Remove code duplication

crates/ra_syntax/src/ast.rs

@@ -42,11 +42,6 @@ pub trait AstNode {
     fn syntax(&self) -> &SyntaxNode;
 }
 
-#[test]
-fn assert_ast_is_object_safe() {
-    fn _f(_: &dyn AstNode, _: &dyn NameOwner) {}
-}
-
 /// Like `AstNode`, but wraps tokens rather than interior nodes.
 pub trait AstToken {
     fn can_cast(token: SyntaxKind) -> bool
@@ -64,22 +59,6 @@ pub trait AstToken {
     }
 }
 
-mod support {
-    use super::{AstChildren, AstNode, AstToken, SyntaxNode};
-
-    pub(super) fn child<N: AstNode>(parent: &SyntaxNode) -> Option<N> {
-        parent.children().find_map(N::cast)
-    }
-
-    pub(super) fn children<N: AstNode>(parent: &SyntaxNode) -> AstChildren<N> {
-        AstChildren::new(parent)
-    }
-
-    pub(super) fn token<T: AstToken>(parent: &SyntaxNode) -> Option<T> {
-        parent.children_with_tokens().filter_map(|it| it.into_token()).find_map(T::cast)
-    }
-}
-
 /// An iterator over `SyntaxNode` children of a particular AST type.
 #[derive(Debug, Clone)]
 pub struct AstChildren<N> {
@@ -100,12 +79,25 @@ impl<N: AstNode> Iterator for AstChildren<N> {
     }
 }
 
-fn child_opt<P: AstNode + ?Sized, C: AstNode>(parent: &P) -> Option<C> {
-    children(parent).next()
+mod support {
+    use super::{AstChildren, AstNode, AstToken, SyntaxNode};
+
+    pub(super) fn child<N: AstNode>(parent: &SyntaxNode) -> Option<N> {
+        parent.children().find_map(N::cast)
+    }
+
+    pub(super) fn children<N: AstNode>(parent: &SyntaxNode) -> AstChildren<N> {
+        AstChildren::new(parent)
+    }
+
+    pub(super) fn token<T: AstToken>(parent: &SyntaxNode) -> Option<T> {
+        parent.children_with_tokens().filter_map(|it| it.into_token()).find_map(T::cast)
+    }
 }
 
-fn children<P: AstNode + ?Sized, C: AstNode>(parent: &P) -> AstChildren<C> {
-    AstChildren::new(parent.syntax())
+#[test]
+fn assert_ast_is_object_safe() {
+    fn _f(_: &dyn AstNode, _: &dyn NameOwner) {}
 }
 
 #[test]

crates/ra_syntax/src/ast/edit.rs

@@ -6,7 +6,7 @@ use std::{iter, ops::RangeInclusive};
 use arrayvec::ArrayVec;
 
 use crate::{
-    algo,
+    algo::{self, neighbor, SyntaxRewriter},
     ast::{
         self,
         make::{self, tokens},
@@ -16,7 +16,6 @@ use crate::{
     SyntaxKind::{ATTR, COMMENT, WHITESPACE},
     SyntaxNode, SyntaxToken, T,
 };
-use algo::{neighbor, SyntaxRewriter};
 
 impl ast::BinExpr {
     #[must_use]

crates/ra_syntax/src/ast/expr_extensions.rs

@@ -1,7 +1,7 @@
 //! Various extension methods to ast Expr Nodes, which are hard to code-generate.
 
 use crate::{
-    ast::{self, child_opt, children, AstChildren, AstNode},
+    ast::{self, support, AstChildren, AstNode},
     SmolStr,
     SyntaxKind::*,
     SyntaxToken, T,
@@ -36,7 +36,7 @@ impl ast::IfExpr {
         let res = match self.blocks().nth(1) {
             Some(block) => ElseBranch::Block(block),
             None => {
-                let elif: ast::IfExpr = child_opt(self)?;
+                let elif: ast::IfExpr = support::child(self.syntax())?;
                 ElseBranch::IfExpr(elif)
             }
         };
@@ -44,7 +44,7 @@ impl ast::IfExpr {
     }
 
     fn blocks(&self) -> AstChildren<ast::BlockExpr> {
-        children(self)
+        support::children(self.syntax())
     }
 }
 
@@ -212,15 +212,15 @@ impl ast::BinExpr {
     }
 
     pub fn lhs(&self) -> Option<ast::Expr> {
-        children(self).next()
+        support::children(self.syntax()).next()
     }
 
     pub fn rhs(&self) -> Option<ast::Expr> {
-        children(self).nth(1)
+        support::children(self.syntax()).nth(1)
     }
 
     pub fn sub_exprs(&self) -> (Option<ast::Expr>, Option<ast::Expr>) {
-        let mut children = children(self);
+        let mut children = support::children(self.syntax());
         let first = children.next();
         let second = children.next();
         (first, second)
@@ -275,10 +275,10 @@ impl ast::RangeExpr {
 
 impl ast::IndexExpr {
     pub fn base(&self) -> Option<ast::Expr> {
-        children(self).next()
+        support::children(self.syntax()).next()
     }
     pub fn index(&self) -> Option<ast::Expr> {
-        children(self).nth(1)
+        support::children(self.syntax()).nth(1)
     }
 }
 
