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Merge pull request #2899 from topecongiro/chain-with-comments

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Format chains with comment
This commit is contained in:
Nick Cameron 2018-08-07 15:07:23 +12:00 committed by GitHub
commit 66d3924aa8
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5 changed files with 617 additions and 215 deletions
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353
src/chains.rs
View File

@ -65,12 +65,14 @@
//! .qux
//! ```
use codemap::SpanUtils;
use comment::rewrite_comment;
use config::IndentStyle;
use expr::rewrite_call;
use lists::{extract_post_comment, extract_pre_comment, get_comment_end};
use macros::convert_try_mac;
use rewrite::{Rewrite, RewriteContext};
use shape::Shape;
use spanned::Spanned;
use utils::{
first_line_width, last_line_extendable, last_line_width, mk_sp, trimmed_last_line_width,
wrap_str,
@ -80,7 +82,7 @@ use std::borrow::Cow;
use std::cmp::min;
use std::iter;
use syntax::codemap::Span;
use syntax::codemap::{BytePos, Span};
use syntax::{ast, ptr};
pub fn rewrite_chain(expr: &ast::Expr, context: &RewriteContext, shape: Shape) -> Option<String> {
@ -96,64 +98,45 @@ pub fn rewrite_chain(expr: &ast::Expr, context: &RewriteContext, shape: Shape) -
chain.rewrite(context, shape)
}
#[derive(Debug)]
enum CommentPosition {
Back,
Top,
}
// An expression plus trailing `?`s to be formatted together.
#[derive(Debug)]
struct ChainItem {
// FIXME: we can't use a reference here because to convert `try!` to `?` we
// synthesise the AST node. However, I think we could use `Cow` and that
// would remove a lot of cloning.
expr: ast::Expr,
kind: ChainItemKind,
tries: usize,
span: Span,
}
impl Rewrite for ChainItem {
fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
let rewrite = self.expr.rewrite(context, shape.sub_width(self.tries)?)?;
Some(format!("{}{}", rewrite, "?".repeat(self.tries)))
}
// FIXME: we can't use a reference here because to convert `try!` to `?` we
// synthesise the AST node. However, I think we could use `Cow` and that
// would remove a lot of cloning.
#[derive(Debug)]
enum ChainItemKind {
Parent(ast::Expr),
MethodCall(
ast::PathSegment,
Vec<ast::GenericArg>,
Vec<ptr::P<ast::Expr>>,
),
StructField(ast::Ident),
TupleField(ast::Ident, bool),
Comment(String, CommentPosition),
}
impl ChainItem {
// Rewrite the last element in the chain `expr`. E.g., given `a.b.c` we rewrite
// `.c` and any trailing `?`s.
fn rewrite_postfix(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
let shape = shape.sub_width(self.tries)?;
let mut rewrite = match self.expr.node {
ast::ExprKind::MethodCall(ref segment, ref expressions) => {
let types = match segment.args {
Some(ref params) => match **params {
ast::GenericArgs::AngleBracketed(ref data) => &data.args[..],
_ => &[],
},
_ => &[],
};
Self::rewrite_method_call(
segment.ident,
types,
expressions,
self.expr.span,
context,
shape,
)?
}
ast::ExprKind::Field(ref nested, ref field) => {
let space =
if Self::is_tup_field_access(&self.expr) && Self::is_tup_field_access(nested) {
" "
} else {
""
};
let result = format!("{}.{}", space, field.name);
if result.len() <= shape.width {
result
} else {
return None;
}
}
_ => unreachable!(),
};
rewrite.push_str(&"?".repeat(self.tries));
Some(rewrite)
impl ChainItemKind {
fn is_block_like(&self, context: &RewriteContext, reps: &str) -> bool {
match self {
ChainItemKind::Parent(ref expr) => is_block_expr(context, expr, reps),
ChainItemKind::MethodCall(..) => reps.contains('\n'),
ChainItemKind::StructField(..)
| ChainItemKind::TupleField(..)
