//! .qux
//! ```
-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 lists::extract_pre_comment;
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, rewrite_ident,
+ self, first_line_width, last_line_extendable, last_line_width, mk_sp, rewrite_ident,
trimmed_last_line_width, wrap_str,
};
use std::borrow::Cow;
use std::cmp::min;
-use std::iter;
use syntax::source_map::{BytePos, Span};
use syntax::{ast, ptr};
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::Parent(ref expr) => utils::is_block_expr(context, expr, reps),
+ ChainItemKind::MethodCall(..)
+ | ChainItemKind::StructField(..)
| ChainItemKind::TupleField(..)
| ChainItemKind::Comment(..) => false,
}
s.chars().all(|c| c == '?')
}
+ fn is_post_comment(s: &str) -> bool {
+ let comment_start_index = s.chars().position(|c| c == '/');
+ if comment_start_index.is_none() {
+ return false;
+ }
+
+ let newline_index = s.chars().position(|c| c == '\n');
+ if newline_index.is_none() {
+ return true;
+ }
+
+ comment_start_index.unwrap() < newline_index.unwrap()
+ }
+
fn handle_post_comment(
post_comment_span: Span,
post_comment_snippet: &str,
// 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 {
+ let trimmed_snippet = trim_tries(post_comment_snippet);
+ if is_post_comment(&trimmed_snippet) {
children.push(ChainItem::comment(
post_comment_span,
- post_comment,
+ trimmed_snippet.trim().to_owned(),
CommentPosition::Back,
));
- *prev_span_end = *prev_span_end + BytePos(comment_end as u32);
+ *prev_span_end = post_comment_span.hi();
}
}
// 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);
+ 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(
// Parent is the first item in the chain, e.g., `foo` in `foo.bar.baz()`.
// Root is the parent plus any other chain items placed on the first line to
// avoid an orphan. E.g.,
- // ```
+ // ```ignore
// foo.bar
// .baz()
// ```
// know whether 'overflowing' the last child make a better formatting:
//
// A chain with overflowing the last child:
- // ```
+ // ```ignore
// parent.child1.child2.last_child(
// a,
// b,
// ```
//
// A chain without overflowing the last child (in vertical layout):
- // ```
+ // ```ignore
// parent
// .child1
// .child2
//
// In particular, overflowing is effective when the last child is a method with a multi-lined
// block-like argument (e.g. closure):
- // ```
+ // ```ignore
// parent.child1.child2.last_child(|a, b, c| {
// let x = foo(a, b, c);
// let y = bar(a, b, c);
shape.width
} else {
min(shape.width, context.config.width_heuristics().chain_width)
- }.saturating_sub(almost_total);
+ }
+ .saturating_sub(almost_total);
let all_in_one_line = !self.children.iter().any(ChainItem::is_comment)
&& self.rewrites.iter().all(|s| !s.contains('\n'))
if all_in_one_line || extendable {
// 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) {
+ let one_line_shape = if context.use_block_indent() {
+ last_shape.offset_left(almost_total)
+ } else {
+ last_shape
+ .visual_indent(almost_total)
+ .sub_width(almost_total)
+ };
+
+ if let Some(one_line_shape) = 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.
}
}
+ let last_shape = if context.use_block_indent() {
+ last_shape
+ } else {
+ child_shape.sub_width(shape.rhs_overhead(context.config) + last.tries)?
+ };
+
last_subexpr_str = last_subexpr_str.or_else(|| last.rewrite(context, last_shape));
self.rewrites.push(last_subexpr_str?);
Some(())
}
- fn join_rewrites(
- &self,
- context: &RewriteContext,
- child_shape: Shape,
- block_like_iter: impl Iterator<Item = bool>,
- ) -> Option<String> {
+ fn join_rewrites(&self, context: &RewriteContext, child_shape: Shape) -> Option<String> {
let connector = if self.fits_single_line {
// Yay, we can put everything on one line.
