From 7afd84febc76a75a3ed1be75c57ff35d7b8b3de6 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Sat, 11 Aug 2018 12:28:59 +0300
Subject: [PATCH] visitor

---
 crates/libeditor/src/extend_selection.rs    |  7 +-
 crates/libeditor/src/lib.rs                 | 14 ++--
 crates/libeditor/src/symbols.rs             | 67 +++++++++++++++++
 crates/libeditor/tests/test.rs              | 25 ++++++-
 crates/libsyntax2/src/algo/mod.rs           |  1 +
 crates/libsyntax2/src/algo/visit.rs         | 52 ++++++++++++++
 crates/libsyntax2/src/ast/generated.rs      | 80 +++++++--------------
 crates/libsyntax2/src/ast/generated.rs.tera |  8 +++
 crates/libsyntax2/src/ast/mod.rs            |  9 +++
 crates/libsyntax2/src/grammar.ron           | 28 ++------
 crates/libsyntax2/src/yellow/syntax.rs      |  6 ++
 11 files changed, 211 insertions(+), 86 deletions(-)
 create mode 100644 crates/libeditor/src/symbols.rs
 create mode 100644 crates/libsyntax2/src/algo/visit.rs

diff --git a/crates/libeditor/src/extend_selection.rs b/crates/libeditor/src/extend_selection.rs
index 16d4bc0844..ed7d9b3f77 100644
--- a/crates/libeditor/src/extend_selection.rs
+++ b/crates/libeditor/src/extend_selection.rs
@@ -1,11 +1,16 @@
 use libsyntax2::{
+    ast, AstNode,
     TextRange, SyntaxNodeRef,
     SyntaxKind::WHITESPACE,
     algo::{find_leaf_at_offset, find_covering_node, ancestors},
 };
 
+pub fn extend_selection(file: &ast::File, range: TextRange) -> Option<TextRange> {
+    let syntax = file.syntax();
+    extend(syntax.as_ref(), range)
+}
 
-pub(crate) fn extend_selection(root: SyntaxNodeRef, range: TextRange) -> Option<TextRange> {
+pub(crate) fn extend(root: SyntaxNodeRef, range: TextRange) -> Option<TextRange> {
     if range.is_empty() {
         let offset = range.start();
         let mut leaves = find_leaf_at_offset(root, offset);
diff --git a/crates/libeditor/src/lib.rs b/crates/libeditor/src/lib.rs
index 293fafae79..4ea344b178 100644
--- a/crates/libeditor/src/lib.rs
+++ b/crates/libeditor/src/lib.rs
@@ -2,16 +2,21 @@ extern crate libsyntax2;
 extern crate superslice;
 
 mod extend_selection;
+mod symbols;
 mod line_index;
 
 use libsyntax2::{
-    ast,
+    ast::{self, NameOwner},
     SyntaxNodeRef, AstNode,
     algo::walk,
     SyntaxKind::*,
 };
 pub use libsyntax2::{File, TextRange, TextUnit};
-pub use self::line_index::{LineIndex, LineCol};
+pub use self::{
+    line_index::{LineIndex, LineCol},
+    extend_selection::extend_selection,
+    symbols::{FileSymbol, file_symbols}
+};
 
 #[derive(Debug)]
 pub struct HighlightedRange {
@@ -108,11 +113,6 @@ pub fn symbols(file: &ast::File) -> Vec<Symbol> {
     res // NLL :-(
 }
 
