use let else to remove nested if let statements

5 files changed, 146 insertions, 144 deletions

diff --git a/src/event_exec.rs b/src/event_exec.rs
index e592661f..8031f707 100644
--- a/src/event_exec.rs
+++ b/src/event_exec.rs
@@ -96,11 +96,10 @@ impl EventExec {
 
         match tab.mode {
             Mode::Normal => {
-                if let Some(file) = tab.path_content.selected() {
-                    let path = file.path.clone();
-                    status.toggle_flag_on_path(&path);
-                    Self::event_down_one_row(status.selected());
-                }
+                let Some(file) = tab.path_content.selected() else { return Ok(()) };
+                let path = file.path.clone();
+                status.toggle_flag_on_path(&path);
+                Self::event_down_one_row(status.selected());
             }
             Mode::Tree => {
                 let path = tab.directory.tree.current_node.filepath();
@@ -260,22 +259,22 @@ impl EventExec {
     /// If the user selected a directory, we jump inside it.
     /// Otherwise, we jump to the parent and select the file.
     pub fn exec_jump(status: &mut Status) -> FmResult<()> {
-        if let Some(jump_target) = status.flagged.selected() {
-            let jump_target = jump_target.to_owned();
-            let target_dir = match jump_target.parent() {
-                Some(parent) => parent,
-                None => &jump_target,
-            };
-            let tab = status.selected();
-            tab.input.clear();
-            tab.history.push(target_dir);
-            tab.path_content
-                .change_directory(target_dir, &tab.filter, tab.show_hidden)?;
-            let index = tab.find_jump_index(&jump_target).unwrap_or_default();
-            tab.path_content.select_index(index);
-            tab.set_window();
-            tab.scroll_to(index);
-        }
+        let Some(jump_target) = status.flagged.selected() else { return Ok(()) };
+        let jump_target = jump_target.to_owned();
+        let target_dir = match jump_target.parent() {
+            Some(parent) => parent,
+            None => &jump_target,
+        };
+        let tab = status.selected();
+        tab.input.clear();
+        tab.history.push(target_dir);
+        tab.path_content
+            .change_directory(target_dir, &tab.filter, tab.show_hidden)?;
+        let index = tab.find_jump_index(&jump_target).unwrap_or_default();
+        tab.path_content.select_index(index);
+        tab.set_window();
+        tab.scroll_to(index);
+
         Ok(())
     }
 
@@ -591,19 +590,19 @@ impl EventExec {
             return Ok(());
         }
         let unmutable_tab = status.selected_non_mut();
-        if let Some(file_info) = unmutable_tab.selected() {
-            match file_info.file_kind {
-                FileKind::NormalFile => {
-                    let preview =
-                        Preview::new(file_info, &unmutable_tab.path_content.users_cache, status)?;
-                    status.selected().set_mode(Mode::Preview);
-                    status.selected().window.reset(preview.len());
-                    status.selected().preview = preview;
-                }
-                FileKind::Directory => Self::event_tree(status)?,
-                _ => (),
+        let Some(file_info) = unmutable_tab.selected() else { return Ok(()) };
+        match file_info.file_kind {
+            FileKind::NormalFile => {
+                let preview =
+                    Preview::new(file_info, &unmutable_tab.path_content.users_cache, status)?;
+                status.selected().set_mode(Mode::Preview);
+                status.selected().window.reset(preview.len());
+                status.selected().preview = preview;
             }
+            FileKind::Directory => Self::event_tree(status)?,
+            _ => (),
         }
+
         Ok(())
     }
 
@@ -998,14 +997,13 @@ impl EventExec {
     /// It obviously requires the `dragon-drop` command to be installed.
     pub fn event_drag_n_drop(status: &mut Status) -> FmResult<()> {
         let tab = status.selected_non_mut();
-        if let Some(file) = tab.selected() {
-            let path_str = file
-                .path
-                .to_str()
-                .ok_or_else(|| FmError::custom("event drag n drop", "Couldn't read path"))?;
+        let Some(file) = tab.selected() else { return Ok(()) };
+        let path_str = file
+            .path
+            .to_str()
+            .ok_or_else(|| FmError::custom("event drag n drop", "Couldn't read path"))?;
 
