name res uses paths

4 files changed, 74 insertions, 47 deletions

diff --git a/crates/ra_analysis/src/completion/reference_completion.rs b/crates/ra_analysis/src/completion/reference_completion.rs
index 84383b547..a96570415 100644
--- a/crates/ra_analysis/src/completion/reference_completion.rs
+++ b/crates/ra_analysis/src/completion/reference_completion.rs
@@ -10,8 +10,11 @@ use ra_syntax::{
 use crate::{
     db::RootDatabase,
     completion::CompletionItem,
-    descriptors::module::{ModuleDescriptor},
-    descriptors::function::FnScopes,
+    descriptors::{
+        module::{ModuleDescriptor},
+        function::FnScopes,
+        Path, PathKind,
+    },
     Cancelable
 };
 
@@ -55,7 +58,7 @@ pub(super) fn completions(
                     }),
             );
         }
-        NameRefKind::CratePath(path) => complete_path(acc, db, module, path)?,
+        NameRefKind::Path(path) => complete_path(acc, db, module, path)?,
         NameRefKind::BareIdentInMod => {
             let name_range = name_ref.syntax().range();
             let top_node = name_ref
@@ -79,8 +82,8 @@ enum NameRefKind<'a> {
     LocalRef {
         enclosing_fn: Option<ast::FnDef<'a>>,
     },
-    /// NameRef is the last segment in crate:: path
-    CratePath(Vec<ast::NameRef<'a>>),
+    /// NameRef is the last segment in some path
+    Path(Path),
     /// NameRef is bare identifier at the module's root.
     /// Used for keyword completion
     BareIdentInMod,
@@ -102,8 +105,10 @@ fn classify_name_ref(name_ref: ast::NameRef) -> Option<NameRefKind> {
     let parent = name_ref.syntax().parent()?;
     if let Some(segment) = ast::PathSegment::cast(parent) {
         let path = segment.parent_path();
-        if let Some(crate_path) = crate_path(path) {
-            return Some(NameRefKind::CratePath(crate_path));
+        if let Some(path) = Path::from_ast(path) {
+            if !path.is_ident() {
+                return Some(NameRefKind::Path(path));
+            }
         }
         if path.qualifier().is_none() {
             let enclosing_fn = name_ref
@@ -117,32 +122,6 @@ fn classify_name_ref(name_ref: ast::NameRef) -> Option<NameRefKind> {
     None
 }
 
-fn crate_path(mut path: ast::Path) -> Option<Vec<ast::NameRef>> {
-    let mut res = Vec::new();
-    loop {
-        let segment = path.segment()?;
-        match segment.kind()? {
-            ast::PathSegmentKind::Name(name) => res.push(name),
-            ast::PathSegmentKind::CrateKw => break,
-            ast::PathSegmentKind::SelfKw | ast::PathSegmentKind::SuperKw => return None,
-        }
-        path = qualifier(path)?;
-    }
-    res.reverse();
-    return Some(res);
-
-    fn qualifier(path: ast::Path) -> Option<ast::Path> {
-        if let Some(q) = path.qualifier() {
-            return Some(q);
-        }
-        // TODO: this bottom up traversal is not too precise.
-        // Should we handle do a top-down analysiss, recording results?
-        let use_tree_list = path.syntax().ancestors().find_map(ast::UseTreeList::cast)?;
-        let use_tree = use_tree_list.parent_use_tree();
-        use_tree.path()
-    }
-}
-
 fn complete_fn(name_ref: ast::NameRef, scopes: &FnScopes, acc: &mut Vec<CompletionItem>) {
     let mut shadowed = FxHashSet::default();
     acc.extend(
@@ -169,9 +148,9 @@ fn complete_path(
     acc: &mut Vec<CompletionItem>,
     db: &RootDatabase,
     module: &ModuleDescriptor,
-    crate_path: Vec<ast::NameRef>,
+    path: Path,
 ) -> Cancelable<()> {
-    let target_module = match find_target_module(module, crate_path) {
+    let target_module = match find_target_module(module, path) {
         None => return Ok(()),
         Some(it) => it,
     };
@@ -188,14 +167,15 @@ fn complete_path(
     Ok(())
 }
 
