1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // Formatting and tools for comments.
13 use std::{self, borrow::Cow, iter};
15 use itertools::{multipeek, MultiPeek};
16 use syntax::source_map::Span;
19 use rewrite::RewriteContext;
20 use shape::{Indent, Shape};
21 use string::{rewrite_string, StringFormat};
23 count_newlines, first_line_width, last_line_width, trim_left_preserve_layout, unicode_str_width,
25 use {ErrorKind, FormattingError};
27 fn is_custom_comment(comment: &str) -> bool {
28 if !comment.starts_with("//") {
30 } else if let Some(c) = comment.chars().nth(2) {
31 !c.is_alphanumeric() && !c.is_whitespace()
37 #[derive(Copy, Clone, PartialEq, Eq)]
38 pub enum CommentStyle<'a> {
48 fn custom_opener(s: &str) -> &str {
49 s.lines().next().map_or("", |first_line| {
52 .map_or(first_line, |space_index| &first_line[0..=space_index])
56 impl<'a> CommentStyle<'a> {
57 /// Returns true if the commenting style covers a line only.
58 pub fn is_line_comment(&self) -> bool {
60 CommentStyle::DoubleSlash
61 | CommentStyle::TripleSlash
63 | CommentStyle::Custom(_) => true,
68 /// Returns true if the commenting style can span over multiple lines.
69 pub fn is_block_comment(&self) -> bool {
71 CommentStyle::SingleBullet | CommentStyle::DoubleBullet | CommentStyle::Exclamation => {
78 /// Returns true if the commenting style is for documentation.
79 pub fn is_doc_comment(&self) -> bool {
81 CommentStyle::TripleSlash | CommentStyle::Doc => true,
86 pub fn opener(&self) -> &'a str {
88 CommentStyle::DoubleSlash => "// ",
89 CommentStyle::TripleSlash => "/// ",
90 CommentStyle::Doc => "//! ",
91 CommentStyle::SingleBullet => "/* ",
92 CommentStyle::DoubleBullet => "/** ",
93 CommentStyle::Exclamation => "/*! ",
94 CommentStyle::Custom(opener) => opener,
98 pub fn closer(&self) -> &'a str {
100 CommentStyle::DoubleSlash
101 | CommentStyle::TripleSlash
102 | CommentStyle::Custom(..)
103 | CommentStyle::Doc => "",
104 CommentStyle::DoubleBullet => " **/",
105 CommentStyle::SingleBullet | CommentStyle::Exclamation => " */",
109 pub fn line_start(&self) -> &'a str {
111 CommentStyle::DoubleSlash => "// ",
112 CommentStyle::TripleSlash => "/// ",
113 CommentStyle::Doc => "//! ",
114 CommentStyle::SingleBullet | CommentStyle::Exclamation => " * ",
115 CommentStyle::DoubleBullet => " ** ",
116 CommentStyle::Custom(opener) => opener,
120 pub fn to_str_tuplet(&self) -> (&'a str, &'a str, &'a str) {
121 (self.opener(), self.closer(), self.line_start())
125 fn comment_style(orig: &str, normalize_comments: bool) -> CommentStyle {
126 if !normalize_comments {
127 if orig.starts_with("/**") && !orig.starts_with("/**/") {
128 CommentStyle::DoubleBullet
129 } else if orig.starts_with("/*!") {
130 CommentStyle::Exclamation
131 } else if orig.starts_with("/*") {
132 CommentStyle::SingleBullet
133 } else if orig.starts_with("///") && orig.chars().nth(3).map_or(true, |c| c != '/') {
134 CommentStyle::TripleSlash
135 } else if orig.starts_with("//!") {
137 } else if is_custom_comment(orig) {
138 CommentStyle::Custom(custom_opener(orig))
140 CommentStyle::DoubleSlash
142 } else if (orig.starts_with("///") && orig.chars().nth(3).map_or(true, |c| c != '/'))
143 || (orig.starts_with("/**") && !orig.starts_with("/**/"))
145 CommentStyle::TripleSlash
146 } else if orig.starts_with("//!") || orig.starts_with("/*!") {
148 } else if is_custom_comment(orig) {
149 CommentStyle::Custom(custom_opener(orig))
151 CommentStyle::DoubleSlash
155 /// Combine `prev_str` and `next_str` into a single `String`. `span` may contain
156 /// comments between two strings. If there are such comments, then that will be
157 /// recovered. If `allow_extend` is true and there is no comment between the two
158 /// strings, then they will be put on a single line as long as doing so does not
159 /// exceed max width.
160 pub fn combine_strs_with_missing_comments(
161 context: &RewriteContext,
167 ) -> Option<String> {
169 "combine_strs_with_missing_comments `{}` `{}` {:?} {:?}",
177 String::with_capacity(prev_str.len() + next_str.len() + shape.indent.width() + 128);
178 result.push_str(prev_str);
179 let mut allow_one_line = !prev_str.contains('\n') && !next_str.contains('\n');
180 let first_sep = if prev_str.is_empty() || next_str.is_empty() {
185 let mut one_line_width =
186 last_line_width(prev_str) + first_line_width(next_str) + first_sep.len();
188 let config = context.config;
189 let indent = shape.indent;
190 let missing_comment = rewrite_missing_comment(span, shape, context)?;
192 if missing_comment.is_empty() {
193 if allow_extend && prev_str.len() + first_sep.len() + next_str.len() <= shape.width {
194 result.push_str(first_sep);
195 } else if !prev_str.is_empty() {
196 result.push_str(&indent.to_string_with_newline(config))
198 result.push_str(next_str);
202 // We have a missing comment between the first expression and the second expression.
204 // Peek the the original source code and find out whether there is a newline between the first
205 // expression and the second expression or the missing comment. We will preserve the original
206 // layout whenever possible.
