6 files changed, 114 insertions, 187 deletions

diff --git a/crates/libeditor/src/code_actions.rs b/crates/libeditor/src/code_actions.rs
index 7c9874588..6e2c73f29 100644
--- a/crates/libeditor/src/code_actions.rs
+++ b/crates/libeditor/src/code_actions.rs
@@ -1,11 +1,12 @@
 use {TextUnit, File, EditBuilder, Edit};
 use libsyntax2::{
-    ast::AstNode,
+    ast::{self, AstNode},
     SyntaxKind::COMMA,
     SyntaxNodeRef,
+    SyntaxRoot,
     algo::{
         Direction, siblings,
-        find_leaf_at_offset,
+        find_leaf_at_offset, ancestors,
     },
 };
 
@@ -24,10 +25,32 @@ pub fn flip_comma<'a>(file: &'a File, offset: TextUnit) -> Option<impl FnOnce()
     })
 }
 
+pub fn add_derive<'a>(file: &'a File, offset: TextUnit) -> Option<impl FnOnce() -> Edit + 'a> {
+    let syntax = file.syntax();
+    let syntax = syntax.as_ref();
+    let nominal = find_node::<ast::NominalDef<_>>(syntax, offset)?;
+    Some(move || {
+        let mut edit = EditBuilder::new();
+        edit.insert(nominal.syntax().range().start(), "#[derive()]\n".to_string());
+        edit.finish()
+    })
+}
+
 fn non_trivia_sibling(node: SyntaxNodeRef, direction: Direction) -> Option<SyntaxNodeRef> {
     siblings(node, direction)
         .skip(1)
         .find(|node| !node.kind().is_trivia())
 }
 
+fn find_non_trivia_leaf(syntax: SyntaxNodeRef, offset: TextUnit) -> Option<SyntaxNodeRef> {
+    find_leaf_at_offset(syntax, offset)
+        .find(|leaf| !leaf.kind().is_trivia())
+}
+
+fn find_node<'a, N: AstNode<&'a SyntaxRoot>>(syntax: SyntaxNodeRef<'a>, offset: TextUnit) -> Option<N> {
+    let leaf = find_non_trivia_leaf(syntax, offset)?;
+    ancestors(leaf)
+        .filter_map(N::cast)
+        .next()
+}
 
diff --git a/crates/libeditor/src/lib.rs b/crates/libeditor/src/lib.rs
index b40db2c66..2c46ca45f 100644
--- a/crates/libeditor/src/lib.rs
+++ b/crates/libeditor/src/lib.rs
@@ -21,7 +21,7 @@ pub use self::{
     extend_selection::extend_selection,
     symbols::{StructureNode, file_structure, FileSymbol, file_symbols},
     edit::{EditBuilder, Edit, AtomEdit},
-    code_actions::{flip_comma},
+    code_actions::{flip_comma, add_derive},
 };
 
