2 files changed, 155 insertions, 144 deletions

diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index ffd115cef..3e81fa990 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -1,17 +1,22 @@
 //! Abstract Syntax Tree, layered on top of untyped `SyntaxNode`s
 mod generated;
+mod traits;
 
 use std::marker::PhantomData;
 
 use itertools::Itertools;
 
-pub use self::generated::*;
 use crate::{
-    syntax_node::{SyntaxNode, SyntaxNodeChildren, TreeArc, RaTypes, SyntaxToken, SyntaxElement, SyntaxElementChildren},
+    syntax_node::{SyntaxNode, SyntaxNodeChildren, TreeArc, RaTypes, SyntaxToken, SyntaxElement},
     SmolStr,
     SyntaxKind::*,
 };
 
+pub use self::{
+    generated::*,
+    traits::*,
+};
+
 /// The main trait to go from untyped `SyntaxNode`  to a typed ast. The
 /// conversion itself has zero runtime cost: ast and syntax nodes have exactly
 /// the same representation: a pointer to the tree root and a pointer to the
@@ -25,137 +30,6 @@ pub trait AstNode:
     fn syntax(&self) -> &SyntaxNode;
 }
 
-pub trait TypeAscriptionOwner: AstNode {
-    fn ascribed_type(&self) -> Option<&TypeRef> {
-        child_opt(self)
-    }
-}
-
-pub trait NameOwner: AstNode {
-    fn name(&self) -> Option<&Name> {
-        child_opt(self)
-    }
-}
-
-pub trait VisibilityOwner: AstNode {
-    fn visibility(&self) -> Option<&Visibility> {
-        child_opt(self)
-    }
-}
-
-pub trait LoopBodyOwner: AstNode {
-    fn loop_body(&self) -> Option<&Block> {
-        child_opt(self)
-    }
-}
-
-pub trait ArgListOwner: AstNode {
-    fn arg_list(&self) -> Option<&ArgList> {
-        child_opt(self)
-    }
-}
-
-pub trait FnDefOwner: AstNode {
-    fn functions(&self) -> AstChildren<FnDef> {
-        children(self)
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum ItemOrMacro<'a> {
-    Item(&'a ModuleItem),
-    Macro(&'a MacroCall),
-}
-
-pub trait ModuleItemOwner: AstNode {
-    fn items(&self) -> AstChildren<ModuleItem> {
-        children(self)
-    }
-    fn items_with_macros(&self) -> ItemOrMacroIter {
-        ItemOrMacroIter(self.syntax().children())
-    }
-}
-
-#[derive(Debug)]
-pub struct ItemOrMacroIter<'a>(SyntaxNodeChildren<'a>);
-
-impl<'a> Iterator for ItemOrMacroIter<'a> {
-    type Item = ItemOrMacro<'a>;
-    fn next(&mut self) -> Option<ItemOrMacro<'a>> {
-        loop {
-            let n = self.0.next()?;
-            if let Some(item) = ModuleItem::cast(n) {
-                return Some(ItemOrMacro::Item(item));
-            }
-            if let Some(call) = MacroCall::cast(n) {
-                return Some(ItemOrMacro::Macro(call));
-            }
-        }
-    }
-}
-
-pub trait TypeParamsOwner: AstNode {
-    fn type_param_list(&self) -> Option<&TypeParamList> {
-        child_opt(self)
-    }
-
-    fn where_clause(&self) -> Option<&WhereClause> {
-        child_opt(self)
-    }
-}
-
-pub trait TypeBoundsOwner: AstNode {
-    fn type_bound_list(&self) -> Option<&TypeBoundList> {
-        child_opt(self)
-    }
-}
-
-pub trait AttrsOwner: AstNode {
-    fn attrs(&self) -> AstChildren<Attr> {
-        children(self)
-    }
-    fn has_atom_attr(&self, atom: &str) -> bool {
-        self.attrs().filter_map(|x| x.as_atom()).any(|x| x == atom)
-    }
-}
-
-pub trait DocCommentsOwner: AstNode {
-    fn doc_comments(&self) -> CommentIter {
-        CommentIter { iter: self.syntax().children_with_tokens() }
-    }
-
-    /// Returns the textual content of a doc comment block as a single string.
-    /// That is, strips leading `///` (+ optional 1 character of whitespace)
-    /// and joins lines.
-    fn doc_comment_text(&self) -> Option<std::string::String> {
-        let docs = self
-            .doc_comments()
-            .filter(|comment| comment.is_doc_comment())
-            .map(|comment| {
-                let prefix_len = comment.prefix().len();
-
-                let line = comment.text().as_str();
-
-                // Determine if the prefix or prefix + 1 char is stripped
-                let pos =
-                    if line.chars().nth(prefix_len).map(|c| c.is_whitespace()).unwrap_or(false) {
-                        prefix_len + 1
-                    } else {
-                        prefix_len
-                    };
-
-                line[pos..].to_owned()
-            })
-            .join("\n");
-
-        if docs.is_empty() {
-            None
-        } else {
-            Some(docs)
-        }
-    }
-}
-
 impl Attr {
     pub fn is_inner(&self) -> bool {
         let tt = match self.value() {
@@ -245,17 +119,6 @@ impl<'a> Comment<'a> {
     }
 }
 
