-// 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 comment::{rewrite_comment, CharClasses, FullCodeCharKind, RichChar};
-use config::IndentStyle;
-use expr::rewrite_call;
-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,
- trimmed_last_line_width, wrap_str,
-};
-
use std::borrow::Cow;
use std::cmp::min;
-use syntax::source_map::{BytePos, 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);
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::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::StructField(ident) => format!(".{}", rewrite_ident(context, ident)),
ChainItemKind::TupleField(ident, nested) => format!(
"{}.{}",
- if nested { " " } else { "" },
+ 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)?
}
}
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 is_comment(&self) -> bool {
- match self.kind {
- ChainItemKind::Comment(..) => true,
- _ => false,
- }
+ 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() {
}
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 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,
_ => {
rev_children.push(ChainItem::new(context, subexpr, sub_tries));
// 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)
+ min(shape.width, context.config.chain_width())
}
.saturating_sub(almost_total);
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.
Some(())
}
- fn join_rewrites(&self, context: &RewriteContext, child_shape: Shape) -> 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)
ChainItemKind::Comment(_, CommentPosition::Top) => result.push_str(&connector),
_ => result.push_str(&connector),
}
- result.push_str(&rewrite);
+ result.push_str(rewrite);
}
Some(result)
fn format_root(
&mut self,
parent: &ChainItem,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
) -> Option<()> {
let mut root_rewrite: String = parent.rewrite(context, shape)?;
Some(())
}
- fn child_shape(&self, context: &RewriteContext, shape: Shape) -> Option<Shape> {
+ fn child_shape(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<Shape> {
Some(
if self.root_ends_with_block {
shape.block_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(true, context, shape, child_shape)
}
- fn join_rewrites(&self, context: &RewriteContext, child_shape: Shape) -> Option<String> {
+ fn join_rewrites(&self, context: &RewriteContext<'_>, child_shape: Shape) -> Option<String> {
self.shared.join_rewrites(context, child_shape)
}
fn format_root(
&mut self,
parent: &ChainItem,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
shape: Shape,
) -> Option<()> {
let parent_shape = shape.visual_indent(0);
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> {
+ fn join_rewrites(&self, context: &RewriteContext<'_>, child_shape: Shape) -> Option<String> {
self.shared.join_rewrites(context, child_shape)
}
}
}
-// 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::Array(..)
- | 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()
- }
- _ => false,
- }
-}
-
-/// Remove try operators (`?`s) that appear in the given string. If removing
+/// 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 {
projects / rust.git / blobdiff