| ChainItemKind::Comment(..) => false,
}
}
fn is_tup_field_access(expr: &ast::Expr) -> bool {
@ -165,6 +148,81 @@ impl ChainItem {
}
}
fn from_ast(context: &RewriteContext, expr: &ast::Expr) -> (ChainItemKind, Span) {
let (kind, span) = match expr.node {
ast::ExprKind::MethodCall(ref segment, ref expressions) => {
let types = if let Some(ref generic_args) = segment.args {
if let ast::GenericArgs::AngleBracketed(ref data) = **generic_args {
data.args.clone()
} else {
vec![]
}
} else {
vec![]
};
let span = mk_sp(expressions[0].span.hi(), expr.span.hi());
let kind = ChainItemKind::MethodCall(segment.clone(), types, expressions.clone());
(kind, span)
}
ast::ExprKind::Field(ref nested, field) => {
let kind = if Self::is_tup_field_access(expr) {
ChainItemKind::TupleField(field, Self::is_tup_field_access(nested))
} else {
ChainItemKind::StructField(field)
};
let span = mk_sp(nested.span.hi(), field.span.hi());
(kind, span)
}
_ => return (ChainItemKind::Parent(expr.clone()), expr.span),
};
// Remove comments from the span.
let lo = context.snippet_provider.span_before(span, ".");
(kind, mk_sp(lo, span.hi()))
}
}
impl Rewrite for ChainItem {
fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
let shape = shape.sub_width(self.tries)?;
let rewrite = match self.kind {
ChainItemKind::Parent(ref expr) => expr.rewrite(context, shape)?,
ChainItemKind::MethodCall(ref segment, ref types, ref exprs) => {
Self::rewrite_method_call(segment.ident, types, exprs, self.span, context, shape)?
}
ChainItemKind::StructField(ident) => format!(".{}", ident.name),
ChainItemKind::TupleField(ident, nested) => {
format!("{}.{}", if nested { " " } else { "" }, ident.name)
}
ChainItemKind::Comment(ref comment, _) => {
rewrite_comment(comment, false, shape, context.config)?
}
};
Some(format!("{}{}", rewrite, "?".repeat(self.tries)))
}
}
impl ChainItem {
fn new(context: &RewriteContext, expr: &ast::Expr, tries: usize) -> ChainItem {
let (kind, span) = ChainItemKind::from_ast(context, expr);
ChainItem { kind, tries, span }
}
fn comment(span: Span, comment: String, pos: CommentPosition) -> ChainItem {
ChainItem {
kind: ChainItemKind::Comment(comment, pos),
tries: 0,
span,
}
}
fn is_comment(&self) -> bool {
match self.kind {
ChainItemKind::Comment(..) => true,
_ => false,
}
}
fn rewrite_method_call(
method_name: ast::Ident,
types: &[ast::GenericArg],
@ -173,22 +231,17 @@ impl ChainItem {
context: &RewriteContext,
shape: Shape,
) -> Option<String> {
let (lo, type_str) = if types.is_empty() {
(args[0].span.hi(), String::new())
let type_str = if types.is_empty() {
String::new()
} else {
let type_list = types
.iter()
.map(|ty| ty.rewrite(context, shape))
.collect::<Option<Vec<_>>>()?;
let type_str = format!("::<{}>", type_list.join(", "));
(types.last().unwrap().span().hi(), type_str)
format!("::<{}>", type_list.join(", "))
};
let callee_str = format!(".{}{}", method_name, type_str);
let span = mk_sp(lo, span.hi());
rewrite_call(context, &callee_str, &args[1..], span, shape)
}
}
@ -204,25 +257,118 @@ impl Chain {
let subexpr_list = Self::make_subexpr_list(expr, context);
// Un-parse the expression tree into ChainItems
let mut children = vec![];
let mut rev_children = vec![];
let mut sub_tries = 0;
for subexpr in subexpr_list {
for subexpr in &subexpr_list {
match subexpr.node {
ast::ExprKind::Try(_) => sub_tries += 1,
_ => {
children.push(ChainItem {
expr: subexpr,
tries: sub_tries,
});
rev_children.push(ChainItem::new(context, subexpr, sub_tries));
sub_tries = 0;
}
}
}
Chain {
parent: children.pop().unwrap(),
children,
fn is_tries(s: &str) -> bool {
s.chars().all(|c| c == '?')
