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() && !config.wrap_comments() {
337 light_rewrite_comment(first_group, shape.indent, config, is_doc_comment)?
339 rewrite_comment_inner(
345 is_doc_comment || style.is_doc_comment(),
349 Some(rewritten_first_group)
351 identify_comment(rest.trim_left(), block_style, shape, config, is_doc_comment).map(
355 rewritten_first_group,
356 // insert back the blank line
357 if has_bare_lines && style.is_line_comment() {
362 shape.indent.to_string(config),
370 /// Trims a minimum of leading whitespaces so that the content layout is kept and aligns to indent.
371 fn light_rewrite_block_comment_with_bare_lines(
375 ) -> Option<String> {
376 let prefix_whitespace_min = orig
378 // skip the line with the starting sigil since the leading whitespace is removed
379 // otherwise, the minimum would always be zero
381 .filter(|line| !line.is_empty())
384 for c in line.chars() {
387 '\t' => width += config.tab_spaces(),
395 let indent_str = shape.indent.to_string(config);
396 let mut lines = orig.lines();
397 let first_line = lines.next()?;
403 &line[prefix_whitespace_min..]
406 .collect::<Vec<&str>>()
407 .join(&format!("\n{}", indent_str));
408 Some(format!("{}\n{}{}", first_line, indent_str, rest))
411 /// Attributes for code blocks in rustdoc.
412 /// See https://doc.rust-lang.org/rustdoc/print.html#attributes
413 enum CodeBlockAttribute {
422 impl CodeBlockAttribute {
423 fn new(attribute: &str) -> CodeBlockAttribute {
425 "rust" | "" => CodeBlockAttribute::Rust,
426 "ignore" => CodeBlockAttribute::Ignore,
427 "text" => CodeBlockAttribute::Text,
428 "should_panic" => CodeBlockAttribute::ShouldPanic,
429 "no_run" => CodeBlockAttribute::NoRun,
430 "compile_fail" => CodeBlockAttribute::CompileFail,
431 _ => CodeBlockAttribute::Text,
436 /// Block that is formatted as an item.
438 /// An item starts with either a star `*` or a dash `-`. Different level of indentation are
440 struct ItemizedBlock {
441 /// the number of whitespaces up to the item sigil
443 /// the string that marks the start of an item
445 /// sequence of whitespaces to prefix new lines that are part of the item
450 /// Returns true if the line is formatted as an item
451 fn is_itemized_line(line: &str) -> bool {
452 let trimmed = line.trim_left();
453 trimmed.starts_with("* ") || trimmed.starts_with("- ")
456 /// Creates a new ItemizedBlock described with the given line.
457 /// The `is_itemized_line` needs to be called first.
458 fn new(line: &str) -> ItemizedBlock {
459 let space_to_sigil = line.chars().take_while(|c| c.is_whitespace()).count();
460 let indent = space_to_sigil + 2;
463 opener: line[..indent].to_string(),
464 line_start: " ".repeat(indent),
468 /// Returns a `StringFormat` used for formatting the content of an item
469 fn create_string_format<'a>(&'a self, fmt: &'a StringFormat) -> StringFormat<'a> {
475 shape: Shape::legacy(fmt.shape.width.saturating_sub(self.indent), Indent::empty()),
481 /// Returns true if the line is part of the current itemized block
482 fn in_block(&self, line: &str) -> bool {
483 !ItemizedBlock::is_itemized_line(line)
484 && self.indent <= line.chars().take_while(|c| c.is_whitespace()).count()
488 fn rewrite_comment_inner(
494 is_doc_comment: bool,
495 ) -> Option<String> {
496 let (opener, closer, line_start) = if block_style {
497 CommentStyle::SingleBullet.to_str_tuplet()
499 comment_style(orig, config.normalize_comments()).to_str_tuplet()
502 let max_chars = shape
504 .checked_sub(closer.len() + opener.len())
506 let indent_str = shape.indent.to_string_with_newline(config);
507 let fmt_indent = shape.indent + (opener.len() - line_start.len());
508 let mut fmt = StringFormat {
513 shape: Shape::legacy(max_chars, fmt_indent),
518 let line_breaks = count_newlines(orig.trim_right());
522 .map(|(i, mut line)| {
523 line = trim_right_unless_two_whitespaces(line.trim_left(), is_doc_comment);
525 if i == line_breaks && line.ends_with("*/") && !line.starts_with("//") {
526 line = line[..(line.len() - 2)].trim_right();
531 .map(|s| left_trim_comment_line(s, &style))
532 .map(|(line, has_leading_whitespace)| {
533 if orig.starts_with("/*") && line_breaks == 0 {
536 has_leading_whitespace || config.normalize_comments(),
539 (line, has_leading_whitespace || config.normalize_comments())
543 let mut result = String::with_capacity(orig.len() * 2);
544 result.push_str(opener);
545 let mut code_block_buffer = String::with_capacity(128);