@@ -291,11 +291,11 @@ impl ast::ArrayExpr {
     pub fn kind(&self) -> ArrayExprKind {
         if self.is_repeat() {
             ArrayExprKind::Repeat {
-                initializer: children(self).next(),
-                repeat: children(self).nth(1),
+                initializer: support::children(self.syntax()).next(),
+                repeat: support::children(self.syntax()).nth(1),
             }
         } else {
-            ArrayExprKind::ElementList(children(self))
+            ArrayExprKind::ElementList(support::children(self.syntax()))
         }
     }
 

crates/ra_syntax/src/ast/extensions.rs

@@ -5,9 +5,7 @@ use itertools::Itertools;
 use ra_parser::SyntaxKind;
 
 use crate::{
-    ast::{
-        self, child_opt, children, support, AstNode, AstToken, AttrInput, NameOwner, SyntaxNode,
-    },
+    ast::{self, support, AstNode, AstToken, AttrInput, NameOwner, SyntaxNode},
     SmolStr, SyntaxElement, SyntaxToken, T,
 };
 
@@ -161,7 +159,7 @@ impl ast::ImplDef {
     }
 
     fn target(&self) -> (Option<ast::TypeRef>, Option<ast::TypeRef>) {
-        let mut types = children(self);
+        let mut types = support::children(self.syntax());
         let first = types.next();
         let second = types.next();
         (first, second)
@@ -177,9 +175,9 @@ pub enum StructKind {
 
 impl StructKind {
     fn from_node<N: AstNode>(node: &N) -> StructKind {
-        if let Some(nfdl) = child_opt::<_, ast::RecordFieldDefList>(node) {
+        if let Some(nfdl) = support::child::<ast::RecordFieldDefList>(node.syntax()) {
             StructKind::Record(nfdl)
-        } else if let Some(pfl) = child_opt::<_, ast::TupleFieldDefList>(node) {
+        } else if let Some(pfl) = support::child::<ast::TupleFieldDefList>(node.syntax()) {
             StructKind::Tuple(pfl)
         } else {
             StructKind::Unit
@@ -322,9 +320,9 @@ pub enum TypeBoundKind {
 
 impl ast::TypeBound {
     pub fn kind(&self) -> TypeBoundKind {
-        if let Some(path_type) = children(self).next() {
+        if let Some(path_type) = support::children(self.syntax()).next() {
             TypeBoundKind::PathType(path_type)
-        } else if let Some(for_type) = children(self).next() {
+        } else if let Some(for_type) = support::children(self.syntax()).next() {
             TypeBoundKind::ForType(for_type)
         } else if let Some(lifetime) = self.lifetime_token() {
             TypeBoundKind::Lifetime(lifetime)
@@ -364,7 +362,7 @@ pub enum VisibilityKind {
 
 impl ast::Visibility {
     pub fn kind(&self) -> VisibilityKind {
-        if let Some(path) = children(self).next() {
+        if let Some(path) = support::children(self.syntax()).next() {
             VisibilityKind::In(path)
         } else if self.crate_kw_token().is_some() {
             VisibilityKind::PubCrate

crates/ra_syntax/src/ast/traits.rs

@@ -5,69 +5,69 @@
 use itertools::Itertools;
 
 use crate::{
-    ast::{self, child_opt, children, support, AstChildren, AstNode, AstToken},
+    ast::{self, support, AstChildren, AstNode, AstToken},
     syntax_node::SyntaxElementChildren,
 };
 
 pub trait TypeAscriptionOwner: AstNode {
     fn ascribed_type(&self) -> Option<ast::TypeRef> {
-        child_opt(self)
+        support::child(self.syntax())
     }
 }
 
 pub trait NameOwner: AstNode {
     fn name(&self) -> Option<ast::Name> {
-        child_opt(self)
+        support::child(self.syntax())
     }
 }
 
 pub trait VisibilityOwner: AstNode {
     fn visibility(&self) -> Option<ast::Visibility> {
-        child_opt(self)
+        support::child(self.syntax())
     }
 }
 
 pub trait LoopBodyOwner: AstNode {
     fn loop_body(&self) -> Option<ast::BlockExpr> {
-        child_opt(self)
+        support::child(self.syntax())
     }
 
     fn label(&self) -> Option<ast::Label> {
-        child_opt(self)
+        support::child(self.syntax())
     }
 }
 
 pub trait ArgListOwner: AstNode {
     fn arg_list(&self) -> Option<ast::ArgList> {
-        child_opt(self)
+        support::child(self.syntax())
     }
 }
 
 pub trait FnDefOwner: AstNode {
     fn functions(&self) -> AstChildren<ast::FnDef> {
-        children(self)
+        support::children(self.syntax())
     }
 }
 
 pub trait ModuleItemOwner: AstNode {
     fn items(&self) -> AstChildren<ast::ModuleItem> {
-        children(self)
+        support::children(self.syntax())
     }
 }
 
 pub trait TypeParamsOwner: AstNode {
     fn type_param_list(&self) -> Option<ast::TypeParamList> {
-        child_opt(self)
+        support::child(self.syntax())
     }
 
     fn where_clause(&self) -> Option<ast::WhereClause> {
-        child_opt(self)
+        support::child(self.syntax())
     }
 }
 
 pub trait TypeBoundsOwner: AstNode {
     fn type_bound_list(&self) -> Option<ast::TypeBoundList> {
-        child_opt(self)
+        support::child(self.syntax())
     }
 
     fn colon(&self) -> Option<ast::Colon> {
@@ -77,7 +77,7 @@ pub trait TypeBoundsOwner: AstNode {
 
 pub trait AttrsOwner: AstNode {
     fn attrs(&self) -> AstChildren<ast::Attr> {
-        children(self)
+        support::children(self.syntax())
     }
     fn has_atom_attr(&self, atom: &str) -> bool {
         self.attrs().filter_map(|x| x.as_simple_atom()).any(|x| x == atom)