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};
22 use utils::{count_newlines, first_line_width, last_line_width};
23 use {ErrorKind, FormattingError};
25 fn is_custom_comment(comment: &str) -> bool {
26 if !comment.starts_with("//") {
28 } else if let Some(c) = comment.chars().nth(2) {
29 !c.is_alphanumeric() && !c.is_whitespace()
35 #[derive(Copy, Clone, PartialEq, Eq)]
36 pub enum CommentStyle<'a> {
46 fn custom_opener(s: &str) -> &str {
47 s.lines().next().map_or("", |first_line| {
50 .map_or(first_line, |space_index| &first_line[0..=space_index])
54 impl<'a> CommentStyle<'a> {
55 /// Returns true if the commenting style covers a line only.
56 pub fn is_line_comment(&self) -> bool {
58 CommentStyle::DoubleSlash
59 | CommentStyle::TripleSlash
61 | CommentStyle::Custom(_) => true,
66 /// Returns true if the commenting style can span over multiple lines.
67 pub fn is_block_comment(&self) -> bool {
69 CommentStyle::SingleBullet | CommentStyle::DoubleBullet | CommentStyle::Exclamation => {
76 /// Returns true if the commenting style is for documentation.
77 pub fn is_doc_comment(&self) -> bool {
79 CommentStyle::TripleSlash | CommentStyle::Doc => true,
84 pub fn opener(&self) -> &'a str {
86 CommentStyle::DoubleSlash => "// ",
87 CommentStyle::TripleSlash => "/// ",
88 CommentStyle::Doc => "//! ",
89 CommentStyle::SingleBullet => "/* ",
90 CommentStyle::DoubleBullet => "/** ",
91 CommentStyle::Exclamation => "/*! ",
92 CommentStyle::Custom(opener) => opener,
96 pub fn closer(&self) -> &'a str {
98 CommentStyle::DoubleSlash
99 | CommentStyle::TripleSlash
100 | CommentStyle::Custom(..)
101 | CommentStyle::Doc => "",
102 CommentStyle::DoubleBullet => " **/",
103 CommentStyle::SingleBullet | CommentStyle::Exclamation => " */",
107 pub fn line_start(&self) -> &'a str {
109 CommentStyle::DoubleSlash => "// ",
110 CommentStyle::TripleSlash => "/// ",
111 CommentStyle::Doc => "//! ",
112 CommentStyle::SingleBullet | CommentStyle::Exclamation => " * ",
113 CommentStyle::DoubleBullet => " ** ",
114 CommentStyle::Custom(opener) => opener,
118 pub fn to_str_tuplet(&self) -> (&'a str, &'a str, &'a str) {
119 (self.opener(), self.closer(), self.line_start())
123 fn comment_style(orig: &str, normalize_comments: bool) -> CommentStyle {
124 if !normalize_comments {
125 if orig.starts_with("/**") && !orig.starts_with("/**/") {
126 CommentStyle::DoubleBullet
127 } else if orig.starts_with("/*!") {
128 CommentStyle::Exclamation
129 } else if orig.starts_with("/*") {
130 CommentStyle::SingleBullet
131 } else if orig.starts_with("///") && orig.chars().nth(3).map_or(true, |c| c != '/') {
132 CommentStyle::TripleSlash
133 } else if orig.starts_with("//!") {
135 } else if is_custom_comment(orig) {
136 CommentStyle::Custom(custom_opener(orig))
138 CommentStyle::DoubleSlash
140 } else if (orig.starts_with("///") && orig.chars().nth(3).map_or(true, |c| c != '/'))
141 || (orig.starts_with("/**") && !orig.starts_with("/**/"))
143 CommentStyle::TripleSlash
144 } else if orig.starts_with("//!") || orig.starts_with("/*!") {
146 } else if is_custom_comment(orig) {
147 CommentStyle::Custom(custom_opener(orig))
149 CommentStyle::DoubleSlash
153 /// Combine `prev_str` and `next_str` into a single `String`. `span` may contain
154 /// comments between two strings. If there are such comments, then that will be
155 /// recovered. If `allow_extend` is true and there is no comment between the two
156 /// strings, then they will be put on a single line as long as doing so does not
157 /// exceed max width.
158 pub fn combine_strs_with_missing_comments(
159 context: &RewriteContext,
165 ) -> Option<String> {
167 String::with_capacity(prev_str.len() + next_str.len() + shape.indent.width() + 128);
168 result.push_str(prev_str);
169 let mut allow_one_line = !prev_str.contains('\n') && !next_str.contains('\n');
170 let first_sep = if prev_str.is_empty() || next_str.is_empty() {
175 let mut one_line_width =
176 last_line_width(prev_str) + first_line_width(next_str) + first_sep.len();
178 let config = context.config;
179 let indent = shape.indent;
180 let missing_comment = rewrite_missing_comment(span, shape, context)?;
182 if missing_comment.is_empty() {
183 if allow_extend && prev_str.len() + first_sep.len() + next_str.len() <= shape.width {
184 result.push_str(first_sep);
185 } else if !prev_str.is_empty() {
186 result.push_str(&indent.to_string_with_newline(config))
188 result.push_str(next_str);
192 // We have a missing comment between the first expression and the second expression.
194 // Peek the the original source code and find out whether there is a newline between the first
195 // expression and the second expression or the missing comment. We will preserve the original
196 // layout whenever possible.
197 let original_snippet = context.snippet(span);
198 let prefer_same_line = if let Some(pos) = original_snippet.find('/') {
199 !original_snippet[..pos].contains('\n')
201 !original_snippet.contains('\n')
204 one_line_width -= first_sep.len();
205 let first_sep = if prev_str.is_empty() || missing_comment.is_empty() {
208 let one_line_width = last_line_width(prev_str) + first_line_width(&missing_comment) + 1;
209 if prefer_same_line && one_line_width <= shape.width {
212 indent.to_string_with_newline(config)
215 result.push_str(&first_sep);
216 result.push_str(&missing_comment);
218 let second_sep = if missing_comment.is_empty() || next_str.is_empty() {
220 } else if missing_comment.starts_with("//") {
221 indent.to_string_with_newline(config)
223 one_line_width += missing_comment.len() + first_sep.len() + 1;
224 allow_one_line &= !missing_comment.starts_with("//") && !missing_comment.contains('\n');
225 if prefer_same_line && allow_one_line && one_line_width <= shape.width {
228 indent.to_string_with_newline(config)
231 result.push_str(&second_sep);
232 result.push_str(next_str);
237 pub fn rewrite_doc_comment(orig: &str, shape: Shape, config: &Config) -> Option<String> {
238 identify_comment(orig, false, shape, config, true)
241 pub fn rewrite_comment(
246 ) -> Option<String> {
247 identify_comment(orig, block_style, shape, config, false)
255 is_doc_comment: bool,
256 ) -> Option<String> {
257 let style = comment_style(orig, false);
259 // Computes the len of line taking into account a newline if the line is part of a paragraph.
