use std::borrow::Cow;
use std::cmp::min;
-use std::iter::repeat;
-use syntax::{ast, ptr};
+use config::lists::*;
use syntax::codemap::{BytePos, CodeMap, Span};
+use syntax::parse::token::DelimToken;
+use syntax::{ast, ptr};
use chains::rewrite_chain;
use closures;
use codemap::{LineRangeUtils, SpanUtils};
-use comment::{combine_strs_with_missing_comments, contains_comment, recover_comment_removed,
- rewrite_comment, rewrite_missing_comment, FindUncommented};
+use comment::{
+ combine_strs_with_missing_comments, contains_comment, recover_comment_removed, rewrite_comment,
+ rewrite_missing_comment, CharClasses, FindUncommented,
+};
use config::{Config, ControlBraceStyle, IndentStyle};
-use lists::{definitive_tactic, itemize_list, shape_for_tactic, struct_lit_formatting,
- struct_lit_shape, struct_lit_tactic, write_list, DefinitiveListTactic, ListFormatting,
- ListItem, ListTactic, Separator, SeparatorPlace, SeparatorTactic};
+use lists::{
+ definitive_tactic, itemize_list, shape_for_tactic, struct_lit_formatting, struct_lit_shape,
+ struct_lit_tactic, write_list, ListFormatting, ListItem, Separator,
+};
use macros::{rewrite_macro, MacroArg, MacroPosition};
-use patterns::{can_be_overflowed_pat, TuplePatField};
+use matches::rewrite_match;
+use overflow;
+use patterns::{can_be_overflowed_pat, is_short_pattern, TuplePatField};
use rewrite::{Rewrite, RewriteContext};
use shape::{Indent, Shape};
use spanned::Spanned;
use string::{rewrite_string, StringFormat};
use types::{can_be_overflowed_type, rewrite_path, PathContext};
-use utils::{colon_spaces, contains_skip, count_newlines, extra_offset, first_line_width,
- inner_attributes, last_line_extendable, last_line_width, mk_sp, outer_attributes,
- paren_overhead, ptr_vec_to_ref_vec, semicolon_for_stmt, trimmed_last_line_width,
- wrap_str};
+use utils::{
+ colon_spaces, contains_skip, count_newlines, first_line_width, inner_attributes,
+ last_line_extendable, last_line_width, mk_sp, outer_attributes, ptr_vec_to_ref_vec,
+ semicolon_for_stmt, wrap_str,
+};
use vertical::rewrite_with_alignment;
use visitor::FmtVisitor;
let expr_rw = match expr.node {
ast::ExprKind::Array(ref expr_vec) => rewrite_array(
+ "",
&ptr_vec_to_ref_vec(expr_vec),
- mk_sp(context.codemap.span_after(expr.span, "["), expr.span.hi()),
+ expr.span,
context,
shape,
- false,
+ choose_separator_tactic(context, expr.span),
+ None,
),
ast::ExprKind::Lit(ref l) => rewrite_literal(context, l, shape),
ast::ExprKind::Call(ref callee, ref args) => {
let callee_str = callee.rewrite(context, shape)?;
rewrite_call(context, &callee_str, args, inner_span, shape)
}
- ast::ExprKind::Paren(ref subexpr) => rewrite_paren(context, subexpr, shape),
- ast::ExprKind::Binary(ref op, ref lhs, ref rhs) => {
+ ast::ExprKind::Paren(ref subexpr) => rewrite_paren(context, subexpr, shape, expr.span),
+ ast::ExprKind::Binary(op, ref lhs, ref rhs) => {
// FIXME: format comments between operands and operator
- rewrite_pair(
- &**lhs,
- &**rhs,
- PairParts::new("", &format!(" {} ", context.snippet(op.span)), ""),
- context,
- shape,
- context.config.binop_separator(),
- )
+ rewrite_simple_binaries(context, expr, shape, op).or_else(|| {
+ rewrite_pair(
+ &**lhs,
+ &**rhs,
+ PairParts::new("", &format!(" {} ", context.snippet(op.span)), ""),
+ context,
+ shape,
+ context.config.binop_separator(),
+ )
+ })
}
ast::ExprKind::Unary(ref op, ref subexpr) => rewrite_unary_op(context, op, subexpr, shape),
ast::ExprKind::Struct(ref path, ref fields, ref base) => rewrite_struct_lit(
| ast::ExprKind::While(..)
| ast::ExprKind::WhileLet(..) => to_control_flow(expr, expr_type)
.and_then(|control_flow| control_flow.rewrite(context, shape)),
- ast::ExprKind::Block(ref block) => {
+ // FIXME(topecongiro): Handle label on a block (#2722).