207 let original_snippet = context.snippet(span);
208 let prefer_same_line = if let Some(pos) = original_snippet.find('/') {
209 !original_snippet[..pos].contains('\n')
211 !original_snippet.contains('\n')
214 one_line_width -= first_sep.len();
215 let first_sep = if prev_str.is_empty() || missing_comment.is_empty() {
218 let one_line_width = last_line_width(prev_str) + first_line_width(&missing_comment) + 1;
219 if prefer_same_line && one_line_width <= shape.width {
222 indent.to_string_with_newline(config)
225 result.push_str(&first_sep);
226 result.push_str(&missing_comment);
228 let second_sep = if missing_comment.is_empty() || next_str.is_empty() {
230 } else if missing_comment.starts_with("//") {
231 indent.to_string_with_newline(config)
233 one_line_width += missing_comment.len() + first_sep.len() + 1;
234 allow_one_line &= !missing_comment.starts_with("//") && !missing_comment.contains('\n');
235 if prefer_same_line && allow_one_line && one_line_width <= shape.width {
238 indent.to_string_with_newline(config)
241 result.push_str(&second_sep);
242 result.push_str(next_str);
247 pub fn rewrite_doc_comment(orig: &str, shape: Shape, config: &Config) -> Option<String> {
248 identify_comment(orig, false, shape, config, true)
251 pub fn rewrite_comment(
256 ) -> Option<String> {
257 identify_comment(orig, block_style, shape, config, false)
265 is_doc_comment: bool,
266 ) -> Option<String> {
267 let style = comment_style(orig, false);
269 // Computes the byte length of line taking into account a newline if the line is part of a
271 fn compute_len(orig: &str, line: &str) -> usize {
272 if orig.len() > line.len() {
273 if orig.as_bytes()[line.len()] == b'\r' {
283 // Get the first group of line comments having the same commenting style.
285 // Returns a tuple with:
286 // - a boolean indicating if there is a blank line
287 // - a number indicating the size of the first group of comments
288 fn consume_same_line_comments(
293 let mut first_group_ending = 0;
296 for line in orig.lines() {
297 let trimmed_line = line.trim_start();
298 if trimmed_line.is_empty() {
301 } else if trimmed_line.starts_with(line_start)
302 || comment_style(trimmed_line, false) == style
304 first_group_ending += compute_len(&orig[first_group_ending..], line);
309 (hbl, first_group_ending)
312 let (has_bare_lines, first_group_ending) = match style {
313 CommentStyle::DoubleSlash | CommentStyle::TripleSlash | CommentStyle::Doc => {
314 let line_start = style.line_start().trim_start();
315 consume_same_line_comments(style, orig, line_start)
317 CommentStyle::Custom(opener) => {
318 let trimmed_opener = opener.trim_end();
319 consume_same_line_comments(style, orig, trimmed_opener)
321 // for a block comment, search for the closing symbol
322 CommentStyle::DoubleBullet | CommentStyle::SingleBullet | CommentStyle::Exclamation => {
323 let closer = style.closer().trim_start();
324 let mut closing_symbol_offset = 0;
326 let mut first = true;
327 for line in orig.lines() {
328 closing_symbol_offset += compute_len(&orig[closing_symbol_offset..], line);
329 let mut trimmed_line = line.trim_start();
330 if !trimmed_line.starts_with('*')
331 && !trimmed_line.starts_with("//")
332 && !trimmed_line.starts_with("/*")
337 // Remove opener from consideration when searching for closer
339 let opener = style.opener().trim_end();
340 trimmed_line = &trimmed_line[opener.len()..];
343 if trimmed_line.ends_with(closer) {
347 (hbl, closing_symbol_offset)
351 let (first_group, rest) = orig.split_at(first_group_ending);
352 let rewritten_first_group =
353 if !config.normalize_comments() && has_bare_lines && style.is_block_comment() {
354 trim_left_preserve_layout(first_group, shape.indent, config)?
355 } else if !config.normalize_comments()
356 && !config.wrap_comments()
357 && !config.format_doc_comments()
359 light_rewrite_comment(first_group, shape.indent, config, is_doc_comment)
361 rewrite_comment_inner(
367 is_doc_comment || style.is_doc_comment(),
371 Some(rewritten_first_group)
383 rewritten_first_group,
384 // insert back the blank line
385 if has_bare_lines && style.is_line_comment() {
390 shape.indent.to_string(config),
397 /// Attributes for code blocks in rustdoc.
398 /// See https://doc.rust-lang.org/rustdoc/print.html#attributes
399 enum CodeBlockAttribute {
408 impl CodeBlockAttribute {
409 fn new(attribute: &str) -> CodeBlockAttribute {
411 "rust" | "" => CodeBlockAttribute::Rust,
412 "ignore" => CodeBlockAttribute::Ignore,
413 "text" => CodeBlockAttribute::Text,
414 "should_panic" => CodeBlockAttribute::ShouldPanic,
415 "no_run" => CodeBlockAttribute::NoRun,
416 "compile_fail" => CodeBlockAttribute::CompileFail,
417 _ => CodeBlockAttribute::Text,
422 /// Block that is formatted as an item.
424 /// An item starts with either a star `*` or a dash `-`. Different level of indentation are
425 /// handled by shrinking the shape accordingly.
426 struct ItemizedBlock {
427 /// the lines that are identified as part of an itemized block
429 /// the number of whitespaces up to the item sigil
431 /// the string that marks the start of an item
433 /// sequence of whitespaces to prefix new lines that are part of the item
438 /// Returns true if the line is formatted as an item
439 fn is_itemized_line(line: &str) -> bool {
440 let trimmed = line.trim_start();
441 trimmed.starts_with("* ") || trimmed.starts_with("- ")
444 /// Creates a new ItemizedBlock described with the given line.
445 /// The `is_itemized_line` needs to be called first.
446 fn new(line: &str) -> ItemizedBlock {
447 let space_to_sigil = line.chars().take_while(|c| c.is_whitespace()).count();
448 let indent = space_to_sigil + 2;
450 lines: vec![line[indent..].to_string()],
452 opener: line[..indent].to_string(),
453 line_start: " ".repeat(indent),
457 /// Returns a `StringFormat` used for formatting the content of an item
458 fn create_string_format<'a>(&'a self, fmt: &'a StringFormat) -> StringFormat<'a> {
464 shape: Shape::legacy(fmt.shape.width.saturating_sub(self.indent), Indent::empty()),
470 /// Returns true if the line is part of the current itemized block.
471 /// If it is, then it is added to the internal lines vec.
472 fn add_line(&mut self, line: &str) -> bool {
473 if !ItemizedBlock::is_itemized_line(line)
474 && self.indent <= line.chars().take_while(|c| c.is_whitespace()).count()
476 self.lines.push(line.to_string());
482 /// Returns the block as a string, with each line trimmed at the start.
