tree-sitter/highlight/src/lib.rs

1204 lines
46 KiB
Rust

#![doc = include_str!("../README.md")]
pub mod c_lib;
pub mod util;
pub use c_lib as c;
use lazy_static::lazy_static;
use std::collections::HashSet;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::{iter, mem, ops, str, usize};
use thiserror::Error;
use tree_sitter::{
Language, LossyUtf8, Node, Parser, Point, Query, QueryCaptures, QueryCursor, QueryError,
QueryMatch, Range, Tree,
};
const CANCELLATION_CHECK_INTERVAL: usize = 100;
const BUFFER_HTML_RESERVE_CAPACITY: usize = 10 * 1024;
const BUFFER_LINES_RESERVE_CAPACITY: usize = 1000;
lazy_static! {
static ref STANDARD_CAPTURE_NAMES: HashSet<&'static str> = vec![
"attribute",
"boolean",
"carriage-return",
"comment",
"comment.documentation",
"constant",
"constant.builtin",
"constructor",
"constructor.builtin",
"embedded",
"error",
"escape",
"function",
"function.builtin",
"keyword",
"markup",
"markup.bold",
"markup.heading",
"markup.italic",
"markup.link",
"markup.link.url",
"markup.list",
"markup.list.checked",
"markup.list.numbered",
"markup.list.unchecked",
"markup.list.unnumbered",
"markup.quote",
"markup.raw",
"markup.raw.block",
"markup.raw.inline",
"markup.strikethrough",
"module",
"number",
"operator",
"property",
"property.builtin",
"punctuation",
"punctuation.bracket",
"punctuation.delimiter",
"punctuation.special",
"string",
"string.escape",
"string.regexp",
"string.special",
"string.special.symbol",
"tag",
"type",
"type.builtin",
"variable",
"variable.builtin",
"variable.member",
"variable.parameter",
]
.into_iter()
.collect();
}
/// Indicates which highlight should be applied to a region of source code.
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub struct Highlight(pub usize);
/// Represents the reason why syntax highlighting failed.
#[derive(Debug, Error, PartialEq, Eq)]
pub enum Error {
#[error("Cancelled")]
Cancelled,
#[error("Invalid language")]
InvalidLanguage,
#[error("Unknown error")]
Unknown,
}
/// Represents a single step in rendering a syntax-highlighted document.
#[derive(Copy, Clone, Debug)]
pub enum HighlightEvent {
Source { start: usize, end: usize },
HighlightStart(Highlight),
HighlightEnd,
}
/// Contains the data needed to highlight code written in a particular language.
///
/// This struct is immutable and can be shared between threads.
pub struct HighlightConfiguration {
pub language: Language,
pub language_name: String,
pub query: Query,
pub apply_all_captures: bool,
combined_injections_query: Option<Query>,
locals_pattern_index: usize,
highlights_pattern_index: usize,
highlight_indices: Vec<Option<Highlight>>,
non_local_variable_patterns: Vec<bool>,
injection_content_capture_index: Option<u32>,
injection_language_capture_index: Option<u32>,
local_scope_capture_index: Option<u32>,
local_def_capture_index: Option<u32>,
local_def_value_capture_index: Option<u32>,
local_ref_capture_index: Option<u32>,
}
/// Performs syntax highlighting, recognizing a given list of highlight names.
///
/// For the best performance `Highlighter` values should be reused between
/// syntax highlighting calls. A separate highlighter is needed for each thread that
/// is performing highlighting.
pub struct Highlighter {
parser: Parser,
cursors: Vec<QueryCursor>,
}
/// Converts a general-purpose syntax highlighting iterator into a sequence of lines of HTML.
