use std::{borrow::Cow, collections::HashMap}; use tree_sitter::{Query, QueryCursor, QueryPredicateArg}; use crate::{ chars::{char_is_line_ending, char_is_whitespace}, find_first_non_whitespace_char, graphemes::{grapheme_width, tab_width_at}, syntax::{IndentationHeuristic, LanguageConfiguration, RopeProvider, Syntax}, tree_sitter::Node, Position, Rope, RopeGraphemes, RopeSlice, }; /// Enum representing indentation style. /// /// Only values 1-8 are valid for the `Spaces` variant. #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)] pub enum IndentStyle { Tabs, Spaces(u8), } // 16 spaces const INDENTS: &str = " "; const MAX_INDENT: u8 = 16; impl IndentStyle { /// Creates an `IndentStyle` from an indentation string. /// /// For example, passing `" "` (four spaces) will create `IndentStyle::Spaces(4)`. #[allow(clippy::should_implement_trait)] #[inline] pub fn from_str(indent: &str) -> Self { // XXX: do we care about validating the input more than this? Probably not...? debug_assert!(!indent.is_empty() && indent.len() <= MAX_INDENT as usize); if indent.starts_with(' ') { IndentStyle::Spaces(indent.len().clamp(1, MAX_INDENT as usize) as u8) } else { IndentStyle::Tabs } } #[inline] pub fn as_str(&self) -> &'static str { match *self { IndentStyle::Tabs => "\t", IndentStyle::Spaces(n) => { // Unsupported indentation style. This should never happen, debug_assert!(n > 0 && n <= MAX_INDENT); // Either way, clamp to the nearest supported value let closest_n = n.clamp(1, MAX_INDENT) as usize; &INDENTS[0..closest_n] } } } #[inline] pub fn indent_width(&self, tab_width: usize) -> usize { match *self { IndentStyle::Tabs => tab_width, IndentStyle::Spaces(width) => width as usize, } } } /// Attempts to detect the indentation style used in a document. /// /// Returns the indentation style if the auto-detect confidence is /// reasonably high, otherwise returns `None`. pub fn auto_detect_indent_style(document_text: &Rope) -> Option { // Build a histogram of the indentation *increases* between // subsequent lines, ignoring lines that are all whitespace. // // Index 0 is for tabs, the rest are 1-MAX_INDENT spaces. let histogram: [usize; MAX_INDENT as usize + 1] = { let mut histogram = [0; MAX_INDENT as usize + 1]; let mut prev_line_is_tabs = false; let mut prev_line_leading_count = 0usize; // Loop through the lines, checking for and recording indentation // increases as we go. 'outer: for line in document_text.lines().take(1000) { let mut c_iter = line.chars(); // Is first character a tab or space? let is_tabs = match c_iter.next() { Some('\t') => true, Some(' ') => false, // Ignore blank lines. Some(c) if char_is_line_ending(c) => continue, _ => { prev_line_is_tabs = false; prev_line_leading_count = 0; continue; } }; // Count the line's total leading tab/space characters. let mut leading_count = 1; let mut count_is_done = false; for c in c_iter { match c { '\t' if is_tabs && !count_is_done => leading_count += 1, ' ' if !is_tabs && !count_is_done => leading_count += 1, // We stop counting if we hit whitespace that doesn't // qualify as indent or doesn't match the leading // whitespace, but we don't exit the loop yet because // we still want to determine if the line is blank. c if char_is_whitespace(c) => count_is_done = true, // Ignore blank lines. c if char_is_line_ending(c) => continue 'outer, _ => break, } // Bound the worst-case execution time for weird text files. if leading_count > 256 { continue 'outer; } } // If there was an increase in indentation over the previous // line, update the histogram with that increase. if (prev_line_is_tabs == is_tabs || prev_line_leading_count == 0) && prev_line_leading_count < leading_count { if is_tabs { histogram[0] += 1; } else { let amount = leading_count - prev_line_leading_count; if amount <= MAX_INDENT as usize { histogram[amount] += 1; } } } // Store this line's leading whitespace info for use with // the next line. prev_line_is_tabs = is_tabs; prev_line_leading_count = leading_count; } // Give more weight to tabs, because their presence is a very // strong indicator. histogram[0] *= 2; histogram }; // Find the most frequent indent, its frequency, and the frequency of // the