Make ast editing more ergonomic

changelog internal

Author: matklad

crates/syntax/src/ast/edit_in_place.rs

@@ -8,7 +8,7 @@ use parser::T;
 use crate::{
     ast,
     ted::{self, Position},
-    AstNode, Direction, SyntaxElement,
+    AstNode, Direction,
 };
 
 use super::NameOwner;
@@ -21,11 +21,11 @@ impl GenericParamsOwnerEdit for ast::Fn {
     fn get_or_create_where_clause(&self) -> WhereClause {
         if self.where_clause().is_none() {
             let position = if let Some(ty) = self.ret_type() {
-                Position::after(ty.syntax().clone())
+                Position::after(ty.syntax())
             } else if let Some(param_list) = self.param_list() {
-                Position::after(param_list.syntax().clone())
+                Position::after(param_list.syntax())
             } else {
-                Position::last_child_of(self.syntax().clone())
+                Position::last_child_of(self.syntax())
             };
             create_where_clause(position)
         }
@@ -37,9 +37,9 @@ impl GenericParamsOwnerEdit for ast::Impl {
     fn get_or_create_where_clause(&self) -> WhereClause {
         if self.where_clause().is_none() {
             let position = if let Some(items) = self.assoc_item_list() {
-                Position::before(items.syntax().clone())
+                Position::before(items.syntax())
             } else {
-                Position::last_child_of(self.syntax().clone())
+                Position::last_child_of(self.syntax())
             };
             create_where_clause(position)
         }
@@ -51,9 +51,9 @@ impl GenericParamsOwnerEdit for ast::Trait {
     fn get_or_create_where_clause(&self) -> WhereClause {
         if self.where_clause().is_none() {
             let position = if let Some(items) = self.assoc_item_list() {
-                Position::before(items.syntax().clone())
+                Position::before(items.syntax())
             } else {
-                Position::last_child_of(self.syntax().clone())
+                Position::last_child_of(self.syntax())
             };
             create_where_clause(position)
         }
@@ -69,13 +69,13 @@ impl GenericParamsOwnerEdit for ast::Struct {
                 ast::FieldList::TupleFieldList(it) => Some(it),
             });
             let position = if let Some(tfl) = tfl {
-                Position::after(tfl.syntax().clone())
+                Position::after(tfl.syntax())
             } else if let Some(gpl) = self.generic_param_list() {
-                Position::after(gpl.syntax().clone())
+                Position::after(gpl.syntax())
             } else if let Some(name) = self.name() {
-                Position::after(name.syntax().clone())
+                Position::after(name.syntax())
             } else {
-                Position::last_child_of(self.syntax().clone())
+                Position::last_child_of(self.syntax())
             };
             create_where_clause(position)
         }
@@ -87,11 +87,11 @@ impl GenericParamsOwnerEdit for ast::Enum {
     fn get_or_create_where_clause(&self) -> WhereClause {
         if self.where_clause().is_none() {
             let position = if let Some(gpl) = self.generic_param_list() {
-                Position::after(gpl.syntax().clone())
+                Position::after(gpl.syntax())
             } else if let Some(name) = self.name() {
-                Position::after(name.syntax().clone())
+                Position::after(name.syntax())
             } else {
-                Position::last_child_of(self.syntax().clone())
+                Position::last_child_of(self.syntax())
             };
             create_where_clause(position)
         }
@@ -100,19 +100,18 @@ impl GenericParamsOwnerEdit for ast::Enum {
 }
 
 fn create_where_clause(position: Position) {
-    let where_clause: SyntaxElement =
-        make::where_clause(empty()).clone_for_update().syntax().clone().into();
-    ted::insert(position, where_clause);
+    let where_clause = make::where_clause(empty()).clone_for_update();
+    ted::insert(position, where_clause.syntax());
 }
 
 impl ast::WhereClause {
     pub fn add_predicate(&self, predicate: ast::WherePred) {
         if let Some(pred) = self.predicates().last() {
             if !pred.syntax().siblings_with_tokens(Direction::Next).any(|it| it.kind() == T![,]) {
-                ted::append_child_raw(self.syntax().clone(), make::token(T![,]));
+                ted::append_child_raw(self.syntax(), make::token(T![,]));
             }
         }
-        ted::append_child(self.syntax().clone(), predicate.syntax().clone())
+        ted::append_child(self.syntax(), predicate.syntax())
     }
 }
 
@@ -123,7 +122,7 @@ impl ast::TypeBoundList {
         {
             ted::remove_all(colon..=self.syntax().clone().into())
         } else {
-            ted::remove(self.syntax().clone())
+            ted::remove(self.syntax())
         }
     }
 }

crates/syntax/src/ted.rs

@@ -8,6 +8,33 @@ use parser::T;
 
 use crate::{ast::make, SyntaxElement, SyntaxKind, SyntaxNode, SyntaxToken};
 