pub struct HtmlRenderer {
pub html: Vec<u8>,
pub line_offsets: Vec<u32>,
carriage_return_highlight: Option<Highlight>,
}
#[derive(Debug)]
struct LocalDef<'a> {
name: &'a str,
value_range: ops::Range<usize>,
highlight: Option<Highlight>,
}
#[derive(Debug)]
struct LocalScope<'a> {
inherits: bool,
range: ops::Range<usize>,
local_defs: Vec<LocalDef<'a>>,
}
struct HighlightIter<'a, F>
where
F: FnMut(&str) -> Option<&'a HighlightConfiguration> + 'a,
{
source: &'a [u8],
language_name: &'a str,
byte_offset: usize,
highlighter: &'a mut Highlighter,
injection_callback: F,
cancellation_flag: Option<&'a AtomicUsize>,
layers: Vec<HighlightIterLayer<'a>>,
iter_count: usize,
next_event: Option<HighlightEvent>,
last_highlight_range: Option<(usize, usize, usize)>,
apply_all_captures: bool,
}
struct HighlightIterLayer<'a> {
_tree: Tree,
cursor: QueryCursor,
captures: iter::Peekable<QueryCaptures<'a, 'a, &'a [u8], &'a [u8]>>,
config: &'a HighlightConfiguration,
highlight_end_stack: Vec<usize>,
scope_stack: Vec<LocalScope<'a>>,
ranges: Vec<Range>,
depth: usize,
}
impl Highlighter {
pub fn new() -> Self {
Highlighter {
parser: Parser::new(),
cursors: Vec::new(),
}
}
pub fn parser(&mut self) -> &mut Parser {
&mut self.parser
}
/// Iterate over the highlighted regions for a given slice of source code.
pub fn highlight<'a>(
&'a mut self,
config: &'a HighlightConfiguration,
source: &'a [u8],
cancellation_flag: Option<&'a AtomicUsize>,
mut injection_callback: impl FnMut(&str) -> Option<&'a HighlightConfiguration> + 'a,
) -> Result<impl Iterator<Item = Result<HighlightEvent, Error>> + 'a, Error> {
let layers = HighlightIterLayer::new(
source,
None,
self,
cancellation_flag,
&mut injection_callback,
config,
0,
vec![Range {
start_byte: 0,
end_byte: usize::MAX,
start_point: Point::new(0, 0),
end_point: Point::new(usize::MAX, usize::MAX),
}],
)?;
assert_ne!(layers.len(), 0);
let mut result = HighlightIter {
source,
language_name: &config.language_name,
byte_offset: 0,
injection_callback,
cancellation_flag,
highlighter: self,
iter_count: 0,
layers,
next_event: None,
last_highlight_range: None,
apply_all_captures: config.apply_all_captures,
};
result.sort_layers();
Ok(result)
}
}
impl HighlightConfiguration {
/// Creates a `HighlightConfiguration` for a given `Language` and set of highlighting
/// queries.
///
/// # Parameters
///
/// * `language` - The Tree-sitter `Language` that should be used for parsing.
/// * `highlights_query` - A string containing tree patterns for syntax highlighting. This
/// should be non-empty, otherwise no syntax highlights will be added.
/// * `injections_query` - A string containing tree patterns for injecting other languages
/// into the document. This can be empty if no injections are desired.
/// * `locals_query` - A string containing tree patterns for tracking local variable
/// definitions and references. This can be empty if local variable tracking is not needed.
///
/// Returns a `HighlightConfiguration` that can then be used with the `highlight` method.
pub fn new(
language: Language,
name: impl Into<String>,
highlights_query: &str,
injection_query: &str,
locals_query: &str,
apply_all_captures: bool,
) -> Result<Self, QueryError> {
// Concatenate the query strings, keeping track of the start offset of each section.
let mut query_source = String::new();
query_source.push_str(injection_query);
let locals_query_offset = query_source.len();
query_source.push_str(locals_query);
let highlights_query_offset = query_source.len();
query_source.push_str(highlights_query);
// Construct a single query by concatenating the three query strings, but record the
// range of pattern indices that belong to each individual string.
let mut query = Query::new(language, &query_source)?;
let mut locals_pattern_index = 0;
let mut highlights_pattern_index = 0;
for i in 0..(query.pattern_count()) {
let pattern_offset = query.start_byte_for_pattern(i);
if pattern_offset < highlights_query_offset {
if pattern_offset < highlights_query_offset {
highlights_pattern_index += 1;
}
if pattern_offset < locals_query_offset {
locals_pattern_index += 1;
}
}
}
// Construct a separate query just for dealing with the 'combined injections'.
