diff options
| -rw-r--r-- | helix-core/src/match_brackets.rs | 112 |
1 files changed, 99 insertions, 13 deletions
diff --git a/helix-core/src/match_brackets.rs b/helix-core/src/match_brackets.rs index fd43a110..01deb82c 100644 --- a/helix-core/src/match_brackets.rs +++ b/helix-core/src/match_brackets.rs @@ -1,8 +1,11 @@ +use std::iter; + use tree_sitter::Node; use crate::{Rope, Syntax}; const MAX_PLAINTEXT_SCAN: usize = 10000; +const MATCH_LIMIT: usize = 16; // Limit matching pairs to only ( ) { } [ ] < > ' ' " " const PAIRS: &[(char, char)] = &[ @@ -50,26 +53,55 @@ fn find_pair(syntax: &Syntax, doc: &Rope, pos: usize, traverse_parents: bool) -> let tree = syntax.tree(); let pos = doc.char_to_byte(pos); - let mut node = tree.root_node().named_descendant_for_byte_range(pos, pos)?; + let mut node = tree.root_node().descendant_for_byte_range(pos, pos)?; loop { - let (start_byte, end_byte) = surrounding_bytes(doc, &node)?; - let (start_char, end_char) = (doc.byte_to_char(start_byte), doc.byte_to_char(end_byte)); + if node.is_named() { + let (start_byte, end_byte) = surrounding_bytes(doc, &node)?; + let (start_char, end_char) = (doc.byte_to_char(start_byte), doc.byte_to_char(end_byte)); - if is_valid_pair(doc, start_char, end_char) { - if end_byte == pos { - return Some(start_char); + if is_valid_pair(doc, start_char, end_char) { + if end_byte == pos { + return Some(start_char); + } + // We return the end char if the cursor is either on the start char + // or at some arbitrary position between start and end char. + return Some(end_char); } - // We return the end char if the cursor is either on the start char - // or at some arbitrary position between start and end char. - return Some(end_char); } + // this node itselt wasn't a pair but maybe its siblings are - if traverse_parents { - node = node.parent()?; - } else { - return None; + // check if we are *on* the pair (special cased so we don't look + // at the current node twice and to jump to the start on that case) + if let Some(open) = as_close_pair(doc, &node) { + if let Some(pair_start) = find_pair_end(doc, node.prev_sibling(), open, Backward) { + return Some(pair_start); + } } + + if !traverse_parents { + // check if we are *on* the opening pair (special cased here as + // an opptimization since we only care about bracket on the cursor + // here) + if let Some(close) = as_open_pair(doc, &node) { + if let Some(pair_end) = find_pair_end(doc, node.next_sibling(), close, Forward) { + return Some(pair_end); + } + } + if node.is_named() { + return None; + } + } + + for close in + iter::successors(node.next_sibling(), |node| node.next_sibling()).take(MATCH_LIMIT) + { + let Some(open) = as_close_pair(doc, &close) else { continue; }; + if find_pair_end(doc, Some(node), open, Backward).is_some() { + return doc.try_byte_to_char(close.start_byte()).ok(); + } + } + node = node.parent()?; } } @@ -161,6 +193,60 @@ fn surrounding_bytes(doc: &Rope, node: &Node) -> Option<(usize, usize)> { Some((start_byte, end_byte)) } +/// Checks if `node` or its siblings (at most MATCH_LIMIT nodes) is the specified openiing char +/// +/// # Returns +/// +/// The position of the found node or `None` otherwise +fn find_open_pair(doc: &Rope, node: Option<Node>, open: char) -> Option<usize> { + iter::successors(node, |node| node.prev_sibling()) + .take(MATCH_LIMIT) + .find_map(|node| { + let (pos, c) = as_char(doc, &node)?; + (c == open).then_some(pos) + }) +} + +/// Tests if this node is a pair close char and returns the expected open char +fn as_close_pair(doc: &Rope, node: &Node) -> Option<char> { + let close = as_char(doc, node)?.1; + PAIRS + .iter() + .find_map(|&(open, close_)| (close_ == close).then_some(open)) +} + +/// Checks if `node` or its siblings (at most MATCH_LIMIT nodes) is the specified closing char +/// +/// # Returns +/// +/// The position of the found node or `None` otherwise +fn find_close_pair(doc: &Rope, node: Option<Node>, close: char) -> Option<usize> { + iter::successors(node, |node| node.next_sibling()) + .take(MATCH_LIMIT) + .find_map(|node| { + let (pos, c) = as_char(doc, &node)?; + (end_char == c).then_some(pos) + }) +} + +/// Tests if this node is a pair close char and returns the expected open char +fn as_open_pair(doc: &Rope, node: &Node) -> Option<char> { + let close = as_char(doc, node)?.1; + PAIRS + .iter() + .find_map(|&(open_, close)| (open_ == open).then_some(close)) +} + +/// Tests if this node is a pair opening and returns the expected close char +fn as_char(doc: &Rope, node: &Node) -> Option<(usize, char)> { + // TODO: multi char/non ASCII pairs + if node.byte_range().len() != 1 { + return None; + } + let pos = doc.try_byte_to_char(node.start_byte()).ok()?; + Some((pos, doc.char(pos))) +} + #[cfg(test)] mod tests { use super::*; |