 #[derive(Debug)]
diff --git a/crates/libsyntax2/src/algo/search.rs b/crates/libsyntax2/src/algo/search.rs
deleted file mode 100644
index 46404f537..000000000
--- a/crates/libsyntax2/src/algo/search.rs
+++ /dev/null
@@ -1,136 +0,0 @@
-use {Node, NodeType, TextUnit, TextRange};
-use ::visitor::{visitor, process_subtree_bottom_up};
-
-pub fn child_of_type(node: Node, ty: NodeType) -> Option<Node> {
-    node.children().find(|n| n.ty() == ty)
-}
-
-pub fn children_of_type<'f>(node: Node<'f>, ty: NodeType) -> Box<Iterator<Item=Node<'f>> + 'f> {
-    Box::new(node.children().filter(move |n| n.ty() == ty))
-}
-
-pub fn subtree<'f>(node: Node<'f>) -> Box<Iterator<Item=Node<'f>> + 'f> {
-    Box::new(node.children().flat_map(subtree).chain(::std::iter::once(node)))
-}
-
-pub fn descendants_of_type<'f>(node: Node<'f>, ty: NodeType) -> Vec<Node<'f>> {
-    process_subtree_bottom_up(
-        node,
-        visitor(Vec::new())
-            .visit_nodes(&[ty], |node, nodes| nodes.push(node))
-    )
-}
-
-pub fn child_of_type_exn(node: Node, ty: NodeType) -> Node {
-    child_of_type(node, ty).unwrap_or_else(|| {
-        panic!("No child of type {:?} for {:?}\
-                ----\
-                {}\
-                ----", ty, node.ty(), node.text())
-    })
-}
-
-
-pub fn ancestors(node: Node) -> Ancestors {
-    Ancestors(Some(node))
-}
-
-pub struct Ancestors<'f>(Option<Node<'f>>);
-
-impl<'f> Iterator for Ancestors<'f> {
-    type Item = Node<'f>;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        let current = self.0;
-        self.0 = current.and_then(|n| n.parent());
-        current
-    }
-}
-
-pub fn is_leaf(node: Node) -> bool {
-    node.children().next().is_none() && !node.range().is_empty()
-}
-
-
-#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
-pub enum Direction {
-    Left, Right
-}
-
-pub fn sibling(node: Node, dir: Direction) -> Option<Node> {
-    let (parent, idx) = child_position(node)?;
-    let idx = match dir {
-        Direction::Left => idx.checked_sub(1)?,
-        Direction::Right => idx + 1,
-    };
-    parent.children().nth(idx)
-}
-
-pub mod ast {
-    use {Node, AstNode, TextUnit, AstChildren};
-    use visitor::{visitor, process_subtree_bottom_up};
-    use super::{ancestors, find_leaf_at_offset, LeafAtOffset};
-
-    pub fn ancestor<'f, T: AstNode<'f>>(node: Node<'f>) -> Option<T> {
-        ancestors(node)
-            .filter_map(T::wrap)
-            .next()
-    }
-
-    pub fn ancestor_exn<'f, T: AstNode<'f>>(node: Node<'f>) -> T {
-        ancestor(node).unwrap()
-    }
-
-    pub fn children_of_type<'f, N: AstNode<'f>>(node: Node<'f>) -> AstChildren<N> {
-        AstChildren::new(node.children())
-    }
-
-    pub fn descendants_of_type<'f, N: AstNode<'f>>(node: Node<'f>) -> Vec<N> {
-        process_subtree_bottom_up(
-            node,
-            visitor(Vec::new())
-                .visit::<N, _>(|node, acc| acc.push(node))
-        )
-    }
-
-    pub fn node_at_offset<'f, T: AstNode<'f>>(node: Node<'f>, offset: TextUnit) -> Option<T> {
-        match find_leaf_at_offset(node, offset) {
-            LeafAtOffset::None => None,
-            LeafAtOffset::Single(node) => ancestor(node),
-            LeafAtOffset::Between(left, right) => ancestor(left).or_else(|| ancestor(right)),
-        }
-    }
-}
-
-pub mod traversal {
-    use {Node};
-
-    pub fn bottom_up<'f, F: FnMut(Node<'f>)>(node: Node<'f>, mut f: F)
-    {
-        go(node, &mut f);
-
-        fn go<'f, F: FnMut(Node<'f>)>(node: Node<'f>, f: &mut F) {
-            for child in node.children() {
-                go(child, f)
-            }
-            f(node);
-        }
-    }
-}
-
-fn child_position(child: Node) -> Option<(Node, usize)> {
-    child.parent()
-        .map(|parent| {
-            (parent, parent.children().position(|n| n == child).unwrap())
-        })
-}
-
-fn common_ancestor<'f>(n1: Node<'f>, n2: Node<'f>) -> Node<'f> {
-    for p in ancestors(n1) {
-        if ancestors(n2).any(|a| a == p) {
-            return p;
-        }
-    }
-    panic!("Can't find common ancestor of {:?} and {:?}", n1, n2)
-}
-
diff --git a/crates/libsyntax2/src/ast/generated.rs b/crates/libsyntax2/src/ast/generated.rs
index 3e6c673ab..80670ce71 100644
--- a/crates/libsyntax2/src/ast/generated.rs
+++ b/crates/libsyntax2/src/ast/generated.rs
@@ -267,6 +267,31 @@ impl<R: TreeRoot> AstNode<R> for NeverType<R> {
 