546 let mut is_prev_line_multi_line = false;
547 let mut code_block_attr = None;
548 let mut item_block_buffer = String::with_capacity(128);
549 let mut item_block: Option<ItemizedBlock> = None;
550 let comment_line_separator = format!("{}{}", indent_str, line_start);
551 let join_block = |s: &str, sep: &str| {
552 let mut result = String::with_capacity(s.len() + 128);
553 let mut iter = s.lines().peekable();
554 while let Some(line) = iter.next() {
555 result.push_str(line);
556 result.push_str(match iter.peek() {
557 Some(next_line) if next_line.is_empty() => sep.trim_right(),
565 for (i, (line, has_leading_whitespace)) in lines.enumerate() {
566 let is_last = i == count_newlines(orig);
568 if let Some(ref ib) = item_block {
569 if ib.in_block(&line) {
570 item_block_buffer.push_str(&line);
571 item_block_buffer.push('\n');
574 is_prev_line_multi_line = false;
575 fmt.shape = Shape::legacy(max_chars, fmt_indent);
576 let item_fmt = ib.create_string_format(&fmt);
577 result.push_str(&comment_line_separator);
578 result.push_str(&ib.opener);
579 match rewrite_string(&item_block_buffer.replace("\n", " "), &item_fmt) {
580 Some(s) => result.push_str(&join_block(
582 &format!("{}{}", &comment_line_separator, ib.line_start),
584 None => result.push_str(&join_block(&item_block_buffer, &comment_line_separator)),
586 item_block_buffer.clear();
587 } else if let Some(ref attr) = code_block_attr {
588 if line.starts_with("```") {
589 let code_block = match attr {
590 CodeBlockAttribute::Ignore | CodeBlockAttribute::Text => {
591 trim_custom_comment_prefix(&code_block_buffer)
593 _ if code_block_buffer.is_empty() => String::new(),
595 let mut config = config.clone();
596 config.set().wrap_comments(false);
597 match ::format_code_block(&code_block_buffer, &config) {
598 Some(ref s) => trim_custom_comment_prefix(s),
599 None => trim_custom_comment_prefix(&code_block_buffer),
603 if !code_block.is_empty() {
604 result.push_str(&comment_line_separator);
605 result.push_str(&join_block(&code_block, &comment_line_separator));
607 code_block_buffer.clear();
608 result.push_str(&comment_line_separator);
609 result.push_str(line);
610 code_block_attr = None;
612 code_block_buffer.push_str(&hide_sharp_behind_comment(line));
613 code_block_buffer.push('\n');
618 code_block_attr = None;
620 if line.starts_with("```") {
621 code_block_attr = Some(CodeBlockAttribute::new(&line[3..]))
622 } else if config.wrap_comments() && ItemizedBlock::is_itemized_line(&line) {
623 let ib = ItemizedBlock::new(&line);
624 item_block_buffer.push_str(&line[ib.indent..]);
625 item_block_buffer.push('\n');
626 item_block = Some(ib);
630 if result == opener {
631 let force_leading_whitespace = opener == "/* " && count_newlines(orig) == 0;
632 if !has_leading_whitespace && !force_leading_whitespace && result.ends_with(' ') {
638 } else if is_prev_line_multi_line && !line.is_empty() {
640 } else if is_last && line.is_empty() {
641 // trailing blank lines are unwanted
642 if !closer.is_empty() {
643 result.push_str(&indent_str);
647 result.push_str(&comment_line_separator);
648 if !has_leading_whitespace && result.ends_with(' ') {
653 if config.wrap_comments() && line.len() > fmt.shape.width && !has_url(line) {
654 match rewrite_string(line, &fmt) {
656 is_prev_line_multi_line = s.contains('\n');
659 None if is_prev_line_multi_line => {
660 // We failed to put the current `line` next to the previous `line`.
661 // Remove the trailing space, then start rewrite on the next line.
663 result.push_str(&comment_line_separator);
664 fmt.shape = Shape::legacy(max_chars, fmt_indent);
665 match rewrite_string(line, &fmt) {
667 is_prev_line_multi_line = s.contains('\n');
671 is_prev_line_multi_line = false;
672 result.push_str(line);
677 is_prev_line_multi_line = false;
678 result.push_str(line);
682 fmt.shape = if is_prev_line_multi_line {
684 let offset = 1 + last_line_width(&result) - line_start.len();
686 width: max_chars.saturating_sub(offset),
688 offset: fmt.shape.offset + offset,
691 Shape::legacy(max_chars, fmt_indent)
694 if line.is_empty() && result.ends_with(' ') && !is_last {
695 // Remove space if this is an empty comment or a doc comment.
698 result.push_str(line);
699 fmt.shape = Shape::legacy(max_chars, fmt_indent);
700 is_prev_line_multi_line = false;
703 if !code_block_buffer.is_empty() {
704 // There is a code block that is not properly enclosed by backticks.
705 // We will leave them untouched.