260 fn compute_len(orig: &str, line: &str) -> usize {
261 if orig.len() > line.len() {
262 if orig.as_bytes()[line.len()] == b'\r' {
272 // Get the first group of line comments having the same commenting style.
274 // Returns a tuple with:
275 // - a boolean indicating if there is a blank line
276 // - a number indicating the size of the first group of comments
277 fn consume_same_line_comments(
282 let mut first_group_ending = 0;
285 for line in orig.lines() {
286 let trimmed_line = line.trim_left();
287 if trimmed_line.is_empty() {
290 } else if trimmed_line.starts_with(line_start)
291 || comment_style(trimmed_line, false) == style
293 first_group_ending += compute_len(&orig[first_group_ending..], line);
298 (hbl, first_group_ending)
301 let (has_bare_lines, first_group_ending) = match style {
302 CommentStyle::DoubleSlash | CommentStyle::TripleSlash | CommentStyle::Doc => {
303 let line_start = style.line_start().trim_left();
304 consume_same_line_comments(style, orig, line_start)
306 CommentStyle::Custom(opener) => {
307 let trimmed_opener = opener.trim_right();
308 consume_same_line_comments(style, orig, trimmed_opener)
310 // for a block comment, search for the closing symbol
311 CommentStyle::DoubleBullet | CommentStyle::SingleBullet | CommentStyle::Exclamation => {
312 let closer = style.closer().trim_left();
313 let mut closing_symbol_offset = 0;
315 for line in orig.lines() {
316 closing_symbol_offset += compute_len(&orig[closing_symbol_offset..], line);
317 let trimmed_line = line.trim_left();
318 if !trimmed_line.starts_with('*')
319 && !trimmed_line.starts_with("//")
320 && !trimmed_line.starts_with("/*")
324 if trimmed_line.ends_with(closer) {
328 (hbl, closing_symbol_offset)
332 let (first_group, rest) = orig.split_at(first_group_ending);
333 let rewritten_first_group =
334 if !config.normalize_comments() && has_bare_lines && style.is_block_comment() {
335 light_rewrite_block_comment_with_bare_lines(first_group, shape, config)?
336 } else if !config.normalize_comments()
337 && !config.wrap_comments()
338 && !config.format_doc_comments()
340 light_rewrite_comment(first_group, shape.indent, config, is_doc_comment)?
342 rewrite_comment_inner(
348 is_doc_comment || style.is_doc_comment(),
352 Some(rewritten_first_group)
354 identify_comment(rest.trim_left(), block_style, shape, config, is_doc_comment).map(
358 rewritten_first_group,
359 // insert back the blank line
360 if has_bare_lines && style.is_line_comment() {
365 shape.indent.to_string(config),
373 /// Trims a minimum of leading whitespaces so that the content layout is kept and aligns to indent.
374 fn light_rewrite_block_comment_with_bare_lines(
378 ) -> Option<String> {
379 let prefix_whitespace_min = orig
381 // skip the line with the starting sigil since the leading whitespace is removed
382 // otherwise, the minimum would always be zero
384 .filter(|line| !line.is_empty())
387 for c in line.chars() {
390 '\t' => width += config.tab_spaces(),
398 let indent_str = shape.indent.to_string(config);
399 let mut lines = orig.lines();
400 let first_line = lines.next()?;
406 &line[prefix_whitespace_min..]
409 .collect::<Vec<&str>>()
410 .join(&format!("\n{}", indent_str));
411 Some(format!("{}\n{}{}", first_line, indent_str, rest))
414 /// Attributes for code blocks in rustdoc.
415 /// See https://doc.rust-lang.org/rustdoc/print.html#attributes
416 enum CodeBlockAttribute {
425 impl CodeBlockAttribute {
426 fn new(attribute: &str) -> CodeBlockAttribute {
428 "rust" | "" => CodeBlockAttribute::Rust,
429 "ignore" => CodeBlockAttribute::Ignore,
430 "text" => CodeBlockAttribute::Text,
431 "should_panic" => CodeBlockAttribute::ShouldPanic,
432 "no_run" => CodeBlockAttribute::NoRun,
433 "compile_fail" => CodeBlockAttribute::CompileFail,
434 _ => CodeBlockAttribute::Text,
439 /// Block that is formatted as an item.
441 /// An item starts with either a star `*` or a dash `-`. Different level of indentation are
443 struct ItemizedBlock {
444 /// the number of whitespaces up to the item sigil
446 /// the string that marks the start of an item
448 /// sequence of whitespaces to prefix new lines that are part of the item
453 /// Returns true if the line is formatted as an item
454 fn is_itemized_line(line: &str) -> bool {
455 let trimmed = line.trim_left();
456 trimmed.starts_with("* ") || trimmed.starts_with("- ")
459 /// Creates a new ItemizedBlock described with the given line.
460 /// The `is_itemized_line` needs to be called first.