// Disable the combined injection patterns in the main query.
let mut combined_injections_query = Query::new(language, injection_query)?;
let mut has_combined_queries = false;
for pattern_index in 0..locals_pattern_index {
let settings = query.property_settings(pattern_index);
if settings.iter().any(|s| &*s.key == "injection.combined") {
has_combined_queries = true;
query.disable_pattern(pattern_index);
} else {
combined_injections_query.disable_pattern(pattern_index);
}
}
let combined_injections_query = if has_combined_queries {
Some(combined_injections_query)
} else {
None
};
// Find all of the highlighting patterns that are disabled for nodes that
// have been identified as local variables.
let non_local_variable_patterns = (0..query.pattern_count())
.map(|i| {
query
.property_predicates(i)
.iter()
.any(|(prop, positive)| !*positive && prop.key.as_ref() == "local")
})
.collect();
// Store the numeric ids for all of the special captures.
let mut injection_content_capture_index = None;
let mut injection_language_capture_index = None;
let mut local_def_capture_index = None;
let mut local_def_value_capture_index = None;
let mut local_ref_capture_index = None;
let mut local_scope_capture_index = None;
for (i, name) in query.capture_names().iter().enumerate() {
let i = Some(i as u32);
match *name {
"injection.content" => injection_content_capture_index = i,
"injection.language" => injection_language_capture_index = i,
"local.definition" => local_def_capture_index = i,
"local.definition-value" => local_def_value_capture_index = i,
"local.reference" => local_ref_capture_index = i,
"local.scope" => local_scope_capture_index = i,
_ => {}
}
}
let highlight_indices = vec![None; query.capture_names().len()];
Ok(HighlightConfiguration {
language,
language_name: name.into(),
query,
apply_all_captures,
combined_injections_query,
locals_pattern_index,
highlights_pattern_index,
highlight_indices,
non_local_variable_patterns,
injection_content_capture_index,
injection_language_capture_index,
local_def_capture_index,
local_def_value_capture_index,
local_ref_capture_index,
local_scope_capture_index,
})
}
/// Get a slice containing all of the highlight names used in the configuration.
pub fn names(&self) -> &[&str] {
self.query.capture_names()
}
/// Set the list of recognized highlight names.
///
/// Tree-sitter syntax-highlighting queries specify highlights in the form of dot-separated
/// highlight names like `punctuation.bracket` and `function.method.builtin`. Consumers of
/// these queries can choose to recognize highlights with different levels of specificity.
/// For example, the string `function.builtin` will match against `function.method.builtin`
/// and `function.builtin.constructor`, but will not match `function.method`.
///
/// When highlighting, results are returned as `Highlight` values, which contain the index
/// of the matched highlight this list of highlight names.
pub fn configure(&mut self, recognized_names: &[impl AsRef<str>]) {
let mut capture_parts = Vec::new();
self.highlight_indices.clear();
self.highlight_indices
.extend(self.query.capture_names().iter().map(move |capture_name| {
capture_parts.clear();
capture_parts.extend(capture_name.split('.'));
let mut best_index = None;
let mut best_match_len = 0;
for (i, recognized_name) in recognized_names.into_iter().enumerate() {
let mut len = 0;
let mut matches = true;
for part in recognized_name.as_ref().split('.') {
len += 1;
if !capture_parts.contains(&part) {
matches = false;
break;
}
}
if matches && len > best_match_len {
best_index = Some(i);
best_match_len = len;
}
}
best_index.map(Highlight)
}));
}
// Return the list of this configuration's capture names that are neither present in the
// list of predefined 'canonical' names nor start with an underscore (denoting 'private' captures
// used as part of capture internals).
pub fn nonconformant_capture_names(&self, capture_names: &HashSet<&str>) -> Vec<&str> {
let capture_names = if capture_names.is_empty() {
&*STANDARD_CAPTURE_NAMES
} else {
&capture_names
};
self.names()
.iter()
.filter(|&n| !(n.starts_with('_') || capture_names.contains(n)))
.map(|n| *n)
.collect()
}
}
impl<'a> HighlightIterLayer<'a> {
/// Create a new 'layer' of highlighting for this document.