706 result.push_str(&comment_line_separator);
707 result.push_str(&join_block(
708 &trim_custom_comment_prefix(&code_block_buffer),
709 &comment_line_separator,
712 if !item_block_buffer.is_empty() {
713 // the last few lines are part of an itemized block
714 let ib = item_block.unwrap();
715 fmt.shape = Shape::legacy(max_chars, fmt_indent);
716 let item_fmt = ib.create_string_format(&fmt);
717 result.push_str(&comment_line_separator);
718 result.push_str(&ib.opener);
719 match rewrite_string(&item_block_buffer.replace("\n", " "), &item_fmt) {
720 Some(s) => result.push_str(&join_block(
722 &format!("{}{}", &comment_line_separator, ib.line_start),
724 None => result.push_str(&join_block(&item_block_buffer, &comment_line_separator)),
728 result.push_str(closer);
729 if result.ends_with(opener) && opener.ends_with(' ') {
737 const RUSTFMT_CUSTOM_COMMENT_PREFIX: &str = "//#### ";
739 fn hide_sharp_behind_comment(s: &str) -> Cow<str> {
740 if s.trim_left().starts_with("# ") {
741 Cow::from(format!("{}{}", RUSTFMT_CUSTOM_COMMENT_PREFIX, s))
747 fn trim_custom_comment_prefix(s: &str) -> String {
750 let left_trimmed = line.trim_left();
751 if left_trimmed.starts_with(RUSTFMT_CUSTOM_COMMENT_PREFIX) {
752 left_trimmed.trim_left_matches(RUSTFMT_CUSTOM_COMMENT_PREFIX)
761 /// Returns true if the given string MAY include URLs or alike.
762 fn has_url(s: &str) -> bool {
763 // This function may return false positive, but should get its job done in most cases.
764 s.contains("https://") || s.contains("http://") || s.contains("ftp://") || s.contains("file://")
767 /// Given the span, rewrite the missing comment inside it if available.
768 /// Note that the given span must only include comments (or leading/trailing whitespaces).
769 pub fn rewrite_missing_comment(
772 context: &RewriteContext,
773 ) -> Option<String> {
774 let missing_snippet = context.snippet(span);
775 let trimmed_snippet = missing_snippet.trim();
776 if !trimmed_snippet.is_empty() {
777 rewrite_comment(trimmed_snippet, false, shape, context.config)
783 /// Recover the missing comments in the specified span, if available.
784 /// The layout of the comments will be preserved as long as it does not break the code
785 /// and its total width does not exceed the max width.
786 pub fn recover_missing_comment_in_span(
789 context: &RewriteContext,
791 ) -> Option<String> {
792 let missing_comment = rewrite_missing_comment(span, shape, context)?;
793 if missing_comment.is_empty() {
796 let missing_snippet = context.snippet(span);
797 let pos = missing_snippet.find('/').unwrap_or(0);
799 let total_width = missing_comment.len() + used_width + 1;
800 let force_new_line_before_comment =
801 missing_snippet[..pos].contains('\n') || total_width > context.config.max_width();
802 let sep = if force_new_line_before_comment {
803 shape.indent.to_string_with_newline(context.config)
807 Some(format!("{}{}", sep, missing_comment))
811 /// Trim trailing whitespaces unless they consist of two or more whitespaces.
812 fn trim_right_unless_two_whitespaces(s: &str, is_doc_comment: bool) -> &str {
813 if is_doc_comment && s.ends_with(" ") {
820 /// Trims whitespace and aligns to indent, but otherwise does not change comments.
821 fn light_rewrite_comment(
825 is_doc_comment: bool,
826 ) -> Option<String> {
827 let lines: Vec<&str> = orig
830 // This is basically just l.trim(), but in the case that a line starts
831 // with `*` we want to leave one space before it, so it aligns with the
833 let first_non_whitespace = l.find(|c| !char::is_whitespace(c));
834 let left_trimmed = if let Some(fnw) = first_non_whitespace {
835 if l.as_bytes()[fnw] == b'*' && fnw > 0 {
843 // Preserve markdown's double-space line break syntax in doc comment.
844 trim_right_unless_two_whitespaces(left_trimmed, is_doc_comment)
847 Some(lines.join(&format!("\n{}", offset.to_string(config))))
850 /// Trims comment characters and possibly a single space from the left of a string.
851 /// Does not trim all whitespace. If a single space is trimmed from the left of the string,
852 /// this function returns true.
853 fn left_trim_comment_line<'a>(line: &'a str, style: &CommentStyle) -> (&'a str, bool) {
854 if line.starts_with("//! ")
855 || line.starts_with("/// ")
856 || line.starts_with("/*! ")
857 || line.starts_with("/** ")
860 } else if let CommentStyle::Custom(opener) = *style {
861 if line.starts_with(opener) {
862 (&line[opener.len()..], true)
864 (&line[opener.trim_right().len()..], false)
866 } else if line.starts_with("/* ")
867 || line.starts_with("// ")
868 || line.starts_with("//!")
869 || line.starts_with("///")
870 || line.starts_with("** ")
871 || line.starts_with("/*!")
