-// Copyright 2018 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.
-
use syntax::ast;
-use config::lists::*;
-use config::IndentStyle;
-use rewrite::{Rewrite, RewriteContext};
-use shape::Shape;
-use utils::{first_line_width, is_single_line, last_line_width, trimmed_last_line_width, wrap_str};
+use crate::config::lists::*;
+use crate::config::IndentStyle;
+use crate::rewrite::{Rewrite, RewriteContext};
+use crate::shape::Shape;
+use crate::utils::{
+ first_line_width, is_single_line, last_line_width, trimmed_last_line_width, wrap_str,
+};
/// Sigils that decorate a binop pair.
#[derive(new, Clone, Copy)]
pub(crate) fn rewrite_all_pairs(
expr: &ast::Expr,
shape: Shape,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
) -> Option<String> {
- // First we try formatting on one line.
- if let Some(list) = expr.flatten(false) {
- if let Some(r) = rewrite_pairs_one_line(&list, shape, context) {
- return Some(r);
- }
- }
-
- // We can't format on line, so try many. When we flatten here we make sure
- // to only flatten pairs with the same operator, that way we don't
- // necessarily need one line per sub-expression, but we don't do anything
- // too funny wrt precedence.
- expr.flatten(true)
- .and_then(|list| rewrite_pairs_multiline(&list, shape, context))
+ expr.flatten(context, shape).and_then(|list| {
+ // First we try formatting on one line.
+ rewrite_pairs_one_line(&list, shape, context)
+ .or_else(|| rewrite_pairs_multiline(&list, shape, context))
+ })
}
// This may return a multi-line result since we allow the last expression to go
// multiline in a 'single line' formatting.
fn rewrite_pairs_one_line<T: Rewrite>(
- list: &PairList<T>,
+ list: &PairList<'_, '_, T>,
shape: Shape,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
) -> Option<String> {
assert!(list.list.len() >= 2, "Not a pair?");
let mut result = String::new();
let base_shape = shape.block();
- for (e, s) in list.list.iter().zip(list.separators.iter()) {
- let cur_shape = base_shape.offset_left(last_line_width(&result))?;
- let rewrite = e.rewrite(context, cur_shape)?;
+ for ((_, rewrite), s) in list.list.iter().zip(list.separators.iter()) {
+ if let Some(rewrite) = rewrite {
+ if !is_single_line(&rewrite) || result.len() > shape.width {
+ return None;
+ }
- if !is_single_line(&rewrite) || result.len() > shape.width {
+ result.push_str(&rewrite);
+ result.push(' ');
+ result.push_str(s);
+ result.push(' ');
+ } else {
return None;
}
-
- result.push_str(&rewrite);
- result.push(' ');
- result.push_str(s);
- result.push(' ');
}
let prefix_len = result.len();
- let last = list.list.last().unwrap();
+ let last = list.list.last()?.0;
let cur_shape = base_shape.offset_left(last_line_width(&result))?;
let last_rewrite = last.rewrite(context, cur_shape)?;
result.push_str(&last_rewrite);
}
fn rewrite_pairs_multiline<T: Rewrite>(
- list: &PairList<T>,
+ list: &PairList<'_, '_, T>,
shape: Shape,
- context: &RewriteContext,
+ context: &RewriteContext<'_>,
) -> Option<String> {
let rhs_offset = shape.rhs_overhead(&context.config);
let nested_shape = (match context.config.indent_style() {
let indent_str = nested_shape.indent.to_string_with_newline(context.config);
let mut result = String::new();
- let rewrite = list.list[0].rewrite(context, shape)?;
- result.push_str(&rewrite);
+ result.push_str(&list.list[0].1.as_ref()?);
- for (e, s) in list.list[1..].iter().zip(list.separators.iter()) {
+ for ((e, default_rw), s) in list.list[1..].iter().zip(list.separators.iter()) {
// The following test checks if we should keep two subexprs on the same
// line. We do this if not doing so would create an orphan and there is
// enough space to do so.