}
fn handle_post_comment(
post_comment_span: Span,
post_comment_snippet: &str,
prev_span_end: &mut BytePos,
children: &mut Vec<ChainItem>,
) {
let white_spaces: &[_] = &[' ', '\t'];
if post_comment_snippet
.trim_matches(white_spaces)
.starts_with('\n')
{
// No post comment.
return;
}
// HACK: Treat `?`s as separators.
let trimmed_snippet = post_comment_snippet.trim_matches('?');
let comment_end = get_comment_end(trimmed_snippet, "?", "", false);
let maybe_post_comment = extract_post_comment(trimmed_snippet, comment_end, "?")
.and_then(|comment| {
if comment.is_empty() {
None
} else {
Some((comment, comment_end))
}
});
if let Some((post_comment, comment_end)) = maybe_post_comment {
children.push(ChainItem::comment(
post_comment_span,
post_comment,
CommentPosition::Back,
));
*prev_span_end = *prev_span_end + BytePos(comment_end as u32);
}
}
let parent = rev_children.pop().unwrap();
let mut children = vec![];
let mut prev_span_end = parent.span.hi();
let mut iter = rev_children.into_iter().rev().peekable();
if let Some(first_chain_item) = iter.peek() {
let comment_span = mk_sp(prev_span_end, first_chain_item.span.lo());
let comment_snippet = context.snippet(comment_span);
if !is_tries(comment_snippet.trim()) {
handle_post_comment(
comment_span,
comment_snippet,
&mut prev_span_end,
&mut children,
);
}
}
while let Some(chain_item) = iter.next() {
let comment_snippet = context.snippet(chain_item.span);
// FIXME: Figure out the way to get a correct span when converting `try!` to `?`.
let handle_comment =
!(context.config.use_try_shorthand() || is_tries(comment_snippet.trim()));
// Pre-comment
if handle_comment {
let pre_comment_span = mk_sp(prev_span_end, chain_item.span.lo());
let pre_comment_snippet = context.snippet(pre_comment_span);
let pre_comment_snippet = pre_comment_snippet.trim().trim_matches('?');
let (pre_comment, _) = extract_pre_comment(pre_comment_snippet);
match pre_comment {
Some(ref comment) if !comment.is_empty() => {
children.push(ChainItem::comment(
pre_comment_span,
comment.to_owned(),
CommentPosition::Top,
));
}
_ => (),
}
}
prev_span_end = chain_item.span.hi();
children.push(chain_item);
// Post-comment
if !handle_comment || iter.peek().is_none() {
continue;
}
let next_lo = iter.peek().unwrap().span.lo();
let post_comment_span = mk_sp(prev_span_end, next_lo);
let post_comment_snippet = context.snippet(post_comment_span);
handle_post_comment(
post_comment_span,
post_comment_snippet,
&mut prev_span_end,
&mut children,
);
}
Chain { parent, children }
}
// Returns a Vec of the prefixes of the chain.
@ -395,10 +541,9 @@ impl<'a> ChainFormatterShared<'a> {
shape: Shape,
child_shape: Shape,
) -> Option<()> {
let last = &self.children[0];
let extendable =
may_extend && last_line_extendable(&self.rewrites[self.rewrites.len() - 1]);
let prev_last_line_width = last_line_width(&self.rewrites[self.rewrites.len() - 1]);
let last = self.children.last()?;
let extendable = may_extend && last_line_extendable(&self.rewrites[0]);
let prev_last_line_width = last_line_width(&self.rewrites[0]);
// Total of all items excluding the last.
let almost_total = if extendable {
@ -412,8 +557,9 @@ impl<'a> ChainFormatterShared<'a> {
min(shape.width, context.config.width_heuristics().chain_width)
}.saturating_sub(almost_total);
let all_in_one_line =
self.rewrites.iter().all(|s| !s.contains('\n')) && one_line_budget > 0;
let all_in_one_line = !self.children.iter().any(ChainItem::is_comment)
&& self.rewrites.iter().all(|s| !s.contains('\n'))
&& one_line_budget > 0;
let last_shape = if all_in_one_line {
shape.sub_width(last.tries)?
} else if extendable {
@ -427,7 +573,7 @@ impl<'a> ChainFormatterShared<'a> {
// First we try to 'overflow' the last child and see if it looks better than using
// vertical layout.
if let Some(one_line_shape) = last_shape.offset_left(almost_total) {
if let Some(rw) = last.rewrite_postfix(context, one_line_shape) {
if let Some(rw) = last.rewrite(context, one_line_shape) {
// We allow overflowing here only if both of the following conditions match:
// 1. The entire chain fits in a single line except the last child.