483 fn trimmed_block_as_string(&self) -> String {
486 .map(|line| format!("{} ", line.trim_start()))
490 /// Returns the block as a string under its original form
491 fn original_block_as_string(&self) -> String {
492 self.lines.join("\n")
496 struct CommentRewrite<'a> {
498 code_block_buffer: String,
499 is_prev_line_multi_line: bool,
500 code_block_attr: Option<CodeBlockAttribute>,
501 item_block: Option<ItemizedBlock>,
502 comment_line_separator: String,
506 fmt: StringFormat<'a>,
513 impl<'a> CommentRewrite<'a> {
519 ) -> CommentRewrite<'a> {
520 let (opener, closer, line_start) = if block_style {
521 CommentStyle::SingleBullet.to_str_tuplet()
523 comment_style(orig, config.normalize_comments()).to_str_tuplet()
526 let max_width = shape
528 .checked_sub(closer.len() + opener.len())
530 let indent_str = shape.indent.to_string_with_newline(config).to_string();
531 let fmt_indent = shape.indent + (opener.len() - line_start.len());
533 let mut cr = CommentRewrite {
534 result: String::with_capacity(orig.len() * 2),
535 code_block_buffer: String::with_capacity(128),
536 is_prev_line_multi_line: false,
537 code_block_attr: None,
539 comment_line_separator: format!("{}{}", indent_str, line_start),
549 shape: Shape::legacy(max_width, fmt_indent),
554 opener: opener.to_owned(),
555 closer: closer.to_owned(),
556 line_start: line_start.to_owned(),
558 cr.result.push_str(opener);
562 fn join_block(s: &str, sep: &str) -> String {
563 let mut result = String::with_capacity(s.len() + 128);
564 let mut iter = s.lines().peekable();
565 while let Some(line) = iter.next() {
566 result.push_str(line);
567 result.push_str(match iter.peek() {
568 Some(next_line) if next_line.is_empty() => sep.trim_end(),
576 fn finish(mut self) -> String {
577 if !self.code_block_buffer.is_empty() {
578 // There is a code block that is not properly enclosed by backticks.
579 // We will leave them untouched.
580 self.result.push_str(&self.comment_line_separator);
581 self.result.push_str(&Self::join_block(
582 &trim_custom_comment_prefix(&self.code_block_buffer),
583 &self.comment_line_separator,
587 if let Some(ref ib) = self.item_block {
588 // the last few lines are part of an itemized block
589 self.fmt.shape = Shape::legacy(self.max_width, self.fmt_indent);
590 let item_fmt = ib.create_string_format(&self.fmt);
591 self.result.push_str(&self.comment_line_separator);
592 self.result.push_str(&ib.opener);
593 match rewrite_string(
594 &ib.trimmed_block_as_string(),
596 self.max_width.saturating_sub(ib.indent),
598 Some(s) => self.result.push_str(&Self::join_block(
600 &format!("{}{}", &self.comment_line_separator, ib.line_start),
602 None => self.result.push_str(&Self::join_block(
603 &ib.original_block_as_string(),
604 &self.comment_line_separator,
609 self.result.push_str(&self.closer);
610 if self.result.ends_with(&self.opener) && self.opener.ends_with(' ') {
623 has_leading_whitespace: bool,
625 let is_last = i == count_newlines(orig);
627 if let Some(ref mut ib) = self.item_block {
628 if ib.add_line(&line) {
631 self.is_prev_line_multi_line = false;
632 self.fmt.shape = Shape::legacy(self.max_width, self.fmt_indent);
633 let item_fmt = ib.create_string_format(&self.fmt);
634 self.result.push_str(&self.comment_line_separator);
635 self.result.push_str(&ib.opener);
636 match rewrite_string(
637 &ib.trimmed_block_as_string(),
639 self.max_width.saturating_sub(ib.indent),
641 Some(s) => self.result.push_str(&Self::join_block(
643 &format!("{}{}", &self.comment_line_separator, ib.line_start),
645 None => self.result.push_str(&Self::join_block(
646 &ib.original_block_as_string(),
647 &self.comment_line_separator,
650 } else if self.code_block_attr.is_some() {
651 if line.starts_with("```") {
652 let code_block = match self.code_block_attr.as_ref().unwrap() {
653 CodeBlockAttribute::Ignore | CodeBlockAttribute::Text => {
654 trim_custom_comment_prefix(&self.code_block_buffer)
656 _ if self.code_block_buffer.is_empty() => String::new(),
658 let mut config = self.fmt.config.clone();
659 config.set().wrap_comments(false);
660 match ::format_code_block(&self.code_block_buffer, &config) {
661 Some(ref s) => trim_custom_comment_prefix(&s.snippet),
662 None => trim_custom_comment_prefix(&self.code_block_buffer),
666 if !code_block.is_empty() {
667 self.result.push_str(&self.comment_line_separator);
669 .push_str(&Self::join_block(&code_block, &self.comment_line_separator));
671 self.code_block_buffer.clear();
672 self.result.push_str(&self.comment_line_separator);
673 self.result.push_str(line);
674 self.code_block_attr = None;
676 self.code_block_buffer
677 .push_str(&hide_sharp_behind_comment(line));
678 self.code_block_buffer.push('\n');
683 self.code_block_attr = None;
684 self.item_block = None;
685 if line.starts_with("```") {
686 self.code_block_attr = Some(CodeBlockAttribute::new(&line[3..]))
687 } else if self.fmt.config.wrap_comments() && ItemizedBlock::is_itemized_line(&line) {
688 let ib = ItemizedBlock::new(&line);
689 self.item_block = Some(ib);
693 if self.result == self.opener {
694 let force_leading_whitespace = &self.opener == "/* " && count_newlines(orig) == 0;
695 if !has_leading_whitespace && !force_leading_whitespace && self.result.ends_with(' ') {
701 } else if self.is_prev_line_multi_line && !line.is_empty() {
702 self.result.push(' ')
703 } else if is_last && line.is_empty() {
704 // trailing blank lines are unwanted
705 if !self.closer.is_empty() {
706 self.result.push_str(&self.indent_str);
710 self.result.push_str(&self.comment_line_separator);
711 if !has_leading_whitespace && self.result.ends_with(' ') {
716 if self.fmt.config.wrap_comments()
717 && unicode_str_width(line) > self.fmt.shape.width
720 match rewrite_string(line, &self.fmt, self.max_width) {
722 self.is_prev_line_multi_line = s.contains('\n');
723 self.result.push_str(s);
725 None if self.is_prev_line_multi_line => {
726 // We failed to put the current `line` next to the previous `line`.
