//! .qux
//! ```
-use codemap::SpanUtils;
+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 spanned::Spanned;
+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(String, CommentPosition),
}
impl ChainItemKind {
match self {
ChainItemKind::Parent(ref expr) => is_block_expr(context, expr, reps),
ChainItemKind::MethodCall(..) => reps.contains('\n'),
- ChainItemKind::StructField(..) | ChainItemKind::TupleField(..) => false,
+ ChainItemKind::StructField(..)
+ | ChainItemKind::TupleField(..)
+ | ChainItemKind::Comment(..) => false,
}
}
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)))
}
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],
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 {
match subexpr.node {
ast::ExprKind::Try(_) => sub_tries += 1,
_ => {
- children.push(ChainItem::new(context, subexpr, 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 = 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_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 = 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_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.
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 {
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 {
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);
}
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(context, shape) {
Some(rewrite) => root_rewrite.push_str(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;
}
}
fn format_children(&mut self, context: &RewriteContext, child_shape: Shape) -> Option<()> {
- for item in self.shared.children[1..].iter().rev() {
+ for item in &self.shared.children[..self.shared.children.len() - 1] {
let rewrite = item.rewrite(context, child_shape)?;
self.is_block_like
.push(item.kind.is_block_like(context, &rewrite));
};
if !multiline || parent.kind.is_block_like(context, &root_rewrite) {
- let item = &self.shared.children[self.shared.children.len() - 1];
+ 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)?;
}
}
- self.shared.children = &self.shared.children[..self.shared.children.len() - 1];
+ self.shared.children = &self.shared.children[1..];
}
self.shared.rewrites.push(root_rewrite);
}
fn format_children(&mut self, context: &RewriteContext, child_shape: Shape) -> Option<()> {
- for item in self.shared.children[1..].iter().rev() {
+ for item in &self.shared.children[..self.shared.children.len() - 1] {
let rewrite = item.rewrite(context, child_shape)?;
self.shared.rewrites.push(rewrite);
}
_ => 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
+}
projects / rust.git / blobdiff