next-most frequent indent. let indent = histogram .iter() .enumerate() .max_by_key(|kv| kv.1) .unwrap() .0; let indent_freq = histogram[indent]; let indent_freq_2 = *histogram .iter() .enumerate() .filter(|kv| kv.0 != indent) .map(|kv| kv.1) .max() .unwrap(); // Return the the auto-detected result if we're confident enough in its // accuracy, based on some heuristics. if indent_freq >= 1 && (indent_freq_2 as f64 / indent_freq as f64) < 0.66 { Some(match indent { 0 => IndentStyle::Tabs, _ => IndentStyle::Spaces(indent as u8), }) } else { None } } /// To determine indentation of a newly inserted line, figure out the indentation at the last col /// of the previous line. pub fn indent_level_for_line(line: RopeSlice, tab_width: usize, indent_width: usize) -> usize { let mut len = 0; for ch in line.chars() { match ch { '\t' => len += tab_width_at(len, tab_width as u16), ' ' => len += 1, _ => break, } } len / indent_width } /// Create a string of tabs & spaces that has the same visual width as the given RopeSlice (independent of the tab width). fn whitespace_with_same_width(text: RopeSlice) -> String { let mut s = String::new(); for grapheme in RopeGraphemes::new(text) { if grapheme == "\t" { s.push('\t'); } else { s.extend(std::iter::repeat(' ').take(grapheme_width(&Cow::from(grapheme)))); } } s } fn add_indent_level( mut base_indent: String, added_indent_level: isize, indent_style: &IndentStyle, tab_width: usize, ) -> String { if added_indent_level >= 0 { // Adding a non-negative indent is easy, we can simply append the indent string base_indent.push_str(&indent_style.as_str().repeat(added_indent_level as usize)); base_indent } else { // In this case, we want to return a prefix of `base_indent`. // Since the width of a tab depends on its offset, we cannot simply iterate over // the chars of `base_indent` in reverse until we have the desired indent reduction, // instead we iterate over them twice in forward direction. let base_indent_rope = RopeSlice::from(base_indent.as_str()); #[allow(deprecated)] let base_indent_width = crate::visual_coords_at_pos(base_indent_rope, base_indent_rope.len_chars(), tab_width) .col; let target_indent_width = base_indent_width .saturating_sub((-added_indent_level) as usize * indent_style.indent_width(tab_width)); #[allow(deprecated)] let char_end_idx = crate::pos_at_visual_coords( base_indent_rope, Position { row: 0, col: target_indent_width, }, tab_width, ); let byte_end_idx = base_indent_rope.char_to_byte(char_end_idx); base_indent.truncate(byte_end_idx); base_indent } } /// Computes for node and all ancestors whether they are the first node on their line. /// The first entry in the return value represents the root node, the last one the node itself fn get_first_in_line(mut node: Node, new_line_byte_pos: Option) -> Vec { let mut first_in_line = Vec::new(); loop { if let Some(prev) = node.prev_sibling() { // If we insert a new line, the first node at/after the cursor is considered to be the first in its line let first = prev.end_position().row != node.start_position().row || new_line_byte_pos.map_or(false, |byte_pos| { node.start_byte() >= byte_pos && prev.start_byte() < byte_pos }); first_in_line.push(Some(first)); } else { // Nodes that have no previous siblings are first in their line if and only if their parent is // (which we don't know yet) first_in_line.push(None); } if let Some(parent) = node.parent() { node = parent; } else { break; } } let mut result = Vec::with_capacity(first_in_line.len()); let mut parent_is_first = true; // The root node is by definition the first node in its line for first in first_in_line.into_iter().rev() { if let Some(first) = first { result.push(first); parent_is_first = first; } else { result.push(parent_is_first); } } result } /// The total indent for some line of code. /// This is usually constructed in one of 2 ways: /// - Successively add indent captures to get the (added) indent from a single line /// - Successively add the indent results for each line /// The string that this indentation defines starts with the string contained in the align field (unless it is None), followed by: /// - max(0, indent - outdent) tabs, if tabs are used for indentation /// - max(0, indent - outdent)*indent_width spaces, if spaces are used for indentation #[derive(Default, Debug, PartialEq, Eq, Clone)] pub struct Indentation<'a> { indent: usize, indent_always: usize, outdent: usize, outdent_always: usize, /// The alignment, as a string containing only tabs & spaces. Storing this as a string instead of e.g. /// the (visual) width ensures that the alignment is preserved even if the tab width changes. align: Option>, } impl<'a> Indentation<'a> { /// Add some other [Indentation] to this. /// The added indent should be the total added indent from one line. /// Indent should always be added starting from the bottom (or equivalently, the innermost tree-sitter node). fn add_line(&mut self, added: Indentation<'a>) { // Align overrides the indent from outer scopes. if self.align.is_some() { return; } if added.align.is_some() { self.align = added.align; return; } self.indent += added.indent; self.indent_always += added.indent_always; self.outdent += added.outdent; self.outdent_always += added.outdent_always; } /// Add an indent capture to this indent. /// Only captures that apply to the same line should be added together in this way (otherwise use `add_line`) /// and the captures should be added starting from the innermost tree-sitter node (currently this only matters /// if multiple `@align` patterns occur on the same line). fn add_capture(&mut self, added: IndentCaptureType<'a>) { match added { IndentCaptureType::Indent => { if self.indent_always == 0 { self.indent = 1; } } IndentCaptureType::IndentAlways => { // any time we encounter an `indent.always` on the same line, we // want to cancel out all regular indents self.indent_always += 1; self.indent = 0; } IndentCaptureType::Outdent => { if self.outdent_always == 0 { self.outdent = 1; } } IndentCaptureType::OutdentAlways => { self.outdent_always += 1; self.outdent = 0; } IndentCaptureType::Align(align) => { if self.align.is_none() { self.align = Some(align); } } } } fn net_indent(&self) -> isize { (self.indent + self.indent_always) as isize - ((self.outdent + self.outdent_always) as isize) } /// Convert `self` into a string, taking into account the computed and actual indentation of some other line. fn relative_indent( &self, other_computed_indent: &Self, other_leading_whitespace: RopeSlice, indent_style: &IndentStyle, tab_width: usize, ) -> Option { if self.align == other_computed_indent.align { // If self and baseline are either not aligned to anything or both aligned the same way, // we can simply take `other_leading_whitespace` and add some indent / outdent to it (in the second // case, the alignment should already be accounted for in `other_leading_whitespace`). let indent_diff = self.net_indent() - other_computed_indent.net_indent(); Some(add_indent_level( String::from(other_leading_whitespace), indent_diff, indent_style, tab_width, )) } else { // If the alignment of both lines is different, we cannot compare their indentation in any meaningful way None } } pub fn to_string(&self, indent_style: &IndentStyle, tab_width: usize) -> String { add_indent_level( self.align .map_or_else(String::new, whitespace_with_same_width), self.net_indent(), indent_style, tab_width, ) } } /// An indent definition which corresponds to a capture from the indent query #[derive(Debug)] struct IndentCapture<'a> { capture_type: IndentCaptureType<'a>, scope: IndentScope, } #[derive(Debug, Clone, PartialEq)] enum IndentCaptureType<'a> { Indent, IndentAlways, Outdent, OutdentAlways, /// Alignment given as a string of whitespace Align(RopeSlice<'a>), } impl<'a> IndentCaptureType<'a> { fn default_scope(&self) -> IndentScope { match self { IndentCaptureType::Indent | IndentCaptureType::IndentAlways => IndentScope::Tail, IndentCaptureType::Outdent | IndentCaptureType::OutdentAlways => IndentScope::All, IndentCaptureType::Align(_) => IndentScope::All, } } } /// This defines which part of a node an [IndentCapture] applies to. /// Each [IndentCaptureType] has a default scope, but the scope can be changed /// with `#set!