-// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! Formatting of chained expressions, i.e. expressions which are chained by
-//! dots: struct and enum field access, method calls, and try shorthand (?).
+//! Formatting of chained expressions, i.e., expressions that are chained by
+//! dots: struct and enum field access, method calls, and try shorthand (`?`).
//!
//! Instead of walking these subexpressions one-by-one, as is our usual strategy
//! for expression formatting, we collect maximal sequences of these expressions
//! following values of `chain_indent`:
//! Block:
//!
-//! ```ignore
+//! ```text
//! let foo = {
//! aaaa;
//! bbb;
//!
//! Visual:
//!
-//! ```ignore
+//! ```text
//! let foo = {
//! aaaa;
//! bbb;
//! the braces.
//! Block:
//!
-//! ```ignore
+//! ```text
//! let a = foo.bar
//! .baz()
//! .qux
//!
//! Visual:
//!
-//! ```ignore
+//! ```text
//! let a = foo.bar
//! .baz()
//! .qux
//! ```
-use codemap::SpanUtils;
-use config::IndentStyle;
-use expr::rewrite_call;
-use macros::convert_try_mac;
-use rewrite::{Rewrite, RewriteContext};
-use shape::Shape;
-use utils::{
- first_line_width, last_line_extendable, last_line_width, mk_sp, trimmed_last_line_width,
- wrap_str,
-};
-
use std::borrow::Cow;
use std::cmp::min;
-use std::iter;
-use syntax::codemap::Span;
-use syntax::{ast, ptr};
+use rustc_ast::{ast, ptr};
+use rustc_span::{symbol, BytePos, Span};
+
+use crate::comment::{rewrite_comment, CharClasses, FullCodeCharKind, RichChar};
+use crate::config::{IndentStyle, Version};
+use crate::expr::rewrite_call;
+use crate::lists::extract_pre_comment;
+use crate::macros::convert_try_mac;
+use crate::rewrite::{Rewrite, RewriteContext};
+use crate::shape::Shape;
+use crate::source_map::SpanUtils;
+use crate::utils::{
+ self, first_line_width, last_line_extendable, last_line_width, mk_sp, rewrite_ident,
+ trimmed_last_line_width, wrap_str,
+};
-pub fn rewrite_chain(expr: &ast::Expr, context: &RewriteContext, shape: Shape) -> Option<String> {
+pub(crate) fn rewrite_chain(
+ expr: &ast::Expr,
+ context: &RewriteContext<'_>,
+ shape: Shape,
+) -> Option<String> {
let chain = Chain::from_ast(expr, context);
debug!("rewrite_chain {:?} {:?}", chain, shape);
chain.rewrite(context, shape)
}
+#[derive(Debug)]
+enum CommentPosition {
+ Back,
+ Top,
+}
+
// An expression plus trailing `?`s to be formatted together.
#[derive(Debug)]
struct ChainItem {
Vec<ast::GenericArg>,
Vec<ptr::P<ast::Expr>>,
),
- StructField(ast::Ident),
- TupleField(ast::Ident, bool),
+ StructField(symbol::Ident),
+ TupleField(symbol::Ident, bool),
+ Await,
+ Comment(String, CommentPosition),
}
impl ChainItemKind {
- fn is_block_like(&self, context: &RewriteContext, reps: &str) -> bool {
+ 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(..) => false,
+ ChainItemKind::Parent(ref expr) => utils::is_block_expr(context, expr, reps),
+ ChainItemKind::MethodCall(..)
+ | ChainItemKind::StructField(..)
+ | ChainItemKind::TupleField(..)
+ | ChainItemKind::Await
+ | ChainItemKind::Comment(..) => false,
}
}
fn is_tup_field_access(expr: &ast::Expr) -> bool {
- match expr.node {
+ match expr.kind {
ast::ExprKind::Field(_, ref field) => {
field.name.to_string().chars().all(|c| c.is_digit(10))
}
}
}
- fn from_ast(context: &RewriteContext, expr: &ast::Expr) -> (ChainItemKind, Span) {
- let (kind, span) = match expr.node {
- ast::ExprKind::MethodCall(ref segment, ref expressions) => {
+ fn from_ast(context: &RewriteContext<'_>, expr: &ast::Expr) -> (ChainItemKind, Span) {
+ let (kind, span) = match expr.kind {
+ 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()
+ data.args
+ .iter()
+ .filter_map(|x| match x {
+ ast::AngleBracketedArg::Arg(ref generic_arg) => {
+ Some(generic_arg.clone())
+ }
+ _ => None,
+ })
+ .collect::<Vec<_>>()
} else {
vec![]
}
let span = mk_sp(nested.span.hi(), field.span.hi());
(kind, span)
}
+ ast::ExprKind::Await(ref nested) => {
+ let span = mk_sp(nested.span.hi(), expr.span.hi());
+ (ChainItemKind::Await, span)
+ }
_ => return (ChainItemKind::Parent(expr.clone()), expr.span),
};
}
impl Rewrite for ChainItem {
- fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
+ 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::StructField(ident) => format!(".{}", rewrite_ident(context, ident)),
+ ChainItemKind::TupleField(ident, nested) => format!(
+ "{}.{}",
+ if nested && context.config.version() == Version::One {
+ " "
+ } else {
+ ""
+ },
+ rewrite_ident(context, ident)
+ ),
+ ChainItemKind::Await => ".await".to_owned(),
+ 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 {
+ 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 {
+ matches!(self.kind, ChainItemKind::Comment(..))