461 fn new(line: &str) -> ItemizedBlock {
462 let space_to_sigil = line.chars().take_while(|c| c.is_whitespace()).count();
463 let indent = space_to_sigil + 2;
466 opener: line[..indent].to_string(),
467 line_start: " ".repeat(indent),
471 /// Returns a `StringFormat` used for formatting the content of an item
472 fn create_string_format<'a>(&'a self, fmt: &'a StringFormat) -> StringFormat<'a> {
478 shape: Shape::legacy(fmt.shape.width.saturating_sub(self.indent), Indent::empty()),
484 /// Returns true if the line is part of the current itemized block
485 fn in_block(&self, line: &str) -> bool {
486 !ItemizedBlock::is_itemized_line(line)
487 && self.indent <= line.chars().take_while(|c| c.is_whitespace()).count()
491 fn rewrite_comment_inner(
497 is_doc_comment: bool,
498 ) -> Option<String> {
499 let (opener, closer, line_start) = if block_style {
500 CommentStyle::SingleBullet.to_str_tuplet()
502 comment_style(orig, config.normalize_comments()).to_str_tuplet()
505 let max_chars = shape
507 .checked_sub(closer.len() + opener.len())
509 let indent_str = shape.indent.to_string_with_newline(config);
510 let fmt_indent = shape.indent + (opener.len() - line_start.len());
511 let mut fmt = StringFormat {
516 shape: Shape::legacy(max_chars, fmt_indent),
521 let line_breaks = count_newlines(orig.trim_right());
525 .map(|(i, mut line)| {
526 line = trim_right_unless_two_whitespaces(line.trim_left(), is_doc_comment);
528 if i == line_breaks && line.ends_with("*/") && !line.starts_with("//") {
529 line = line[..(line.len() - 2)].trim_right();
534 .map(|s| left_trim_comment_line(s, &style))
535 .map(|(line, has_leading_whitespace)| {
536 if orig.starts_with("/*") && line_breaks == 0 {
539 has_leading_whitespace || config.normalize_comments(),
542 (line, has_leading_whitespace || config.normalize_comments())
546 let mut result = String::with_capacity(orig.len() * 2);
547 result.push_str(opener);
548 let mut code_block_buffer = String::with_capacity(128);
549 let mut is_prev_line_multi_line = false;
550 let mut code_block_attr = None;
551 let mut item_block_buffer = String::with_capacity(128);
552 let mut item_block: Option<ItemizedBlock> = None;
553 let comment_line_separator = format!("{}{}", indent_str, line_start);
554 let join_block = |s: &str, sep: &str| {
555 let mut result = String::with_capacity(s.len() + 128);
556 let mut iter = s.lines().peekable();
557 while let Some(line) = iter.next() {
558 result.push_str(line);
559 result.push_str(match iter.peek() {
560 Some(next_line) if next_line.is_empty() => sep.trim_right(),
568 for (i, (line, has_leading_whitespace)) in lines.enumerate() {
569 let is_last = i == count_newlines(orig);
571 if let Some(ref ib) = item_block {
572 if ib.in_block(&line) {
573 item_block_buffer.push_str(&line);
574 item_block_buffer.push('\n');
577 is_prev_line_multi_line = false;
578 fmt.shape = Shape::legacy(max_chars, fmt_indent);
579 let item_fmt = ib.create_string_format(&fmt);
580 result.push_str(&comment_line_separator);
581 result.push_str(&ib.opener);
582 match rewrite_string(&item_block_buffer.replace("\n", " "), &item_fmt) {
583 Some(s) => result.push_str(&join_block(
585 &format!("{}{}", &comment_line_separator, ib.line_start),
587 None => result.push_str(&join_block(&item_block_buffer, &comment_line_separator)),
589 item_block_buffer.clear();
590 } else if let Some(ref attr) = code_block_attr {
591 if line.starts_with("```") {
592 let code_block = match attr {
593 CodeBlockAttribute::Ignore | CodeBlockAttribute::Text => {
594 trim_custom_comment_prefix(&code_block_buffer)
596 _ if code_block_buffer.is_empty() => String::new(),
598 let mut config = config.clone();
599 config.set().format_doc_comments(false);
600 match ::format_code_block(&code_block_buffer, &config) {
601 Some(ref s) => trim_custom_comment_prefix(s),
602 None => trim_custom_comment_prefix(&code_block_buffer),
606 if !code_block.is_empty() {
607 result.push_str(&comment_line_separator);
608 result.push_str(&join_block(&code_block, &comment_line_separator));
610 code_block_buffer.clear();
611 result.push_str(&comment_line_separator);
612 result.push_str(line);
613 code_block_attr = None;
615 code_block_buffer.push_str(&hide_sharp_behind_comment(line));
616 code_block_buffer.push('\n');
621 code_block_attr = None;
623 if line.starts_with("```") {
624 code_block_attr = Some(CodeBlockAttribute::new(&line[3..]))
625 } else if config.wrap_comments() && ItemizedBlock::is_itemized_line(&line) {
626 let ib = ItemizedBlock::new(&line);
627 item_block_buffer.push_str(&line[ib.indent..]);
628 item_block_buffer.push('\n');
629 item_block = Some(ib);
633 if result == opener {
634 let force_leading_whitespace = opener == "/* " && count_newlines(orig) == 0;
635 if !has_leading_whitespace && !force_leading_whitespace && result.ends_with(' ') {
641 } else if is_prev_line_multi_line && !line.is_empty() {
643 } else if is_last && line.is_empty() {
644 // trailing blank lines are unwanted
645 if !closer.is_empty() {
646 result.push_str(&indent_str);
650 result.push_str(&comment_line_separator);
651 if !has_leading_whitespace && result.ends_with(' ') {
656 if config.wrap_comments() && line.len() > fmt.shape.width && !has_url(line) {
657 match rewrite_string(line, &fmt) {
659 is_prev_line_multi_line = s.contains('\n');
662 None if is_prev_line_multi_line => {
663 // We failed to put the current `line` next to the previous `line`.
664 // Remove the trailing space, then start rewrite on the next line.
666 result.push_str(&comment_line_separator);
667 fmt.shape = Shape::legacy(max_chars, fmt_indent);
668 match rewrite_string(line, &fmt) {
670 is_prev_line_multi_line = s.contains('\n');
674 is_prev_line_multi_line = false;
675 result.push_str(line);
680 is_prev_line_multi_line = false;
681 result.push_str(line);
685 fmt.shape = if is_prev_line_multi_line {
687 let offset = 1 + last_line_width(&result) - line_start.len();
689 width: max_chars.saturating_sub(offset),
691 offset: fmt.shape.offset + offset,
694 Shape::legacy(max_chars, fmt_indent)
697 if line.is_empty() && result.ends_with(' ') && !is_last {
698 // Remove space if this is an empty comment or a doc comment.
701 result.push_str(line);
702 fmt.shape = Shape::legacy(max_chars, fmt_indent);
703 is_prev_line_multi_line = false;
706 if !code_block_buffer.is_empty() {
707 // There is a code block that is not properly enclosed by backticks.