-pub fn extend_selection(file: &ast::File, range: TextRange) -> Option<TextRange> {
-    let syntax = file.syntax();
-    extend_selection::extend_selection(syntax.as_ref(), range)
-}
-
 pub fn runnables(file: &ast::File) -> Vec<Runnable> {
     file
         .functions()
diff --git a/crates/libeditor/src/symbols.rs b/crates/libeditor/src/symbols.rs
new file mode 100644
index 0000000000..3faf96868f
--- /dev/null
+++ b/crates/libeditor/src/symbols.rs
@@ -0,0 +1,67 @@
+use libsyntax2::{
+    SyntaxKind, SyntaxNodeRef, SyntaxRoot, AstNode,
+    ast::{self, NameOwner},
+    algo::{
+        visit::{visitor, Visitor},
+        walk::{walk, WalkEvent},
+    },
+};
+use TextRange;
+
+#[derive(Debug)]
+pub struct FileSymbol {
+    pub parent: Option<usize>,
+    pub name: String,
+    pub name_range: TextRange,
+    pub node_range: TextRange,
+    pub kind: SyntaxKind,
+}
+
+
+pub fn file_symbols(file: &ast::File) -> Vec<FileSymbol> {
+    let mut res = Vec::new();
+    let mut stack = Vec::new();
+    let syntax = file.syntax();
+
+    for event in walk(syntax.as_ref()) {
+        match event {
+            WalkEvent::Enter(node) => {
+                match to_symbol(node) {
+                    Some(mut symbol) => {
+                        symbol.parent = stack.last().map(|&n| n);
+                        stack.push(res.len());
+                        res.push(symbol);
+                    }
+                    None => (),
+                }
+            }
+            WalkEvent::Exit(node) => {
+                if to_symbol(node).is_some() {
+                    stack.pop().unwrap();
+                }
+            }
+        }
+    }
+    res
+}
+
+fn to_symbol(node: SyntaxNodeRef) -> Option<FileSymbol> {
+    fn decl<'a, N: NameOwner<&'a SyntaxRoot>>(node: N) -> Option<FileSymbol> {
+        let name = node.name()?;
+        Some(FileSymbol {
+            parent: None,
+            name: name.text(),
+            name_range: name.syntax().range(),
+            node_range: node.syntax().range(),
+            kind: node.syntax().kind(),
+        })
+    }
+
+    visitor()
+        .visit(decl::<ast::Function<_>>)
+        .visit(decl::<ast::Struct<_>>)
+        .visit(decl::<ast::Enum<_>>)
+        .visit(decl::<ast::Trait<_>>)
+        .visit(decl::<ast::Module<_>>)
+        .accept(node)?
+}
diff --git a/crates/libeditor/tests/test.rs b/crates/libeditor/tests/test.rs
index d617f4b995..ba7181ab88 100644
--- a/crates/libeditor/tests/test.rs
+++ b/crates/libeditor/tests/test.rs
@@ -3,7 +3,7 @@ extern crate itertools;
 
 use std::fmt;
 use itertools::Itertools;
-use libeditor::{File, highlight, runnables, extend_selection, TextRange};
+use libeditor::{File, highlight, runnables, extend_selection, TextRange, file_symbols};
 
 #[test]
 fn test_extend_selection() {
@@ -58,6 +58,29 @@ fn test_foo() {}
     )
 }
 
+#[test]
+fn symbols() {
+    let file = file(r#"
+struct Foo {
+    x: i32
+}
+
+mod m {
+    fn bar() {}
+}
+
+enum E { X, Y(i32) }
+"#);
+    let symbols = file_symbols(&file);
+    dbg_eq(
+        &symbols,
+        r#"[FileSymbol { parent: None, name: "Foo", name_range: [8; 11), node_range: [1; 26), kind: STRUCT },
+            FileSymbol { parent: None, name: "m", name_range: [32; 33), node_range: [28; 53), kind: MODULE },
+            FileSymbol { parent: Some(1), name: "bar", name_range: [43; 46), node_range: [40; 51), kind: FUNCTION },
+            FileSymbol { parent: None, name: "E", name_range: [60; 61), node_range: [55; 75), kind: ENUM }]"#,
+    )
+}
+
 fn file(text: &str) -> File {
     File::parse(text)
 }
diff --git a/crates/libsyntax2/src/algo/mod.rs b/crates/libsyntax2/src/algo/mod.rs
index d2de70fd4c..263b58d979 100644
--- a/crates/libsyntax2/src/algo/mod.rs
+++ b/crates/libsyntax2/src/algo/mod.rs
@@ -1,4 +1,5 @@
 pub mod walk;
+pub mod visit;
 
 use {SyntaxNodeRef, TextUnit, TextRange};
 