872 || (line.starts_with("/**") && !line.starts_with("/**/"))
874 (&line[3..], line.chars().nth(2).unwrap() == ' ')
875 } else if line.starts_with("/*")
876 || line.starts_with("* ")
877 || line.starts_with("//")
878 || line.starts_with("**")
880 (&line[2..], line.chars().nth(1).unwrap() == ' ')
881 } else if line.starts_with('*') {
884 (line, line.starts_with(' '))
888 pub trait FindUncommented {
889 fn find_uncommented(&self, pat: &str) -> Option<usize>;
892 impl FindUncommented for str {
893 fn find_uncommented(&self, pat: &str) -> Option<usize> {
894 let mut needle_iter = pat.chars();
895 for (kind, (i, b)) in CharClasses::new(self.char_indices()) {
896 match needle_iter.next() {
898 return Some(i - pat.len());
900 Some(c) => match kind {
901 FullCodeCharKind::Normal | FullCodeCharKind::InString if b == c => {}
903 needle_iter = pat.chars();
909 // Handle case where the pattern is a suffix of the search string
910 match needle_iter.next() {
912 None => Some(self.len() - pat.len()),
917 // Returns the first byte position after the first comment. The given string
918 // is expected to be prefixed by a comment, including delimiters.
919 // Good: "/* /* inner */ outer */ code();"
920 // Bad: "code(); // hello\n world!"
921 pub fn find_comment_end(s: &str) -> Option<usize> {
922 let mut iter = CharClasses::new(s.char_indices());
923 for (kind, (i, _c)) in &mut iter {
924 if kind == FullCodeCharKind::Normal || kind == FullCodeCharKind::InString {
929 // Handle case where the comment ends at the end of s.
930 if iter.status == CharClassesStatus::Normal {
937 /// Returns true if text contains any comment.
938 pub fn contains_comment(text: &str) -> bool {
939 CharClasses::new(text.chars()).any(|(kind, _)| kind.is_comment())
942 /// Remove trailing spaces from the specified snippet. We do not remove spaces
943 /// inside strings or comments.
944 pub fn remove_trailing_white_spaces(text: &str) -> String {
945 let mut buffer = String::with_capacity(text.len());
946 let mut space_buffer = String::with_capacity(128);
947 for (char_kind, c) in CharClasses::new(text.chars()) {
950 if char_kind == FullCodeCharKind::InString {
951 buffer.push_str(&space_buffer);
953 space_buffer.clear();
956 _ if c.is_whitespace() => {
957 space_buffer.push(c);
960 if !space_buffer.is_empty() {
961 buffer.push_str(&space_buffer);
962 space_buffer.clear();
971 pub struct CharClasses<T>
977 status: CharClassesStatus,
981 fn get_char(&self) -> char;
984 impl RichChar for char {
985 fn get_char(&self) -> char {
990 impl RichChar for (usize, char) {
991 fn get_char(&self) -> char {
996 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
997 enum CharClassesStatus {
1002 RawStringPrefix(u32),
1003 RawStringSuffix(u32),
1006 // The u32 is the nesting deepness of the comment
1008 // Status when the '/' has been consumed, but not yet the '*', deepness is
1009 // the new deepness (after the comment opening).
1010 BlockCommentOpening(u32),
1011 // Status when the '*' has been consumed, but not yet the '/', deepness is
1012 // the new deepness (after the comment closing).
1013 BlockCommentClosing(u32),
1017 /// Distinguish between functional part of code and comments
1018 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
1019 pub enum CodeCharKind {
1024 /// Distinguish between functional part of code and comments,
1025 /// describing opening and closing of comments for ease when chunking
1026 /// code from tagged characters
1027 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
1028 pub enum FullCodeCharKind {
1030 /// The first character of a comment, there is only one for a comment (always '/')
1032 /// Any character inside a comment including the second character of comment
1033 /// marks ("//", "/*")
1035 /// Last character of a comment, '\n' for a line comment, '/' for a block comment.
1037 /// Start of a mutlitine string
1039 /// End of a mutlitine string
1041 /// Inside a string.
1045 impl FullCodeCharKind {
1046 pub fn is_comment(self) -> bool {
1048 FullCodeCharKind::StartComment
1049 | FullCodeCharKind::InComment
1050 | FullCodeCharKind::EndComment => true,
1055 pub fn is_string(self) -> bool {
1056 self == FullCodeCharKind::InString || self == FullCodeCharKind::StartString
1059 fn to_codecharkind(self) -> CodeCharKind {
1060 if self.is_comment() {
1061 CodeCharKind::Comment
1063 CodeCharKind::Normal
1068 impl<T> CharClasses<T>
1073 pub fn new(base: T) -> CharClasses<T> {
1075 base: multipeek(base),
1076 status: CharClassesStatus::Normal,
1081 fn is_raw_string_suffix<T>(iter: &mut MultiPeek<T>, count: u32) -> bool
1088 Some(c) if c.get_char() == '#' => continue,
1095 impl<T> Iterator for CharClasses<T>
1100 type Item = (FullCodeCharKind, T::Item);
1102 fn next(&mut self) -> Option<(FullCodeCharKind, T::Item)> {
1103 let item = self.base.next()?;
1104 let chr = item.get_char();
1105 let mut char_kind = FullCodeCharKind::Normal;
1106 self.status = match self.status {
1107 CharClassesStatus::LitRawString(sharps) => {
1108 char_kind = FullCodeCharKind::InString;
1112 char_kind = FullCodeCharKind::Normal;
1113 CharClassesStatus::Normal
1114 } else if is_raw_string_suffix(&mut self.base, sharps) {
1115 CharClassesStatus::RawStringSuffix(sharps)
1117 CharClassesStatus::LitRawString(sharps)
1120 _ => CharClassesStatus::LitRawString(sharps),
1123 CharClassesStatus::RawStringPrefix(sharps) => {
1124 char_kind = FullCodeCharKind::InString;
1126 '#' => CharClassesStatus::RawStringPrefix(sharps + 1),
1127 '"' => CharClassesStatus::LitRawString(sharps),
1128 _ => CharClassesStatus::Normal, // Unreachable.