// 2. `last_child_str.lines().count() >= 5`.
@ -443,7 +589,7 @@ impl<'a> ChainFormatterShared<'a> {
// better.
let last_shape = child_shape
.sub_width(shape.rhs_overhead(context.config) + last.tries)?;
match last.rewrite_postfix(context, last_shape) {
match last.rewrite(context, last_shape) {
Some(ref new_rw) if !could_fit_single_line => {
last_subexpr_str = Some(new_rw.clone());
}
@ -464,7 +610,7 @@ impl<'a> ChainFormatterShared<'a> {
}
}
last_subexpr_str = last_subexpr_str.or_else(|| last.rewrite_postfix(context, last_shape));
last_subexpr_str = last_subexpr_str.or_else(|| last.rewrite(context, last_shape));
self.rewrites.push(last_subexpr_str?);
Some(())
}
@ -488,10 +634,18 @@ impl<'a> ChainFormatterShared<'a> {
let mut rewrite_iter = self.rewrites.iter();
let mut result = rewrite_iter.next().unwrap().clone();
let children_iter = self.children.iter();
let iter = rewrite_iter.zip(block_like_iter).zip(children_iter);
for (rewrite, prev_is_block_like) in rewrite_iter.zip(block_like_iter) {
if !prev_is_block_like {
result.push_str(&connector);
for ((rewrite, prev_is_block_like), chain_item) in iter {
match chain_item.kind {
ChainItemKind::Comment(_, CommentPosition::Back) => result.push(' '),
ChainItemKind::Comment(_, CommentPosition::Top) => result.push_str(&connector),
_ => {
if !prev_is_block_like {
result.push_str(&connector);
}
}
}
result.push_str(&rewrite);
}
@ -525,20 +679,23 @@ impl<'a> ChainFormatter for ChainFormatterBlock<'a> {
) -> Option<()> {
let mut root_rewrite: String = parent.rewrite(context, shape)?;
let mut root_ends_with_block = is_block_expr(context, &parent.expr, &root_rewrite);
let mut root_ends_with_block = parent.kind.is_block_like(context, &root_rewrite);
let tab_width = context.config.tab_spaces().saturating_sub(shape.offset);
while root_rewrite.len() <= tab_width && !root_rewrite.contains('\n') {
let item = &self.shared.children[self.shared.children.len() - 1];
let item = &self.shared.children[0];
if let ChainItemKind::Comment(..) = item.kind {
break;
}
let shape = shape.offset_left(root_rewrite.len())?;
match &item.rewrite_postfix(context, shape) {
match &item.rewrite(context, shape) {
Some(rewrite) => root_rewrite.push_str(rewrite),
None => break,
}
root_ends_with_block = is_block_expr(context, &item.expr, &root_rewrite);
root_ends_with_block = item.kind.is_block_like(context, &root_rewrite);
self.shared.children = &self.shared.children[..self.shared.children.len() - 1];
self.shared.children = &self.shared.children[1..];
if self.shared.children.is_empty() {
break;
}
@ -559,10 +716,10 @@ impl<'a> ChainFormatter for ChainFormatterBlock<'a> {
}
fn format_children(&mut self, context: &RewriteContext, child_shape: Shape) -> Option<()> {
for item in self.shared.children[1..].iter().rev() {
let rewrite = item.rewrite_postfix(context, child_shape)?;
for item in &self.shared.children[..self.shared.children.len() - 1] {
let rewrite = item.rewrite(context, child_shape)?;
self.is_block_like
.push(is_block_expr(context, &item.expr, &rewrite));
.push(item.kind.is_block_like(context, &rewrite));
self.shared.rewrites.push(rewrite);
}
Some(())
@ -620,24 +777,28 @@ impl<'a> ChainFormatter for ChainFormatterVisual<'a> {
trimmed_last_line_width(&root_rewrite)
};
if !multiline || is_block_expr(context, &parent.expr, &root_rewrite) {
let item = &self.shared.children[self.shared.children.len() - 1];
if !multiline || parent.kind.is_block_like(context, &root_rewrite) {
let item = &self.shared.children[0];
if let ChainItemKind::Comment(..) = item.kind {
self.shared.rewrites.push(root_rewrite);
return Some(());
}
let child_shape = parent_shape
.visual_indent(self.offset)
.sub_width(self.offset)?;
let rewrite = item.rewrite_postfix(context, child_shape)?;
let rewrite = item.rewrite(context, child_shape)?;
match wrap_str(rewrite, context.config.max_width(), shape) {
Some(rewrite) => root_rewrite.push_str(&rewrite),
None => {
// We couldn't fit in at the visual indent, try the last
// indent.