` property declarations. #[derive(Debug, Clone, Copy)] enum IndentScope { /// The indent applies to the whole node All, /// The indent applies to everything except for the first line of the node Tail, } /// A capture from the indent query which does not define an indent but extends /// the range of a node. This is used before the indent is calculated. #[derive(Debug)] enum ExtendCapture { Extend, PreventOnce, } /// The result of running a tree-sitter indent query. This stores for /// each node (identified by its ID) the relevant captures (already filtered /// by predicates). #[derive(Debug)] struct IndentQueryResult<'a> { indent_captures: HashMap>>, extend_captures: HashMap>, } fn get_node_start_line(node: Node, new_line_byte_pos: Option) -> usize { let mut node_line = node.start_position().row; // Adjust for the new line that will be inserted if new_line_byte_pos.map_or(false, |pos| node.start_byte() >= pos) { node_line += 1; } node_line } fn get_node_end_line(node: Node, new_line_byte_pos: Option) -> usize { let mut node_line = node.end_position().row; // Adjust for the new line that will be inserted (with a strict inequality since end_byte is exclusive) if new_line_byte_pos.map_or(false, |pos| node.end_byte() > pos) { node_line += 1; } node_line } fn query_indents<'a>( query: &Query, syntax: &Syntax, cursor: &mut QueryCursor, text: RopeSlice<'a>, range: std::ops::Range, new_line_byte_pos: Option, ) -> IndentQueryResult<'a> { let mut indent_captures: HashMap> = HashMap::new(); let mut extend_captures: HashMap> = HashMap::new(); cursor.set_byte_range(range); // Iterate over all captures from the query for m in cursor.matches(query, syntax.tree().root_node(), RopeProvider(text)) { // Skip matches where not all custom predicates are fulfilled if !query.general_predicates(m.pattern_index).iter().all(|pred| { match pred.operator.as_ref() { "not-kind-eq?" => match (pred.args.get(0), pred.args.get(1)) { ( Some(QueryPredicateArg::Capture(capture_idx)), Some(QueryPredicateArg::String(kind)), ) => { let node = m.nodes_for_capture_index(*capture_idx).next(); match node { Some(node) => node.kind()!=kind.as_ref(), _ => true, } } _ => { panic!("Invalid indent query: Arguments to \"not-kind-eq?\" must be a capture and a string"); } }, "same-line?" | "not-same-line?" => { match (pred.args.get(0), pred.args.get(1)) { ( Some(QueryPredicateArg::Capture(capt1)), Some(QueryPredicateArg::Capture(capt2)) ) => { let n1 = m.nodes_for_capture_index(*capt1).next(); let n2 = m.nodes_for_capture_index(*capt2).next(); match (n1, n2) { (Some(n1), Some(n2)) => { let n1_line = get_node_start_line(n1, new_line_byte_pos); let n2_line = get_node_start_line(n2, new_line_byte_pos); let same_line = n1_line == n2_line; same_line==(pred.operator.as_ref()=="same-line?") } _ => true, } } _ => { panic!("Invalid indent query: Arguments to \"{}\" must be 2 captures", pred.operator); } } } "one-line?" | "not-one-line?" => match pred.args.get(0) { Some(QueryPredicateArg::Capture(capture_idx)) => { let node = m.nodes_for_capture_index(*capture_idx).next(); match node { Some(node) => { let (start_line, end_line) = (get_node_start_line(node,new_line_byte_pos), get_node_end_line(node, new_line_byte_pos)); let one_line = end_line == start_line; one_line != (pred.operator.as_ref() == "not-one-line?") }, _ => true, } } _ => { panic!("Invalid indent query: Arguments to \"not-kind-eq?\" must be a capture and a string"); } }, _ => { panic!( "Invalid indent query: Unknown predicate (\"{}\")", pred.operator ); } } }) { continue; } // A list of pairs (node_id, indent_capture) that are added by this match. // They cannot be added to indent_captures immediately since they may depend on other captures (such as an @anchor). let mut added_indent_captures: Vec<(usize, IndentCapture)> = Vec::new(); // The row/column position of the optional anchor in this query let mut anchor: Option = None; for capture in m.captures { let capture_name = query.capture_names()[capture.index as usize].as_str(); let capture_type = match capture_name { "indent" => IndentCaptureType::Indent, "indent.always" => IndentCaptureType::IndentAlways, "outdent" => IndentCaptureType::Outdent, "outdent.always" => IndentCaptureType::OutdentAlways, // The alignment will be updated to the correct value at the end, when the anchor is known. "align" => IndentCaptureType::Align(RopeSlice::from("")), "anchor" => { if anchor.is_some() { log::error!