///
/// In the even that the new layer contains "combined injections" (injections where multiple
/// disjoint ranges are parsed as one syntax tree), these will be eagerly processed and
/// added to the returned vector.
fn new<F: FnMut(&str) -> Option<&'a HighlightConfiguration> + 'a>(
source: &'a [u8],
parent_name: Option<&str>,
highlighter: &mut Highlighter,
cancellation_flag: Option<&'a AtomicUsize>,
injection_callback: &mut F,
mut config: &'a HighlightConfiguration,
mut depth: usize,
mut ranges: Vec<Range>,
) -> Result<Vec<Self>, Error> {
let mut result = Vec::with_capacity(1);
let mut queue = Vec::new();
loop {
if highlighter.parser.set_included_ranges(&ranges).is_ok() {
highlighter
.parser
.set_language(config.language)
.map_err(|_| Error::InvalidLanguage)?;
unsafe { highlighter.parser.set_cancellation_flag(cancellation_flag) };
let tree = highlighter
.parser
.parse(source, None)
.ok_or(Error::Cancelled)?;
unsafe { highlighter.parser.set_cancellation_flag(None) };
let mut cursor = highlighter.cursors.pop().unwrap_or(QueryCursor::new());
// Process combined injections.
if let Some(combined_injections_query) = &config.combined_injections_query {
let mut injections_by_pattern_index =
vec![(None, Vec::new(), false); combined_injections_query.pattern_count()];
let matches =
cursor.matches(combined_injections_query, tree.root_node(), source);
for mat in matches {
let entry = &mut injections_by_pattern_index[mat.pattern_index];
let (language_name, content_node, include_children) = injection_for_match(
config,
parent_name,
combined_injections_query,
&mat,
source,
);
if language_name.is_some() {
entry.0 = language_name;
}
if let Some(content_node) = content_node {
entry.1.push(content_node);
}
entry.2 = include_children;
}
for (lang_name, content_nodes, includes_children) in injections_by_pattern_index
{
if let (Some(lang_name), false) = (lang_name, content_nodes.is_empty()) {
if let Some(next_config) = (injection_callback)(lang_name) {
let ranges = Self::intersect_ranges(
&ranges,
&content_nodes,
includes_children,
);
if !ranges.is_empty() {
queue.push((next_config, depth + 1, ranges));
}
}
}
}
}
// The `captures` iterator borrows the `Tree` and the `QueryCursor`, which
// prevents them from being moved. But both of these values are really just
// pointers, so it's actually ok to move them.
let tree_ref = unsafe { mem::transmute::<_, &'static Tree>(&tree) };
let cursor_ref =
unsafe { mem::transmute::<_, &'static mut QueryCursor>(&mut cursor) };
let captures = cursor_ref
.captures(&config.query, tree_ref.root_node(), source)
.peekable();
result.push(HighlightIterLayer {
highlight_end_stack: Vec::new(),
scope_stack: vec![LocalScope {
inherits: false,
range: 0..usize::MAX,
local_defs: Vec::new(),
}],
cursor,
depth,
_tree: tree,
captures,
config,
ranges,
});
}
if queue.is_empty() {
break;
} else {
let (next_config, next_depth, next_ranges) = queue.remove(0);
config = next_config;
depth = next_depth;
ranges = next_ranges;
}
}
Ok(result)
}
// Compute the ranges that should be included when parsing an injection.
// This takes into account three things:
// * `parent_ranges` - The ranges must all fall within the *current* layer's ranges.
// * `nodes` - Every injection takes place within a set of nodes. The injection ranges
// are the ranges of those nodes.
// * `includes_children` - For some injections, the content nodes' children should be
// excluded from the nested document, so that only the content nodes' *own* content
// is reparsed. For other injections, the content nodes' entire ranges should be
// reparsed, including the ranges of their children.
fn intersect_ranges(
parent_ranges: &[Range],
nodes: &[Node],
includes_children: bool,
) -> Vec<Range> {
let mut cursor = nodes[0].walk();
let mut result = Vec::new();
let mut parent_range_iter = parent_ranges.iter();
let mut parent_range = parent_range_iter
.next()
.expect("Layers should only be constructed with non-empty ranges vectors");
for node in nodes.iter() {
let mut preceding_range = Range {
start_byte: 0,
start_point: Point::new(0, 0),
end_byte: node.start_byte(),
end_point: node.start_position(),
};
let following_range = Range {
start_byte: node.end_byte(),
start_point: node.end_position(),
end_byte: usize::MAX,
end_point: Point::new(usize::MAX, usize::MAX),
};
for excluded_range in node
.children(&mut cursor)
.filter_map(|child| {
if includes_children {
None
} else {
Some(child.range())
}
})
.chain([following_range].iter().cloned())
{
let mut range = Range {
start_byte: preceding_range.end_byte,
start_point: preceding_range.end_point,
end_byte: excluded_range.start_byte,
end_point: excluded_range.start_point,
};
preceding_range = excluded_range;
if range.end_byte < parent_range.start_byte {
continue;
}
while parent_range.start_byte <= range.end_byte {
if parent_range.end_byte > range.start_byte {
if range.start_byte < parent_range.start_byte {
range.start_byte = parent_range.start_byte;
range.start_point = parent_range.start_point;
}
if parent_range.end_byte < range.end_byte {
if range.start_byte < parent_range.end_byte {
result.push(Range {
start_byte: range.start_byte,
start_point: range.start_point,
end_byte: parent_range.end_byte,
end_point: parent_range.end_point,
});
}
range.start_byte = parent_range.end_byte;
range.start_point = parent_range.end_point;
} else {
if range.start_byte < range.end_byte {
result.push(range);
}
break;
}
}
if let Some(next_range) = parent_range_iter.next() {
parent_range = next_range;
} else {
return result;
}
}
}
}
result
}
// First, sort scope boundaries by their byte offset in the document. At a
// given position, emit scope endings before scope beginnings. Finally, emit
// scope boundaries from deeper layers first.