diff --git a/crates/libsyntax2/src/algo/visit.rs b/crates/libsyntax2/src/algo/visit.rs
new file mode 100644
index 0000000000..dc5afa5a91
--- /dev/null
+++ b/crates/libsyntax2/src/algo/visit.rs
@@ -0,0 +1,52 @@
+use std::marker::PhantomData;
+use {SyntaxNodeRef, AstNode, SyntaxRoot};
+
+
+pub fn visitor<'a, T>() -> impl Visitor<'a, Output=T> {
+    EmptyVisitor { ph: PhantomData }
+}
+
+pub trait Visitor<'a>: Sized {
+    type Output;
+    fn accept(self, node: SyntaxNodeRef<'a>) -> Option<Self::Output>;
+    fn visit<N, F>(self, f: F) -> Vis<Self, N, F>
+        where N: AstNode<&'a SyntaxRoot>,
+              F: FnOnce(N) -> Self::Output,
+    {
+        Vis { inner: self, f, ph: PhantomData }
+    }
+}
+
+#[derive(Debug)]
+struct EmptyVisitor<T> {
+    ph: PhantomData<fn() -> T>
+}
+
+impl<'a, T> Visitor<'a> for EmptyVisitor<T> {
+    type Output = T;
+
+    fn accept(self, _node: SyntaxNodeRef<'a>) -> Option<T> {
+        None
+    }
+}
+
+#[derive(Debug)]
+pub struct Vis<V, N, F> {
+    inner: V,
+    f: F,
+    ph: PhantomData<fn(N)>,
+}
+
+impl<'a, V, N, F> Visitor<'a> for Vis<V, N, F>
+    where
+        V: Visitor<'a>,
+        N: AstNode<&'a SyntaxRoot>,
+        F: FnOnce(N) -> <V as Visitor<'a>>::Output,
+{
+    type Output = <V as Visitor<'a>>::Output;
+
+    fn accept(self, node: SyntaxNodeRef<'a>) -> Option<Self::Output> {
+        let Vis { inner, f, .. } = self;
+        inner.accept(node).or_else(|| N::cast(node).map(f))
+    }
+}
diff --git a/crates/libsyntax2/src/ast/generated.rs b/crates/libsyntax2/src/ast/generated.rs
index 7a2a9c7d46..a4b1169414 100644
--- a/crates/libsyntax2/src/ast/generated.rs
+++ b/crates/libsyntax2/src/ast/generated.rs
@@ -1,9 +1,11 @@
 use std::sync::Arc;
 use {
+    ast,
     SyntaxNode, SyntaxRoot, TreeRoot, AstNode,
     SyntaxKind::*,
 };
 
+// ConstItem
 #[derive(Debug, Clone, Copy)]
 pub struct ConstItem<R: TreeRoot = Arc<SyntaxRoot>> {
     syntax: SyntaxNode<R>,
@@ -19,15 +21,10 @@ impl<R: TreeRoot> AstNode<R> for ConstItem<R> {
     fn syntax(&self) -> &SyntaxNode<R> { &self.syntax }
 }
 
-impl<R: TreeRoot> ConstItem<R> {
-    pub fn name(&self) -> Option<Name<R>> {
-        self.syntax()
-            .children()
-            .filter_map(Name::cast)
-            .next()
-    }
-}
+impl<R: TreeRoot> ast::NameOwner<R> for ConstItem<R> {}
+impl<R: TreeRoot> ConstItem<R> {}
 
+// Enum
 #[derive(Debug, Clone, Copy)]
 pub struct Enum<R: TreeRoot = Arc<SyntaxRoot>> {
     syntax: SyntaxNode<R>,
@@ -43,15 +40,10 @@ impl<R: TreeRoot> AstNode<R> for Enum<R> {
     fn syntax(&self) -> &SyntaxNode<R> { &self.syntax }
 }
 
-impl<R: TreeRoot> Enum<R> {
-    pub fn name(&self) -> Option<Name<R>> {
-        self.syntax()
-            .children()
-            .filter_map(Name::cast)
-            .next()
-    }
-}
+impl<R: TreeRoot> ast::NameOwner<R> for Enum<R> {}
+impl<R: TreeRoot> Enum<R> {}
 
+// File
 #[derive(Debug, Clone, Copy)]
 pub struct File<R: TreeRoot = Arc<SyntaxRoot>> {
     syntax: SyntaxNode<R>,
@@ -75,6 +67,7 @@ impl<R: TreeRoot> File<R> {
     }
 }
 