1131 CharClassesStatus::RawStringSuffix(sharps) => {
1135 CharClassesStatus::Normal
1137 char_kind = FullCodeCharKind::InString;
1138 CharClassesStatus::RawStringSuffix(sharps - 1)
1141 _ => CharClassesStatus::Normal, // Unreachable
1144 CharClassesStatus::LitString => {
1145 char_kind = FullCodeCharKind::InString;
1147 '"' => CharClassesStatus::Normal,
1148 '\\' => CharClassesStatus::LitStringEscape,
1149 _ => CharClassesStatus::LitString,
1152 CharClassesStatus::LitStringEscape => {
1153 char_kind = FullCodeCharKind::InString;
1154 CharClassesStatus::LitString
1156 CharClassesStatus::LitChar => match chr {
1157 '\\' => CharClassesStatus::LitCharEscape,
1158 '\'' => CharClassesStatus::Normal,
1159 _ => CharClassesStatus::LitChar,
1161 CharClassesStatus::LitCharEscape => CharClassesStatus::LitChar,
1162 CharClassesStatus::Normal => match chr {
1163 'r' => match self.base.peek().map(|c| c.get_char()) {
1164 Some('#') | Some('"') => {
1165 char_kind = FullCodeCharKind::InString;
1166 CharClassesStatus::RawStringPrefix(0)
1168 _ => CharClassesStatus::Normal,
1171 char_kind = FullCodeCharKind::InString;
1172 CharClassesStatus::LitString
1175 // HACK: Work around mut borrow.
1176 match self.base.peek() {
1177 Some(next) if next.get_char() == '\\' => {
1178 self.status = CharClassesStatus::LitChar;
1179 return Some((char_kind, item));
1184 match self.base.peek() {
1185 Some(next) if next.get_char() == '\'' => CharClassesStatus::LitChar,
1186 _ => CharClassesStatus::Normal,
1189 '/' => match self.base.peek() {
1190 Some(next) if next.get_char() == '*' => {
1191 self.status = CharClassesStatus::BlockCommentOpening(1);
1192 return Some((FullCodeCharKind::StartComment, item));
1194 Some(next) if next.get_char() == '/' => {
1195 self.status = CharClassesStatus::LineComment;
1196 return Some((FullCodeCharKind::StartComment, item));
1198 _ => CharClassesStatus::Normal,
1200 _ => CharClassesStatus::Normal,
1202 CharClassesStatus::BlockComment(deepness) => {
1203 assert_ne!(deepness, 0);
1204 self.status = match self.base.peek() {
1205 Some(next) if next.get_char() == '/' && chr == '*' => {
1206 CharClassesStatus::BlockCommentClosing(deepness - 1)
1208 Some(next) if next.get_char() == '*' && chr == '/' => {
1209 CharClassesStatus::BlockCommentOpening(deepness + 1)
1211 _ => CharClassesStatus::BlockComment(deepness),
1213 return Some((FullCodeCharKind::InComment, item));
1215 CharClassesStatus::BlockCommentOpening(deepness) => {
1216 assert_eq!(chr, '*');
1217 self.status = CharClassesStatus::BlockComment(deepness);
1218 return Some((FullCodeCharKind::InComment, item));
1220 CharClassesStatus::BlockCommentClosing(deepness) => {
1221 assert_eq!(chr, '/');
1223 self.status = CharClassesStatus::Normal;
1224 return Some((FullCodeCharKind::EndComment, item));
1226 self.status = CharClassesStatus::BlockComment(deepness);
1227 return Some((FullCodeCharKind::InComment, item));
1230 CharClassesStatus::LineComment => match chr {
1232 self.status = CharClassesStatus::Normal;
1233 return Some((FullCodeCharKind::EndComment, item));
1236 self.status = CharClassesStatus::LineComment;
1237 return Some((FullCodeCharKind::InComment, item));
1241 Some((char_kind, item))
1245 /// An iterator over the lines of a string, paired with the char kind at the
1246 /// end of the line.
1247 pub struct LineClasses<'a> {
1248 base: iter::Peekable<CharClasses<std::str::Chars<'a>>>,
1249 kind: FullCodeCharKind,
1252 impl<'a> LineClasses<'a> {
1253 pub fn new(s: &'a str) -> Self {
1255 base: CharClasses::new(s.chars()).peekable(),
1256 kind: FullCodeCharKind::Normal,
1261 impl<'a> Iterator for LineClasses<'a> {
1262 type Item = (FullCodeCharKind, String);
1264 fn next(&mut self) -> Option<Self::Item> {
1267 let mut line = String::new();
1269 let start_class = match self.base.peek() {
1270 Some((kind, _)) => *kind,
1271 None => FullCodeCharKind::Normal,
1274 while let Some((kind, c)) = self.base.next() {
1276 self.kind = match (start_class, kind) {
1277 (FullCodeCharKind::Normal, FullCodeCharKind::InString) => {
1278 FullCodeCharKind::StartString
1280 (FullCodeCharKind::InString, FullCodeCharKind::Normal) => {
1281 FullCodeCharKind::EndString
1291 Some((self.kind, line))
1295 /// Iterator over functional and commented parts of a string. Any part of a string is either
1296 /// functional code, either *one* block comment, either *one* line comment. Whitespace between
1297 /// comments is functional code. Line comments contain their ending newlines.
