251,20 +251,15 @@ impl Analysis {
     }
     pub fn approximately_resolve_symbol(
         &self,
-        file_id: FileId,
-        offset: TextUnit,
+        position: FilePosition,
     ) -> Cancelable<Vec<(FileId, FileSymbol)>> {
-        self.imp.approximately_resolve_symbol(file_id, offset)
+        self.imp.approximately_resolve_symbol(position)
     }
-    pub fn find_all_refs(
-        &self,
-        file_id: FileId,
-        offset: TextUnit,
-    ) -> Cancelable<Vec<(FileId, TextRange)>> {
-        Ok(self.imp.find_all_refs(file_id, offset))
+    pub fn find_all_refs(&self, position: FilePosition) -> Cancelable<Vec<(FileId, TextRange)>> {
+        Ok(self.imp.find_all_refs(position))
     }
-    pub fn parent_module(&self, file_id: FileId) -> Cancelable<Vec<(FileId, FileSymbol)>> {
-        self.imp.parent_module(file_id)
+    pub fn parent_module(&self, position: FilePosition) -> Cancelable<Vec<(FileId, FileSymbol)>> {
+        self.imp.parent_module(position)
     }
     pub fn crate_for(&self, file_id: FileId) -> Cancelable<Vec<CrateId>> {
         self.imp.crate_for(file_id)
@@ -280,12 +275,8 @@ impl Analysis {
         let file = self.imp.file_syntax(file_id);
         Ok(ra_editor::highlight(&file))
     }
-    pub fn completions(
-        &self,
-        file_id: FileId,
-        offset: TextUnit,
-    ) -> Cancelable<Option<Vec<CompletionItem>>> {
-        self.imp.completions(file_id, offset)
+    pub fn completions(&self, position: FilePosition) -> Cancelable<Option<Vec<CompletionItem>>> {
+        self.imp.completions(position)
     }
     pub fn assists(&self, file_id: FileId, range: TextRange) -> Cancelable<Vec<SourceChange>> {
         Ok(self.imp.assists(file_id, range))
@@ -295,10 +286,9 @@ impl Analysis {
     }
     pub fn resolve_callable(
         &self,
-        file_id: FileId,
-        offset: TextUnit,
+        position: FilePosition,
     ) -> Cancelable<Option<(FnDescriptor, Option<usize>)>> {
-        self.imp.resolve_callable(file_id, offset)
+        self.imp.resolve_callable(position)
     }
 }
 
diff --git a/crates/ra_analysis/src/mock_analysis.rs b/crates/ra_analysis/src/mock_analysis.rs
index a7134a0e6..8e8f969f4 100644
--- a/crates/ra_analysis/src/mock_analysis.rs
+++ b/crates/ra_analysis/src/mock_analysis.rs
@@ -1,16 +1,9 @@
 use std::sync::Arc;
 
-use ra_syntax::TextUnit;
 use relative_path::{RelativePath, RelativePathBuf};
 use test_utils::{extract_offset, parse_fixture, CURSOR_MARKER};
 
-use crate::{Analysis, AnalysisChange, AnalysisHost, FileId, FileResolver};
-
-#[derive(Debug)]
-pub struct FilePosition {
-    pub file_id: FileId,
-    pub offset: TextUnit,
-}
+use crate::{Analysis, AnalysisChange, AnalysisHost, FileId, FileResolver, FilePosition};
 
 /// Mock analysis is used in test to bootstrap an AnalysisHost/Analysis
 /// from a set of in-memory files.
diff --git a/crates/ra_analysis/src/syntax_ptr.rs b/crates/ra_analysis/src/syntax_ptr.rs
index 4db1529c2..4afb1fc93 100644
--- a/crates/ra_analysis/src/syntax_ptr.rs
+++ b/crates/ra_analysis/src/syntax_ptr.rs
@@ -22,6 +22,10 @@ impl SyntaxPtr {
         let local = LocalSyntaxPtr::new(node);
         SyntaxPtr { file_id, local }
     }
+
+    pub(crate) fn file_id(self) -> FileId {
+        self.file_id
+    }
 }
 
 /// A pionter to a syntax node inside a file.