fn sort_key(&mut self) -> Option<(usize, bool, isize)> {
let depth = -(self.depth as isize);
let next_start = self
.captures
.peek()
.map(|(m, i)| m.captures[*i].node.start_byte());
let next_end = self.highlight_end_stack.last().cloned();
match (next_start, next_end) {
(Some(start), Some(end)) => {
if start < end {
Some((start, true, depth))
} else {
Some((end, false, depth))
}
}
(Some(i), None) => Some((i, true, depth)),
(None, Some(j)) => Some((j, false, depth)),
_ => None,
}
}
}
impl<'a, F> HighlightIter<'a, F>
where
F: FnMut(&str) -> Option<&'a HighlightConfiguration> + 'a,
{
fn emit_event(
&mut self,
offset: usize,
event: Option<HighlightEvent>,
) -> Option<Result<HighlightEvent, Error>> {
let result;
if self.byte_offset < offset {
result = Some(Ok(HighlightEvent::Source {
start: self.byte_offset,
end: offset,
}));
self.byte_offset = offset;
self.next_event = event;
} else {
result = event.map(Ok);
}
self.sort_layers();
result
}
fn sort_layers(&mut self) {
while !self.layers.is_empty() {
if let Some(sort_key) = self.layers[0].sort_key() {
let mut i = 0;
while i + 1 < self.layers.len() {
if let Some(next_offset) = self.layers[i + 1].sort_key() {
if next_offset < sort_key {
i += 1;
continue;
}
}
break;
}
if i > 0 {
self.layers[0..(i + 1)].rotate_left(1);
}
break;
} else {
let layer = self.layers.remove(0);
self.highlighter.cursors.push(layer.cursor);
}
}
}
fn insert_layer(&mut self, mut layer: HighlightIterLayer<'a>) {
if let Some(sort_key) = layer.sort_key() {
let mut i = 1;
while i < self.layers.len() {
if let Some(sort_key_i) = self.layers[i].sort_key() {
if sort_key_i > sort_key {
self.layers.insert(i, layer);
return;
}
i += 1;
} else {
self.layers.remove(i);
}
}
self.layers.push(layer);
}
}
}
impl<'a, F> Iterator for HighlightIter<'a, F>
where
F: FnMut(&str) -> Option<&'a HighlightConfiguration> + 'a,
{
type Item = Result<HighlightEvent, Error>;
fn next(&mut self) -> Option<Self::Item> {
'main: loop {
// If we've already determined the next highlight boundary, just return it.
if let Some(e) = self.next_event.take() {
return Some(Ok(e));
}
// Periodically check for cancellation, returning `Cancelled` error if the
// cancellation flag was flipped.
if let Some(cancellation_flag) = self.cancellation_flag {
self.iter_count += 1;
if self.iter_count >= CANCELLATION_CHECK_INTERVAL {
self.iter_count = 0;
if cancellation_flag.load(Ordering::Relaxed) != 0 {
return Some(Err(Error::Cancelled));
}
}
}
// If none of the layers have any more highlight boundaries, terminate.
if self.layers.is_empty() {
return if self.byte_offset < self.source.len() {
let result = Some(Ok(HighlightEvent::Source {
start: self.byte_offset,
end: self.source.len(),
}));
self.byte_offset = self.source.len();
result
} else {
None
};
}
// Get the next capture from whichever layer has the earliest highlight boundary.