708 // We will leave them untouched.
709 result.push_str(&comment_line_separator);
710 result.push_str(&join_block(
711 &trim_custom_comment_prefix(&code_block_buffer),
712 &comment_line_separator,
715 if !item_block_buffer.is_empty() {
716 // the last few lines are part of an itemized block
717 let ib = item_block.unwrap();
718 fmt.shape = Shape::legacy(max_chars, fmt_indent);
719 let item_fmt = ib.create_string_format(&fmt);
720 result.push_str(&comment_line_separator);
721 result.push_str(&ib.opener);
722 match rewrite_string(&item_block_buffer.replace("\n", " "), &item_fmt) {
723 Some(s) => result.push_str(&join_block(
725 &format!("{}{}", &comment_line_separator, ib.line_start),
727 None => result.push_str(&join_block(&item_block_buffer, &comment_line_separator)),
731 result.push_str(closer);
732 if result.ends_with(opener) && opener.ends_with(' ') {
740 const RUSTFMT_CUSTOM_COMMENT_PREFIX: &str = "//#### ";
742 fn hide_sharp_behind_comment(s: &str) -> Cow<str> {
743 if s.trim_left().starts_with("# ") {
744 Cow::from(format!("{}{}", RUSTFMT_CUSTOM_COMMENT_PREFIX, s))
750 fn trim_custom_comment_prefix(s: &str) -> String {
753 let left_trimmed = line.trim_left();
754 if left_trimmed.starts_with(RUSTFMT_CUSTOM_COMMENT_PREFIX) {
755 left_trimmed.trim_left_matches(RUSTFMT_CUSTOM_COMMENT_PREFIX)
764 /// Returns true if the given string MAY include URLs or alike.
765 fn has_url(s: &str) -> bool {
766 // This function may return false positive, but should get its job done in most cases.
767 s.contains("https://") || s.contains("http://") || s.contains("ftp://") || s.contains("file://")
770 /// Given the span, rewrite the missing comment inside it if available.
771 /// Note that the given span must only include comments (or leading/trailing whitespaces).
772 pub fn rewrite_missing_comment(
775 context: &RewriteContext,
776 ) -> Option<String> {
777 let missing_snippet = context.snippet(span);
778 let trimmed_snippet = missing_snippet.trim();
779 if !trimmed_snippet.is_empty() {
780 rewrite_comment(trimmed_snippet, false, shape, context.config)
786 /// Recover the missing comments in the specified span, if available.
787 /// The layout of the comments will be preserved as long as it does not break the code
788 /// and its total width does not exceed the max width.
789 pub fn recover_missing_comment_in_span(
792 context: &RewriteContext,
794 ) -> Option<String> {
795 let missing_comment = rewrite_missing_comment(span, shape, context)?;
796 if missing_comment.is_empty() {
799 let missing_snippet = context.snippet(span);
800 let pos = missing_snippet.find('/').unwrap_or(0);
802 let total_width = missing_comment.len() + used_width + 1;
803 let force_new_line_before_comment =
804 missing_snippet[..pos].contains('\n') || total_width > context.config.max_width();
805 let sep = if force_new_line_before_comment {
806 shape.indent.to_string_with_newline(context.config)
810 Some(format!("{}{}", sep, missing_comment))
814 /// Trim trailing whitespaces unless they consist of two or more whitespaces.
815 fn trim_right_unless_two_whitespaces(s: &str, is_doc_comment: bool) -> &str {
816 if is_doc_comment && s.ends_with(" ") {
823 /// Trims whitespace and aligns to indent, but otherwise does not change comments.
824 fn light_rewrite_comment(
828 is_doc_comment: bool,
829 ) -> Option<String> {
830 let lines: Vec<&str> = orig
833 // This is basically just l.trim(), but in the case that a line starts
834 // with `*` we want to leave one space before it, so it aligns with the
836 let first_non_whitespace = l.find(|c| !char::is_whitespace(c));
837 let left_trimmed = if let Some(fnw) = first_non_whitespace {
838 if l.as_bytes()[fnw] == b'*' && fnw > 0 {
846 // Preserve markdown's double-space line break syntax in doc comment.
847 trim_right_unless_two_whitespaces(left_trimmed, is_doc_comment)
850 Some(lines.join(&format!("\n{}", offset.to_string(config))))
853 /// Trims comment characters and possibly a single space from the left of a string.
854 /// Does not trim all whitespace. If a single space is trimmed from the left of the string,
855 /// this function returns true.
856 fn left_trim_comment_line<'a>(line: &'a str, style: &CommentStyle) -> (&'a str, bool) {
857 if line.starts_with("//! ")
858 || line.starts_with("/// ")
859 || line.starts_with("/*! ")
860 || line.starts_with("/** ")
863 } else if let CommentStyle::Custom(opener) = *style {
864 if line.starts_with(opener) {
865 (&line[opener.len()..], true)
867 (&line[opener.trim_right().len()..], false)
869 } else if line.starts_with("/* ")
870 || line.starts_with("// ")
871 || line.starts_with("//!")
872 || line.starts_with("///")
873 || line.starts_with("** ")
874 || line.starts_with("/*!")
875 || (line.starts_with("/**") && !line.starts_with("/**/"))
877 (&line[3..], line.chars().nth(2).unwrap() == ' ')
878 } else if line.starts_with("/*")
879 || line.starts_with("* ")
880 || line.starts_with("//")
881 || line.starts_with("**")
883 (&line[2..], line.chars().nth(1).unwrap() == ' ')
884 } else if line.starts_with('*') {
887 (line, line.starts_with(' '))
891 pub trait FindUncommented {
892 fn find_uncommented(&self, pat: &str) -> Option<usize>;
895 impl FindUncommented for str {
896 fn find_uncommented(&self, pat: &str) -> Option<usize> {
897 let mut needle_iter = pat.chars();
898 for (kind, (i, b)) in CharClasses::new(self.char_indices()) {
899 match needle_iter.next() {
901 return Some(i - pat.len());
903 Some(c) => match kind {
904 FullCodeCharKind::Normal | FullCodeCharKind::InString if b == c => {}
906 needle_iter = pat.chars();
912 // Handle case where the pattern is a suffix of the search string
913 match needle_iter.next() {
915 None => Some(self.len() - pat.len()),
920 // Returns the first byte position after the first comment. The given string
921 // is expected to be prefixed by a comment, including delimiters.