+// Function
 #[derive(Debug, Clone, Copy)]
 pub struct Function<R: TreeRoot = Arc<SyntaxRoot>> {
     syntax: SyntaxNode<R>,
@@ -90,15 +83,10 @@ impl<R: TreeRoot> AstNode<R> for Function<R> {
     fn syntax(&self) -> &SyntaxNode<R> { &self.syntax }
 }
 
-impl<R: TreeRoot> Function<R> {
-    pub fn name(&self) -> Option<Name<R>> {
-        self.syntax()
-            .children()
-            .filter_map(Name::cast)
-            .next()
-    }
-}
+impl<R: TreeRoot> ast::NameOwner<R> for Function<R> {}
+impl<R: TreeRoot> Function<R> {}
 
+// Module
 #[derive(Debug, Clone, Copy)]
 pub struct Module<R: TreeRoot = Arc<SyntaxRoot>> {
     syntax: SyntaxNode<R>,
@@ -114,15 +102,10 @@ impl<R: TreeRoot> AstNode<R> for Module<R> {
     fn syntax(&self) -> &SyntaxNode<R> { &self.syntax }
 }
 
-impl<R: TreeRoot> Module<R> {
-    pub fn name(&self) -> Option<Name<R>> {
-        self.syntax()
-            .children()
-            .filter_map(Name::cast)
-            .next()
-    }
-}
+impl<R: TreeRoot> ast::NameOwner<R> for Module<R> {}
+impl<R: TreeRoot> Module<R> {}
 
+// Name
 #[derive(Debug, Clone, Copy)]
 pub struct Name<R: TreeRoot = Arc<SyntaxRoot>> {
     syntax: SyntaxNode<R>,
@@ -140,6 +123,7 @@ impl<R: TreeRoot> AstNode<R> for Name<R> {
 
 impl<R: TreeRoot> Name<R> {}
 
+// StaticItem
 #[derive(Debug, Clone, Copy)]
 pub struct StaticItem<R: TreeRoot = Arc<SyntaxRoot>> {
     syntax: SyntaxNode<R>,
@@ -155,15 +139,10 @@ impl<R: TreeRoot> AstNode<R> for StaticItem<R> {
     fn syntax(&self) -> &SyntaxNode<R> { &self.syntax }
 }
 
-impl<R: TreeRoot> StaticItem<R> {
-    pub fn name(&self) -> Option<Name<R>> {
-        self.syntax()
-            .children()
-            .filter_map(Name::cast)
-            .next()
-    }
-}
+impl<R: TreeRoot> ast::NameOwner<R> for StaticItem<R> {}
+impl<R: TreeRoot> StaticItem<R> {}
 
+// Struct
 #[derive(Debug, Clone, Copy)]
 pub struct Struct<R: TreeRoot = Arc<SyntaxRoot>> {
     syntax: SyntaxNode<R>,
@@ -179,15 +158,10 @@ impl<R: TreeRoot> AstNode<R> for Struct<R> {
     fn syntax(&self) -> &SyntaxNode<R> { &self.syntax }
 }
 
-impl<R: TreeRoot> Struct<R> {
-    pub fn name(&self) -> Option<Name<R>> {
-        self.syntax()
-            .children()
-            .filter_map(Name::cast)
-            .next()
-    }
-}
+impl<R: TreeRoot> ast::NameOwner<R> for Struct<R> {}
+impl<R: TreeRoot> Struct<R> {}
 
+// Trait
 #[derive(Debug, Clone, Copy)]
 pub struct Trait<R: TreeRoot = Arc<SyntaxRoot>> {
     syntax: SyntaxNode<R>,
@@ -203,12 +177,6 @@ impl<R: TreeRoot> AstNode<R> for Trait<R> {
     fn syntax(&self) -> &SyntaxNode<R> { &self.syntax }
 }
 
