use std::iter::Peekable;
use config::lists::*;
-use syntax::codemap::BytePos;
+use syntax::source_map::BytePos;
use comment::{find_comment_end, rewrite_comment, FindUncommented};
use config::{Config, IndentStyle};
use visitor::SnippetProvider;
pub struct ListFormatting<'a> {
- pub tactic: DefinitiveListTactic,
- pub separator: &'a str,
- pub trailing_separator: SeparatorTactic,
- pub separator_place: SeparatorPlace,
- pub shape: Shape,
+ tactic: DefinitiveListTactic,
+ separator: &'a str,
+ trailing_separator: SeparatorTactic,
+ separator_place: SeparatorPlace,
+ shape: Shape,
// Non-expressions, e.g. items, will have a new line at the end of the list.
// Important for comment styles.
- pub ends_with_newline: bool,
+ ends_with_newline: bool,
// Remove newlines between list elements for expressions.
- pub preserve_newline: bool,
- pub config: &'a Config,
+ preserve_newline: bool,
+ // Nested import lists get some special handling for the "Mixed" list type
+ nested: bool,
+ config: &'a Config,
}
impl<'a> ListFormatting<'a> {
+ pub fn new(shape: Shape, config: &'a Config) -> Self {
+ ListFormatting {
+ tactic: DefinitiveListTactic::Vertical,
+ separator: ",",
+ trailing_separator: SeparatorTactic::Never,
+ separator_place: SeparatorPlace::Back,
+ shape,
+ ends_with_newline: true,
+ preserve_newline: false,
+ nested: false,
+ config: config,
+ }
+ }
+
+ pub fn tactic(mut self, tactic: DefinitiveListTactic) -> Self {
+ self.tactic = tactic;
+ self
+ }
+
+ pub fn separator(mut self, separator: &'a str) -> Self {
+ self.separator = separator;
+ self
+ }
+
+ pub fn trailing_separator(mut self, trailing_separator: SeparatorTactic) -> Self {
+ self.trailing_separator = trailing_separator;
+ self
+ }
+
+ pub fn separator_place(mut self, separator_place: SeparatorPlace) -> Self {
+ self.separator_place = separator_place;
+ self
+ }
+
+ pub fn ends_with_newline(mut self, ends_with_newline: bool) -> Self {
+ self.ends_with_newline = ends_with_newline;
+ self
+ }
+
+ pub fn preserve_newline(mut self, preserve_newline: bool) -> Self {
+ self.preserve_newline = preserve_newline;
+ self
+ }
+
+ pub fn nested(mut self, nested: bool) -> Self {
+ self.nested = nested;
+ self
+ }
+
pub fn needs_trailing_separator(&self) -> bool {
match self.trailing_separator {
// We always put separator in front.
}
}
-#[derive(PartialEq, Eq)]
+#[derive(PartialEq, Eq, Debug, Copy, Clone)]
pub enum ListItemCommentStyle {
// Try to keep the comment on the same line with the item.
SameLine,
None,
}
+#[derive(Debug, Clone)]
pub struct ListItem {
// None for comments mean that they are not present.
pub pre_comment: Option<String>,
}
impl ListItem {
+ pub fn empty() -> ListItem {
+ ListItem {
+ pre_comment: None,
+ pre_comment_style: ListItemCommentStyle::None,
+ item: None,
+ post_comment: None,
+ new_lines: false,
+ }
+ }
+
pub fn inner_as_ref(&self) -> &str {
self.item.as_ref().map_or("", |s| s)
}
pub fn is_different_group(&self) -> bool {
- self.inner_as_ref().contains('\n') || self.pre_comment.is_some()
- || self.post_comment
- .as_ref()
- .map_or(false, |s| s.contains('\n'))
+ self.inner_as_ref().contains('\n') || self.pre_comment.is_some() || self
+ .post_comment
+ .as_ref()
+ .map_or(false, |s| s.contains('\n'))
}
pub fn is_multiline(&self) -> bool {
self.inner_as_ref().contains('\n')
- || self.pre_comment
+ || self
+ .pre_comment
.as_ref()
.map_or(false, |s| s.contains('\n'))
- || self.post_comment
+ || self
+ .post_comment
.as_ref()
.map_or(false, |s| s.contains('\n'))
}
- pub fn has_comment(&self) -> bool {
+ pub fn has_single_line_comment(&self) -> bool {
self.pre_comment
.as_ref()
.map_or(false, |comment| comment.trim_left().starts_with("//"))
- || self.post_comment
+ || self
+ .post_comment
.as_ref()
.map_or(false, |comment| comment.trim_left().starts_with("//"))
}
+ pub fn has_comment(&self) -> bool {
+ self.pre_comment.is_some() || self.post_comment.is_some()
+ }
+
pub fn from_str<S: Into<String>>(s: S) -> ListItem {
ListItem {
pre_comment: None,
new_lines: false,
}
}
+
+ // true if the item causes something to be written.