922 // Good: "/* /* inner */ outer */ code();"
923 // Bad: "code(); // hello\n world!"
924 pub fn find_comment_end(s: &str) -> Option<usize> {
925 let mut iter = CharClasses::new(s.char_indices());
926 for (kind, (i, _c)) in &mut iter {
927 if kind == FullCodeCharKind::Normal || kind == FullCodeCharKind::InString {
932 // Handle case where the comment ends at the end of s.
933 if iter.status == CharClassesStatus::Normal {
940 /// Returns true if text contains any comment.
941 pub fn contains_comment(text: &str) -> bool {
942 CharClasses::new(text.chars()).any(|(kind, _)| kind.is_comment())
945 /// Remove trailing spaces from the specified snippet. We do not remove spaces
946 /// inside strings or comments.
947 pub fn remove_trailing_white_spaces(text: &str) -> String {
948 let mut buffer = String::with_capacity(text.len());
949 let mut space_buffer = String::with_capacity(128);
950 for (char_kind, c) in CharClasses::new(text.chars()) {
953 if char_kind == FullCodeCharKind::InString {
954 buffer.push_str(&space_buffer);
956 space_buffer.clear();
959 _ if c.is_whitespace() => {
960 space_buffer.push(c);
963 if !space_buffer.is_empty() {
964 buffer.push_str(&space_buffer);
965 space_buffer.clear();
974 pub struct CharClasses<T>
980 status: CharClassesStatus,
984 fn get_char(&self) -> char;
987 impl RichChar for char {
988 fn get_char(&self) -> char {
993 impl RichChar for (usize, char) {
994 fn get_char(&self) -> char {
999 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
1000 enum CharClassesStatus {
1005 RawStringPrefix(u32),
1006 RawStringSuffix(u32),
1009 // The u32 is the nesting deepness of the comment
1011 // Status when the '/' has been consumed, but not yet the '*', deepness is
1012 // the new deepness (after the comment opening).
1013 BlockCommentOpening(u32),
1014 // Status when the '*' has been consumed, but not yet the '/', deepness is
1015 // the new deepness (after the comment closing).
1016 BlockCommentClosing(u32),
1020 /// Distinguish between functional part of code and comments
1021 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
1022 pub enum CodeCharKind {
1027 /// Distinguish between functional part of code and comments,
1028 /// describing opening and closing of comments for ease when chunking
1029 /// code from tagged characters
1030 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
1031 pub enum FullCodeCharKind {
1033 /// The first character of a comment, there is only one for a comment (always '/')
1035 /// Any character inside a comment including the second character of comment
1036 /// marks ("//", "/*")
1038 /// Last character of a comment, '\n' for a line comment, '/' for a block comment.
1040 /// Start of a mutlitine string
1042 /// End of a mutlitine string
1044 /// Inside a string.
1048 impl FullCodeCharKind {
1049 pub fn is_comment(self) -> bool {
1051 FullCodeCharKind::StartComment
1052 | FullCodeCharKind::InComment
1053 | FullCodeCharKind::EndComment => true,
1058 pub fn is_string(self) -> bool {
1059 self == FullCodeCharKind::InString || self == FullCodeCharKind::StartString
1062 fn to_codecharkind(self) -> CodeCharKind {
1063 if self.is_comment() {
1064 CodeCharKind::Comment
1066 CodeCharKind::Normal
1071 impl<T> CharClasses<T>
1076 pub fn new(base: T) -> CharClasses<T> {
1078 base: multipeek(base),
1079 status: CharClassesStatus::Normal,
1084 fn is_raw_string_suffix<T>(iter: &mut MultiPeek<T>, count: u32) -> bool
1091 Some(c) if c.get_char() == '#' => continue,
1098 impl<T> Iterator for CharClasses<T>
1103 type Item = (FullCodeCharKind, T::Item);
1105 fn next(&mut self) -> Option<(FullCodeCharKind, T::Item)> {
1106 let item = self.base.next()?;
1107 let chr = item.get_char();
1108 let mut char_kind = FullCodeCharKind::Normal;
1109 self.status = match self.status {
1110 CharClassesStatus::LitRawString(sharps) => {
1111 char_kind = FullCodeCharKind::InString;
1115 char_kind = FullCodeCharKind::Normal;
1116 CharClassesStatus::Normal
1117 } else if is_raw_string_suffix(&mut self.base, sharps) {
1118 CharClassesStatus::RawStringSuffix(sharps)
1120 CharClassesStatus::LitRawString(sharps)
1123 _ => CharClassesStatus::LitRawString(sharps),
1126 CharClassesStatus::RawStringPrefix(sharps) => {
1127 char_kind = FullCodeCharKind::InString;
1129 '#' => CharClassesStatus::RawStringPrefix(sharps + 1),
1130 '"' => CharClassesStatus::LitRawString(sharps),
1131 _ => CharClassesStatus::Normal, // Unreachable.
1134 CharClassesStatus::RawStringSuffix(sharps) => {
1138 CharClassesStatus::Normal
1140 char_kind = FullCodeCharKind::InString;
1141 CharClassesStatus::RawStringSuffix(sharps - 1)
1144 _ => CharClassesStatus::Normal, // Unreachable
1147 CharClassesStatus::LitString => {
1148 char_kind = FullCodeCharKind::InString;
1150 '"' => CharClassesStatus::Normal,
1151 '\\' => CharClassesStatus::LitStringEscape,
1152 _ => CharClassesStatus::LitString,
1155 CharClassesStatus::LitStringEscape => {
1156 char_kind = FullCodeCharKind::InString;
1157 CharClassesStatus::LitString
1159 CharClassesStatus::LitChar => match chr {
1160 '\\' => CharClassesStatus::LitCharEscape,
1161 '\'' => CharClassesStatus::Normal,
1162 _ => CharClassesStatus::LitChar,
1164 CharClassesStatus::LitCharEscape => CharClassesStatus::LitChar,
1165 CharClassesStatus::Normal => match chr {
1166 'r' => match self.base.peek().map(|c| c.get_char()) {
1167 Some('#') | Some('"') => {
1168 char_kind = FullCodeCharKind::InString;
1169 CharClassesStatus::RawStringPrefix(0)
1171 _ => CharClassesStatus::Normal,
1174 char_kind = FullCodeCharKind::InString;
1175 CharClassesStatus::LitString
1178 // HACK: Work around mut borrow.