1298 struct UngroupedCommentCodeSlices<'a> {
1300 iter: iter::Peekable<CharClasses<std::str::CharIndices<'a>>>,
1303 impl<'a> UngroupedCommentCodeSlices<'a> {
1304 fn new(code: &'a str) -> UngroupedCommentCodeSlices<'a> {
1305 UngroupedCommentCodeSlices {
1307 iter: CharClasses::new(code.char_indices()).peekable(),
1312 impl<'a> Iterator for UngroupedCommentCodeSlices<'a> {
1313 type Item = (CodeCharKind, usize, &'a str);
1315 fn next(&mut self) -> Option<Self::Item> {
1316 let (kind, (start_idx, _)) = self.iter.next()?;
1318 FullCodeCharKind::Normal | FullCodeCharKind::InString => {
1319 // Consume all the Normal code
1320 while let Some(&(char_kind, _)) = self.iter.peek() {
1321 if char_kind.is_comment() {
1324 let _ = self.iter.next();
1327 FullCodeCharKind::StartComment => {
1328 // Consume the whole comment
1329 while let Some((FullCodeCharKind::InComment, (_, _))) = self.iter.next() {}
1333 let slice = match self.iter.peek() {
1334 Some(&(_, (end_idx, _))) => &self.slice[start_idx..end_idx],
1335 None => &self.slice[start_idx..],
1338 if kind.is_comment() {
1339 CodeCharKind::Comment
1341 CodeCharKind::Normal
1349 /// Iterator over an alternating sequence of functional and commented parts of
1350 /// a string. The first item is always a, possibly zero length, subslice of
1351 /// functional text. Line style comments contain their ending newlines.
1352 pub struct CommentCodeSlices<'a> {
1354 last_slice_kind: CodeCharKind,
1355 last_slice_end: usize,
1358 impl<'a> CommentCodeSlices<'a> {
1359 pub fn new(slice: &'a str) -> CommentCodeSlices<'a> {
1362 last_slice_kind: CodeCharKind::Comment,
1368 impl<'a> Iterator for CommentCodeSlices<'a> {
1369 type Item = (CodeCharKind, usize, &'a str);
1371 fn next(&mut self) -> Option<Self::Item> {
1372 if self.last_slice_end == self.slice.len() {
1376 let mut sub_slice_end = self.last_slice_end;
1377 let mut first_whitespace = None;
1378 let subslice = &self.slice[self.last_slice_end..];
1379 let mut iter = CharClasses::new(subslice.char_indices());
1381 for (kind, (i, c)) in &mut iter {
1382 let is_comment_connector = self.last_slice_kind == CodeCharKind::Normal
1383 && &subslice[..2] == "//"
1384 && [' ', '\t'].contains(&c);
1386 if is_comment_connector && first_whitespace.is_none() {
1387 first_whitespace = Some(i);
1390 if kind.to_codecharkind() == self.last_slice_kind && !is_comment_connector {
1391 let last_index = match first_whitespace {
1395 sub_slice_end = self.last_slice_end + last_index;
1399 if !is_comment_connector {
1400 first_whitespace = None;
1404 if let (None, true) = (iter.next(), sub_slice_end == self.last_slice_end) {
1405 // This was the last subslice.
1406 sub_slice_end = match first_whitespace {
1407 Some(i) => self.last_slice_end + i,
1408 None => self.slice.len(),
1412 let kind = match self.last_slice_kind {
1413 CodeCharKind::Comment => CodeCharKind::Normal,
1414 CodeCharKind::Normal => CodeCharKind::Comment,
1418 self.last_slice_end,
1419 &self.slice[self.last_slice_end..sub_slice_end],
1421 self.last_slice_end = sub_slice_end;
1422 self.last_slice_kind = kind;
1428 /// Checks is `new` didn't miss any comment from `span`, if it removed any, return previous text
1429 /// (if it fits in the width/offset, else return None), else return `new`
1430 pub fn recover_comment_removed(
1433 context: &RewriteContext,
1434 ) -> Option<String> {
1435 let snippet = context.snippet(span);
1436 if snippet != new && changed_comment_content(snippet, &new) {
1437 // We missed some comments. Warn and keep the original text.
1438 if context.config.error_on_unformatted() {
1439 context.report.append(
1440 context.source_map.span_to_filename(span).into(),
1441 vec![FormattingError::from_span(
1443 &context.source_map,
1444 ErrorKind::LostComment,
1448 Some(snippet.to_owned())
1454 pub fn filter_normal_code(code: &str) -> String {
1455 let mut buffer = String::with_capacity(code.len());
1456 LineClasses::new(code).for_each(|(kind, line)| match kind {
1457 FullCodeCharKind::Normal
1458 | FullCodeCharKind::StartString
1459 | FullCodeCharKind::InString
1460 | FullCodeCharKind::EndString => {
1461 buffer.push_str(&line);
1466 if !code.ends_with('\n') && buffer.ends_with('\n') {
1472 /// Return true if the two strings of code have the same payload of comments.