-impl<R: TreeRoot> Trait<R> {
-    pub fn name(&self) -> Option<Name<R>> {
-        self.syntax()
-            .children()
-            .filter_map(Name::cast)
-            .next()
-    }
-}
+impl<R: TreeRoot> ast::NameOwner<R> for Trait<R> {}
+impl<R: TreeRoot> Trait<R> {}
 
diff --git a/crates/libsyntax2/src/ast/generated.rs.tera b/crates/libsyntax2/src/ast/generated.rs.tera
index 86b8b05d1a..3d79b5543b 100644
--- a/crates/libsyntax2/src/ast/generated.rs.tera
+++ b/crates/libsyntax2/src/ast/generated.rs.tera
@@ -1,9 +1,11 @@
 use std::sync::Arc;
 use {
+    ast,
     SyntaxNode, SyntaxRoot, TreeRoot, AstNode,
     SyntaxKind::*,
 };
 {% for node, methods in ast %}
+// {{ node }}
 #[derive(Debug, Clone, Copy)]
 pub struct {{ node }}<R: TreeRoot = Arc<SyntaxRoot>> {
     syntax: SyntaxNode<R>,
@@ -19,6 +21,12 @@ impl<R: TreeRoot> AstNode<R> for {{ node }}<R> {
     fn syntax(&self) -> &SyntaxNode<R> { &self.syntax }
 }
 
+{% if methods.traits -%}
+{%- for t in methods.traits -%}
+impl<R: TreeRoot> ast::{{ t }}<R> for {{ node }}<R> {}
+{% endfor -%}
+{%- endif -%}
+
 impl<R: TreeRoot> {{ node }}<R> {
 {%- if methods.collections -%}
 {%- for m in methods.collections -%}
diff --git a/crates/libsyntax2/src/ast/mod.rs b/crates/libsyntax2/src/ast/mod.rs
index 7d3cdb93db..56bc099fea 100644
--- a/crates/libsyntax2/src/ast/mod.rs
+++ b/crates/libsyntax2/src/ast/mod.rs
@@ -12,6 +12,15 @@ pub trait AstNode<R: TreeRoot>: Sized {
     fn syntax(&self) -> &SyntaxNode<R>;
 }
 
+pub trait NameOwner<R: TreeRoot>: AstNode<R> {
+    fn name(&self) -> Option<Name<R>> {
+        self.syntax()
+            .children()
+            .filter_map(Name::cast)
+            .next()
+    }
+}
+
 impl File<Arc<SyntaxRoot>> {
     pub fn parse(text: &str) -> Self {
         File::cast(::parse(text)).unwrap()
diff --git a/crates/libsyntax2/src/grammar.ron b/crates/libsyntax2/src/grammar.ron
index c9470d4fad..3fe8fdf0bf 100644
--- a/crates/libsyntax2/src/grammar.ron
+++ b/crates/libsyntax2/src/grammar.ron
@@ -220,39 +220,25 @@ Grammar(
             ]
         ),
         "Function": (
-            options: [
-                ["name", "Name"]
-            ]
+            traits: ["NameOwner"]
         ),
         "Struct": (
-            options: [
-                ["name", "Name"]
-            ]
+            traits: ["NameOwner"]
         ),
         "Enum": (
-            options: [
-                ["name", "Name"]
-            ]
+            traits: ["NameOwner"]
         ),
         "Trait": (
-            options: [
-                ["name", "Name"]
-            ]
+            traits: ["NameOwner"]
         ),
         "Module": (
-            options: [
-                ["name", "Name"]
-            ]
+            traits: ["NameOwner"]
         ),
         "ConstItem": (
-            options: [
-                ["name", "Name"]
-            ]
+            traits: ["NameOwner"]
         ),
         "StaticItem": (
-            options: [
-                ["name", "Name"]
-            ]
+            traits: ["NameOwner"]
         ),
         "Name": (),
     },
diff --git a/crates/libsyntax2/src/yellow/syntax.rs b/crates/libsyntax2/src/yellow/syntax.rs
index 6e33310f1b..a22275ed95 100644
--- a/crates/libsyntax2/src/yellow/syntax.rs
+++ b/crates/libsyntax2/src/yellow/syntax.rs
@@ -28,6 +28,12 @@ impl<R: TreeRoot> Eq for SyntaxNode<R> {}
 
 pub type SyntaxNodeRef<'a> = SyntaxNode<&'a SyntaxRoot>;
 
+#[test]
+fn syntax_node_ref_is_copy() {
+    fn assert_copy<T: Copy>(){}
+    assert_copy::<SyntaxNodeRef>()
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub struct SyntaxError {
     pub msg: String,