+ ast::ExprKind::Block(ref block, _) => {
match expr_type {
ExprType::Statement => {
if is_unsafe_block(block) {
- block.rewrite(context, shape)
- } else if let rw @ Some(_) = rewrite_empty_block(context, block, shape) {
+ rewrite_block(block, Some(&expr.attrs), context, shape)
+ } else if let rw @ Some(_) =
+ rewrite_empty_block(context, block, Some(&expr.attrs), "", shape)
+ {
// Rewrite block without trying to put it in a single line.
rw
} else {
let prefix = block_prefix(context, block, shape)?;
- rewrite_block_with_visitor(context, &prefix, block, shape, true)
+ rewrite_block_with_visitor(
+ context,
+ &prefix,
+ block,
+ Some(&expr.attrs),
+ shape,
+ true,
+ )
}
}
- ExprType::SubExpression => block.rewrite(context, shape),
+ ExprType::SubExpression => rewrite_block(block, Some(&expr.attrs), context, shape),
}
}
ast::ExprKind::Match(ref cond, ref arms) => {
ast::ExprKind::AssignOp(ref op, ref lhs, ref rhs) => {
rewrite_assignment(context, lhs, rhs, Some(op), shape)
}
- ast::ExprKind::Continue(ref opt_ident) => {
- let id_str = match *opt_ident {
- Some(ident) => format!(" {}", ident.node),
+ ast::ExprKind::Continue(ref opt_label) => {
+ let id_str = match *opt_label {
+ Some(label) => format!(" {}", label.ident),
None => String::new(),
};
Some(format!("continue{}", id_str))
}
- ast::ExprKind::Break(ref opt_ident, ref opt_expr) => {
- let id_str = match *opt_ident {
- Some(ident) => format!(" {}", ident.node),
+ ast::ExprKind::Break(ref opt_label, ref opt_expr) => {
+ let id_str = match *opt_label {
+ Some(label) => format!(" {}", label.ident),
None => String::new(),
};
} else {
Some("yield".to_string())
},
- ast::ExprKind::Closure(capture, ref fn_decl, ref body, _) => {
- closures::rewrite_closure(capture, fn_decl, body, expr.span, context, shape)
+ ast::ExprKind::Closure(capture, movability, ref fn_decl, ref body, _) => {
+ closures::rewrite_closure(
+ capture, movability, fn_decl, body, expr.span, context, shape,
+ )
+ }
+ ast::ExprKind::Try(..) | ast::ExprKind::Field(..) | ast::ExprKind::MethodCall(..) => {
+ rewrite_chain(expr, context, shape)
}
- ast::ExprKind::Try(..)
- | ast::ExprKind::Field(..)
- | ast::ExprKind::TupField(..)
- | ast::ExprKind::MethodCall(..) => rewrite_chain(expr, context, shape),
ast::ExprKind::Mac(ref mac) => {
rewrite_macro(mac, None, context, shape, MacroPosition::Expression).or_else(|| {
wrap_str(
ast::ExprKind::Index(ref expr, ref index) => {
rewrite_index(&**expr, &**index, context, shape)
}
- ast::ExprKind::Repeat(ref expr, ref repeats) => {
- let (lbr, rbr) = if context.config.spaces_within_parens_and_brackets() {
- ("[ ", " ]")
- } else {
- ("[", "]")
- };
- rewrite_pair(
- &**expr,
- &**repeats,
- PairParts::new(lbr, "; ", rbr),
- context,
- shape,
- SeparatorPlace::Back,
- )
- }
+ ast::ExprKind::Repeat(ref expr, ref repeats) => rewrite_pair(
+ &**expr,
+ &**repeats,
+ PairParts::new("[", "; ", "]"),
+ context,
+ shape,
+ SeparatorPlace::Back,
+ ),
ast::ExprKind::Range(ref lhs, ref rhs, limits) => {
let delim = match limits {
ast::RangeLimits::HalfOpen => "..",
}
}
+ fn needs_space_after_range(rhs: &ast::Expr) -> bool {
+ match rhs.node {
+ // Don't format `.. ..` into `....`, which is invalid.