1473 /// The payload of comments is everything in the string except:
1474 /// - actual code (not comments)
1475 /// - comment start/end marks
1477 /// - '*' at the beginning of lines in block comments
1478 fn changed_comment_content(orig: &str, new: &str) -> bool {
1479 // Cannot write this as a fn since we cannot return types containing closures
1480 let code_comment_content = |code| {
1481 let slices = UngroupedCommentCodeSlices::new(code);
1483 .filter(|&(ref kind, _, _)| *kind == CodeCharKind::Comment)
1484 .flat_map(|(_, _, s)| CommentReducer::new(s))
1486 let res = code_comment_content(orig).ne(code_comment_content(new));
1488 "comment::changed_comment_content: {}\norig: '{}'\nnew: '{}'\nraw_old: {}\nraw_new: {}",
1492 code_comment_content(orig).collect::<String>(),
1493 code_comment_content(new).collect::<String>()
1498 /// Iterator over the 'payload' characters of a comment.
1499 /// It skips whitespace, comment start/end marks, and '*' at the beginning of lines.
1500 /// The comment must be one comment, ie not more than one start mark (no multiple line comments,
1502 struct CommentReducer<'a> {
1504 at_start_line: bool,
1505 iter: std::str::Chars<'a>,
1508 impl<'a> CommentReducer<'a> {
1509 fn new(comment: &'a str) -> CommentReducer<'a> {
1510 let is_block = comment.starts_with("/*");
1511 let comment = remove_comment_header(comment);
1514 at_start_line: false, // There are no supplementary '*' on the first line
1515 iter: comment.chars(),
1520 impl<'a> Iterator for CommentReducer<'a> {
1523 fn next(&mut self) -> Option<Self::Item> {
1525 let mut c = self.iter.next()?;
1526 if self.is_block && self.at_start_line {
1527 while c.is_whitespace() {
1528 c = self.iter.next()?;
1530 // Ignore leading '*'
1532 c = self.iter.next()?;
1534 } else if c == '\n' {
1535 self.at_start_line = true;
1537 if !c.is_whitespace() {
1544 fn remove_comment_header(comment: &str) -> &str {
1545 if comment.starts_with("///") || comment.starts_with("//!") {
1547 } else if comment.starts_with("//") {
1549 } else if (comment.starts_with("/**") && !comment.starts_with("/**/"))
1550 || comment.starts_with("/*!")
1552 &comment[3..comment.len() - 2]
1555 comment.starts_with("/*"),
1556 format!("string '{}' is not a comment", comment)
1558 &comment[2..comment.len() - 2]
1565 use shape::{Indent, Shape};
1569 let mut iter = CharClasses::new("//\n\n".chars());
1571 assert_eq!((FullCodeCharKind::StartComment, '/'), iter.next().unwrap());
1572 assert_eq!((FullCodeCharKind::InComment, '/'), iter.next().unwrap());
1573 assert_eq!((FullCodeCharKind::EndComment, '\n'), iter.next().unwrap());
1574 assert_eq!((FullCodeCharKind::Normal, '\n'), iter.next().unwrap());
1575 assert_eq!(None, iter.next());
1579 fn comment_code_slices() {
1580 let input = "code(); /* test */ 1 + 1";
1581 let mut iter = CommentCodeSlices::new(input);
1583 assert_eq!((CodeCharKind::Normal, 0, "code(); "), iter.next().unwrap());
1585 (CodeCharKind::Comment, 8, "/* test */"),
1586 iter.next().unwrap()
1588 assert_eq!((CodeCharKind::Normal, 18, " 1 + 1"), iter.next().unwrap());
1589 assert_eq!(None, iter.next());
1593 fn comment_code_slices_two() {
1594 let input = "// comment\n test();";
1595 let mut iter = CommentCodeSlices::new(input);
1597 assert_eq!((CodeCharKind::Normal, 0, ""), iter.next().unwrap());
1599 (CodeCharKind::Comment, 0, "// comment\n"),
1600 iter.next().unwrap()
1603 (CodeCharKind::Normal, 11, " test();"),
1604 iter.next().unwrap()
1606 assert_eq!(None, iter.next());
1610 fn comment_code_slices_three() {
1611 let input = "1 // comment\n // comment2\n\n";
1612 let mut iter = CommentCodeSlices::new(input);
1614 assert_eq!((CodeCharKind::Normal, 0, "1 "), iter.next().unwrap());
1616 (CodeCharKind::Comment, 2, "// comment\n // comment2\n"),
1617 iter.next().unwrap()
1619 assert_eq!((CodeCharKind::Normal, 29, "\n"), iter.next().unwrap());
1620 assert_eq!(None, iter.next());
1625 fn format_comments() {
1626 let mut wrap_normalize_config: ::config::Config = Default::default();
1627 wrap_normalize_config.set().wrap_comments(true);
1628 wrap_normalize_config.set().normalize_comments(true);
