From aca9aa8b7e7f363779aeba1dfc60397f46b9544d Mon Sep 17 00:00:00 2001
From: veetaha <veetaha2@gmail.com>
Date: Sat, 9 May 2020 02:24:51 +0300
Subject: [PATCH 1/2] Simplify

---
 crates/rust-analyzer/src/main_loop.rs | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index b77f0c5a9c..17b0b95b9d 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -96,23 +96,21 @@ pub fn main_loop(ws_roots: Vec<PathBuf>, config: Config, connection: Connection)
     let mut world_state = {
         let workspaces = {
             // FIXME: support dynamic workspace loading.
-            let mut visited = FxHashSet::default();
-            let project_roots = ws_roots
+            let project_roots: FxHashSet<_> = ws_roots
                 .iter()
                 .filter_map(|it| ra_project_model::ProjectRoot::discover(it).ok())
                 .flatten()
-                .filter(|it| visited.insert(it.clone()))
-                .collect::<Vec<_>>();
+                .collect();
 
             if project_roots.is_empty() && config.notifications.cargo_toml_not_found {
                 show_message(
-                        req::MessageType::Error,
-                        format!(
-                            "rust-analyzer failed to discover workspace, no Cargo.toml found, dirs searched: {}",
-                            ws_roots.iter().format_with(", ", |it, f| f(&it.display()))
-                        ),
-                        &connection.sender,
-                    );
+                    req::MessageType::Error,
+                    format!(
+                        "rust-analyzer failed to discover workspace, no Cargo.toml found, dirs searched: {}",
+                        ws_roots.iter().format_with(", ", |it, f| f(&it.display()))
+                    ),
+                    &connection.sender,
+                );
             };
 
             project_roots

From e83a2912b8deaab560d1ea39232c06a29530d6e5 Mon Sep 17 00:00:00 2001
From: veetaha <veetaha2@gmail.com>
Date: Sat, 9 May 2020 02:51:59 +0300
Subject: [PATCH 2/2] Simpify project discovery

---
 crates/ra_project_model/src/lib.rs | 53 +++++++++---------------------
 1 file changed, 16 insertions(+), 37 deletions(-)

diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index 3adb8baf6a..4f098b706b 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -88,46 +88,28 @@ impl ProjectRoot {
     }
 
     pub fn discover(path: &Path) -> io::Result<Vec<ProjectRoot>> {
-        if let Some(project_json) = find_rust_project_json(path) {
+        if let Some(project_json) = find_in_parent_dirs(path, "rust-project.json") {
             return Ok(vec![ProjectRoot::ProjectJson(project_json)]);
         }
         return find_cargo_toml(path)
             .map(|paths| paths.into_iter().map(ProjectRoot::CargoToml).collect());
 
-        fn find_rust_project_json(path: &Path) -> Option<PathBuf> {
-            if path.ends_with("rust-project.json") {
-                return Some(path.to_path_buf());
-            }
-
-            let mut curr = Some(path);
-            while let Some(path) = curr {
-                let candidate = path.join("rust-project.json");
-                if candidate.exists() {
-                    return Some(candidate);
-                }
-                curr = path.parent();
-            }
-
-            None
-        }
-
         fn find_cargo_toml(path: &Path) -> io::Result<Vec<PathBuf>> {
-            if path.ends_with("Cargo.toml") {
-                return Ok(vec![path.to_path_buf()]);
+            match find_in_parent_dirs(path, "Cargo.toml") {
+                Some(it) => Ok(vec![it]),
+                None => Ok(find_cargo_toml_in_child_dir(read_dir(path)?)),
             }
-
-            if let Some(p) = find_cargo_toml_in_parent_dir(path) {
-                return Ok(vec![p]);
-            }
-
-            let entities = read_dir(path)?;
-            Ok(find_cargo_toml_in_child_dir(entities))
         }
 
-        fn find_cargo_toml_in_parent_dir(path: &Path) -> Option<PathBuf> {
+        fn find_in_parent_dirs(path: &Path, target_file_name: &str) -> Option<PathBuf> {
+            if path.ends_with(target_file_name) {
+                return Some(path.to_owned());
+            }
+
             let mut curr = Some(path);
+
             while let Some(path) = curr {
-                let candidate = path.join("Cargo.toml");
+                let candidate = path.join(target_file_name);
                 if candidate.exists() {
                     return Some(candidate);
                 }
@@ -139,14 +121,11 @@ impl ProjectRoot {
 
         fn find_cargo_toml_in_child_dir(entities: ReadDir) -> Vec<PathBuf> {
             // Only one level down to avoid cycles the easy way and stop a runaway scan with large projects
-            let mut valid_canditates = vec![];
-            for entity in entities.filter_map(Result::ok) {
-                let candidate = entity.path().join("Cargo.toml");
-                if candidate.exists() {
-                    valid_canditates.push(candidate)
-                }
-            }
-            valid_canditates
+            entities
+                .filter_map(Result::ok)
+                .map(|it| it.path().join("Cargo.toml"))
+                .filter(|it| it.exists())
+                .collect()
         }
     }
 }