let range;
let layer = &mut self.layers[0];
if let Some((next_match, capture_index)) = layer.captures.peek() {
let next_capture = next_match.captures[*capture_index];
range = next_capture.node.byte_range();
// If any previous highlight ends before this node starts, then before
// processing this capture, emit the source code up until the end of the
// previous highlight, and an end event for that highlight.
if let Some(end_byte) = layer.highlight_end_stack.last().cloned() {
if end_byte <= range.start {
layer.highlight_end_stack.pop();
return self.emit_event(end_byte, Some(HighlightEvent::HighlightEnd));
}
}
}
// If there are no more captures, then emit any remaining highlight end events.
// And if there are none of those, then just advance to the end of the document.
else if let Some(end_byte) = layer.highlight_end_stack.last().cloned() {
layer.highlight_end_stack.pop();
return self.emit_event(end_byte, Some(HighlightEvent::HighlightEnd));
} else {
return self.emit_event(self.source.len(), None);
};
let (mut match_, capture_index) = layer.captures.next().unwrap();
let mut capture = match_.captures[capture_index];
// If this capture represents an injection, then process the injection.
if match_.pattern_index < layer.config.locals_pattern_index {
let (language_name, content_node, include_children) = injection_for_match(
layer.config,
Some(self.language_name),
&layer.config.query,
&match_,
self.source,
);
// Explicitly remove this match so that none of its other captures will remain
// in the stream of captures.
match_.remove();
// If a language is found with the given name, then add a new language layer
// to the highlighted document.
if let (Some(language_name), Some(content_node)) = (language_name, content_node) {
if let Some(config) = (self.injection_callback)(language_name) {
let ranges = HighlightIterLayer::intersect_ranges(
&self.layers[0].ranges,
&[content_node],
include_children,
);
if !ranges.is_empty() {
match HighlightIterLayer::new(
self.source,
Some(self.language_name),
self.highlighter,
self.cancellation_flag,
&mut self.injection_callback,
config,
self.layers[0].depth + 1,
ranges,
) {
Ok(layers) => {
for layer in layers {
self.insert_layer(layer);
}
}
Err(e) => return Some(Err(e)),
}
}
}
}
self.sort_layers();
continue 'main;
}
// Remove from the local scope stack any local scopes that have already ended.
while range.start > layer.scope_stack.last().unwrap().range.end {
layer.scope_stack.pop();
}
// If this capture is for tracking local variables, then process the
// local variable info.
let mut reference_highlight = None;
let mut definition_highlight = None;
while match_.pattern_index < layer.config.highlights_pattern_index {
// If the node represents a local scope, push a new local scope onto
// the scope stack.
if Some(capture.index) == layer.config.local_scope_capture_index {
definition_highlight = None;
let mut scope = LocalScope {
inherits: true,
range: range.clone(),
local_defs: Vec::new(),
};
for prop in layer.config.query.property_settings(match_.pattern_index) {
match prop.key.as_ref() {
"local.scope-inherits" => {
scope.inherits =
prop.value.as_ref().map_or(true, |r| r.as_ref() == "true");
}
_ => {}
}
}
layer.scope_stack.push(scope);
}
// If the node represents a definition, add a new definition to the
// local scope at the top of the scope stack.
else if Some(capture.index) == layer.config.local_def_capture_index {
reference_highlight = None;
definition_highlight = None;
let scope = layer.scope_stack.last_mut().unwrap();
let mut value_range = 0..0;
for capture in match_.captures {
if Some(capture.index) == layer.config.local_def_value_capture_index {
value_range = capture.node.byte_range();
}
}
if let Ok(name) = str::from_utf8(&self.source[range.clone()]) {
scope.local_defs.push(LocalDef {
name,
value_range,
highlight: None,
});
definition_highlight =
scope.local_defs.last_mut().map(|s| &mut s.highlight);
}
}
// If the node represents a reference, then try to find the corresponding
// definition in the scope stack.
else if Some(capture.index) == layer.config.local_ref_capture_index {
if definition_highlight.is_none() {
definition_highlight = None;
if let Ok(name) = str::from_utf8(&self.source[range.clone()]) {
for scope in layer.scope_stack.iter().rev() {
if let Some(highlight) =
scope.local_defs.iter().rev().find_map(|def| {
if def.name == name && range.start >= def.value_range.end {
Some(def.highlight)
} else {
None
}
})
{
reference_highlight = highlight;
break;
}
if !scope.inherits {
break;
}
}
}
}
}
// Continue processing any additional matches for the same node.
if let Some((next_match, next_capture_index)) = layer.captures.peek() {
let next_capture = next_match.captures[*next_capture_index];
if next_capture.node == capture.node {
capture = next_capture;
match_ = layer.captures.next().unwrap().0;
continue;
}
}
self.sort_layers();
continue 'main;
}
// Otherwise, this capture must represent a highlight.