 impl<R: TreeRoot> NeverType<R> {}
 
+// NominalDef
+#[derive(Debug, Clone, Copy)]
+pub enum NominalDef<R: TreeRoot = Arc<SyntaxRoot>> {
+    StructDef(StructDef<R>),
+    EnumDef(EnumDef<R>),
+}
+
+impl<R: TreeRoot> AstNode<R> for NominalDef<R> {
+    fn cast(syntax: SyntaxNode<R>) -> Option<Self> {
+        match syntax.kind() {
+            STRUCT_DEF => Some(NominalDef::StructDef(StructDef { syntax })),
+            ENUM_DEF => Some(NominalDef::EnumDef(EnumDef { syntax })),
+            _ => None,
+        }
+    }
+    fn syntax(&self) -> &SyntaxNode<R> {
+        match self {
+            NominalDef::StructDef(inner) => inner.syntax(),
+            NominalDef::EnumDef(inner) => inner.syntax(),
+        }
+    }
+}
+
+impl<R: TreeRoot> NominalDef<R> {}
+
 // ParenType
 #[derive(Debug, Clone, Copy)]
 pub struct ParenType<R: TreeRoot = Arc<SyntaxRoot>> {
diff --git a/crates/libsyntax2/src/grammar.ron b/crates/libsyntax2/src/grammar.ron
index 3641b65e2..3ae403bb5 100644
--- a/crates/libsyntax2/src/grammar.ron
+++ b/crates/libsyntax2/src/grammar.ron
@@ -261,6 +261,8 @@ Grammar(
             "ForType",
             "ImplTraitType",
             "DynTraitType",
-        ])
+        ]),
+
+        "NominalDef": ( enum: ["StructDef", "EnumDef"]),
     },
 )
diff --git a/crates/server/src/main_loop/handlers.rs b/crates/server/src/main_loop/handlers.rs
index 8789ef0d2..9de6f480b 100644
--- a/crates/server/src/main_loop/handlers.rs
+++ b/crates/server/src/main_loop/handlers.rs
@@ -87,27 +87,28 @@ pub fn handle_code_action(
     let file = world.file_syntax(&path)?;
     let line_index = world.file_line_index(&path)?;
     let offset = params.range.conv_with(&line_index).start();
-    let ret = if libeditor::flip_comma(&file, offset).is_some() {
-        let cmd = apply_code_action_cmd(
-            ActionId::FlipComma,
-            params.text_document,
-            offset,
-        );
-        Some(vec![cmd])
-    } else {
-        None
-    };
-    Ok(ret)
+    let mut ret = Vec::new();
+
+    let actions = &[
+        (ActionId::FlipComma, libeditor::flip_comma(&file, offset).is_some()),
+        (ActionId::AddDerive, libeditor::add_derive(&file, offset).is_some()),
+    ];
+
+    for (id, edit) in actions {
+        if *edit {
+            let cmd = apply_code_action_cmd(*id, params.text_document.clone(), offset);
+            ret.push(cmd);
+        }
+    }
+    return Ok(Some(ret));
 }
 
 pub fn handle_workspace_symbol(
     world: World,
     params: req::WorkspaceSymbolParams,
 ) -> Result<Option<Vec<SymbolInformation>>> {
-    let mut acc = Vec::new();
-
+    let all_symbols = params.query.contains("#");
     let query = {
-        let all_symbols = params.query.contains("#");
         let query: String = params.query.chars()
             .filter(|&c| c != '#')
             .collect();
@@ -118,19 +119,29 @@ pub fn handle_workspace_symbol(
         q.limit(128);
         q
     };
+    let mut res = exec_query(&world, query)?;
+    if res.is_empty() && !all_symbols {
+        let mut query = Query::new(params.query);
+        query.limit(128);
+        res = exec_query(&world, query)?;
+    }
 