let rewrite = item.rewrite_postfix(context, parent_shape)?;
let rewrite = item.rewrite(context, parent_shape)?;
root_rewrite.push_str(&rewrite);
self.offset = 0;
}
}
self.shared.children = &self.shared.children[..self.shared.children.len() - 1];
self.shared.children = &self.shared.children[1..];
}
self.shared.rewrites.push(root_rewrite);
@ -652,8 +813,8 @@ impl<'a> ChainFormatter for ChainFormatterVisual<'a> {
}
fn format_children(&mut self, context: &RewriteContext, child_shape: Shape) -> Option<()> {
for item in self.shared.children[1..].iter().rev() {
let rewrite = item.rewrite_postfix(context, child_shape)?;
for item in &self.shared.children[..self.shared.children.len() - 1] {
let rewrite = item.rewrite(context, child_shape)?;
self.shared.rewrites.push(rewrite);
}
Some(())

6
src/codemap.rs
View File

@ -51,7 +51,11 @@ impl<'a> SpanUtils for SnippetProvider<'a> {
}
fn span_before(&self, original: Span, needle: &str) -> BytePos {
self.opt_span_before(original, needle).expect("bad span")
self.opt_span_before(original, needle).expect(&format!(
"bad span: {}: {}",
needle,
self.span_to_snippet(original).unwrap()
))
}
fn opt_span_after(&self, original: Span, needle: &str) -> Option<BytePos> {

260
src/lists.rs
View File

@ -564,6 +564,139 @@ where
leave_last: bool,
}
pub fn extract_pre_comment(pre_snippet: &str) -> (Option<String>, ListItemCommentStyle) {
let trimmed_pre_snippet = pre_snippet.trim();
let has_single_line_comment = trimmed_pre_snippet.starts_with("//");
let has_block_comment = trimmed_pre_snippet.starts_with("/*");
if has_single_line_comment {
(
Some(trimmed_pre_snippet.to_owned()),
ListItemCommentStyle::DifferentLine,
)
} else if has_block_comment {
let comment_end = pre_snippet.chars().rev().position(|c| c == '/').unwrap();
if pre_snippet
.chars()
.rev()
.take(comment_end + 1)
.any(|c| c == '\n')
{
(
Some(trimmed_pre_snippet.to_owned()),
ListItemCommentStyle::DifferentLine,
)
} else {
(
Some(trimmed_pre_snippet.to_owned()),
ListItemCommentStyle::SameLine,
)
}
} else {
(None, ListItemCommentStyle::None)
}
}
pub fn extract_post_comment(
post_snippet: &str,
comment_end: usize,
separator: &str,
) -> Option<String> {
let white_space: &[_] = &[' ', '\t'];
// Cleanup post-comment: strip separators and whitespace.
let post_snippet = post_snippet[..comment_end].trim();
let post_snippet_trimmed = if post_snippet.starts_with(|c| c == ',' || c == ':') {
post_snippet[1..].trim_matches(white_space)
} else if post_snippet.starts_with(separator) {
post_snippet[separator.len()..].trim_matches(white_space)
} else if post_snippet.ends_with(',') {
post_snippet[..(post_snippet.len() - 1)].trim_matches(white_space)
} else {
post_snippet
};
if !post_snippet_trimmed.is_empty() {
Some(post_snippet_trimmed.to_owned())
} else {
None
}
}
pub fn get_comment_end(
post_snippet: &str,
separator: &str,
terminator: &str,
is_last: bool,
) -> usize {
if is_last {
return post_snippet
.find_uncommented(terminator)
.unwrap_or_else(|| post_snippet.len());
}
let mut block_open_index = post_snippet.find("/*");
// check if it really is a block comment (and not `//*` or a nested comment)
if let Some(i) = block_open_index {
match post_snippet.find('/') {
Some(j) if j < i => block_open_index = None,
_ if i > 0 && &post_snippet[i - 1..i] == "/" => block_open_index = None,
_ => (),
}
}
let newline_index = post_snippet.find('\n');
if let Some(separator_index) = post_snippet.find_uncommented(separator) {
match (block_open_index, newline_index) {
// Separator before comment, with the next item on same line.