// If this exact range has already been highlighted by an earlier pattern, or by
// a different layer, then skip over this one.
if let Some((last_start, last_end, last_depth)) = self.last_highlight_range {
if range.start == last_start && range.end == last_end && layer.depth < last_depth {
self.sort_layers();
continue 'main;
}
}
// If the current node was found to be a local variable, then skip over any
// highlighting patterns that are disabled for local variables.
if definition_highlight.is_some() || reference_highlight.is_some() {
while layer.config.non_local_variable_patterns[match_.pattern_index] {
match_.remove();
if let Some((next_match, next_capture_index)) = layer.captures.peek() {
let next_capture = next_match.captures[*next_capture_index];
if next_capture.node == capture.node {
capture = next_capture;
match_ = layer.captures.next().unwrap().0;
continue;
}
}
self.sort_layers();
continue 'main;
}
}
// Once a highlighting pattern is found for the current node, skip over
// any later highlighting patterns that also match this node. Captures
// for a given node are ordered by pattern index, so these subsequent
// captures are guaranteed to be for highlighting, not injections or
// local variables.
while let Some((next_match, next_capture_index)) = layer.captures.peek() {
let next_capture = next_match.captures[*next_capture_index];
if next_capture.node == capture.node {
if self.apply_all_captures {
match_.remove();
capture = next_capture;
match_ = layer.captures.next().unwrap().0;
} else {
layer.captures.next();
}
} else {
break;
}
}
let current_highlight = layer.config.highlight_indices[capture.index as usize];
// If this node represents a local definition, then store the current
// highlight value on the local scope entry representing this node.
if let Some(definition_highlight) = definition_highlight {
*definition_highlight = current_highlight;
}
// Emit a scope start event and push the node's end position to the stack.
if let Some(highlight) = reference_highlight.or(current_highlight) {
self.last_highlight_range = Some((range.start, range.end, layer.depth));
layer.highlight_end_stack.push(range.end);
return self
.emit_event(range.start, Some(HighlightEvent::HighlightStart(highlight)));
}
self.sort_layers();
}
}
}
impl HtmlRenderer {
pub fn new() -> Self {
let mut result = HtmlRenderer {
html: Vec::with_capacity(BUFFER_HTML_RESERVE_CAPACITY),
line_offsets: Vec::with_capacity(BUFFER_LINES_RESERVE_CAPACITY),
carriage_return_highlight: None,
};
result.line_offsets.push(0);
result
}
pub fn set_carriage_return_highlight(&mut self, highlight: Option<Highlight>) {
self.carriage_return_highlight = highlight;
}
pub fn reset(&mut self) {
shrink_and_clear(&mut self.html, BUFFER_HTML_RESERVE_CAPACITY);
shrink_and_clear(&mut self.line_offsets, BUFFER_LINES_RESERVE_CAPACITY);
self.line_offsets.push(0);
}
pub fn render<'a, F>(
&mut self,
highlighter: impl Iterator<Item = Result<HighlightEvent, Error>>,
source: &'a [u8],
attribute_callback: &F,
) -> Result<(), Error>
where
F: Fn(Highlight) -> &'a [u8],
{
let mut highlights = Vec::new();
for event in highlighter {
match event {
Ok(HighlightEvent::HighlightStart(s)) => {
highlights.push(s);
self.start_highlight(s, attribute_callback);
}
Ok(HighlightEvent::HighlightEnd) => {
highlights.pop();
self.end_highlight();
}
Ok(HighlightEvent::Source { start, end }) => {
self.add_text(&source[start..end], &highlights, attribute_callback);
}
Err(a) => return Err(a),
}
}
if self.html.last() != Some(&b'\n') {
self.html.push(b'\n');
}
if self.line_offsets.last() == Some(&(self.html.len() as u32)) {
self.line_offsets.pop();
}
Ok(())
}
pub fn lines(&self) -> impl Iterator<Item = &str> {
self.line_offsets
.iter()
.enumerate()
.map(move |(i, line_start)| {
let line_start = *line_start as usize;
let line_end = if i + 1 == self.line_offsets.len() {
self.html.len()