+ }
+
fn rewrite_method_call(
- method_name: ast::Ident,
+ method_name: symbol::Ident,
types: &[ast::GenericArg],
args: &[ptr::P<ast::Expr>],
span: Span,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
) -> Option<String> {
let type_str = if types.is_empty() {
format!("::<{}>", type_list.join(", "))
};
- let callee_str = format!(".{}{}", method_name, type_str);
+ let callee_str = format!(".{}{}", rewrite_ident(context, method_name), type_str);
rewrite_call(context, &callee_str, &args[1..], span, shape)
}
}
}
impl Chain {
- fn from_ast(expr: &ast::Expr, context: &RewriteContext) -> Chain {
+ fn from_ast(expr: &ast::Expr, context: &RewriteContext<'_>) -> 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 {
- match subexpr.node {
+ match subexpr.kind {
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: children.into_iter().rev().collect(),
+ fn is_tries(s: &str) -> bool {
+ 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,
+ 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;
+ }
+ let trimmed_snippet = trim_tries(post_comment_snippet);
+ if is_post_comment(&trimmed_snippet) {
+ children.push(ChainItem::comment(
+ post_comment_span,
+ trimmed_snippet.trim().to_owned(),
+ CommentPosition::Back,
+ ));
+ *prev_span_end = post_comment_span.hi();
+ }
+ }
+
+ 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.
// E.g., for input `a.b.c` we return [`a.b.c`, `a.b`, 'a']
- fn make_subexpr_list(expr: &ast::Expr, context: &RewriteContext) -> Vec<ast::Expr> {
+ fn make_subexpr_list(expr: &ast::Expr, context: &RewriteContext
<'_>) -> Vec<ast::Expr> {
let mut subexpr_list = vec![expr.clone()];
while let Some(subexpr) = Self::pop_expr_chain(subexpr_list.last().unwrap(), context) {
// Returns the expression's subexpression, if it exists. When the subexpr
// is a try! macro, we'll convert it to shorthand when the option is set.
- fn pop_expr_chain(expr: &ast::Expr, context: &RewriteContext) -> Option<ast::Expr> {
- match expr.node {
- ast::ExprKind::MethodCall(_, ref expressions) => {
+ fn pop_expr_chain(expr: &ast::Expr, context: &RewriteContext
<'_>) -> Option<ast::Expr> {
+ match expr.kind {
+ ast::ExprKind::MethodCall(_, ref expressions, _) => {
Some(Self::convert_try(&expressions[0], context))
}
- ast::ExprKind::Field(ref subexpr, _) | ast::ExprKind::Try(ref subexpr) => {
- Some(Self::convert_try(subexpr, context))
- }
+ ast::ExprKind::Field(ref subexpr, _)
+ | ast::ExprKind::Try(ref subexpr)
+ | ast::ExprKind::Await(ref subexpr) => Some(Self::convert_try(subexpr, context)),
_ => None,
}
}
- fn convert_try(expr: &ast::Expr, context: &RewriteContext) -> ast::Expr {
- match expr.node {
- ast::ExprKind::Mac(ref mac) if context.config.use_try_shorthand() => {
+ fn convert_try(expr: &ast::Expr, context: &RewriteContext<'_>) -> ast::Expr {
+ match expr.kind {
+ ast::ExprKind::MacCall(ref mac) if context.config.use_try_shorthand() => {
if let Some(subexpr) = convert_try_mac(mac, context) {
subexpr
} else {
}
impl Rewrite for Chain {
- fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
+ fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
debug!("rewrite chain {:?} {:?}", self, shape);
let mut formatter = match context.config.indent_style() {
- IndentStyle::Block => Box::new(ChainFormatterBlock::new(self)) as Box<ChainFormatter>,
- IndentStyle::Visual => Box::new(ChainFormatterVisual::new(self)) as Box<ChainFormatter>,
+ IndentStyle::Block => {
+ Box::new(ChainFormatterBlock::new(self)) as Box<dyn ChainFormatter>
+ }
+ IndentStyle::Visual => {
+ Box::new(ChainFormatterVisual::new(self)) as Box<dyn ChainFormatter>
+ }
};
formatter.format_root(&self.parent, context, shape)?;
// 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.,
- // ```
+ // ```text
// foo.bar
// .baz()
// ```
fn format_root(
&mut self,
parent: &ChainItem,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
) -> Option<()>;
- fn child_shape(&self, context: &RewriteContext, shape: Shape) -> Option<Shape>;
- fn format_children(&mut self, context: &RewriteContext, child_shape: Shape) -> Option<()>;
+ fn child_shape(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<Shape>;
+ fn format_children(&mut self, context: &RewriteContext<'_>, child_shape: Shape) -> Option<()>;
fn format_last_child(
&mut self,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
child_shape: Shape,
) -> Option<()>;
- fn join_rewrites(&self, context: &RewriteContext, child_shape: Shape) -> Option<String>;
+ fn join_rewrites(&self, context: &RewriteContext<'_>, child_shape: Shape) -> Option<String>;
// Returns `Some` if the chain is only a root, None otherwise.