// Comment belongs to next item.
(Some(i), None) if i > separator_index => separator_index + 1,
// Block-style post-comment before the separator.
(Some(i), None) => cmp::max(
find_comment_end(&post_snippet[i..]).unwrap() + i,
separator_index + 1,
),
// Block-style post-comment. Either before or after the separator.
(Some(i), Some(j)) if i < j => cmp::max(
find_comment_end(&post_snippet[i..]).unwrap() + i,
separator_index + 1,
),
// Potential *single* line comment.
(_, Some(j)) if j > separator_index => j + 1,
_ => post_snippet.len(),
}
} else if let Some(newline_index) = newline_index {
// Match arms may not have trailing comma. In any case, for match arms,
// we will assume that the post comment belongs to the next arm if they
// do not end with trailing comma.
newline_index + 1
} else {
0
}
}
// Account for extra whitespace between items. This is fiddly
// because of the way we divide pre- and post- comments.
fn has_extra_newline(post_snippet: &str, comment_end: usize) -> bool {
if post_snippet.is_empty() || comment_end == 0 {
return false;
}
// Everything from the separator to the next item.
let test_snippet = &post_snippet[comment_end - 1..];
let first_newline = test_snippet
.find('\n')
.unwrap_or_else(|| test_snippet.len());
// From the end of the first line of comments.
let test_snippet = &test_snippet[first_newline..];
let first = test_snippet
.find(|c: char| !c.is_whitespace())
.unwrap_or_else(|| test_snippet.len());
// From the end of the first line of comments to the next non-whitespace char.
let test_snippet = &test_snippet[..first];
// There were multiple line breaks which got trimmed to nothing.
count_newlines(test_snippet) > 1
}
impl<'a, T, I, F1, F2, F3> Iterator for ListItems<'a, I, F1, F2, F3>
where
I: Iterator<Item = T>,
@ -574,44 +707,13 @@ where
type Item = ListItem;
fn next(&mut self) -> Option<Self::Item> {
let white_space: &[_] = &[' ', '\t'];
self.inner.next().map(|item| {
let mut new_lines = false;
// Pre-comment
let pre_snippet = self
.snippet_provider
.span_to_snippet(mk_sp(self.prev_span_end, (self.get_lo)(&item)))
.unwrap_or("");
let trimmed_pre_snippet = pre_snippet.trim();
let has_single_line_comment = trimmed_pre_snippet.starts_with("//");
let has_block_comment = trimmed_pre_snippet.starts_with("/*");
let (pre_comment, pre_comment_style) = if has_single_line_comment {
(
Some(trimmed_pre_snippet.to_owned()),
ListItemCommentStyle::DifferentLine,
)
} else if has_block_comment {
let comment_end = pre_snippet.chars().rev().position(|c| c == '/').unwrap();
if pre_snippet
.chars()
.rev()
.take(comment_end + 1)
.any(|c| c == '\n')
{
(
Some(trimmed_pre_snippet.to_owned()),
ListItemCommentStyle::DifferentLine,
)
} else {
(
Some(trimmed_pre_snippet.to_owned()),
ListItemCommentStyle::SameLine,
)
}
} else {
(None, ListItemCommentStyle::None)
};
let (pre_comment, pre_comment_style) = extract_pre_comment(pre_snippet);
// Post-comment
let next_start = match self.inner.peek() {
@ -622,94 +724,16 @@ where
.snippet_provider
.span_to_snippet(mk_sp((self.get_hi)(&item), next_start))
.unwrap_or("");
let comment_end = get_comment_end(
post_snippet,
self.separator,
self.terminator,
self.inner.peek().is_none(),
);
let new_lines = has_extra_newline(post_snippet, comment_end);
let post_comment = extract_post_comment(post_snippet, comment_end, self.separator);
let comment_end = match self.inner.peek() {
Some(..) => {
let mut block_open_index = post_snippet.find("/*");
// check if it really is a block comment (and not `//*` or a nested comment)
if let Some(i) = block_open_index {
match post_snippet.find('/') {
Some(j) if j < i => block_open_index = None,
_ if i > 0 && &post_snippet[i - 1..i] == "/" => block_open_index = None,
_ => (),
}
}
let newline_index = post_snippet.find('\n');
if let Some(separator_index) = post_snippet.find_uncommented(self.separator) {
match (block_open_index, newline_index) {
// Separator before comment, with the next item on same line.