727 // Remove the trailing space, then start rewrite on the next line.
729 self.result.push_str(&self.comment_line_separator);
730 self.fmt.shape = Shape::legacy(self.max_width, self.fmt_indent);
731 match rewrite_string(line, &self.fmt, self.max_width) {
733 self.is_prev_line_multi_line = s.contains('\n');
734 self.result.push_str(s);
737 self.is_prev_line_multi_line = false;
738 self.result.push_str(line);
743 self.is_prev_line_multi_line = false;
744 self.result.push_str(line);
748 self.fmt.shape = if self.is_prev_line_multi_line {
750 let offset = 1 + last_line_width(&self.result) - self.line_start.len();
752 width: self.max_width.saturating_sub(offset),
753 indent: self.fmt_indent,
754 offset: self.fmt.shape.offset + offset,
757 Shape::legacy(self.max_width, self.fmt_indent)
760 if line.is_empty() && self.result.ends_with(' ') && !is_last {
761 // Remove space if this is an empty comment or a doc comment.
764 self.result.push_str(line);
765 self.fmt.shape = Shape::legacy(self.max_width, self.fmt_indent);
766 self.is_prev_line_multi_line = false;
773 fn rewrite_comment_inner(
779 is_doc_comment: bool,
780 ) -> Option<String> {
781 let mut rewriter = CommentRewrite::new(orig, block_style, shape, config);
783 let line_breaks = count_newlines(orig.trim_end());
787 .map(|(i, mut line)| {
788 line = trim_end_unless_two_whitespaces(line.trim_start(), is_doc_comment);
790 if i == line_breaks && line.ends_with("*/") && !line.starts_with("//") {
791 line = line[..(line.len() - 2)].trim_end();
796 .map(|s| left_trim_comment_line(s, &style))
797 .map(|(line, has_leading_whitespace)| {
798 if orig.starts_with("/*") && line_breaks == 0 {
801 has_leading_whitespace || config.normalize_comments(),
804 (line, has_leading_whitespace || config.normalize_comments())
808 for (i, (line, has_leading_whitespace)) in lines.enumerate() {
809 if rewriter.handle_line(orig, i, line, has_leading_whitespace) {
814 Some(rewriter.finish())
817 const RUSTFMT_CUSTOM_COMMENT_PREFIX: &str = "//#### ";
819 fn hide_sharp_behind_comment(s: &str) -> Cow<str> {
820 if s.trim_start().starts_with("# ") {
821 Cow::from(format!("{}{}", RUSTFMT_CUSTOM_COMMENT_PREFIX, s))
827 fn trim_custom_comment_prefix(s: &str) -> String {
830 let left_trimmed = line.trim_start();
831 if left_trimmed.starts_with(RUSTFMT_CUSTOM_COMMENT_PREFIX) {
832 left_trimmed.trim_start_matches(RUSTFMT_CUSTOM_COMMENT_PREFIX)
841 /// Returns true if the given string MAY include URLs or alike.
842 fn has_url(s: &str) -> bool {
843 // This function may return false positive, but should get its job done in most cases.
844 s.contains("https://") || s.contains("http://") || s.contains("ftp://") || s.contains("file://")
847 /// Given the span, rewrite the missing comment inside it if available.
848 /// Note that the given span must only include comments (or leading/trailing whitespaces).
849 pub fn rewrite_missing_comment(
852 context: &RewriteContext,
853 ) -> Option<String> {
854 let missing_snippet = context.snippet(span);
855 let trimmed_snippet = missing_snippet.trim();
856 if !trimmed_snippet.is_empty() {
857 rewrite_comment(trimmed_snippet, false, shape, context.config)
863 /// Recover the missing comments in the specified span, if available.
864 /// The layout of the comments will be preserved as long as it does not break the code
865 /// and its total width does not exceed the max width.
866 pub fn recover_missing_comment_in_span(
869 context: &RewriteContext,
871 ) -> Option<String> {
872 let missing_comment = rewrite_missing_comment(span, shape, context)?;
873 if missing_comment.is_empty() {
876 let missing_snippet = context.snippet(span);
877 let pos = missing_snippet.find('/').unwrap_or(0);
879 let total_width = missing_comment.len() + used_width + 1;
880 let force_new_line_before_comment =
881 missing_snippet[..pos].contains('\n') || total_width > context.config.max_width();
882 let sep = if force_new_line_before_comment {
883 shape.indent.to_string_with_newline(context.config)
887 Some(format!("{}{}", sep, missing_comment))
891 /// Trim trailing whitespaces unless they consist of two or more whitespaces.
892 fn trim_end_unless_two_whitespaces(s: &str, is_doc_comment: bool) -> &str {
893 if is_doc_comment && s.ends_with(" ") {
900 /// Trims whitespace and aligns to indent, but otherwise does not change comments.
901 fn light_rewrite_comment(
905 is_doc_comment: bool,
907 let lines: Vec<&str> = orig
910 // This is basically just l.trim(), but in the case that a line starts
911 // with `*` we want to leave one space before it, so it aligns with the
913 let first_non_whitespace = l.find(|c| !char::is_whitespace(c));
914 let left_trimmed = if let Some(fnw) = first_non_whitespace {
915 if l.as_bytes()[fnw] == b'*' && fnw > 0 {
923 // Preserve markdown's double-space line break syntax in doc comment.
924 trim_end_unless_two_whitespaces(left_trimmed, is_doc_comment)
927 lines.join(&format!("\n{}", offset.to_string(config)))
930 /// Trims comment characters and possibly a single space from the left of a string.
931 /// Does not trim all whitespace. If a single space is trimmed from the left of the string,
932 /// this function returns true.
933 fn left_trim_comment_line<'a>(line: &'a str, style: &CommentStyle) -> (&'a str, bool) {
934 if line.starts_with("//! ")
935 || line.starts_with("/// ")
936 || line.starts_with("/*! ")
937 || line.starts_with("/** ")
940 } else if let CommentStyle::Custom(opener) = *style {
941 if line.starts_with(opener) {
942 (&line[opener.len()..], true)
944 (&line[opener.trim_end().len()..], false)
946 } else if line.starts_with("/* ")
947 || line.starts_with("// ")
948 || line.starts_with("//!")
949 || line.starts_with("///")
950 || line.starts_with("** ")
951 || line.starts_with("/*!")