-            execute_in_child(DEFAULT_DRAGNDROP, &vec![path_str])?;
-        }
+        execute_in_child(DEFAULT_DRAGNDROP, &vec![path_str])?;
         Ok(())
     }
 
@@ -1048,10 +1046,9 @@ impl EventExec {
         match tab.mode {
             Mode::Tree => (),
             _ => {
-                if let Some(searched) = tab.searched.clone() {
-                    let next_index = (tab.path_content.index + 1) % tab.path_content.content.len();
-                    tab.search_from(&searched, next_index);
-                }
+                let Some(searched) = tab.searched.clone() else { return Ok(()) };
+                let next_index = (tab.path_content.index + 1) % tab.path_content.content.len();
+                tab.search_from(&searched, next_index);
             }
         }
         Ok(())
@@ -1358,12 +1355,11 @@ impl EventExec {
     /// Open a thumbnail of an image, scaled up to the whole window.
     pub fn event_thumbnail(tab: &mut Tab) -> FmResult<()> {
         if let Mode::Normal | Mode::Tree = tab.mode {
-            if let Some(file_info) = tab.selected() {
-                info!("selected {:?}", file_info);
-                tab.preview = Preview::thumbnail(file_info.path.to_owned())?;
-                tab.window.reset(tab.preview.len());
-                tab.set_mode(Mode::Preview);
-            }
+            let Some(file_info) = tab.selected() else { return Ok(())};
+            info!("selected {:?}", file_info);
+            tab.preview = Preview::thumbnail(file_info.path.to_owned())?;
+            tab.window.reset(tab.preview.len());
+            tab.set_mode(Mode::Preview);
         }
         Ok(())
     }
diff --git a/src/status.rs b/src/status.rs
index c99f91ff..136f31cd 100644
--- a/src/status.rs
+++ b/src/status.rs
@@ -146,32 +146,26 @@ impl Status {
     /// Replace the tab content with the first result of skim.
     /// It calls skim, reads its output, then update the tab content.
     pub fn skim_output_to_tab(&mut self) -> FmResult<()> {
-        if let Some(skim_output) = self
-            .skimer
-            .no_source(
-                self.selected_non_mut()
-                    .selected()
-                    .ok_or_else(|| FmError::custom("skim", "no selected file"))?
-                    .path
-                    .to_str()
-                    .ok_or_else(|| FmError::custom("skim", "skim error"))?,
-            )
-            .first()
-        {
-            self._update_tab_from_skim_output(skim_output)?;
-        }
-        Ok(())
+        let skim = self.skimer.no_source(
+            self.selected_non_mut()
+                .selected()
+                .ok_or_else(|| FmError::custom("skim", "no selected file"))?
+                .path
+                .to_str()
+                .ok_or_else(|| FmError::custom("skim", "skim error"))?,
+        );
+        let Some(output) = skim.first() else {return Ok(())};
+        self._update_tab_from_skim_output(output)
     }
 
     fn _update_tab_from_skim_output(&mut self, skim_outut: &Arc<dyn SkimItem>) -> FmResult<()> {
         let path = fs::canonicalize(skim_outut.output().to_string())?;
         let tab = self.selected();
         if path.is_file() {
-            if let Some(parent) = path.parent() {
-                tab.set_pathcontent(parent)?;
-                let filename = filename_from_path(&path)?;
-                tab.search_from(filename, 0);
-            }
+            let Some(parent) = path.parent() else { return Ok(()) };
+            tab.set_pathcontent(parent)?;
+            let filename = filename_from_path(&path)?;
+            tab.search_from(filename, 0);
         } else if path.is_dir() {
             tab.set_pathcontent(&path)?;
         }
diff --git a/src/tab.rs b/src/tab.rs
index 3e4f98f0..dd8ffe59 100644
--- a/src/tab.rs
+++ b/src/tab.rs
@@ -251,10 +251,8 @@ impl Tab {
     /// Move to the parent of current path
     pub fn move_to_parent(&mut self) -> FmResult<()> {
         let path = self.path_content.path.clone();
-        if let Some(parent) = path.parent() {
-            self.set_pathcontent(parent)?;
-        }
-        Ok(())
+        let Some(parent) = path.parent() else { return Ok(()) };
+        self.set_pathcontent(parent)
     }
 