-    for (path, symbol) in world.world_symbols(query) {
-        let line_index = world.file_line_index(path)?;
-        let info = SymbolInformation {
-            name: symbol.name.to_string(),
-            kind: symbol.kind.conv(),
-            location: (path, symbol.node_range).try_conv_with(&line_index)?,
-            container_name: None,
-        };
-        acc.push(info);
-    };
+    return Ok(Some(res));
 
-    Ok(Some(acc))
+    fn exec_query(world: &World, query: Query) -> Result<Vec<SymbolInformation>> {
+        let mut res = Vec::new();
+        for (path, symbol) in world.world_symbols(query) {
+            let line_index = world.file_line_index(path)?;
+            let info = SymbolInformation {
+                name: symbol.name.to_string(),
+                kind: symbol.kind.conv(),
+                location: (path, symbol.node_range).try_conv_with(&line_index)?,
+                container_name: None,
+            };
+            res.push(info);
+        };
+        Ok(res)
+    }
 }
 
 pub fn handle_goto_definition(
@@ -161,28 +172,28 @@ pub fn handle_execute_command(
     }
     let arg = params.arguments.pop().unwrap();
     let arg: ActionRequest = from_value(arg)?;
-    match arg.id {
-        ActionId::FlipComma => {
-            let path = arg.text_document.file_path()?;
-            let file = world.file_syntax(&path)?;
-            let line_index = world.file_line_index(&path)?;
-            let edit = match libeditor::flip_comma(&file, arg.offset) {
-                Some(edit) => edit(),
-                None => bail!("command not applicable"),
-            };
-            let mut changes = HashMap::new();
-            changes.insert(
-                arg.text_document.uri,
-                edit.conv_with(&line_index),
-            );
-            let edit = WorkspaceEdit {
-                changes: Some(changes),
-                document_changes: None,
-            };
+    let path = arg.text_document.file_path()?;
+    let file = world.file_syntax(&path)?;
+    let edit = match arg.id {
+        ActionId::FlipComma => libeditor::flip_comma(&file, arg.offset).map(|edit| edit()),
+        ActionId::AddDerive => libeditor::add_derive(&file, arg.offset).map(|edit| edit()),
+    };
+    let edit = match edit {
+        Some(edit) => edit,
+        None => bail!("command not applicable"),
+    };
+    let line_index = world.file_line_index(&path)?;
+    let mut changes = HashMap::new();
+    changes.insert(
+        arg.text_document.uri,
+        edit.conv_with(&line_index),
+    );
+    let edit = WorkspaceEdit {
+        changes: Some(changes),
+        document_changes: None,
+    };
 
-            Ok(req::ApplyWorkspaceEditParams { edit })
-        }
-    }
+    Ok(req::ApplyWorkspaceEditParams { edit })
 }
 
 #[derive(Serialize, Deserialize)]
@@ -207,13 +218,15 @@ fn apply_code_action_cmd(id: ActionId, doc: TextDocumentIdentifier, offset: Text
 
 #[derive(Serialize, Deserialize, Clone, Copy)]
 enum ActionId {
-    FlipComma
+    FlipComma,
+    AddDerive,
 }
 
 impl ActionId {
     fn title(&self) -> &'static str {
         match *self {
             ActionId::FlipComma => "Flip `,`",
+            ActionId::AddDerive => "Add `#[derive]`",
         }
     }
 }