-pub struct CommentIter<'a> {
-    iter: SyntaxElementChildren<'a>,
-}
-
-impl<'a> Iterator for CommentIter<'a> {
-    type Item = Comment<'a>;
-    fn next(&mut self) -> Option<Comment<'a>> {
-        self.iter.by_ref().find_map(|el| el.as_token().and_then(Comment::cast))
-    }
-}
-
 #[derive(Debug, PartialEq, Eq)]
 pub enum CommentFlavor {
     Line,
diff --git a/crates/ra_syntax/src/ast/traits.rs b/crates/ra_syntax/src/ast/traits.rs
new file mode 100644
index 000000000..85fe6d5e1
--- /dev/null
+++ b/crates/ra_syntax/src/ast/traits.rs
@@ -0,0 +1,148 @@
+use itertools::Itertools;
+
+use crate::{
+    syntax_node::{SyntaxNodeChildren, SyntaxElementChildren},
+    ast::{self, child_opt, children, AstNode, AstChildren},
+};
+
+pub trait TypeAscriptionOwner: AstNode {
+    fn ascribed_type(&self) -> Option<&ast::TypeRef> {
+        child_opt(self)
+    }
+}
+
+pub trait NameOwner: AstNode {
+    fn name(&self) -> Option<&ast::Name> {
+        child_opt(self)
+    }
+}
+
+pub trait VisibilityOwner: AstNode {
+    fn visibility(&self) -> Option<&ast::Visibility> {
+        child_opt(self)
+    }
+}
+
+pub trait LoopBodyOwner: AstNode {
+    fn loop_body(&self) -> Option<&ast::Block> {
+        child_opt(self)
+    }
+}
+
+pub trait ArgListOwner: AstNode {
+    fn arg_list(&self) -> Option<&ast::ArgList> {
+        child_opt(self)
+    }
+}
+
+pub trait FnDefOwner: AstNode {
+    fn functions(&self) -> AstChildren<ast::FnDef> {
+        children(self)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ItemOrMacro<'a> {
+    Item(&'a ast::ModuleItem),
+    Macro(&'a ast::MacroCall),
+}
+
+pub trait ModuleItemOwner: AstNode {
+    fn items(&self) -> AstChildren<ast::ModuleItem> {
+        children(self)
+    }
+    fn items_with_macros(&self) -> ItemOrMacroIter {
+        ItemOrMacroIter(self.syntax().children())
+    }
+}
+
+#[derive(Debug)]
+pub struct ItemOrMacroIter<'a>(SyntaxNodeChildren<'a>);
+
+impl<'a> Iterator for ItemOrMacroIter<'a> {
+    type Item = ItemOrMacro<'a>;
+    fn next(&mut self) -> Option<ItemOrMacro<'a>> {
+        loop {
+            let n = self.0.next()?;
+            if let Some(item) = ast::ModuleItem::cast(n) {
+                return Some(ItemOrMacro::Item(item));
+            }
+            if let Some(call) = ast::MacroCall::cast(n) {
+                return Some(ItemOrMacro::Macro(call));
+            }
+        }
+    }
+}
+
+pub trait TypeParamsOwner: AstNode {
+    fn type_param_list(&self) -> Option<&ast::TypeParamList> {
+        child_opt(self)
+    }
+
+    fn where_clause(&self) -> Option<&ast::WhereClause> {
+        child_opt(self)
+    }
+}
+
+pub trait TypeBoundsOwner: AstNode {
+    fn type_bound_list(&self) -> Option<&ast::TypeBoundList> {
+        child_opt(self)
+    }
+}
+
+pub trait AttrsOwner: AstNode {
+    fn attrs(&self) -> AstChildren<ast::Attr> {
+        children(self)
+    }
+    fn has_atom_attr(&self, atom: &str) -> bool {
+        self.attrs().filter_map(|x| x.as_atom()).any(|x| x == atom)
+    }
+}
+
+pub trait DocCommentsOwner: AstNode {
+    fn doc_comments(&self) -> CommentIter {
+        CommentIter { iter: self.syntax().children_with_tokens() }
+    }
+
+    /// Returns the textual content of a doc comment block as a single string.
+    /// That is, strips leading `///` (+ optional 1 character of whitespace)
+    /// and joins lines.
+    fn doc_comment_text(&self) -> Option<std::string::String> {
+        let docs = self
+            .doc_comments()
+            .filter(|comment| comment.is_doc_comment())
+            .map(|comment| {
+                let prefix_len = comment.prefix().len();
+
+                let line = comment.text().as_str();
+
+                // Determine if the prefix or prefix + 1 char is stripped
+                let pos =
+                    if line.chars().nth(prefix_len).map(|c| c.is_whitespace()).unwrap_or(false) {
+                        prefix_len + 1
+                    } else {
+                        prefix_len
+                    };
+
+                line[pos..].to_owned()
+            })
+            .join("\n");
+
+        if docs.is_empty() {
+            None
+        } else {
+            Some(docs)
+        }
+    }
+}
+
+pub struct CommentIter<'a> {
+    iter: SyntaxElementChildren<'a>,
+}
+
+impl<'a> Iterator for CommentIter<'a> {
+    type Item = ast::Comment<'a>;
+    fn next(&mut self) -> Option<ast::Comment<'a>> {
+        self.iter.by_ref().find_map(|el| el.as_token().and_then(ast::Comment::cast))
+    }
+}