952 || (line.starts_with("/**") && !line.starts_with("/**/"))
954 (&line[3..], line.chars().nth(2).unwrap() == ' ')
955 } else if line.starts_with("/*")
956 || line.starts_with("* ")
957 || line.starts_with("//")
958 || line.starts_with("**")
960 (&line[2..], line.chars().nth(1).unwrap() == ' ')
961 } else if line.starts_with('*') {
964 (line, line.starts_with(' '))
968 pub trait FindUncommented {
969 fn find_uncommented(&self, pat: &str) -> Option<usize>;
972 impl FindUncommented for str {
973 fn find_uncommented(&self, pat: &str) -> Option<usize> {
974 let mut needle_iter = pat.chars();
975 for (kind, (i, b)) in CharClasses::new(self.char_indices()) {
976 match needle_iter.next() {
978 return Some(i - pat.len());
980 Some(c) => match kind {
981 FullCodeCharKind::Normal | FullCodeCharKind::InString if b == c => {}
983 needle_iter = pat.chars();
989 // Handle case where the pattern is a suffix of the search string
990 match needle_iter.next() {
992 None => Some(self.len() - pat.len()),
997 // Returns the first byte position after the first comment. The given string
998 // is expected to be prefixed by a comment, including delimiters.
999 // Good: "/* /* inner */ outer */ code();"
1000 // Bad: "code(); // hello\n world!"
1001 pub fn find_comment_end(s: &str) -> Option<usize> {
1002 let mut iter = CharClasses::new(s.char_indices());
1003 for (kind, (i, _c)) in &mut iter {
1004 if kind == FullCodeCharKind::Normal || kind == FullCodeCharKind::InString {
1009 // Handle case where the comment ends at the end of s.
1010 if iter.status == CharClassesStatus::Normal {
1017 /// Returns true if text contains any comment.
1018 pub fn contains_comment(text: &str) -> bool {
1019 CharClasses::new(text.chars()).any(|(kind, _)| kind.is_comment())
1022 pub struct CharClasses<T>
1028 status: CharClassesStatus,
1031 pub trait RichChar {
1032 fn get_char(&self) -> char;
1035 impl RichChar for char {
1036 fn get_char(&self) -> char {
1041 impl RichChar for (usize, char) {
1042 fn get_char(&self) -> char {
1047 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
1048 enum CharClassesStatus {
1053 RawStringPrefix(u32),
1054 RawStringSuffix(u32),
1057 // The u32 is the nesting deepness of the comment
1059 // Status when the '/' has been consumed, but not yet the '*', deepness is
1060 // the new deepness (after the comment opening).
1061 BlockCommentOpening(u32),
1062 // Status when the '*' has been consumed, but not yet the '/', deepness is
1063 // the new deepness (after the comment closing).
1064 BlockCommentClosing(u32),
1068 /// Distinguish between functional part of code and comments
1069 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
1070 pub enum CodeCharKind {
1075 /// Distinguish between functional part of code and comments,
1076 /// describing opening and closing of comments for ease when chunking
1077 /// code from tagged characters
1078 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
1079 pub enum FullCodeCharKind {
1081 /// The first character of a comment, there is only one for a comment (always '/')
1083 /// Any character inside a comment including the second character of comment
1084 /// marks ("//", "/*")
1086 /// Last character of a comment, '\n' for a line comment, '/' for a block comment.
1088 /// Start of a mutlitine string
1090 /// End of a mutlitine string
1092 /// Inside a string.
1096 impl FullCodeCharKind {
1097 pub fn is_comment(self) -> bool {
1099 FullCodeCharKind::StartComment
1100 | FullCodeCharKind::InComment
1101 | FullCodeCharKind::EndComment => true,
1106 pub fn is_string(self) -> bool {
1107 self == FullCodeCharKind::InString || self == FullCodeCharKind::StartString
1110 fn to_codecharkind(self) -> CodeCharKind {
1111 if self.is_comment() {
1112 CodeCharKind::Comment
1114 CodeCharKind::Normal
1119 impl<T> CharClasses<T>
1124 pub fn new(base: T) -> CharClasses<T> {
1126 base: multipeek(base),
1127 status: CharClassesStatus::Normal,
1132 fn is_raw_string_suffix<T>(iter: &mut MultiPeek<T>, count: u32) -> bool
1139 Some(c) if c.get_char() == '#' => continue,
1146 impl<T> Iterator for CharClasses<T>
1151 type Item = (FullCodeCharKind, T::Item);
1153 fn next(&mut self) -> Option<(FullCodeCharKind, T::Item)> {
1154 let item = self.base.next()?;
1155 let chr = item.get_char();
1156 let mut char_kind = FullCodeCharKind::Normal;
1157 self.status = match self.status {
1158 CharClassesStatus::LitRawString(sharps) => {
1159 char_kind = FullCodeCharKind::InString;
1163 char_kind = FullCodeCharKind::Normal;
1164 CharClassesStatus::Normal
1165 } else if is_raw_string_suffix(&mut self.base, sharps) {
1166 CharClassesStatus::RawStringSuffix(sharps)
1168 CharClassesStatus::LitRawString(sharps)
1171 _ => CharClassesStatus::LitRawString(sharps),
1174 CharClassesStatus::RawStringPrefix(sharps) => {
1175 char_kind = FullCodeCharKind::InString;
1177 '#' => CharClassesStatus::RawStringPrefix(sharps + 1),
1178 '"' => CharClassesStatus::LitRawString(sharps),
1179 _ => CharClassesStatus::Normal, // Unreachable.
1182 CharClassesStatus::RawStringSuffix(sharps) => {
1186 CharClassesStatus::Normal
1188 char_kind = FullCodeCharKind::InString;
1189 CharClassesStatus::RawStringSuffix(sharps - 1)
1192 _ => CharClassesStatus::Normal, // Unreachable
1195 CharClassesStatus::LitString => {
1196 char_kind = FullCodeCharKind::InString;
1198 '"' => CharClassesStatus::Normal,
1199 '\\' => CharClassesStatus::LitStringEscape,
1200 _ => CharClassesStatus::LitString,
1203 CharClassesStatus::LitStringEscape => {
1204 char_kind = FullCodeCharKind::InString;
1205 CharClassesStatus::LitString
1207 CharClassesStatus::LitChar => match chr {
1208 '\\' => CharClassesStatus::LitCharEscape,
1209 '\'' => CharClassesStatus::Normal,
1210 _ => CharClassesStatus::LitChar,
1212 CharClassesStatus::LitCharEscape => CharClassesStatus::LitChar,
1213 CharClassesStatus::Normal => match chr {
1214 'r' => match self.base.peek().map(|c| c.get_char()) {
1215 Some('#') | Some('"') => {
1216 char_kind = FullCodeCharKind::InString;
1217 CharClassesStatus::RawStringPrefix(0)
1219 _ => CharClassesStatus::Normal,
1222 char_kind = FullCodeCharKind::InString;
1223 CharClassesStatus::LitString
1226 // HACK: Work around mut borrow.