+ fn is_substantial(&self) -> bool {
+ fn empty(s: &Option<String>) -> bool {
+ match *s {
+ Some(ref s) if !s.is_empty() => false,
+ _ => true,
+ }
+ }
+
+ !(empty(&self.pre_comment) && empty(&self.item) && empty(&self.post_comment))
+ }
}
/// The type of separator for lists.
}
impl Separator {
- pub fn len(&self) -> usize {
- match *self {
+ pub fn len(self) -> usize {
+ match self {
// 2 = `, `
Separator::Comma => 2,
// 3 = ` | `
let pre_line_comments = items
.clone()
.into_iter()
- .any(|item| item.as_ref().has_comment());
+ .any(|item| item.as_ref().has_single_line_comment());
let limit = match tactic {
_ if pre_line_comments => return DefinitiveListTactic::Vertical,
- ListTactic::Mixed => return DefinitiveListTactic::Mixed,
ListTactic::Horizontal => return DefinitiveListTactic::Horizontal,
ListTactic::Vertical => return DefinitiveListTactic::Vertical,
ListTactic::LimitedHorizontalVertical(limit) => ::std::cmp::min(width, limit),
- ListTactic::HorizontalVertical => width,
+ ListTactic::Mixed | ListTactic::HorizontalVertical => width,
};
let (sep_count, total_width) = calculate_width(items.clone());
- let total_sep_len = sep.len() * sep_count.checked_sub(1).unwrap_or(0);
+ let total_sep_len = sep.len() * sep_count.saturating_sub(1);
let real_total = total_width + total_sep_len;
- if real_total <= limit && !pre_line_comments
+ if real_total <= limit
+ && !pre_line_comments
&& !items.into_iter().any(|item| item.as_ref().is_multiline())
{
DefinitiveListTactic::Horizontal
} else {
- DefinitiveListTactic::Vertical
+ match tactic {
+ ListTactic::Mixed => DefinitiveListTactic::Mixed,
+ _ => DefinitiveListTactic::Vertical,
+ }
}
}
// Format a list of commented items into a string.
-// TODO: add unit tests
pub fn write_list<I, T>(items: I, formatting: &ListFormatting) -> Option<String>
where
I: IntoIterator<Item = T> + Clone,
let mut item_max_width: Option<usize> = None;
let sep_place =
SeparatorPlace::from_tactic(formatting.separator_place, tactic, formatting.separator);
+ let mut prev_item_had_post_comment = false;
+ let mut prev_item_is_nested_import = false;
let mut line_len = 0;
let indent_str = &formatting.shape.indent.to_string(formatting.config);
item_last_line_width -= indent_str.len();
}
+ if !item.is_substantial() {
+ continue;
+ }
+
match tactic {
DefinitiveListTactic::Horizontal if !first => {
result.push(' ');
result.push(' ');
}
}
- DefinitiveListTactic::Vertical if !first => {
+ DefinitiveListTactic::Vertical
+ if !first && !inner_item.is_empty() && !result.is_empty() =>
+ {
result.push('\n');
result.push_str(indent_str);
}
let total_width = total_item_width(item) + item_sep_len;
// 1 is space between separator and item.
- if line_len > 0 && line_len + 1 + total_width > formatting.shape.width {
+ if (line_len > 0 && line_len + 1 + total_width > formatting.shape.width)
+ || prev_item_had_post_comment
+ || (formatting.nested
+ && (prev_item_is_nested_import || (!first && inner_item.contains("::"))))
+ {
result.push('\n');
result.push_str(indent_str);
line_len = 0;
if formatting.ends_with_newline {
- if last {
- separate = true;
- } else {
- trailing_separator = true;
- }
+ trailing_separator = true;
}
- }
-
- if line_len > 0 {
+ } else if line_len > 0 {
result.push(' ');
line_len += 1;
}
+ if last && formatting.ends_with_newline {
+ separate = formatting.trailing_separator != SeparatorTactic::Never;
+ }
+
line_len += total_width;
}
_ => {}
// Pre-comments
if let Some(ref comment) = item.pre_comment {
// Block style in non-vertical mode.
- let block_mode = tactic != DefinitiveListTactic::Vertical;
+ let block_mode = tactic == DefinitiveListTactic::Horizontal;
// Width restriction is only relevant in vertical mode.
let comment =
rewrite_comment(comment, block_mode, formatting.shape, formatting.config)?;
result.push_str(&comment);
- if tactic == DefinitiveListTactic::Vertical {
- // We cannot keep pre-comments on the same line if the comment if normalized.