("Invalid indent query: Encountered more than one @anchor in the same match.") } else { anchor = Some(capture.node); } continue; } "extend" => { extend_captures .entry(capture.node.id()) .or_insert_with(|| Vec::with_capacity(1)) .push(ExtendCapture::Extend); continue; } "extend.prevent-once" => { extend_captures .entry(capture.node.id()) .or_insert_with(|| Vec::with_capacity(1)) .push(ExtendCapture::PreventOnce); continue; } _ => { // Ignore any unknown captures (these may be needed for predicates such as #match?) continue; } }; let scope = capture_type.default_scope(); let mut indent_capture = IndentCapture { capture_type, scope, }; // Apply additional settings for this capture for property in query.property_settings(m.pattern_index) { match property.key.as_ref() { "scope" => { indent_capture.scope = match property.value.as_deref() { Some("all") => IndentScope::All, Some("tail") => IndentScope::Tail, Some(s) => { panic!("Invalid indent query: Unknown value for \"scope\" property (\"{}\")", s); } None => { panic!( "Invalid indent query: Missing value for \"scope\" property" ); } } } _ => { panic!( "Invalid indent query: Unknown property \"{}\"", property.key ); } } } added_indent_captures.push((capture.node.id(), indent_capture)) } for (node_id, mut capture) in added_indent_captures { // Set the anchor for all align queries. if let IndentCaptureType::Align(_) = capture.capture_type { let anchor = match anchor { None => { log::error!( "Invalid indent query: @align requires an accompanying @anchor." ); continue; } Some(anchor) => anchor, }; capture.capture_type = IndentCaptureType::Align( text.line(anchor.start_position().row) .byte_slice(0..anchor.start_position().column), ); } indent_captures .entry(node_id) .or_insert_with(|| Vec::with_capacity(1)) .push(capture); } } let result = IndentQueryResult { indent_captures, extend_captures, }; log::trace!("indent result = {:?}", result); result } /// 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>, mut deepest_preceding: Node<'a>, extend_captures: &HashMap>, text: RopeSlice, line: usize, tab_width: usize, indent_width: usize, ) { let mut stop_extend = false; while deepest_preceding != *node { let mut extend_node = false; // This will be set to true if this node is captured, regardless of whether // it actually will be extended (e.g. because the cursor isn't indented // more than the node). let mut node_captured = false; if let Some(captures) = extend_captures.get(&deepest_preceding.id()) { for capture in captures { match capture { ExtendCapture::PreventOnce => { stop_extend = true; } ExtendCapture::Extend => { node_captured = true; // 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, indent_width); let node_indent = indent_level_for_line( text.line(deepest_preceding.start_position().row), tab_width, indent_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 if node_captured && stop_extend { stop_extend = false; } else if extend_node && !stop_extend { *node = deepest_preceding; break; } // If the tree contains a syntax error, `deepest_preceding` may not // have a parent despite being a descendant of `node`. deepest_preceding = match deepest_preceding.parent() { Some(parent) => parent, None => return, } } } /// Prepare an indent query by computing: /// - The node from which to start the query (this is non-trivial due to `@extend` captures) /// - The indent captures for all relevant nodes. #[allow(clippy::too_many_arguments)] fn init_indent_query<'a, 'b>( query: &Query, syntax: &'a Syntax, text: RopeSlice<'b>, tab_width: usize, indent_width: usize, line: usize, byte_pos: usize, new_line_byte_pos: Option, ) -> Option<(Node<'a>, HashMap>>)> { // The innermost tree-sitter node which is considered for the indent // computation. It may change if some predeceding node is extended let mut node = syntax .tree() .root_node() .descendant_for_byte_range(byte_pos, byte_pos)?; let (query_result, deepest_preceding) = { // The query range should intersect with all nodes directly preceding // the position of the indent query in case one of them is extended. let mut