1227 match self.base.peek() {
1228 Some(next) if next.get_char() == '\\' => {
1229 self.status = CharClassesStatus::LitChar;
1230 return Some((char_kind, item));
1235 match self.base.peek() {
1236 Some(next) if next.get_char() == '\'' => CharClassesStatus::LitChar,
1237 _ => CharClassesStatus::Normal,
1240 '/' => match self.base.peek() {
1241 Some(next) if next.get_char() == '*' => {
1242 self.status = CharClassesStatus::BlockCommentOpening(1);
1243 return Some((FullCodeCharKind::StartComment, item));
1245 Some(next) if next.get_char() == '/' => {
1246 self.status = CharClassesStatus::LineComment;
1247 return Some((FullCodeCharKind::StartComment, item));
1249 _ => CharClassesStatus::Normal,
1251 _ => CharClassesStatus::Normal,
1253 CharClassesStatus::BlockComment(deepness) => {
1254 assert_ne!(deepness, 0);
1255 self.status = match self.base.peek() {
1256 Some(next) if next.get_char() == '/' && chr == '*' => {
1257 CharClassesStatus::BlockCommentClosing(deepness - 1)
1259 Some(next) if next.get_char() == '*' && chr == '/' => {
1260 CharClassesStatus::BlockCommentOpening(deepness + 1)
1262 _ => CharClassesStatus::BlockComment(deepness),
1264 return Some((FullCodeCharKind::InComment, item));
1266 CharClassesStatus::BlockCommentOpening(deepness) => {
1267 assert_eq!(chr, '*');
1268 self.status = CharClassesStatus::BlockComment(deepness);
1269 return Some((FullCodeCharKind::InComment, item));
1271 CharClassesStatus::BlockCommentClosing(deepness) => {
1272 assert_eq!(chr, '/');
1274 self.status = CharClassesStatus::Normal;
1275 return Some((FullCodeCharKind::EndComment, item));
1277 self.status = CharClassesStatus::BlockComment(deepness);
1278 return Some((FullCodeCharKind::InComment, item));
1281 CharClassesStatus::LineComment => match chr {
1283 self.status = CharClassesStatus::Normal;
1284 return Some((FullCodeCharKind::EndComment, item));
1287 self.status = CharClassesStatus::LineComment;
1288 return Some((FullCodeCharKind::InComment, item));
1292 Some((char_kind, item))
1296 /// An iterator over the lines of a string, paired with the char kind at the
1297 /// end of the line.
1298 pub struct LineClasses<'a> {
1299 base: iter::Peekable<CharClasses<std::str::Chars<'a>>>,
1300 kind: FullCodeCharKind,
1303 impl<'a> LineClasses<'a> {
1304 pub fn new(s: &'a str) -> Self {
1306 base: CharClasses::new(s.chars()).peekable(),
1307 kind: FullCodeCharKind::Normal,
1312 impl<'a> Iterator for LineClasses<'a> {
1313 type Item = (FullCodeCharKind, String);
1315 fn next(&mut self) -> Option<Self::Item> {
1318 let mut line = String::new();
1320 let start_class = match self.base.peek() {
1321 Some((kind, _)) => *kind,
1322 None => unreachable!(),
1325 while let Some((kind, c)) = self.base.next() {
1327 self.kind = match (start_class, kind) {
1328 (FullCodeCharKind::Normal, FullCodeCharKind::InString) => {
1329 FullCodeCharKind::StartString
1331 (FullCodeCharKind::InString, FullCodeCharKind::Normal) => {
1332 FullCodeCharKind::EndString
1342 // Workaround for CRLF newline.
1343 if line.ends_with('\r') {
1347 Some((self.kind, line))
1351 /// Iterator over functional and commented parts of a string. Any part of a string is either
1352 /// functional code, either *one* block comment, either *one* line comment. Whitespace between
1353 /// comments is functional code. Line comments contain their ending newlines.
1354 struct UngroupedCommentCodeSlices<'a> {
1356 iter: iter::Peekable<CharClasses<std::str::CharIndices<'a>>>,
1359 impl<'a> UngroupedCommentCodeSlices<'a> {
1360 fn new(code: &'a str) -> UngroupedCommentCodeSlices<'a> {
1361 UngroupedCommentCodeSlices {
1363 iter: CharClasses::new(code.char_indices()).peekable(),
1368 impl<'a> Iterator for UngroupedCommentCodeSlices<'a> {
1369 type Item = (CodeCharKind, usize, &'a str);
1371 fn next(&mut self) -> Option<Self::Item> {
1372 let (kind, (start_idx, _)) = self.iter.next()?;
1374 FullCodeCharKind::Normal | FullCodeCharKind::InString => {
1375 // Consume all the Normal code
1376 while let Some(&(char_kind, _)) = self.iter.peek() {
1377 if char_kind.is_comment() {
1380 let _ = self.iter.next();
1383 FullCodeCharKind::StartComment => {
1384 // Consume the whole comment
1385 while let Some((FullCodeCharKind::InComment, (_, _))) = self.iter.next() {}
1389 let slice = match self.iter.peek() {
1390 Some(&(_, (end_idx, _))) => &self.slice[start_idx..end_idx],
1391 None => &self.slice[start_idx..],
1394 if kind.is_comment() {
1395 CodeCharKind::Comment
1397 CodeCharKind::Normal
1405 /// Iterator over an alternating sequence of functional and commented parts of
1406 /// a string. The first item is always a, possibly zero length, subslice of
1407 /// functional text. Line style comments contain their ending newlines.