- let keep_comment = if formatting.config.normalize_comments()
- || item.pre_comment_style == ListItemCommentStyle::DifferentLine
+ if !inner_item.is_empty() {
+ if tactic == DefinitiveListTactic::Vertical || tactic == DefinitiveListTactic::Mixed
{
- false
+ // We cannot keep pre-comments on the same line if the comment if normalized.
+ let keep_comment = if formatting.config.normalize_comments()
+ || item.pre_comment_style == ListItemCommentStyle::DifferentLine
+ {
+ false
+ } else {
+ // We will try to keep the comment on the same line with the item here.
+ // 1 = ` `
+ let total_width = total_item_width(item) + item_sep_len + 1;
+ total_width <= formatting.shape.width
+ };
+ if keep_comment {
+ result.push(' ');
+ } else {
+ result.push('\n');
+ result.push_str(indent_str);
+ // This is the width of the item (without comments).
+ line_len = item.item.as_ref().map_or(0, |str| str.len());
+ }
} else {
- // We will try to keep the comment on the same line with the item here.
- // 1 = ` `
- let total_width = total_item_width(item) + item_sep_len + 1;
- total_width <= formatting.shape.width
- };
- if keep_comment {
result.push(' ');
- } else {
- result.push('\n');
- result.push_str(indent_str);
}
- } else {
- result.push(' ');
}
item_max_width = None;
}
result.push_str(formatting.separator.trim());
result.push(' ');
}
- result.push_str(&inner_item[..]);
+ result.push_str(inner_item);
// Post-comments
- if tactic != DefinitiveListTactic::Vertical && item.post_comment.is_some() {
+ if tactic == DefinitiveListTactic::Horizontal && item.post_comment.is_some() {
let comment = item.post_comment.as_ref().unwrap();
let formatted_comment = rewrite_comment(
comment,
result.push_str(formatting.separator);
}
- if tactic == DefinitiveListTactic::Vertical && item.post_comment.is_some() {
+ if tactic != DefinitiveListTactic::Horizontal && item.post_comment.is_some() {
let comment = item.post_comment.as_ref().unwrap();
let overhead = last_line_width(&result) + first_line_width(comment.trim());
if !starts_with_newline(comment) {
let mut comment_alignment =
post_comment_alignment(item_max_width, inner_item.len());
- if first_line_width(&formatted_comment) + last_line_width(&result)
- + comment_alignment + 1 > formatting.config.max_width()
+ if first_line_width(&formatted_comment)
+ + last_line_width(&result)
+ + comment_alignment
+ + 1
+ > formatting.config.max_width()
{
item_max_width = None;
formatted_comment = rewrite_post_comment(&mut item_max_width)?;
comment_alignment = post_comment_alignment(item_max_width, inner_item.len());
}
- for _ in 0..(comment_alignment + 1) {
+ for _ in 0..=comment_alignment {
result.push(' ');
}
// An additional space for the missing trailing separator.
item_max_width = None;
}
- if formatting.preserve_newline && !last && tactic == DefinitiveListTactic::Vertical
+ if formatting.preserve_newline
+ && !last
+ && tactic == DefinitiveListTactic::Vertical
&& item.new_lines
{
item_max_width = None;
result.push('\n');
}
+
+ prev_item_had_post_comment = item.post_comment.is_some();
+ prev_item_is_nested_import = inner_item.contains("::");
}
Some(result)
let item = item.as_ref();
let inner_item_width = item.inner_as_ref().len();
if !first
- && (item.is_different_group() || !item.post_comment.is_some()
+ && (item.is_different_group()
+ || item.post_comment.is_none()
|| inner_item_width + overhead > max_budget)
{
return max_width;
}
fn post_comment_alignment(item_max_width: Option<usize>, inner_item_len: usize) -> usize {
- item_max_width
- .and_then(|max_line_width| max_line_width.checked_sub(inner_item_len))
- .unwrap_or(0)
+ item_max_width.unwrap_or(0).saturating_sub(inner_item_len)
}
pub struct ListItems<'a, I, F1, F2, F3>
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>,
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
+ let pre_snippet = self
+ .snippet_provider
.span_to_snippet(mk_sp(self.prev_span_end, (self.get_lo)(&item)))
- .unwrap();
- 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)
- };
+ .unwrap_or("");
+ let (pre_comment, pre_comment_style) = extract_pre_comment(pre_snippet);
// Post-comment
let next_start = match self.inner.peek() {
Some(next_item) => (self.get_lo)(next_item),
None => self.next_span_start,
};
- let post_snippet = self.snippet_provider
+ let post_snippet = self
+ .snippet_provider
.span_to_snippet(mk_sp((self.get_hi)(&item), next_start))
- .unwrap();
-
- 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;
- }
- }
+ .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);
- // 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.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,
shape,
ends_with_newline,
preserve_newline: true,
+ nested: false,
config: context.config,
}
}