1179 match self.base.peek() {
1180 Some(next) if next.get_char() == '\\' => {
1181 self.status = CharClassesStatus::LitChar;
1182 return Some((char_kind, item));
1187 match self.base.peek() {
1188 Some(next) if next.get_char() == '\'' => CharClassesStatus::LitChar,
1189 _ => CharClassesStatus::Normal,
1192 '/' => match self.base.peek() {
1193 Some(next) if next.get_char() == '*' => {
1194 self.status = CharClassesStatus::BlockCommentOpening(1);
1195 return Some((FullCodeCharKind::StartComment, item));
1197 Some(next) if next.get_char() == '/' => {
1198 self.status = CharClassesStatus::LineComment;
1199 return Some((FullCodeCharKind::StartComment, item));
1201 _ => CharClassesStatus::Normal,
1203 _ => CharClassesStatus::Normal,
1205 CharClassesStatus::BlockComment(deepness) => {
1206 assert_ne!(deepness, 0);
1207 self.status = match self.base.peek() {
1208 Some(next) if next.get_char() == '/' && chr == '*' => {
1209 CharClassesStatus::BlockCommentClosing(deepness - 1)
1211 Some(next) if next.get_char() == '*' && chr == '/' => {
1212 CharClassesStatus::BlockCommentOpening(deepness + 1)
1214 _ => CharClassesStatus::BlockComment(deepness),
1216 return Some((FullCodeCharKind::InComment, item));
1218 CharClassesStatus::BlockCommentOpening(deepness) => {
1219 assert_eq!(chr, '*');
1220 self.status = CharClassesStatus::BlockComment(deepness);
1221 return Some((FullCodeCharKind::InComment, item));
1223 CharClassesStatus::BlockCommentClosing(deepness) => {
1224 assert_eq!(chr, '/');
1226 self.status = CharClassesStatus::Normal;
1227 return Some((FullCodeCharKind::EndComment, item));
1229 self.status = CharClassesStatus::BlockComment(deepness);
1230 return Some((FullCodeCharKind::InComment, item));
1233 CharClassesStatus::LineComment => match chr {
1235 self.status = CharClassesStatus::Normal;
1236 return Some((FullCodeCharKind::EndComment, item));
1239 self.status = CharClassesStatus::LineComment;
1240 return Some((FullCodeCharKind::InComment, item));
1244 Some((char_kind, item))
1248 /// An iterator over the lines of a string, paired with the char kind at the
1249 /// end of the line.
1250 pub struct LineClasses<'a> {
1251 base: iter::Peekable<CharClasses<std::str::Chars<'a>>>,
1252 kind: FullCodeCharKind,
1255 impl<'a> LineClasses<'a> {
1256 pub fn new(s: &'a str) -> Self {
1258 base: CharClasses::new(s.chars()).peekable(),
1259 kind: FullCodeCharKind::Normal,
1264 impl<'a> Iterator for LineClasses<'a> {
1265 type Item = (FullCodeCharKind, String);
1267 fn next(&mut self) -> Option<Self::Item> {
1270 let mut line = String::new();
1272 let start_class = match self.base.peek() {
1273 Some((kind, _)) => *kind,
1274 None => FullCodeCharKind::Normal,
1277 while let Some((kind, c)) = self.base.next() {
1279 self.kind = match (start_class, kind) {
1280 (FullCodeCharKind::Normal, FullCodeCharKind::InString) => {
1281 FullCodeCharKind::StartString
1283 (FullCodeCharKind::InString, FullCodeCharKind::Normal) => {
1284 FullCodeCharKind::EndString
1294 Some((self.kind, line))
1298 /// Iterator over functional and commented parts of a string. Any part of a string is either
1299 /// functional code, either *one* block comment, either *one* line comment. Whitespace between
1300 /// comments is functional code. Line comments contain their ending newlines.
1301 struct UngroupedCommentCodeSlices<'a> {
1303 iter: iter::Peekable<CharClasses<std::str::CharIndices<'a>>>,
1306 impl<'a> UngroupedCommentCodeSlices<'a> {
1307 fn new(code: &'a str) -> UngroupedCommentCodeSlices<'a> {
1308 UngroupedCommentCodeSlices {
1310 iter: CharClasses::new(code.char_indices()).peekable(),
1315 impl<'a> Iterator for UngroupedCommentCodeSlices<'a> {
1316 type Item = (CodeCharKind, usize, &'a str);
1318 fn next(&mut self) -> Option<Self::Item> {
1319 let (kind, (start_idx, _)) = self.iter.next()?;
1321 FullCodeCharKind::Normal | FullCodeCharKind::InString => {
1322 // Consume all the Normal code
1323 while let Some(&(char_kind, _)) = self.iter.peek() {
1324 if char_kind.is_comment() {
1327 let _ = self.iter.next();
1330 FullCodeCharKind::StartComment => {
1331 // Consume the whole comment
1332 while let Some((FullCodeCharKind::InComment, (_, _))) = self.iter.next() {}
1336 let slice = match self.iter.peek() {
1337 Some(&(_, (end_idx, _))) => &self.slice[start_idx..end_idx],
1338 None => &self.slice[start_idx..],
1341 if kind.is_comment() {
1342 CodeCharKind::Comment
1344 CodeCharKind::Normal
1352 /// Iterator over an alternating sequence of functional and commented parts of
1353 /// a string. The first item is always a, possibly zero length, subslice of
1354 /// functional text. Line style comments contain their ending newlines.