1408 pub struct CommentCodeSlices<'a> {
1410 last_slice_kind: CodeCharKind,
1411 last_slice_end: usize,
1414 impl<'a> CommentCodeSlices<'a> {
1415 pub fn new(slice: &'a str) -> CommentCodeSlices<'a> {
1418 last_slice_kind: CodeCharKind::Comment,
1424 impl<'a> Iterator for CommentCodeSlices<'a> {
1425 type Item = (CodeCharKind, usize, &'a str);
1427 fn next(&mut self) -> Option<Self::Item> {
1428 if self.last_slice_end == self.slice.len() {
1432 let mut sub_slice_end = self.last_slice_end;
1433 let mut first_whitespace = None;
1434 let subslice = &self.slice[self.last_slice_end..];
1435 let mut iter = CharClasses::new(subslice.char_indices());
1437 for (kind, (i, c)) in &mut iter {
1438 let is_comment_connector = self.last_slice_kind == CodeCharKind::Normal
1439 && &subslice[..2] == "//"
1440 && [' ', '\t'].contains(&c);
1442 if is_comment_connector && first_whitespace.is_none() {
1443 first_whitespace = Some(i);
1446 if kind.to_codecharkind() == self.last_slice_kind && !is_comment_connector {
1447 let last_index = match first_whitespace {
1451 sub_slice_end = self.last_slice_end + last_index;
1455 if !is_comment_connector {
1456 first_whitespace = None;
1460 if let (None, true) = (iter.next(), sub_slice_end == self.last_slice_end) {
1461 // This was the last subslice.
1462 sub_slice_end = match first_whitespace {
1463 Some(i) => self.last_slice_end + i,
1464 None => self.slice.len(),
1468 let kind = match self.last_slice_kind {
1469 CodeCharKind::Comment => CodeCharKind::Normal,
1470 CodeCharKind::Normal => CodeCharKind::Comment,
1474 self.last_slice_end,
1475 &self.slice[self.last_slice_end..sub_slice_end],
1477 self.last_slice_end = sub_slice_end;
1478 self.last_slice_kind = kind;
1484 /// Checks is `new` didn't miss any comment from `span`, if it removed any, return previous text
1485 /// (if it fits in the width/offset, else return None), else return `new`
1486 pub fn recover_comment_removed(
1489 context: &RewriteContext,
1490 ) -> Option<String> {
1491 let snippet = context.snippet(span);
1492 if snippet != new && changed_comment_content(snippet, &new) {
1493 // We missed some comments. Warn and keep the original text.
1494 if context.config.error_on_unformatted() {
1495 context.report.append(
1496 context.source_map.span_to_filename(span).into(),
1497 vec![FormattingError::from_span(
1499 &context.source_map,
1500 ErrorKind::LostComment,
1504 Some(snippet.to_owned())
1510 pub fn filter_normal_code(code: &str) -> String {
1511 let mut buffer = String::with_capacity(code.len());
1512 LineClasses::new(code).for_each(|(kind, line)| match kind {
1513 FullCodeCharKind::Normal
1514 | FullCodeCharKind::StartString
1515 | FullCodeCharKind::InString
1516 | FullCodeCharKind::EndString => {
1517 buffer.push_str(&line);
1522 if !code.ends_with('\n') && buffer.ends_with('\n') {
1528 /// Return true if the two strings of code have the same payload of comments.
1529 /// The payload of comments is everything in the string except:
1530 /// - actual code (not comments)
1531 /// - comment start/end marks
1533 /// - '*' at the beginning of lines in block comments
1534 fn changed_comment_content(orig: &str, new: &str) -> bool {
1535 // Cannot write this as a fn since we cannot return types containing closures
1536 let code_comment_content = |code| {
1537 let slices = UngroupedCommentCodeSlices::new(code);
1539 .filter(|&(ref kind, _, _)| *kind == CodeCharKind::Comment)
1540 .flat_map(|(_, _, s)| CommentReducer::new(s))
1542 let res = code_comment_content(orig).ne(code_comment_content(new));
1544 "comment::changed_comment_content: {}\norig: '{}'\nnew: '{}'\nraw_old: {}\nraw_new: {}",
1548 code_comment_content(orig).collect::<String>(),
1549 code_comment_content(new).collect::<String>()
1554 /// Iterator over the 'payload' characters of a comment.
1555 /// It skips whitespace, comment start/end marks, and '*' at the beginning of lines.
1556 /// The comment must be one comment, ie not more than one start mark (no multiple line comments,
1558 struct CommentReducer<'a> {
1560 at_start_line: bool,
1561 iter: std::str::Chars<'a>,
1564 impl<'a> CommentReducer<'a> {
1565 fn new(comment: &'a str) -> CommentReducer<'a> {
1566 let is_block = comment.starts_with("/*");
1567 let comment = remove_comment_header(comment);
1570 at_start_line: false, // There are no supplementary '*' on the first line
1571 iter: comment.chars(),
1576 impl<'a> Iterator for CommentReducer<'a> {
1579 fn next(&mut self) -> Option<Self::Item> {
1581 let mut c = self.iter.next()?;
1582 if self.is_block && self.at_start_line {
1583 while c.is_whitespace() {
1584 c = self.iter.next()?;
1586 // Ignore leading '*'
1588 c = self.iter.next()?;
1590 } else if c == '\n' {
1591 self.at_start_line = true;
1593 if !c.is_whitespace() {
1600 fn remove_comment_header(comment: &str) -> &str {
1601 if comment.starts_with("///") || comment.starts_with("//!") {
1603 } else if comment.starts_with("//") {
1605 } else if (comment.starts_with("/**") && !comment.starts_with("/**/"))
1606 || comment.starts_with("/*!")