fn pure_root(&mut self) -> Option<String>;
}
// know whether 'overflowing' the last child make a better formatting:
//
// A chain with overflowing the last child:
- // ```
+ // ```text
// parent.child1.child2.last_child(
// a,
// b,
// ```
//
// A chain without overflowing the last child (in vertical layout):
- // ```
+ // ```text
// 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):
- // ```
+ // block-like argument (e.g., closure):
+ // ```text
// parent.child1.child2.last_child(|a, b, c| {
// let x = foo(a, b, c);
// let y = bar(a, b, c);
fn format_last_child(
&mut self,
may_extend: bool,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
child_shape: Shape,
) -> Option<()> {
let almost_total = if extendable {
prev_last_line_width
} else {
- self.rewrites.iter().fold(0, |a, b| a + b.len())
+ self.rewrites
+ .iter()
+ .map(|rw| utils::unicode_str_width(rw))
+ .sum()
} + last.tries;
let one_line_budget = if self.child_count == 1 {
shape.width
} else {
- min(shape.width, context.config.width_heuristics().chain_width)
- }.saturating_sub(almost_total);
+ min(shape.width, context.config.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 {
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("")
} else {
// Use new lines.
- if *context.force_one_line_chain.borrow() {
+ if context.force_one_line_chain.get() {
return None;
}
child_shape.to_string_with_newline(context.config)
let mut rewrite_iter = self.rewrites.iter();
let mut result = rewrite_iter.next().unwrap().clone();
-
- for (rewrite, prev_is_block_like) in rewrite_iter.zip(block_like_iter) {
- if !prev_is_block_like {
- result.push_str(&connector);
+ let children_iter = self.children.iter();
+ let iter = rewrite_iter.zip(children_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),
+ _ => result.push_str(&connector),
}
- result.push_str(&rewrite);
+ result.push_str(rewrite);
}
Some(result)
// 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,
}
}
}
fn format_root(
&mut self,
parent: &ChainItem,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
) -> Option<()> {
let mut root_rewrite: String = parent.rewrite(context, shape)?;
while root_rewrite.len() <= tab_width && !root_rewrite.contains('\n') {
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),
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> {
+ 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<()> {
+ 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 format_last_child(
&mut self,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
child_shape: Shape,
) -> Option<()> {
.format_last_child(true, context, shape, child_shape)
}
- fn join_rewrites(&self, context: &RewriteContext, child_shape: Shape) -> Option<String> {
- self.shared
- .join_rewrites(context, child_shape, self.is_block_like.iter().cloned())
+ fn join_rewrites(&self, context: &RewriteContext<'_>, child_shape: Shape) -> Option<String> {
+ self.shared.join_rewrites(context, child_shape)
}
fn pure_root(&mut self) -> Option<String> {
fn format_root(
&mut self,
parent: &ChainItem,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
) -> Option<()> {
let parent_shape = shape.visual_indent(0);
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)?;
Some(())
}
- fn child_shape(&self, context: &RewriteContext, shape: Shape) -> Option<Shape> {
+ fn child_shape(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<Shape> {
shape
.with_max_width(context.config)
.offset_left(self.offset)
.map(|s| s.visual_indent(0))
}
- fn format_children(&mut self, context: &RewriteContext, child_shape: Shape) -> Option<()> {
+ 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.shared.rewrites.push(rewrite);
fn format_last_child(
&mut self,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
child_shape: Shape,
) -> Option<()> {
.format_last_child(false, context, shape, child_shape)
}
- fn join_rewrites(&self, context: &RewriteContext, child_shape: Shape) -> Option<String> {
- self.shared
- .join_rewrites(context, child_shape, iter::repeat(false))
+ fn join_rewrites(&self, context: &RewriteContext<'_>, child_shape: Shape) -> Option<String> {
+ 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()
+/// Removes 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
}
projects / rust.git / blobdiff