// Comment belongs to next item.
(Some(i), None) if i > separator_index => separator_index + 1,
// Block-style post-comment before the separator.
(Some(i), None) => cmp::max(
find_comment_end(&post_snippet[i..]).unwrap() + i,
separator_index + 1,
),
// Block-style post-comment. Either before or after the separator.
(Some(i), Some(j)) if i < j => cmp::max(
find_comment_end(&post_snippet[i..]).unwrap() + i,
separator_index + 1,
),
// Potential *single* line comment.
(_, Some(j)) if j > separator_index => j + 1,
_ => post_snippet.len(),
}
} else if let Some(newline_index) = newline_index {
// Match arms may not have trailing comma. In any case, for match arms,
// we will assume that the post comment belongs to the next arm if they
// do not end with trailing comma.
newline_index + 1
} else {
0
}
}
None => post_snippet
.find_uncommented(self.terminator)
.unwrap_or_else(|| post_snippet.len()),
};
if !post_snippet.is_empty() && comment_end > 0 {
// Account for extra whitespace between items. This is fiddly
// because of the way we divide pre- and post- comments.
// Everything from the separator to the next item.
let test_snippet = &post_snippet[comment_end - 1..];
let first_newline = test_snippet
.find('\n')
.unwrap_or_else(|| test_snippet.len());
// From the end of the first line of comments.
let test_snippet = &test_snippet[first_newline..];
let first = test_snippet
.find(|c: char| !c.is_whitespace())
.unwrap_or_else(|| test_snippet.len());
// From the end of the first line of comments to the next non-whitespace char.
let test_snippet = &test_snippet[..first];
if count_newlines(test_snippet) > 1 {
// There were multiple line breaks which got trimmed to nothing.
new_lines = true;
}
}
// Cleanup post-comment: strip separators and whitespace.
self.prev_span_end = (self.get_hi)(&item) + BytePos(comment_end as u32);
let post_snippet = post_snippet[..comment_end].trim();
let post_snippet_trimmed = if post_snippet.starts_with(|c| c == ',' || c == ':') {
post_snippet[1..].trim_matches(white_space)
} else if post_snippet.starts_with(self.separator) {
post_snippet[self.separator.len()..].trim_matches(white_space)
} else if post_snippet.ends_with(',') {
post_snippet[..(post_snippet.len() - 1)].trim_matches(white_space)
} else {
post_snippet
};
let post_comment = if !post_snippet_trimmed.is_empty() {
Some(post_snippet_trimmed.to_owned())
} else {
None
};
ListItem {
pre_comment,

95
tests/source/chains_with_comment.rs Normal file
View File

@ -0,0 +1,95 @@
// Chains with comment.
fn main() {
let x = y // comment
.z;
foo // foo
// comment after parent
.x
.y
// comment 1
.bar() // comment after bar()
// comment 2
.foobar
// comment after
// comment 3
.baz(x, y, z);
self.rev_dep_graph
.iter()
// Remove nodes that are not dirty
.filter(|&(unit, _)| dirties.contains(&unit))
// Retain only dirty dependencies of the ones that are dirty
.map(|(k, deps)| {
(
k.clone(),
deps.iter()
.cloned()
.filter(|d| dirties.contains(&d))
.collect(),
)
});
let y = expr /* comment */.kaas()?