1608 &comment[3..comment.len() - 2]
1611 comment.starts_with("/*"),
1612 format!("string '{}' is not a comment", comment)
1614 &comment[2..comment.len() - 2]
1621 use shape::{Indent, Shape};
1625 let mut iter = CharClasses::new("//\n\n".chars());
1627 assert_eq!((FullCodeCharKind::StartComment, '/'), iter.next().unwrap());
1628 assert_eq!((FullCodeCharKind::InComment, '/'), iter.next().unwrap());
1629 assert_eq!((FullCodeCharKind::EndComment, '\n'), iter.next().unwrap());
1630 assert_eq!((FullCodeCharKind::Normal, '\n'), iter.next().unwrap());
1631 assert_eq!(None, iter.next());
1635 fn comment_code_slices() {
1636 let input = "code(); /* test */ 1 + 1";
1637 let mut iter = CommentCodeSlices::new(input);
1639 assert_eq!((CodeCharKind::Normal, 0, "code(); "), iter.next().unwrap());
1641 (CodeCharKind::Comment, 8, "/* test */"),
1642 iter.next().unwrap()
1644 assert_eq!((CodeCharKind::Normal, 18, " 1 + 1"), iter.next().unwrap());
1645 assert_eq!(None, iter.next());
1649 fn comment_code_slices_two() {
1650 let input = "// comment\n test();";
1651 let mut iter = CommentCodeSlices::new(input);
1653 assert_eq!((CodeCharKind::Normal, 0, ""), iter.next().unwrap());
1655 (CodeCharKind::Comment, 0, "// comment\n"),
1656 iter.next().unwrap()
1659 (CodeCharKind::Normal, 11, " test();"),
1660 iter.next().unwrap()
1662 assert_eq!(None, iter.next());
1666 fn comment_code_slices_three() {
1667 let input = "1 // comment\n // comment2\n\n";
1668 let mut iter = CommentCodeSlices::new(input);
1670 assert_eq!((CodeCharKind::Normal, 0, "1 "), iter.next().unwrap());
1672 (CodeCharKind::Comment, 2, "// comment\n // comment2\n"),
1673 iter.next().unwrap()
1675 assert_eq!((CodeCharKind::Normal, 29, "\n"), iter.next().unwrap());
1676 assert_eq!(None, iter.next());
1681 fn format_doc_comments() {
1682 let mut wrap_normalize_config: ::config::Config = Default::default();
1683 wrap_normalize_config.set().wrap_comments(true);
1684 wrap_normalize_config.set().normalize_comments(true);
1686 let mut wrap_config: ::config::Config = Default::default();
1687 wrap_config.set().wrap_comments(true);
1689 let comment = rewrite_comment(" //test",
1691 Shape::legacy(100, Indent::new(0, 100)),
1692 &wrap_normalize_config).unwrap();
1693 assert_eq!("/* test */", comment);
1695 let comment = rewrite_comment("// comment on a",
1697 Shape::legacy(10, Indent::empty()),
1698 &wrap_normalize_config).unwrap();
1699 assert_eq!("// comment\n// on a", comment);
1701 let comment = rewrite_comment("// A multi line comment\n // between args.",
1703 Shape::legacy(60, Indent::new(0, 12)),
1704 &wrap_normalize_config).unwrap();
1705 assert_eq!("// A multi line comment\n // between args.", comment);
1707 let input = "// comment";
1710 let comment = rewrite_comment(input,
1712 Shape::legacy(9, Indent::new(0, 69)),
1713 &wrap_normalize_config).unwrap();
1714 assert_eq!(expected, comment);
1716 let comment = rewrite_comment("/* trimmed */",
1718 Shape::legacy(100, Indent::new(0, 100)),
1719 &wrap_normalize_config).unwrap();
1720 assert_eq!("/* trimmed */", comment);
1722 // check that different comment style are properly recognised
1723 let comment = rewrite_comment(r#"/// test1
1729 Shape::legacy(100, Indent::new(0, 0)),
1730 &wrap_normalize_config).unwrap();
1731 assert_eq!("/// test1\n/// test2\n// test3", comment);
1733 // check that the blank line marks the end of a commented paragraph
1734 let comment = rewrite_comment(r#"// test1
1738 Shape::legacy(100, Indent::new(0, 0)),
1739 &wrap_normalize_config).unwrap();
1740 assert_eq!("// test1\n\n// test2", comment);
1742 // check that the blank line marks the end of a custom-commented paragraph
1743 let comment = rewrite_comment(r#"//@ test1
1747 Shape::legacy(100, Indent::new(0, 0)),
1748 &wrap_normalize_config).unwrap();
1749 assert_eq!("//@ test1\n\n//@ test2", comment);
1751 // check that bare lines are just indented but left unchanged otherwise
1752 let comment = rewrite_comment(r#"// test1
1759 Shape::legacy(100, Indent::new(0, 0)),
1760 &wrap_config).unwrap();
1761 assert_eq!("// test1\n/*\n a bare line!\n\n another bare line!\n*/", comment);
1764 // This is probably intended to be a non-test fn, but it is not used. I'm
1765 // keeping it around unless it helps us test stuff.
1766 fn uncommented(text: &str) -> String {
1767 CharClasses::new(text.chars())
1768 .filter_map(|(s, c)| match s {
1769 FullCodeCharKind::Normal | FullCodeCharKind::InString => Some(c),
1776 fn test_uncommented() {
1777 assert_eq!(&uncommented("abc/*...*/"), "abc");
1779 &uncommented("// .... /* \n../* /* *** / */ */a/* // */c\n"),
1782 assert_eq!(&uncommented("abc \" /* */\" qsdf"), "abc \" /* */\" qsdf");
1786 fn test_contains_comment() {
1787 assert_eq!(contains_comment("abc"), false);
1788 assert_eq!(contains_comment("abc // qsdf"), true);
1789 assert_eq!(contains_comment("abc /* kqsdf"), true);
1790 assert_eq!(contains_comment("abc \" /* */\" qsdf"), false);
1794 fn test_find_uncommented() {
1795 fn check(haystack: &str, needle: &str, expected: Option<usize>) {
1796 assert_eq!(expected, haystack.find_uncommented(needle));
1799 check("/*/ */test", "test", Some(6));
1800 check("//test\ntest", "test", Some(7));
1801 check("/* comment only */", "whatever", None);
1803 "/* comment */ some text /* more commentary */ result",
1807 check("sup // sup", "p", Some(2));
1808 check("sup", "x", None);
1809 check(r#"π? /**/ π is nice!"#, r#"π is nice"#, Some(9));
1810 check("/*sup yo? \n sup*/ sup", "p", Some(20));
1811 check("hel/*lohello*/lo", "hello", None);
1812 check("acb", "ab", None);
1813 check(",/*A*/ ", ",", Some(0));
1814 check("abc", "abc", Some(0));
1815 check("/* abc */", "abc", None);
1816 check("/**/abc/* */", "abc", Some(4));
1817 check("\"/* abc */\"", "abc", Some(4));
1818 check("\"/* abc", "abc", Some(4));
1822 fn test_filter_normal_code() {
1825 println!("hello, world");
1828 assert_eq!(s, filter_normal_code(s));
1829 let s_with_comment = r#"
1832 println!("hello, world");
1835 assert_eq!(s, filter_normal_code(s_with_comment));