     /// Select the parent of current node.
diff --git a/src/term_manager.rs b/src/term_manager.rs
index d13e06cf..045d969e 100644
--- a/src/term_manager.rs
+++ b/src/term_manager.rs
@@ -108,33 +108,30 @@ impl<'a> WinMain<'a> {
     /// In normal mode we display the path and number of files.
     /// When a confirmation is needed we ask the user to input `'y'` or
     /// something else.
+    /// Returns the result of the number of printed chars.
     fn first_line(&self, tab: &Tab, disk_space: &str, canvas: &mut dyn Canvas) -> FmResult<()> {
         draw_colored_strings(0, 0, self.create_first_row(tab, disk_space)?, canvas)
     }
 
-    fn second_line(&self, status: &Status, tab: &Tab, canvas: &mut dyn Canvas) -> FmResult<()> {
+    fn second_line(&self, status: &Status, tab: &Tab, canvas: &mut dyn Canvas) -> FmResult<usize> {
         match tab.mode {
             Mode::Normal => {
                 if !status.display_full {
-                    if let Some(file) = tab.selected() {
-                        self.second_line_detailed(file, status, canvas)?;
-                    }
+                    let Some(file) = tab.selected() else { return Ok(0) };
+                    self.second_line_detailed(file, status, canvas)
                 } else {
-                    self.second_line_simple(status, canvas)?;
+                    self.second_line_simple(status, canvas)
                 }
             }
             Mode::Tree => {
-                if let Some(file) = tab.selected() {
-                    self.second_line_detailed(file, status, canvas)?;
-                }
+                let Some(file) = tab.selected() else { return Ok(0) };
+                self.second_line_detailed(file, status, canvas)
             }
             Mode::InputSimple(InputSimple::Filter) => {
-                canvas.print_with_attr(1, 0, FILTER_PRESENTATION, ATTR_YELLOW_BOLD)?;
+                Ok(canvas.print_with_attr(1, 0, FILTER_PRESENTATION, ATTR_YELLOW_BOLD)?)
             }
-            _ => (),
+            _ => Ok(0),
         }
-
-        Ok(())
     }
 
     fn second_line_detailed(
diff --git a/src/tree.rs b/src/tree.rs
index 957720e3..826e9a6f 100644
--- a/src/tree.rs
+++ b/src/tree.rs
@@ -166,29 +166,15 @@ impl Tree {
         parent_position: Vec<usize>,
     ) -> FmResult<Self> {
         let sort_kind = SortKind::tree_default();
-        let mut leaves = vec![];
-        if let FileKind::Directory = fileinfo.file_kind {
-            if max_depth > 0 {
-                if let Some(mut files) =
-                    files_collection(&fileinfo, users_cache, display_hidden, filter_kind)
-                {
-                    let len = files.len();
-                    sort_kind.sort(&mut files);
-                    for (index, fileinfo) in files.iter().enumerate() {
-                        let mut position = parent_position.clone();
-                        position.push(len - index - 1);
-                        leaves.push(Self::create_tree_from_fileinfo(
-                            fileinfo.to_owned(),
-                            max_depth - 1,
-                            users_cache,
-                            filter_kind,
-                            display_hidden,
-                            position,
-                        )?)
-                    }
-                }
-            }
-        }
+        let leaves = Self::make_leaves(
+            &fileinfo,
+            max_depth,
+            users_cache,
+            display_hidden,
+            filter_kind,
+            &sort_kind,
+            parent_position.clone(),
+        )?;
         let node = Node::from_fileinfo(fileinfo, parent_position);
         let position = vec![0];
         let current_node = node.clone();
@@ -201,6 +187,40 @@ impl Tree {
         })
     }
 