Cow::from("")
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);
+ let iter = rewrite_iter.zip(children_iter);
- for ((rewrite, prev_is_block_like), chain_item) in iter {
+ for (rewrite, 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(&connector),
}
result.push_str(&rewrite);
}
// Formats a chain using block indent.
struct ChainFormatterBlock<'a> {
shared: ChainFormatterShared<'a>,
- // For each rewrite, whether the corresponding item is block-like.
- is_block_like: Vec<bool>,
+ root_ends_with_block: bool,
}
impl<'a> ChainFormatterBlock<'a> {
fn new(chain: &'a Chain) -> ChainFormatterBlock<'a> {
ChainFormatterBlock {
shared: ChainFormatterShared::new(chain),
- is_block_like: Vec::with_capacity(chain.children.len() + 1),
+ root_ends_with_block: false,
}
}
}
None => break,
}
- root_ends_with_block = item.kind.is_block_like(context, &root_rewrite);
+ root_ends_with_block = last_line_extendable(&root_rewrite);
self.shared.children = &self.shared.children[1..];
if self.shared.children.is_empty() {
break;
}
}
- self.is_block_like.push(root_ends_with_block);
self.shared.rewrites.push(root_rewrite);
+ self.root_ends_with_block = root_ends_with_block;
Some(())
}
fn child_shape(&self, context: &RewriteContext, shape: Shape) -> Option<Shape> {
Some(
- if self.is_block_like[0] {
+ if self.root_ends_with_block {
shape.block_indent(0)
} else {
shape.block_indent(context.config.tab_spaces())
- }.with_max_width(context.config),
+ }
+ .with_max_width(context.config),
)
}
fn format_children(&mut self, context: &RewriteContext, child_shape: Shape) -> Option<()> {
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));
self.shared.rewrites.push(rewrite);
}
Some(())
}
fn join_rewrites(&self, context: &RewriteContext, child_shape: Shape) -> Option<String> {
- self.shared
- .join_rewrites(context, child_shape, self.is_block_like.iter().cloned())
+ self.shared.join_rewrites(context, child_shape)
}
fn pure_root(&mut self) -> Option<String> {
}
fn join_rewrites(&self, context: &RewriteContext, child_shape: Shape) -> Option<String> {
- self.shared
- .join_rewrites(context, child_shape, iter::repeat(false))
+ self.shared.join_rewrites(context, child_shape)
}
fn pure_root(&mut self) -> Option<String> {
}
}
-// States whether an expression's last line exclusively consists of closing
-// parens, braces, and brackets in its idiomatic formatting.
-fn is_block_expr(context: &RewriteContext, expr: &ast::Expr, repr: &str) -> bool {
- match expr.node {
- ast::ExprKind::Mac(..)
- | ast::ExprKind::Call(..)
- | ast::ExprKind::MethodCall(..)
- | ast::ExprKind::Struct(..)
- | ast::ExprKind::While(..)
- | ast::ExprKind::WhileLet(..)
- | ast::ExprKind::If(..)
- | ast::ExprKind::IfLet(..)
- | ast::ExprKind::Block(..)
- | ast::ExprKind::Loop(..)
- | ast::ExprKind::ForLoop(..)
- | ast::ExprKind::Match(..) => repr.contains('\n'),
- ast::ExprKind::Paren(ref expr)
- | ast::ExprKind::Binary(_, _, ref expr)
- | ast::ExprKind::Index(_, ref expr)
- | ast::ExprKind::Unary(_, ref expr)
- | ast::ExprKind::Closure(_, _, _, _, ref expr, _)
- | ast::ExprKind::Try(ref expr)
- | ast::ExprKind::Yield(Some(ref expr)) => is_block_expr(context, expr, repr),
- // This can only be a string lit
- ast::ExprKind::Lit(_) => {
- repr.contains('\n') && trimmed_last_line_width(repr) <= context.config.tab_spaces()
+/// 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),
}
- _ => false,
}
+ if !line_buffer.trim().is_empty() {
+ result.push_str(&line_buffer);
+ }
+ result
}