1355 pub struct CommentCodeSlices<'a> {
1357 last_slice_kind: CodeCharKind,
1358 last_slice_end: usize,
1361 impl<'a> CommentCodeSlices<'a> {
1362 pub fn new(slice: &'a str) -> CommentCodeSlices<'a> {
1365 last_slice_kind: CodeCharKind::Comment,
1371 impl<'a> Iterator for CommentCodeSlices<'a> {
1372 type Item = (CodeCharKind, usize, &'a str);
1374 fn next(&mut self) -> Option<Self::Item> {
1375 if self.last_slice_end == self.slice.len() {
1379 let mut sub_slice_end = self.last_slice_end;
1380 let mut first_whitespace = None;
1381 let subslice = &self.slice[self.last_slice_end..];
1382 let mut iter = CharClasses::new(subslice.char_indices());
1384 for (kind, (i, c)) in &mut iter {
1385 let is_comment_connector = self.last_slice_kind == CodeCharKind::Normal
1386 && &subslice[..2] == "//"
1387 && [' ', '\t'].contains(&c);
1389 if is_comment_connector && first_whitespace.is_none() {
1390 first_whitespace = Some(i);
1393 if kind.to_codecharkind() == self.last_slice_kind && !is_comment_connector {
1394 let last_index = match first_whitespace {
1398 sub_slice_end = self.last_slice_end + last_index;
1402 if !is_comment_connector {
1403 first_whitespace = None;
1407 if let (None, true) = (iter.next(), sub_slice_end == self.last_slice_end) {
1408 // This was the last subslice.
1409 sub_slice_end = match first_whitespace {
1410 Some(i) => self.last_slice_end + i,
1411 None => self.slice.len(),
1415 let kind = match self.last_slice_kind {
1416 CodeCharKind::Comment => CodeCharKind::Normal,
1417 CodeCharKind::Normal => CodeCharKind::Comment,
1421 self.last_slice_end,
1422 &self.slice[self.last_slice_end..sub_slice_end],
1424 self.last_slice_end = sub_slice_end;
1425 self.last_slice_kind = kind;
1431 /// Checks is `new` didn't miss any comment from `span`, if it removed any, return previous text
1432 /// (if it fits in the width/offset, else return None), else return `new`
1433 pub fn recover_comment_removed(
1436 context: &RewriteContext,
1437 ) -> Option<String> {
1438 let snippet = context.snippet(span);
1439 if snippet != new && changed_comment_content(snippet, &new) {
1440 // We missed some comments. Warn and keep the original text.
1441 if context.config.error_on_unformatted() {
1442 context.report.append(
1443 context.source_map.span_to_filename(span).into(),
1444 vec![FormattingError::from_span(
1446 &context.source_map,
1447 ErrorKind::LostComment,
1451 Some(snippet.to_owned())
1457 pub fn filter_normal_code(code: &str) -> String {
1458 let mut buffer = String::with_capacity(code.len());
1459 LineClasses::new(code).for_each(|(kind, line)| match kind {
1460 FullCodeCharKind::Normal
1461 | FullCodeCharKind::StartString
1462 | FullCodeCharKind::InString
1463 | FullCodeCharKind::EndString => {
1464 buffer.push_str(&line);
1469 if !code.ends_with('\n') && buffer.ends_with('\n') {
1475 /// Return true if the two strings of code have the same payload of comments.
1476 /// The payload of comments is everything in the string except:
1477 /// - actual code (not comments)
1478 /// - comment start/end marks
1480 /// - '*' at the beginning of lines in block comments
1481 fn changed_comment_content(orig: &str, new: &str) -> bool {
1482 // Cannot write this as a fn since we cannot return types containing closures
1483 let code_comment_content = |code| {
1484 let slices = UngroupedCommentCodeSlices::new(code);
1486 .filter(|&(ref kind, _, _)| *kind == CodeCharKind::Comment)
1487 .flat_map(|(_, _, s)| CommentReducer::new(s))
1489 let res = code_comment_content(orig).ne(code_comment_content(new));
1491 "comment::changed_comment_content: {}\norig: '{}'\nnew: '{}'\nraw_old: {}\nraw_new: {}",
1495 code_comment_content(orig).collect::<String>(),
1496 code_comment_content(new).collect::<String>()
1501 /// Iterator over the 'payload' characters of a comment.
1502 /// It skips whitespace, comment start/end marks, and '*' at the beginning of lines.
1503 /// The comment must be one comment, ie not more than one start mark (no multiple line comments,
1505 struct CommentReducer<'a> {
1507 at_start_line: bool,
1508 iter: std::str::Chars<'a>,
1511 impl<'a> CommentReducer<'a> {
1512 fn new(comment: &'a str) -> CommentReducer<'a> {
1513 let is_block = comment.starts_with("/*");
1514 let comment = remove_comment_header(comment);
1517 at_start_line: false, // There are no supplementary '*' on the first line
1518 iter: comment.chars(),
1523 impl<'a> Iterator for CommentReducer<'a> {
1526 fn next(&mut self) -> Option<Self::Item> {
1528 let mut c = self.iter.next()?;
1529 if self.is_block && self.at_start_line {
1530 while c.is_whitespace() {
1531 c = self.iter.next()?;
1533 // Ignore leading '*'
1535 c = self.iter.next()?;
1537 } else if c == '\n' {
1538 self.at_start_line = true;
1540 if !c.is_whitespace() {
1547 fn remove_comment_header(comment: &str) -> &str {
1548 if comment.starts_with("///") || comment.starts_with("//!") {
1550 } else if comment.starts_with("//") {
1552 } else if (comment.starts_with("/**") && !comment.starts_with("/**/"))
1553 || comment.starts_with("/*!")