}
}
- let nested_overhead = s.len() + 1;
- let line_shape = match context.config.binop_separator() {
+ match context.config.binop_separator() {
SeparatorPlace::Back => {
result.push(' ');
result.push_str(s);
result.push_str(&indent_str);
- nested_shape.sub_width(nested_overhead)?
}
SeparatorPlace::Front => {
result.push_str(&indent_str);
result.push_str(s);
result.push(' ');
- nested_shape.offset_left(nested_overhead)?
}
- };
+ }
- let rewrite = e.rewrite(context, line_shape)?;
- result.push_str(&rewrite);
+ result.push_str(&default_rw.as_ref()?);
}
Some(result)
}
pub(crate) fn rewrite_pair<LHS, RHS>(
lhs: &LHS,
rhs: &RHS,
- pp: PairParts,
- context: &RewriteContext,
+ pp: PairParts<'_>,
+ context: &RewriteContext<'_>,
shape: Shape,
separator_place: SeparatorPlace,
) -> Option<String>
// A pair which forms a tree and can be flattened (e.g., binops).
trait FlattenPair: Rewrite + Sized {
- // If `_same_op` is `true`, then we only combine binops with the same
- // operator into the list. E.g,, if the source is `a * b + c`, if `_same_op`
- // is true, we make `[(a * b), c]` if `_same_op` is false, we make
- // `[a, b, c]`
- fn flatten(&self, _same_op: bool) -> Option<PairList<Self>> {
+ fn flatten(&self, _: &RewriteContext<'_>, _: Shape) -> Option<PairList<'_, '_, Self>> {
None
}
}
-struct PairList<'a, 'b, T: Rewrite + 'b> {
- list: Vec<&'b T>,
+struct PairList<'a, 'b, T: Rewrite> {
+ list: Vec<(&'b T, Option<String>)>,
separators: Vec<&'a str>,
}
impl FlattenPair for ast::Expr {
- fn flatten(&self, same_op: bool) -> Option<PairList<ast::Expr>> {
- let top_op = match self.node {
+ fn flatten(
+ &self,
+ context: &RewriteContext<'_>,
+ shape: Shape,
+ ) -> Option<PairList<'_, '_, ast::Expr>> {
+ let top_op = match self.kind {
ast::ExprKind::Binary(op, _, _) => op.node,
_ => return None,
};
+ let default_rewrite = |node: &ast::Expr, sep: usize, is_first: bool| {
+ if is_first {
+ return node.rewrite(context, shape);
+ }
+ let nested_overhead = sep + 1;
+ let rhs_offset = shape.rhs_overhead(&context.config);
+ let nested_shape = (match context.config.indent_style() {
+ IndentStyle::Visual => shape.visual_indent(0),
+ IndentStyle::Block => shape.block_indent(context.config.tab_spaces()),
+ })
+ .with_max_width(&context.config)
+ .sub_width(rhs_offset)?;
+ let default_shape = match context.config.binop_separator() {
+ SeparatorPlace::Back => nested_shape.sub_width(nested_overhead)?,
+ SeparatorPlace::Front => nested_shape.offset_left(nested_overhead)?,
+ };
+ node.rewrite(context, default_shape)
+ };
+
// Turn a tree of binop expressions into a list using a depth-first,
// in-order traversal.
let mut stack = vec![];
let mut separators = vec![];
let mut node = self;
loop {
- match node.node {
- ast::ExprKind::Binary(op, ref lhs, _) if !same_op || op.node == top_op => {
+ match node.kind {
+ ast::ExprKind::Binary(op, ref lhs, _) if op.node == top_op => {
stack.push(node);
node = lhs;
}
_ => {
- list.push(node);
+ let op_len = separators.last().map_or(0, |s: &&str| s.len());
+ let rw = default_rewrite(node, op_len, list.is_empty());
+ list.push((node, rw));
if let Some(pop) = stack.pop() {
- match pop.node {
+ match pop.kind {
ast::ExprKind::Binary(op, _, ref rhs) => {
separators.push(op.node.to_string());
node = rhs;
projects / rust.git / blobdiff