1630 let mut wrap_config: ::config::Config = Default::default();
1631 wrap_config.set().wrap_comments(true);
1633 let comment = rewrite_comment(" //test",
1635 Shape::legacy(100, Indent::new(0, 100)),
1636 &wrap_normalize_config).unwrap();
1637 assert_eq!("/* test */", comment);
1639 let comment = rewrite_comment("// comment on a",
1641 Shape::legacy(10, Indent::empty()),
1642 &wrap_normalize_config).unwrap();
1643 assert_eq!("// comment\n// on a", comment);
1645 let comment = rewrite_comment("// A multi line comment\n // between args.",
1647 Shape::legacy(60, Indent::new(0, 12)),
1648 &wrap_normalize_config).unwrap();
1649 assert_eq!("// A multi line comment\n // between args.", comment);
1651 let input = "// comment";
1654 let comment = rewrite_comment(input,
1656 Shape::legacy(9, Indent::new(0, 69)),
1657 &wrap_normalize_config).unwrap();
1658 assert_eq!(expected, comment);
1660 let comment = rewrite_comment("/* trimmed */",
1662 Shape::legacy(100, Indent::new(0, 100)),
1663 &wrap_normalize_config).unwrap();
1664 assert_eq!("/* trimmed */", comment);
1666 // check that different comment style are properly recognised
1667 let comment = rewrite_comment(r#"/// test1
1673 Shape::legacy(100, Indent::new(0, 0)),
1674 &wrap_normalize_config).unwrap();
1675 assert_eq!("/// test1\n/// test2\n// test3", comment);
1677 // check that the blank line marks the end of a commented paragraph
1678 let comment = rewrite_comment(r#"// test1
1682 Shape::legacy(100, Indent::new(0, 0)),
1683 &wrap_normalize_config).unwrap();
1684 assert_eq!("// test1\n\n// test2", comment);
1686 // check that the blank line marks the end of a custom-commented paragraph
1687 let comment = rewrite_comment(r#"//@ test1
1691 Shape::legacy(100, Indent::new(0, 0)),
1692 &wrap_normalize_config).unwrap();
1693 assert_eq!("//@ test1\n\n//@ test2", comment);
1695 // check that bare lines are just indented but left unchanged otherwise
1696 let comment = rewrite_comment(r#"// test1
1703 Shape::legacy(100, Indent::new(0, 0)),
1704 &wrap_config).unwrap();
1705 assert_eq!("// test1\n/*\n a bare line!\n\n another bare line!\n*/", comment);
1708 // This is probably intended to be a non-test fn, but it is not used. I'm
1709 // keeping it around unless it helps us test stuff.
1710 fn uncommented(text: &str) -> String {
1711 CharClasses::new(text.chars())
1712 .filter_map(|(s, c)| match s {
1713 FullCodeCharKind::Normal | FullCodeCharKind::InString => Some(c),
1720 fn test_uncommented() {
1721 assert_eq!(&uncommented("abc/*...*/"), "abc");
1723 &uncommented("// .... /* \n../* /* *** / */ */a/* // */c\n"),
1726 assert_eq!(&uncommented("abc \" /* */\" qsdf"), "abc \" /* */\" qsdf");
1730 fn test_contains_comment() {
1731 assert_eq!(contains_comment("abc"), false);
1732 assert_eq!(contains_comment("abc // qsdf"), true);
1733 assert_eq!(contains_comment("abc /* kqsdf"), true);
1734 assert_eq!(contains_comment("abc \" /* */\" qsdf"), false);
1738 fn test_find_uncommented() {
1739 fn check(haystack: &str, needle: &str, expected: Option<usize>) {
1740 assert_eq!(expected, haystack.find_uncommented(needle));
1743 check("/*/ */test", "test", Some(6));
1744 check("//test\ntest", "test", Some(7));
1745 check("/* comment only */", "whatever", None);
1747 "/* comment */ some text /* more commentary */ result",
1751 check("sup // sup", "p", Some(2));
1752 check("sup", "x", None);
1753 check(r#"π? /**/ π is nice!"#, r#"π is nice"#, Some(9));
1754 check("/*sup yo? \n sup*/ sup", "p", Some(20));
1755 check("hel/*lohello*/lo", "hello", None);
1756 check("acb", "ab", None);
1757 check(",/*A*/ ", ",", Some(0));
1758 check("abc", "abc", Some(0));
1759 check("/* abc */", "abc", None);
1760 check("/**/abc/* */", "abc", Some(4));
1761 check("\"/* abc */\"", "abc", Some(4));
1762 check("\"/* abc", "abc", Some(4));
1766 fn test_remove_trailing_white_spaces() {
1767 let s = " r#\"\n test\n \"#";
1768 assert_eq!(remove_trailing_white_spaces(&s), s);
1772 fn test_filter_normal_code() {
1775 println!("hello, world");
1778 assert_eq!(s, filter_normal_code(s));
1779 let s_with_comment = r#"
1782 println!("hello, world");
1785 assert_eq!(s, filter_normal_code(s_with_comment));