} else {
self.line_offsets[i + 1] as usize
};
str::from_utf8(&self.html[line_start..line_end]).unwrap()
})
}
fn add_carriage_return<'a, F>(&mut self, attribute_callback: &F)
where
F: Fn(Highlight) -> &'a [u8],
{
if let Some(highlight) = self.carriage_return_highlight {
let attribute_string = (attribute_callback)(highlight);
if !attribute_string.is_empty() {
self.html.extend(b"<span ");
self.html.extend(attribute_string);
self.html.extend(b"></span>");
}
}
}
fn start_highlight<'a, F>(&mut self, h: Highlight, attribute_callback: &F)
where
F: Fn(Highlight) -> &'a [u8],
{
let attribute_string = (attribute_callback)(h);
self.html.extend(b"<span");
if !attribute_string.is_empty() {
self.html.extend(b" ");
self.html.extend(attribute_string);
}
self.html.extend(b">");
}
fn end_highlight(&mut self) {
self.html.extend(b"</span>");
}
fn add_text<'a, F>(&mut self, src: &[u8], highlights: &Vec<Highlight>, attribute_callback: &F)
where
F: Fn(Highlight) -> &'a [u8],
{
let mut last_char_was_cr = false;
for c in LossyUtf8::new(src).flat_map(|p| p.bytes()) {
// Don't render carriage return characters, but allow lone carriage returns (not
// followed by line feeds) to be styled via the attribute callback.
if c == b'\r' {
last_char_was_cr = true;
continue;
}
if last_char_was_cr {
if c != b'\n' {
self.add_carriage_return(attribute_callback);
}
last_char_was_cr = false;
}
// At line boundaries, close and re-open all of the open tags.
if c == b'\n' {
highlights.iter().for_each(|_| self.end_highlight());
self.html.push(c);
self.line_offsets.push(self.html.len() as u32);
highlights
.iter()
.for_each(|scope| self.start_highlight(*scope, attribute_callback));
} else if let Some(escape) = util::html_escape(c) {
self.html.extend_from_slice(escape);
} else {
self.html.push(c);
}
}
}
}
fn injection_for_match<'a>(
config: &'a HighlightConfiguration,
parent_name: Option<&'a str>,
query: &'a Query,
query_match: &QueryMatch<'a, 'a>,
source: &'a [u8],
) -> (Option<&'a str>, Option<Node<'a>>, bool) {
let content_capture_index = config.injection_content_capture_index;
let language_capture_index = config.injection_language_capture_index;
let mut language_name = None;
let mut content_node = None;
for capture in query_match.captures {
let index = Some(capture.index);
if index == language_capture_index {
language_name = capture.node.utf8_text(source).ok();
} else if index == content_capture_index {
content_node = Some(capture.node);
}
}
let mut include_children = false;
for prop in query.property_settings(query_match.pattern_index) {
match prop.key.as_ref() {
// In addition to specifying the language name via the text of a
// captured node, it can also be hard-coded via a `#set!` predicate
// that sets the injection.language key.
"injection.language" => {
if language_name.is_none() {
language_name = prop.value.as_ref().map(|s| s.as_ref());
}
}
// Setting the `injection.self` key can be used to specify that the
// language name should be the same as the language of the current
// layer.
"injection.self" => {
if language_name.is_none() {
language_name = Some(config.language_name.as_str());
}
}
// Setting the `injection.parent` key can be used to specify that
// the language name should be the same as the language of the
// parent layer
"injection.parent" => {
if language_name.is_none() {
language_name = parent_name;
}
}
// By default, injections do not include the *children* of an
// `injection.content` node - only the ranges that belong to the
// node itself. This can be changed using a `#set!` predicate that
// sets the `injection.include-children` key.
"injection.include-children" => include_children = true,
_ => {}
}
}
(language_name, content_node, include_children)
}
fn shrink_and_clear<T>(vec: &mut Vec<T>, capacity: usize) {
if vec.len() > capacity {
vec.truncate(capacity);
vec.shrink_to_fit();
}
vec.clear();
}