//! .qux
//! ```
-use codemap::SpanUtils;
-use comment::rewrite_comment;
+use comment::{rewrite_comment, CharClasses, FullCodeCharKind, RichChar};
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 source_map::SpanUtils;
use utils::{
first_line_width, last_line_extendable, last_line_width, mk_sp, trimmed_last_line_width,
wrap_str,
use std::cmp::min;
use std::iter;
-use syntax::codemap::Span;
+use syntax::source_map::{BytePos, Span};
use syntax::{ast, ptr};
pub fn rewrite_chain(expr: &ast::Expr, context: &RewriteContext, shape: Shape) -> Option<String> {
chain.rewrite(context, shape)
}
+#[derive(Debug)]
+enum CommentPosition {
+ Back,
+ Top,
+}
+
// An expression plus trailing `?`s to be formatted together.
#[derive(Debug)]
struct ChainItem {
),
StructField(ast::Ident),
TupleField(ast::Ident, bool),
- Comment,
+ Comment(String, CommentPosition),
}
impl ChainItemKind {
ChainItemKind::MethodCall(..) => reps.contains('\n'),
ChainItemKind::StructField(..)
| ChainItemKind::TupleField(..)
- | ChainItemKind::Comment => false,
+ | ChainItemKind::Comment(..) => false,
}
}
ChainItemKind::TupleField(ident, nested) => {
format!("{}.{}", if nested { " " } else { "" }, ident.name)
}
- ChainItemKind::Comment => {
- rewrite_comment(context.snippet(self.span).trim(), false, shape, context.config)?
+ ChainItemKind::Comment(ref comment, _) => {
+ rewrite_comment(comment, false, shape, context.config)?
}
};
Some(format!("{}{}", rewrite, "?".repeat(self.tries)))
ChainItem { kind, tries, span }
}
- fn comment(span: Span) -> ChainItem {
+ fn comment(span: Span, comment: String, pos: CommentPosition) -> ChainItem {
ChainItem {
- kind: ChainItemKind::Comment,
+ kind: ChainItemKind::Comment(comment, pos),
tries: 0,
span,
}
fn is_comment(&self) -> bool {
match self.kind {
- ChainItemKind::Comment => true,
+ ChainItemKind::Comment(..) => true,
_ => false,
}
}
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 = trim_tries(post_comment_snippet);
+ 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_hi = parent.span.hi();
- for chain_item in rev_children.into_iter().rev() {
- let comment_span = mk_sp(prev_hi, chain_item.span.lo());
+ 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 !(context.config.use_try_shorthand()
- || comment_snippet.trim().is_empty()
- || is_tries(comment_snippet.trim()))
- {
- children.push(ChainItem::comment(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 = trim_tries(context.snippet(pre_comment_span));
+ 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_hi = chain_item.span.hi();
+
+ 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 }
min(shape.width, context.config.width_heuristics().chain_width)
}.saturating_sub(almost_total);
- let all_in_one_line =
- !self.children.iter().any(ChainItem::is_comment)
+ 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 {
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);
- } else if rewrite.starts_with('/') {
- // This is comment, add a space before it.
- result.push(' ');
+ 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);
}
while root_rewrite.len() <= tab_width && !root_rewrite.contains('\n') {
let item = &self.shared.children[0];
- if let ChainItemKind::Comment = item.kind {
+ if let ChainItemKind::Comment(..) = item.kind {
break;
}
let shape = shape.offset_left(root_rewrite.len())?;
if !multiline || parent.kind.is_block_like(context, &root_rewrite) {
let item = &self.shared.children[0];
- if let ChainItemKind::Comment = item.kind {
+ if let ChainItemKind::Comment(..) = item.kind {
self.shared.rewrites.push(root_rewrite);
return Some(());
}
_ => false,
}
}
+
+/// Remove try operators (`?`s) that appear in the given string. If removing
+/// them leaves an empty line, remove that line as well unless it is the first
+/// line (we need the first newline for detecting pre/post comment).
+fn trim_tries(s: &str) -> String {
+ let mut result = String::with_capacity(s.len());
+ let mut line_buffer = String::with_capacity(s.len());
+ for (kind, rich_char) in CharClasses::new(s.chars()) {
+ match rich_char.get_char() {
+ '\n' => {
+ if result.is_empty() || !line_buffer.trim().is_empty() {
+ result.push_str(&line_buffer);
+ result.push('\n')
+ }
+ line_buffer.clear();
+ }
+ '?' if kind == FullCodeCharKind::Normal => continue,
+ c => line_buffer.push(c),
+ }
+ }
+ if !line_buffer.trim().is_empty() {
+ result.push_str(&line_buffer);
+ }
+ result
+}