+    fn make_leaves(
+        fileinfo: &FileInfo,
+        max_depth: usize,
+        users_cache: &Rc<UsersCache>,
+        display_hidden: bool,
+        filter_kind: &FilterKind,
+        sort_kind: &SortKind,
+        parent_position: Vec<usize>,
+    ) -> FmResult<Vec<Tree>> {
+        if max_depth <= 0 {
+            return Ok(vec![]);
+        }
+        let mut leaves = vec![];
+        let FileKind::Directory = fileinfo.file_kind else { return Ok(vec![]) };
+        let Some(mut files) =
+                files_collection(fileinfo, users_cache, display_hidden, filter_kind)
+            else { return Ok(leaves) };
+        sort_kind.sort(&mut files);
+        for (index, fileinfo) in files.iter().enumerate() {
+            let mut position = parent_position.clone();
+            position.push(files.len() - index - 1);
+            leaves.push(Self::create_tree_from_fileinfo(
+                fileinfo.to_owned(),
+                max_depth - 1,
+                users_cache,
+                filter_kind,
+                display_hidden,
+                position,
+            )?)
+        }
+
+        Ok(leaves)
+    }
+
     /// Sort the leaves with current sort kind.
     pub fn sort(&mut self) {
         let sort_kind = self.sort_kind.clone();
@@ -383,28 +403,27 @@ impl Tree {
 
         let mut index = 0;
         while !stack.is_empty() {
-            if let Some((prefix, current)) = stack.pop() {
-                if current.node.fileinfo.is_selected {
-                    selected_index = content.len();
-                }
+            let Some((prefix, current)) = stack.pop() else { continue };
+            if current.node.fileinfo.is_selected {
+                selected_index = content.len();
+            }
 
-                current.node.index = Some(index);
-                index += 1;
-                content.push((
-                    prefix.to_owned(),
-                    ColoredString::from_node(&current.node, colors),
-                ));
-
-                let first_prefix = first_prefix(prefix.clone());
-                let other_prefix = other_prefix(prefix);
-
-                if !current.node.folded {
-                    for (index, leaf) in current.leaves.iter_mut().enumerate() {
-                        if index == 0 {
-                            stack.push((first_prefix.clone(), leaf));
-                        } else {
-                            stack.push((other_prefix.clone(), leaf))
-                        }
+            current.node.index = Some(index);
+            index += 1;
+            content.push((
+                prefix.to_owned(),
+                ColoredString::from_node(&current.node, colors),
+            ));
+
+            let first_prefix = first_prefix(prefix.clone());
+            let other_prefix = other_prefix(prefix);
+
+            if !current.node.folded {
+                for (index, leaf) in current.leaves.iter_mut().enumerate() {
+                    if index == 0 {
+                        stack.push((first_prefix.clone(), leaf));
+                    } else {
+                        stack.push((other_prefix.clone(), leaf))
                     }
                 }
             }
@@ -412,7 +431,7 @@ impl Tree {
         (selected_index, content)
     }
 
-    /// Select the first node matching a char.
+    /// Select the first node matching a key.
     /// We use a breath first search algorithm to ensure we select the less deep one.
     pub fn select_first_match(&mut self, key: &str) -> Option<Vec<usize>> {
         if self.node.fileinfo.filename.contains(key) {
@@ -420,9 +439,8 @@ impl Tree {
         }
 
         for tree in self.leaves.iter_mut() {
-            if let Some(position) = tree.select_first_match(key) {
-                return Some(position);
-            }
+            let Some(position) = tree.select_first_match(key) else { continue };
+            return Some(position);
         }
 
         None
@@ -468,20 +486,19 @@ impl Tree {
 
         let mut visited = self;
         let mut counter = 0;
-        while !stack.is_empty() {
-            if let Some(current) = stack.pop() {
-                counter += 1;
-                visited = current;
-                if counter == index {
-                    break;
-                }
-                if !current.node.folded {
-                    for leaf in current.leaves.iter() {
-                        stack.push(leaf);
-                    }
+        while let Some(current) = stack.pop() {
+            counter += 1;
+            visited = current;
+            if counter == index {
+                break;
+            }
+            if !current.node.folded {
+                for leaf in current.leaves.iter() {
+                    stack.push(leaf);
                 }
             }
         }
+
         visited.node.position.clone()
     }
 }