From 2b02785f19cd98d1e943f311377d76ae2dd58cff Mon Sep 17 00:00:00 2001 From: Daniel Ebert Date: Sat, 17 Sep 2022 14:03:45 +0200 Subject: [PATCH] Improve code style for tree-sitter indentation. Split extend logic into a separate file. --- helix-core/src/indent.rs | 189 +++++++++++++++++++++------------------ 1 file changed, 102 insertions(+), 87 deletions(-) diff --git a/helix-core/src/indent.rs b/helix-core/src/indent.rs index 97fe00cde..7556c1699 100644 --- a/helix-core/src/indent.rs +++ b/helix-core/src/indent.rs @@ -456,6 +456,67 @@ fn query_indents( } } +/// Handle extend queries. deepest_preceding is the deepest descendant of node that directly precedes the cursor position. +/// Any ancestor of deepest_preceding which is also a descendant of node may be "extended". In that case, node will be updated, +/// so that the indent computation starts with the correct syntax node. +fn extend_nodes<'a>( + node: &mut Node<'a>, + deepest_preceding: Option>, + extend_captures: &HashMap>, + text: RopeSlice, + line: usize, + tab_width: usize, +) { + if let Some(mut deepest_preceding) = deepest_preceding { + let mut stop_extend = false; + while deepest_preceding != *node { + let mut extend_node = false; + if let Some(captures) = extend_captures.get(&deepest_preceding.id()) { + for capture in captures { + match capture { + ExtendCapture::StopExtend => { + stop_extend = true; + } + ExtendCapture::ExtendIndented => { + // We extend the node if + // - the cursor is on the same line as the end of the node OR + // - the line that the cursor is on is more indented than the + // first line of the node + if deepest_preceding.end_position().row == line { + extend_node = true; + } else { + let cursor_indent = + indent_level_for_line(text.line(line), tab_width); + let node_indent = indent_level_for_line( + text.line(deepest_preceding.start_position().row), + tab_width, + ); + if cursor_indent > node_indent { + extend_node = true; + } + } + } + } + } + } + // If we encountered some `StopExtend` capture before, we don't + // extend the node even if we otherwise would + match (extend_node, stop_extend) { + (true, true) => { + stop_extend = false; + } + (true, false) => { + *node = deepest_preceding; + break; + } + _ => {} + }; + // This parent always exists since node is an ancestor of deepest_preceding + deepest_preceding = deepest_preceding.parent().unwrap(); + } + } +} + /// Use the syntax tree to determine the indentation for a given position. /// This can be used in 2 ways: /// @@ -510,100 +571,54 @@ pub fn treesitter_indent_for_pos( .tree() .root_node() .descendant_for_byte_range(byte_pos, byte_pos)?; - let (query_result, prev_child) = crate::syntax::PARSER.with(|ts_parser| { - let mut ts_parser = ts_parser.borrow_mut(); - let mut cursor = ts_parser.cursors.pop().unwrap_or_else(QueryCursor::new); + let (query_result, deepest_preceding) = { // The query range should intersect with all nodes directly preceding // the cursor in case one of them is extended. - // prev_child is the deepest such node. - let (query_range, prev_child) = { - // TODO Is there some way we can reuse this cursor? - let mut tree_cursor = node.walk(); - let mut prev_child = None; - for child in node.children(&mut tree_cursor) { - if child.byte_range().end <= byte_pos { - prev_child = Some(child); - } + let mut deepest_preceding = None; // The deepest node preceding the cursor + let mut tree_cursor = node.walk(); + for child in node.children(&mut tree_cursor) { + if child.byte_range().end <= byte_pos { + deepest_preceding = Some(child); } - match prev_child { - Some(mut prev_child) => { - // Get the deepest directly preceding node - while prev_child.child_count() > 0 { - prev_child = prev_child.child(prev_child.child_count() - 1).unwrap(); - } - ( - prev_child.byte_range().end - 1..byte_pos + 1, - Some(prev_child), - ) - } - None => (byte_pos..byte_pos + 1, None), + } + deepest_preceding = deepest_preceding.map(|mut prec| { + // Get the deepest directly preceding node + while prec.child_count() > 0 { + prec = prec.child(prec.child_count() - 1).unwrap(); } - }; - let query_result = query_indents( - query, - syntax, - &mut cursor, - text, - query_range, - new_line.then(|| (line, byte_pos)), - ); - ts_parser.cursors.push(cursor); - (query_result, prev_child) - }); + prec + }); + let query_range = deepest_preceding + .map(|prec| prec.byte_range().end - 1..byte_pos + 1) + .unwrap_or(byte_pos..byte_pos + 1); + + crate::syntax::PARSER.with(|ts_parser| { + let mut ts_parser = ts_parser.borrow_mut(); + let mut cursor = ts_parser.cursors.pop().unwrap_or_else(QueryCursor::new); + let query_result = query_indents( + query, + syntax, + &mut cursor, + text, + query_range, + new_line.then(|| (line, byte_pos)), + ); + ts_parser.cursors.push(cursor); + (query_result, deepest_preceding) + }) + }; let indent_captures = query_result.indent_captures; let extend_captures = query_result.extend_captures; - // Check for extend captures (starting with the deepest - // candidate node and then going up the syntax tree). - if let Some(mut prev_child) = prev_child { - let mut stop_extend = false; - while prev_child != node { - let mut extend_node = false; - if let Some(captures) = extend_captures.get(&prev_child.id()) { - for capture in captures { - match capture { - ExtendCapture::StopExtend => { - stop_extend = true; - } - ExtendCapture::ExtendIndented => { - // We extend the node if - // - the cursor is on the same line as the end of the node OR - // - the line that the cursor is on is more indented than the - // first line of the node - if prev_child.end_position().row == line { - extend_node = true; - } else { - let cursor_indent = - indent_level_for_line(text.line(line), tab_width); - let node_indent = indent_level_for_line( - text.line(prev_child.start_position().row), - tab_width, - ); - if cursor_indent > node_indent { - extend_node = true; - } - } - } - } - } - } - // If we encountered some `StopExtend` capture before, we don't - // extend the node even if we otherwise would - match (extend_node, stop_extend) { - (true, true) => { - stop_extend = false; - } - (true, false) => { - node = prev_child; - break; - } - _ => {} - }; - // This parent always exists since node is an ancestor of prev_child - prev_child = prev_child.parent().unwrap(); - } - } - + // Check for extend captures, potentially changing the node that the indent calculation starts with + extend_nodes( + &mut node, + deepest_preceding, + &extend_captures, + text, + line, + tab_width, + ); let mut first_in_line = get_first_in_line(node, new_line.then(|| byte_pos)); let mut result = Indentation::default();