+/// Utility trait to allow calling `ted` functions with references or owned
+/// nodes. Do not use outside of this module.
+pub trait Element {
+    fn syntax_element(self) -> SyntaxElement;
+}
+
+impl<E: Element + Clone> Element for &'_ E {
+    fn syntax_element(self) -> SyntaxElement {
+        self.clone().syntax_element()
+    }
+}
+impl Element for SyntaxElement {
+    fn syntax_element(self) -> SyntaxElement {
+        self
+    }
+}
+impl Element for SyntaxNode {
+    fn syntax_element(self) -> SyntaxElement {
+        self.into()
+    }
+}
+impl Element for SyntaxToken {
+    fn syntax_element(self) -> SyntaxElement {
+        self.into()
+    }
+}
+
 #[derive(Debug)]
 pub struct Position {
     repr: PositionRepr,
@@ -20,24 +47,24 @@ enum PositionRepr {
 }
 
 impl Position {
-    pub fn after(elem: impl Into<SyntaxElement>) -> Position {
-        let repr = PositionRepr::After(elem.into());
+    pub fn after(elem: impl Element) -> Position {
+        let repr = PositionRepr::After(elem.syntax_element());
         Position { repr }
     }
-    pub fn before(elem: impl Into<SyntaxElement>) -> Position {
-        let elem = elem.into();
+    pub fn before(elem: impl Element) -> Position {
+        let elem = elem.syntax_element();
         let repr = match elem.prev_sibling_or_token() {
             Some(it) => PositionRepr::After(it),
             None => PositionRepr::FirstChild(elem.parent().unwrap()),
         };
         Position { repr }
     }
-    pub fn first_child_of(node: impl Into<SyntaxNode>) -> Position {
-        let repr = PositionRepr::FirstChild(node.into());
+    pub fn first_child_of(node: &(impl Into<SyntaxNode> + Clone)) -> Position {
+        let repr = PositionRepr::FirstChild(node.clone().into());
         Position { repr }
     }
-    pub fn last_child_of(node: impl Into<SyntaxNode>) -> Position {
-        let node = node.into();
+    pub fn last_child_of(node: &(impl Into<SyntaxNode> + Clone)) -> Position {
+        let node = node.clone().into();
         let repr = match node.last_child_or_token() {
             Some(it) => PositionRepr::After(it),
             None => PositionRepr::FirstChild(node),
@@ -46,11 +73,11 @@ impl Position {
     }
 }
 
-pub fn insert(position: Position, elem: impl Into<SyntaxElement>) {
-    insert_all(position, vec![elem.into()])
+pub fn insert(position: Position, elem: impl Element) {
+    insert_all(position, vec![elem.syntax_element()])
 }
-pub fn insert_raw(position: Position, elem: impl Into<SyntaxElement>) {
-    insert_all_raw(position, vec![elem.into()])
+pub fn insert_raw(position: Position, elem: impl Element) {
+    insert_all_raw(position, vec![elem.syntax_element()])
 }
 pub fn insert_all(position: Position, mut elements: Vec<SyntaxElement>) {
     if let Some(first) = elements.first() {
@@ -73,17 +100,17 @@ pub fn insert_all_raw(position: Position, elements: Vec<SyntaxElement>) {
     parent.splice_children(index..index, elements);
 }
 
-pub fn remove(elem: impl Into<SyntaxElement>) {
-    let elem = elem.into();
+pub fn remove(elem: impl Element) {
+    let elem = elem.syntax_element();
     remove_all(elem.clone()..=elem)
 }
 pub fn remove_all(range: RangeInclusive<SyntaxElement>) {
     replace_all(range, Vec::new())
 }
 
-pub fn replace(old: impl Into<SyntaxElement>, new: impl Into<SyntaxElement>) {
-    let old = old.into();
-    replace_all(old.clone()..=old, vec![new.into()])
+pub fn replace(old: impl Element, new: impl Element) {
+    let old = old.syntax_element();
+    replace_all(old.clone()..=old, vec![new.syntax_element()])
 }
 pub fn replace_all(range: RangeInclusive<SyntaxElement>, new: Vec<SyntaxElement>) {
     let start = range.start().index();
@@ -92,11 +119,11 @@ pub fn replace_all(range: RangeInclusive<SyntaxElement>, new: Vec<SyntaxElement>
     parent.splice_children(start..end + 1, new)
 }
 
-pub fn append_child(node: impl Into<SyntaxNode>, child: impl Into<SyntaxElement>) {
+pub fn append_child(node: &(impl Into<SyntaxNode> + Clone), child: impl Element) {
     let position = Position::last_child_of(node);
     insert(position, child)
 }
-pub fn append_child_raw(node: impl Into<SyntaxNode>, child: impl Into<SyntaxElement>) {
+pub fn append_child_raw(node: &(impl Into<SyntaxNode> + Clone), child: impl Element) {
     let position = Position::last_child_of(node);
     insert_raw(position, child)
 }