pub mod visit; use std::ops::RangeInclusive; use itertools::Itertools; use crate::{ AstNode, Direction, NodeOrToken, SyntaxElement, SyntaxNode, SyntaxNodePtr, TextRange, TextUnit, }; /// Returns ancestors of the node at the offset, sorted by length. This should /// do the right thing at an edge, e.g. when searching for expressions at `{ /// <|>foo }` we will get the name reference instead of the whole block, which /// we would get if we just did `find_token_at_offset(...).flat_map(|t| /// t.parent().ancestors())`. pub fn ancestors_at_offset( node: &SyntaxNode, offset: TextUnit, ) -> impl Iterator { node.token_at_offset(offset) .map(|token| token.parent().ancestors()) .kmerge_by(|node1, node2| node1.text_range().len() < node2.text_range().len()) } /// Finds a node of specific Ast type at offset. Note that this is slightly /// imprecise: if the cursor is strictly between two nodes of the desired type, /// as in /// /// ```no-run /// struct Foo {}|struct Bar; /// ``` /// /// then the shorter node will be silently preferred. pub fn find_node_at_offset(syntax: &SyntaxNode, offset: TextUnit) -> Option { ancestors_at_offset(syntax, offset).find_map(N::cast) } /// Finds the first sibling in the given direction which is not `trivia` pub fn non_trivia_sibling(element: SyntaxElement, direction: Direction) -> Option { return match element { NodeOrToken::Node(node) => node.siblings_with_tokens(direction).skip(1).find(not_trivia), NodeOrToken::Token(token) => token.siblings_with_tokens(direction).skip(1).find(not_trivia), }; fn not_trivia(element: &SyntaxElement) -> bool { match element { NodeOrToken::Node(_) => true, NodeOrToken::Token(token) => !token.kind().is_trivia(), } } } pub fn find_covering_element(root: &SyntaxNode, range: TextRange) -> SyntaxElement { root.covering_element(range) } #[derive(Debug, PartialEq, Eq, Clone, Copy)] pub enum InsertPosition { First, Last, Before(T), After(T), } /// Adds specified children (tokens or nodes) to the current node at the /// specific position. /// /// This is a type-unsafe low-level editing API, if you need to use it, /// prefer to create a type-safe abstraction on top of it instead. pub fn insert_children( parent: &SyntaxNode, position: InsertPosition, to_insert: &mut dyn Iterator, ) -> SyntaxNode { let mut delta = TextUnit::default(); let to_insert = to_insert.map(|element| { delta += element.text_range().len(); to_green_element(element) }); let old_children = parent.green().children(); let new_children = match &position { InsertPosition::First => { to_insert.chain(old_children.iter().cloned()).collect::>() } InsertPosition::Last => old_children.iter().cloned().chain(to_insert).collect::>(), InsertPosition::Before(anchor) | InsertPosition::After(anchor) => { let take_anchor = if let InsertPosition::After(_) = position { 1 } else { 0 }; let split_at = position_of_child(parent, anchor.clone()) + take_anchor; let (before, after) = old_children.split_at(split_at); before .iter() .cloned() .chain(to_insert) .chain(after.iter().cloned()) .collect::>() } }; with_children(parent, new_children) } /// Replaces all nodes in `to_delete` with nodes from `to_insert` /// /// This is a type-unsafe low-level editing API, if you need to use it, /// prefer to create a type-safe abstraction on top of it instead. pub fn replace_children( parent: &SyntaxNode, to_delete: RangeInclusive, to_insert: &mut dyn Iterator, ) -> SyntaxNode { let start = position_of_child(parent, to_delete.start().clone()); let end = position_of_child(parent, to_delete.end().clone()); let old_children = parent.green().children(); let new_children = old_children[..start] .iter() .cloned() .chain(to_insert.map(to_green_element)) .chain(old_children[end + 1..].iter().cloned()) .collect::>(); with_children(parent, new_children) } fn with_children( parent: &SyntaxNode, new_children: Box<[NodeOrToken]>, ) -> SyntaxNode { let len = new_children.iter().map(|it| it.text_len()).sum::(); let new_node = rowan::GreenNode::new(rowan::cursor::SyntaxKind(parent.kind() as u16), new_children); let new_root_node = parent.replace_with(new_node); let new_root_node = SyntaxNode::new_root(new_root_node); // FIXME: use a more elegant way to re-fetch the node (#1185), make // `range` private afterwards let mut ptr = SyntaxNodePtr::new(parent); ptr.range = TextRange::offset_len(ptr.range().start(), len); ptr.to_node(&new_root_node) } fn position_of_child(parent: &SyntaxNode, child: SyntaxElement) -> usize { parent .children_with_tokens() .position(|it| it == child) .expect("element is not a child of current element") } fn to_green_element(element: SyntaxElement) -> NodeOrToken { match element { NodeOrToken::Node(it) => it.green().clone().into(), NodeOrToken::Token(it) => it.green().clone().into(), } }