deepest_preceding = None; // The deepest node preceding the indent query position 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); } } 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(); } 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_byte_pos, ); ts_parser.cursors.push(cursor); (query_result, deepest_preceding) }) }; let extend_captures = query_result.extend_captures; // Check for extend captures, potentially changing the node that the indent calculation starts with if let Some(deepest_preceding) = deepest_preceding { extend_nodes( &mut node, deepest_preceding, &extend_captures, text, line, tab_width, indent_width, ); } Some((node, query_result.indent_captures)) } /// Use the syntax tree to determine the indentation for a given position. /// This can be used in 2 ways: /// /// - To get the correct indentation for an existing line (new_line=false), not necessarily equal to the current indentation. /// - In this case, pos should be inside the first tree-sitter node on that line. /// In most cases, this can just be the first non-whitespace on that line. /// - To get the indentation for a new line (new_line=true). This behaves like the first usecase if the part of the current line /// after pos were moved to a new line. /// /// The indentation is determined by traversing all the tree-sitter nodes containing the position. /// Each of these nodes produces some [Indentation] for: /// /// - The line of the (beginning of the) node. This is defined by the scope `all` if this is the first node on its line. /// - The line after the node. This is defined by: /// - The scope `tail`. /// - The scope `all` if this node is not the first node on its line. /// Intuitively, `all` applies to everything contained in this node while `tail` applies to everything except for the first line of the node. /// The indents from different nodes for the same line are then combined. /// The result [Indentation] is simply the sum of the [Indentation] for all lines. /// /// Specifying which line exactly an [Indentation] applies to is important because indents on the same line combine differently than indents on different lines: /// ```ignore /// some_function(|| { /// // Both the function parameters as well as the contained block should be indented. /// // Because they are on the same line, this only yields one indent level /// }); /// ``` /// /// ```ignore /// some_function( /// param1, /// || { /// // Here we get 2 indent levels because the 'parameters' and the 'block' node begin on different lines /// }, /// ); /// ``` #[allow(clippy::too_many_arguments)] pub fn treesitter_indent_for_pos<'a>( query: &Query, syntax: &Syntax, tab_width: usize, indent_width: usize, text: RopeSlice<'a>, line: usize, pos: usize, new_line: bool, ) -> Option> { let byte_pos = text.char_to_byte(pos); let new_line_byte_pos = new_line.then_some(byte_pos); let (mut node, mut indent_captures) = init_indent_query( query, syntax, text, tab_width, indent_width, line, byte_pos, new_line_byte_pos, )?; let mut first_in_line = get_first_in_line(node, new_line.then_some(byte_pos)); let mut result = Indentation::default(); // We always keep track of all the indent changes on one line, in order to only indent once // even if there are multiple "indent" nodes on the same line let mut indent_for_line = Indentation::default(); let mut indent_for_line_below = Indentation::default(); loop { // This can safely be unwrapped because `first_in_line` contains // one entry for each ancestor of the node (which is what we iterate over) let is_first = *first_in_line.last().unwrap(); // Apply all indent definitions for this node. // Since we only iterate over each node once, we can remove the // corresponding captures from the HashMap to avoid cloning them. if let Some(definitions) = indent_captures.remove(&node.id()) { for definition in definitions { match definition.scope { IndentScope::All => { if is_first { indent_for_line.add_capture(definition.capture_type); } else { indent_for_line_below.add_capture(definition.capture_type); } } IndentScope::Tail => { indent_for_line_below.add_capture(definition.capture_type); } } } } if let Some(parent) = node.parent() { let node_line = get_node_start_line(node, new_line_byte_pos); let parent_line = get_node_start_line(parent, new_line_byte_pos); if node_line != parent_line { // Don't add indent for the line below the line of the query if node_line < line + (new_line as usize) { result.add_line(indent_for_line_below); } if node_line == parent_line + 1 { indent_for_line_below = indent_for_line; } else { result.add_line(indent_for_line); indent_for_line_below = Indentation::default(); } indent_for_line = Indentation::default(); } node = parent; first_in_line.pop(); } else { // Only add the indentation for the line below if that line // is not after the line that the indentation is calculated for. if (node.start_position().row < line) || (new_line && node.start_position().row == line && node.start_byte() < byte_pos) { result.add_line(indent_for_line_below); } result.add_line(indent_for_line); break; } } Some(result) } /// Returns the indentation for a new line. /// This is done either using treesitter, or if that's not available by copying the indentation from the current line #[allow(clippy::too_many_arguments)] pub fn indent_for_newline( language_config: Option<&LanguageConfiguration>, syntax: Option<&Syntax>, indent_heuristic: &IndentationHeuristic, indent_style: &IndentStyle, tab_width: usize, text: RopeSlice, line_before: usize, line_before_end_pos: usize, current_line: usize, ) -> String { let indent_width = indent_style.indent_width(tab_width); if let ( IndentationHeuristic::TreeSitter | IndentationHeuristic::Hybrid, Some(query), Some(syntax), ) = ( indent_heuristic, language_config.and_then(|config| config.indent_query()), syntax, ) { if let Some(indent) = treesitter_indent_for_pos( query, syntax, tab_width, indent_width, text, line_before, line_before_end_pos, true, ) { if *indent_heuristic == IndentationHeuristic::Hybrid { // We want to compute the indentation not only based on the // syntax tree but also on the actual indentation of a previous // line. This makes indentation computation more resilient to // incomplete queries, incomplete source code & differing indentation // styles for the same language. // However, using the indent of a previous line as a baseline may not // make sense, e.g. if it has a different alignment than the new line. // In order to prevent edge cases with long running times, we only try // a constant number of (non-empty) lines. const MAX_ATTEMPTS: usize = 4; let mut num_attempts = 0; for line_idx in (0..=line_before).rev() { let line = text.line(line_idx); let first_non_whitespace_char = match find_first_non_whitespace_char(line) { Some(i) => i, None => { continue; } }; if let Some(indent) = (|| { let computed_indent = treesitter_indent_for_pos( query, syntax, tab_width, indent_width, text, line_idx, text.line_to_char(line_idx) + first_non_whitespace_char, false, )?; let leading_whitespace = line.slice(0..first_non_whitespace_char); indent.relative_indent( &computed_indent, leading_whitespace, indent_style, tab_width, ) })() { return indent; } num_attempts += 1; if num_attempts == MAX_ATTEMPTS { break; } } } return indent.to_string(indent_style, tab_width); }; } // Fallback in case we either don't have indent queries or they failed for some reason let indent_level = indent_level_for_line(text.line(current_line), tab_width, indent_width); indent_style.as_str().repeat(indent_level) } pub fn get_scopes(syntax: Option<&Syntax>, text: RopeSlice, pos: usize) -> Vec<&'static str> { let mut scopes = Vec::new(); if let Some(syntax) = syntax { let pos = text.char_to_byte(pos); let mut node = match syntax .tree() .root_node() .descendant_for_byte_range(pos, pos) { Some(node) => node, None => return scopes, }; scopes.push(node.kind()); while let Some(parent) = node.parent() { scopes.push(parent.kind()); node = parent; } } scopes.reverse(); scopes } #[cfg(test)] mod test { use super::*; use crate::Rope; #[test] fn test_indent_level() { let tab_width = 4; let indent_width = 4; let line = Rope::from(" fn new"); // 8 spaces assert_eq!( indent_level_for_line(line.slice(..), tab_width, indent_width), 2 ); let line = Rope::from("\t\t\tfn new"); // 3 tabs assert_eq!