1555 &comment[3..comment.len() - 2]
1558 comment.starts_with("/*"),
1559 format!("string '{}' is not a comment", comment)
1561 &comment[2..comment.len() - 2]
1568 use shape::{Indent, Shape};
1572 let mut iter = CharClasses::new("//\n\n".chars());
1574 assert_eq!((FullCodeCharKind::StartComment, '/'), iter.next().unwrap());
1575 assert_eq!((FullCodeCharKind::InComment, '/'), iter.next().unwrap());
1576 assert_eq!((FullCodeCharKind::EndComment, '\n'), iter.next().unwrap());
1577 assert_eq!((FullCodeCharKind::Normal, '\n'), iter.next().unwrap());
1578 assert_eq!(None, iter.next());
1582 fn comment_code_slices() {
1583 let input = "code(); /* test */ 1 + 1";
1584 let mut iter = CommentCodeSlices::new(input);
1586 assert_eq!((CodeCharKind::Normal, 0, "code(); "), iter.next().unwrap());
1588 (CodeCharKind::Comment, 8, "/* test */"),
1589 iter.next().unwrap()
1591 assert_eq!((CodeCharKind::Normal, 18, " 1 + 1"), iter.next().unwrap());
1592 assert_eq!(None, iter.next());
1596 fn comment_code_slices_two() {
1597 let input = "// comment\n test();";
1598 let mut iter = CommentCodeSlices::new(input);
1600 assert_eq!((CodeCharKind::Normal, 0, ""), iter.next().unwrap());
1602 (CodeCharKind::Comment, 0, "// comment\n"),
1603 iter.next().unwrap()
1606 (CodeCharKind::Normal, 11, " test();"),
1607 iter.next().unwrap()
1609 assert_eq!(None, iter.next());
1613 fn comment_code_slices_three() {
1614 let input = "1 // comment\n // comment2\n\n";
1615 let mut iter = CommentCodeSlices::new(input);
1617 assert_eq!((CodeCharKind::Normal, 0, "1 "), iter.next().unwrap());
1619 (CodeCharKind::Comment, 2, "// comment\n // comment2\n"),
1620 iter.next().unwrap()
1622 assert_eq!((CodeCharKind::Normal, 29, "\n"), iter.next().unwrap());
1623 assert_eq!(None, iter.next());
1628 fn format_doc_comments() {
1629 let mut wrap_normalize_config: ::config::Config = Default::default();
1630 wrap_normalize_config.set().wrap_comments(true);
1631 wrap_normalize_config.set().normalize_comments(true);
1633 let mut wrap_config: ::config::Config = Default::default();
1634 wrap_config.set().wrap_comments(true);
1636 let comment = rewrite_comment(" //test",
1638 Shape::legacy(100, Indent::new(0, 100)),
1639 &wrap_normalize_config).unwrap();
1640 assert_eq!("/* test */", comment);
1642 let comment = rewrite_comment("// comment on a",
1644 Shape::legacy(10, Indent::empty()),
1645 &wrap_normalize_config).unwrap();
1646 assert_eq!("// comment\n// on a", comment);
1648 let comment = rewrite_comment("// A multi line comment\n // between args.",
1650 Shape::legacy(60, Indent::new(0, 12)),
1651 &wrap_normalize_config).unwrap();
1652 assert_eq!("// A multi line comment\n // between args.", comment);
1654 let input = "// comment";
1657 let comment = rewrite_comment(input,
1659 Shape::legacy(9, Indent::new(0, 69)),
1660 &wrap_normalize_config).unwrap();
1661 assert_eq!(expected, comment);
1663 let comment = rewrite_comment("/* trimmed */",
1665 Shape::legacy(100, Indent::new(0, 100)),
1666 &wrap_normalize_config).unwrap();
1667 assert_eq!("/* trimmed */", comment);
1669 // check that different comment style are properly recognised
1670 let comment = rewrite_comment(r#"/// test1
1676 Shape::legacy(100, Indent::new(0, 0)),
1677 &wrap_normalize_config).unwrap();
1678 assert_eq!("/// test1\n/// test2\n// test3", comment);
1680 // check that the blank line marks the end of a commented paragraph
1681 let comment = rewrite_comment(r#"// test1
1685 Shape::legacy(100, Indent::new(0, 0)),
1686 &wrap_normalize_config).unwrap();
1687 assert_eq!("// test1\n\n// test2", comment);
1689 // check that the blank line marks the end of a custom-commented paragraph
1690 let comment = rewrite_comment(r#"//@ test1
1694 Shape::legacy(100, Indent::new(0, 0)),
1695 &wrap_normalize_config).unwrap();
1696 assert_eq!("//@ test1\n\n//@ test2", comment);
1698 // check that bare lines are just indented but left unchanged otherwise
1699 let comment = rewrite_comment(r#"// test1
1706 Shape::legacy(100, Indent::new(0, 0)),
1707 &wrap_config).unwrap();
1708 assert_eq!("// test1\n/*\n a bare line!\n\n another bare line!\n*/", comment);
1711 // This is probably intended to be a non-test fn, but it is not used. I'm
1712 // keeping it around unless it helps us test stuff.
1713 fn uncommented(text: &str) -> String {
1714 CharClasses::new(text.chars())
1715 .filter_map(|(s, c)| match s {
1716 FullCodeCharKind::Normal | FullCodeCharKind::InString => Some(c),
1723 fn test_uncommented() {
1724 assert_eq!(&uncommented("abc/*...*/"), "abc");
1726 &uncommented("// .... /* \n../* /* *** / */ */a/* // */c\n"),
1729 assert_eq!(&uncommented("abc \" /* */\" qsdf"), "abc \" /* */\" qsdf");
1733 fn test_contains_comment() {
1734 assert_eq!(contains_comment("abc"), false);
1735 assert_eq!(contains_comment("abc // qsdf"), true);
1736 assert_eq!(contains_comment("abc /* kqsdf"), true);
1737 assert_eq!(contains_comment("abc \" /* */\" qsdf"), false);
1741 fn test_find_uncommented() {
1742 fn check(haystack: &str, needle: &str, expected: Option<usize>) {
1743 assert_eq!(expected, haystack.find_uncommented(needle));
1746 check("/*/ */test", "test", Some(6));
1747 check("//test\ntest", "test", Some(7));
1748 check("/* comment only */", "whatever", None);
1750 "/* comment */ some text /* more commentary */ result",
1754 check("sup // sup", "p", Some(2));
1755 check("sup", "x", None);
1756 check(r#"π? /**/ π is nice!"#, r#"π is nice"#, Some(9));
1757 check("/*sup yo? \n sup*/ sup", "p", Some(20));
1758 check("hel/*lohello*/lo", "hello", None);
1759 check("acb", "ab", None);
1760 check(",/*A*/ ", ",", Some(0));
1761 check("abc", "abc", Some(0));
1762 check("/* abc */", "abc", None);
1763 check("/**/abc/* */", "abc", Some(4));
1764 check("\"/* abc */\"", "abc", Some(4));
1765 check("\"/* abc", "abc", Some(4));
1769 fn test_remove_trailing_white_spaces() {
1770 let s = " r#\"\n test\n \"#";
1771 assert_eq!(remove_trailing_white_spaces(&s), s);
1775 fn test_filter_normal_code() {
1778 println!("hello, world");
1781 assert_eq!(s, filter_normal_code(s));
1782 let s_with_comment = r#"
1785 println!("hello, world");
1788 assert_eq!(s, filter_normal_code(s_with_comment));