// comment
.test();
let loooooooooooooooooooooooooooooooooooooooooong = does_this?.look?.good?.should_we_break?.after_the_first_question_mark?;
let zzzz = expr? // comment after parent
// comment 0
.another??? // comment 1
.another???? // comment 2
.another? // comment 3
.another?;
let y = a.very .loooooooooooooooooooooooooooooooooooooong() /* comment */ .chain()
.inside() /* comment */ .weeeeeeeeeeeeeee()? .test() .0
.x;
parameterized(f,
substs,
def_id,
Ns::Value,
&[],
|tcx| tcx.lookup_item_type(def_id).generics)?;
fooooooooooooooooooooooooooo()?.bar()?.baaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaz()?;
// #2559
App::new("cargo-cache")
.version(crate_version!())
.bin_name("cargo")
.about("Manage cargo cache")
.author("matthiaskrgr")
.subcommand(
SubCommand::with_name("cache")
.version(crate_version!())
.bin_name("cargo-cache")
.about("Manage cargo cache")
.author("matthiaskrgr")
.arg(&list_dirs)
.arg(&remove_dir)
.arg(&gc_repos)
.arg(&info)
.arg(&keep_duplicate_crates) .arg(&dry_run)
.arg(&auto_clean)
.arg(&auto_clean_expensive),
) // subcommand
.arg(&list_dirs);
}
// #2177
impl Foo {
fn dirty_rev_dep_graph(
&self,
dirties: &HashSet<UnitKey>,
) -> HashMap<UnitKey, HashSet<UnitKey>> {
let dirties = self.transitive_dirty_units(dirties);
trace!("transitive_dirty_units: {:?}", dirties);
self.rev_dep_graph.iter()
// Remove nodes that are not dirty
.filter(|&(unit, _)| dirties.contains(&unit))
// Retain only dirty dependencies of the ones that are dirty
.map(|(k, deps)| (k.clone(), deps.iter().cloned().filter(|d| dirties.contains(&d)).collect()))
}
}

118
tests/target/chains_with_comment.rs Normal file
View File

@ -0,0 +1,118 @@
// Chains with comment.
fn main() {
let x = y // comment
.z;
foo // foo
// comment after parent
.x
.y
// comment 1
.bar() // comment after bar()
// comment 2
.foobar
// comment after
// comment 3
.baz(x, y, z);
self.rev_dep_graph
.iter()
// Remove nodes that are not dirty
.filter(|&(unit, _)| dirties.contains(&unit))
// Retain only dirty dependencies of the ones that are dirty
.map(|(k, deps)| {
(
k.clone(),
deps.iter()
.cloned()
.filter(|d| dirties.contains(&d))
.collect(),
)
});
let y = expr
/* comment */
.kaas()?
// comment
.test();
let loooooooooooooooooooooooooooooooooooooooooong = does_this?
.look?
.good?
.should_we_break?
.after_the_first_question_mark?;
let zzzz = expr? // comment after parent
// comment 0
.another??? // comment 1
.another???? // comment 2
.another? // comment 3
.another?;
let y = a
.very
.loooooooooooooooooooooooooooooooooooooong()
/* comment */
.chain()
.inside()
/* comment */
.weeeeeeeeeeeeeee()?
.test()
.0
.x;
parameterized(f, substs, def_id, Ns::Value, &[], |tcx| {
tcx.lookup_item_type(def_id).generics
})?;
fooooooooooooooooooooooooooo()?
.bar()?
.baaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaz()?;
// #2559
App::new("cargo-cache")
.version(crate_version!())
.bin_name("cargo")
.about("Manage cargo cache")
.author("matthiaskrgr")
.subcommand(
SubCommand::with_name("cache")
.version(crate_version!())
.bin_name("cargo-cache")
.about("Manage cargo cache")
.author("matthiaskrgr")
.arg(&list_dirs)
.arg(&remove_dir)
.arg(&gc_repos)
.arg(&info)
.arg(&keep_duplicate_crates)
.arg(&dry_run)
.arg(&auto_clean)
.arg(&auto_clean_expensive),
) // subcommand
.arg(&list_dirs);
}
// #2177
impl Foo {
fn dirty_rev_dep_graph(
&self,
dirties: &HashSet<UnitKey>,
) -> HashMap<UnitKey, HashSet<UnitKey>> {
let dirties = self.transitive_dirty_units(dirties);
trace!("transitive_dirty_units: {:?}", dirties);
self.rev_dep_graph
.iter()
// Remove nodes that are not dirty
.filter(|&(unit, _)| dirties.contains(&unit))
// Retain only dirty dependencies of the ones that are dirty
.map(|(k, deps)| {
(
k.clone(),
deps.iter()
.cloned()
.filter(|d| dirties.contains(&d))
.collect(),
)
})
}
}