( indent_level_for_line(line.slice(..), tab_width, indent_width), 3 ); // mixed indentation let line = Rope::from("\t \tfn new"); // 1 tab, 4 spaces, tab assert_eq!( indent_level_for_line(line.slice(..), tab_width, indent_width), 3 ); } #[test] fn test_large_indent_level() { let tab_width = 16; let indent_width = 16; let line = Rope::from(" fn new"); // 16 spaces assert_eq!( indent_level_for_line(line.slice(..), tab_width, indent_width), 1 ); let line = Rope::from(" fn new"); // 32 spaces assert_eq!( indent_level_for_line(line.slice(..), tab_width, indent_width), 2 ); } #[test] fn add_capture() { let indent = || Indentation { indent: 1, ..Default::default() }; let indent_always = || Indentation { indent_always: 1, ..Default::default() }; let outdent = || Indentation { outdent: 1, ..Default::default() }; let outdent_always = || Indentation { outdent_always: 1, ..Default::default() }; fn add_capture<'a>( mut indent: Indentation<'a>, capture: IndentCaptureType<'a>, ) -> Indentation<'a> { indent.add_capture(capture); indent } // adding an indent to no indent makes an indent assert_eq!( indent(), add_capture(Indentation::default(), IndentCaptureType::Indent) ); assert_eq!( indent_always(), add_capture(Indentation::default(), IndentCaptureType::IndentAlways) ); assert_eq!( outdent(), add_capture(Indentation::default(), IndentCaptureType::Outdent) ); assert_eq!( outdent_always(), add_capture(Indentation::default(), IndentCaptureType::OutdentAlways) ); // adding an indent to an already indented has no effect assert_eq!(indent(), add_capture(indent(), IndentCaptureType::Indent)); assert_eq!( outdent(), add_capture(outdent(), IndentCaptureType::Outdent) ); // adding an always to a regular makes it always assert_eq!( indent_always(), add_capture(indent(), IndentCaptureType::IndentAlways) ); assert_eq!( outdent_always(), add_capture(outdent(), IndentCaptureType::OutdentAlways) ); // adding an always to an always is additive assert_eq!( Indentation { indent_always: 2, ..Default::default() }, add_capture(indent_always(), IndentCaptureType::IndentAlways) ); assert_eq!( Indentation { outdent_always: 2, ..Default::default() }, add_capture(outdent_always(), IndentCaptureType::OutdentAlways) ); // adding regular to always should be associative assert_eq!( Indentation { indent_always: 1, ..Default::default() }, add_capture( add_capture(indent(), IndentCaptureType::Indent), IndentCaptureType::IndentAlways ) ); assert_eq!( Indentation { indent_always: 1, ..Default::default() }, add_capture( add_capture(indent(), IndentCaptureType::IndentAlways), IndentCaptureType::Indent ) ); assert_eq!( Indentation { outdent_always: 1, ..Default::default() }, add_capture( add_capture(outdent(), IndentCaptureType::Outdent), IndentCaptureType::OutdentAlways ) ); assert_eq!( Indentation { outdent_always: 1, ..Default::default() }, add_capture( add_capture(outdent(), IndentCaptureType::OutdentAlways), IndentCaptureType::Outdent ) ); } #[test] fn test_relative_indent() { let indent_style = IndentStyle::Spaces(4); let tab_width: usize = 4; let no_align = [ Indentation::default(), Indentation { indent: 1, ..Default::default() }, Indentation { indent: 5, outdent: 1, ..Default::default() }, ]; let align = no_align.clone().map(|indent| Indentation { align: Some(RopeSlice::from("12345")), ..indent }); let different_align = Indentation { align: Some(RopeSlice::from("123456")), ..Default::default() }; // Check that relative and absolute indentation computation are the same when the line we compare to is // indented as we expect. let check_consistency = |indent: &Indentation, other: &Indentation| { assert_eq!( indent.relative_indent( other, RopeSlice::from(other.to_string(&indent_style, tab_width).as_str()), &indent_style, tab_width ), Some(indent.to_string(&indent_style, tab_width)) ); }; for a in &no_align { for b in &no_align { check_consistency(a, b); } } for a in &align { for b in &align { check_consistency(a, b); } } // Relative indent computation makes no sense if the alignment differs assert_eq!( align[0].relative_indent( &no_align[0], RopeSlice::from(" "), &indent_style, tab_width ), None ); assert_eq!( align[0].relative_indent( &different_align, RopeSlice::from(" "), &indent_style, tab_width ), None ); } }