-fn find_target_module(
-    module: &ModuleDescriptor,
-    mut crate_path: Vec<ast::NameRef>,
-) -> Option<ModuleDescriptor> {
-    crate_path.pop();
+fn find_target_module(module: &ModuleDescriptor, path: Path) -> Option<ModuleDescriptor> {
+    if path.kind != PathKind::Crate {
+        return None;
+    }
+    let mut segments = path.segments;
+    segments.pop();
     let mut target_module = module.crate_root();
-    for name in crate_path {
-        target_module = target_module.child(name.text().as_str())?;
+    for name in segments {
+        target_module = target_module.child(&name)?;
     }
     Some(target_module)
 }
diff --git a/crates/ra_analysis/src/descriptors/mod.rs b/crates/ra_analysis/src/descriptors/mod.rs
index e6225479d..97750ea64 100644
--- a/crates/ra_analysis/src/descriptors/mod.rs
+++ b/crates/ra_analysis/src/descriptors/mod.rs
@@ -5,7 +5,7 @@ mod path;
 use std::sync::Arc;
 
 use ra_syntax::{
-    ast::{self, FnDefNode},
+    ast::{self, FnDefNode, AstNode},
     TextRange,
 };
 
diff --git a/crates/ra_analysis/src/descriptors/module/nameres.rs b/crates/ra_analysis/src/descriptors/module/nameres.rs
index bf671470c..4c555421d 100644
--- a/crates/ra_analysis/src/descriptors/module/nameres.rs
+++ b/crates/ra_analysis/src/descriptors/module/nameres.rs
@@ -23,7 +23,7 @@ use rustc_hash::FxHashMap;
 
 use ra_syntax::{
     SmolStr, SyntaxKind::{self, *},
-    ast::{self, AstNode, ModuleItemOwner}
+    ast::{self, ModuleItemOwner}
 };
 
 use crate::{
@@ -309,7 +309,7 @@ where
 
         let mut curr = match import.path.kind {
             // TODO: handle extern crates
-            PathKind::Abs => return,
+            PathKind::Plain => return,
             PathKind::Self_ => module_id,
             PathKind::Super => {
                 match module_id.parent(&self.module_tree) {
diff --git a/crates/ra_analysis/src/descriptors/path.rs b/crates/ra_analysis/src/descriptors/path.rs
index 4ed561b51..99fca18b1 100644
--- a/crates/ra_analysis/src/descriptors/path.rs
+++ b/crates/ra_analysis/src/descriptors/path.rs
@@ -10,13 +10,14 @@ pub(crate) struct Path {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub(crate) enum PathKind {
-    Abs,
+    Plain,
     Self_,
     Super,
     Crate,
 }
 
 impl Path {
+    /// Calls `cb` with all paths, represented by this use item.
     pub(crate) fn expand_use_item(
         item: ast::UseItem,
         mut cb: impl FnMut(Path, Option<LocalSyntaxPtr>),
@@ -25,6 +26,52 @@ impl Path {
             expand_use_tree(None, tree, &mut cb);
         }
     }
+
+    /// Converts an `ast::Path` to `Path`. Works with use trees.
+    pub(crate) fn from_ast(mut path: ast::Path) -> Option<Path> {
+        let mut kind = PathKind::Plain;
+        let mut segments = Vec::new();
+        loop {
+            let segment = path.segment()?;
+            match segment.kind()? {
+                ast::PathSegmentKind::Name(name) => segments.push(name.text()),
+                ast::PathSegmentKind::CrateKw => {
+                    kind = PathKind::Crate;
+                    break;
+                }
+                ast::PathSegmentKind::SelfKw => {
+                    kind = PathKind::Self_;
+                    break;
+                }
+                ast::PathSegmentKind::SuperKw => {
+                    kind = PathKind::Super;
+                    break;
+                }
+            }
+            path = match qualifier(path) {
+                Some(it) => it,
+                None => break,
+            };
+        }
+        segments.reverse();
+        return Some(Path { kind, segments });
+
+        fn qualifier(path: ast::Path) -> Option<ast::Path> {
+            if let Some(q) = path.qualifier() {
+                return Some(q);
+            }
+            // TODO: this bottom up traversal is not too precise.
+            // Should we handle do a top-down analysiss, recording results?
+            let use_tree_list = path.syntax().ancestors().find_map(ast::UseTreeList::cast)?;
+            let use_tree = use_tree_list.parent_use_tree();
+            use_tree.path()
+        }
+    }
+
+    /// `true` is this path is a single identifier, like `foo`
+    pub(crate) fn is_ident(&self) -> bool {
+        self.kind == PathKind::Plain && self.segments.len() == 1
+    }
 }
 
 fn expand_use_tree(
@@ -68,7 +115,7 @@ fn convert_path(prefix: Option<Path>, path: ast::Path) -> Option<Path> {
     let res = match segment.kind()? {
         ast::PathSegmentKind::Name(name) => {
             let mut res = prefix.unwrap_or_else(|| Path {
-                kind: PathKind::Abs,
+                kind: PathKind::Plain,
                 segments: Vec::with_capacity(1),
             });
             res.segments.push(name.text());