+ //
+ // This check is unnecessary for `lhs`, because a range
+ // starting from another range needs parentheses as `(x ..) ..`
+ // (`x .. ..` is a range from `x` to `..`).
+ ast::ExprKind::Range(None, _, _) => true,
+ _ => false,
+ }
+ }
+
+ let default_sp_delim = |lhs: Option<&ast::Expr>, rhs: Option<&ast::Expr>| {
+ let space_if = |b: bool| if b { " " } else { "" };
+
+ format!(
+ "{}{}{}",
+ lhs.map(|lhs| space_if(needs_space_before_range(context, lhs)))
+ .unwrap_or(""),
+ delim,
+ rhs.map(|rhs| space_if(needs_space_after_range(rhs)))
+ .unwrap_or(""),
+ )
+ };
+
match (lhs.as_ref().map(|x| &**x), rhs.as_ref().map(|x| &**x)) {
(Some(lhs), Some(rhs)) => {
let sp_delim = if context.config.spaces_around_ranges() {
format!(" {} ", delim)
- } else if needs_space_before_range(context, lhs) {
- format!(" {}", delim)
} else {
- delim.to_owned()
+ default_sp_delim(Some(lhs), Some(rhs))
};
rewrite_pair(
&*lhs,
PairParts::new("", &sp_delim, ""),
context,
shape,
- SeparatorPlace::Front,
+ context.config.binop_separator(),
)
}
(None, Some(rhs)) => {
let sp_delim = if context.config.spaces_around_ranges() {
format!("{} ", delim)
} else {
- delim.to_owned()
+ default_sp_delim(None, Some(rhs))
};
rewrite_unary_prefix(context, &sp_delim, &*rhs, shape)
}
let sp_delim = if context.config.spaces_around_ranges() {
format!(" {}", delim)
} else {
- delim.to_owned()
+ default_sp_delim(Some(lhs), None)
};
rewrite_unary_suffix(context, &sp_delim, &*lhs, shape)
}
}
// We do not format these expressions yet, but they should still
// satisfy our width restrictions.
- ast::ExprKind::InPlace(..) | ast::ExprKind::InlineAsm(..) => {
- Some(context.snippet(expr.span).to_owned())
- }
+ ast::ExprKind::InlineAsm(..) => Some(context.snippet(expr.span).to_owned()),
ast::ExprKind::Catch(ref block) => {
- if let rw @ Some(_) = rewrite_single_line_block(context, "do catch ", block, shape) {
+ if let rw @ Some(_) =
+ rewrite_single_line_block(context, "do catch ", block, Some(&expr.attrs), shape)
+ {
rw
} else {
// 9 = `do catch `
- let budget = shape.width.checked_sub(9).unwrap_or(0);
+ let budget = shape.width.saturating_sub(9);
Some(format!(
"{}{}",
"do catch ",
- block.rewrite(context, Shape::legacy(budget, shape.indent))?
+ rewrite_block(
+ block,
+ Some(&expr.attrs),
+ context,
+ Shape::legacy(budget, shape.indent)
+ )?
))
}
}
})
}
+/// Collect operands that appears in the given binary operator in the opposite order.
+/// e.g. `collect_binary_items(e, ||)` for `a && b || c || d` returns `[d, c, a && b]`.
+fn collect_binary_items<'a>(mut expr: &'a ast::Expr, binop: ast::BinOp) -> Vec<&'a ast::Expr> {
+ let mut result = vec![];
+ let mut prev_lhs = None;
+ loop {
+ match expr.node {
+ ast::ExprKind::Binary(inner_binop, ref lhs, ref rhs)
+ if inner_binop.node == binop.node =>
+ {
+ result.push(&**rhs);
+ expr = lhs;
+ prev_lhs = Some(lhs);
+ }
+ _ => {
+ if let Some(lhs) = prev_lhs {
+ result.push(lhs);
+ }
+ break;
+ }
+ }
+ }
+ result
+}
+
+/// Rewrites a binary expression whose operands fits within a single line.
+fn rewrite_simple_binaries(
+ context: &RewriteContext,
+ expr: &ast::Expr,
+ shape: Shape,
+ op: ast::BinOp,
+) -> Option<String> {
+ let op_str = context.snippet(op.span);
+
+ // 2 = spaces around a binary operator.
+ let sep_overhead = op_str.len() + 2;
+ let nested_overhead = sep_overhead - 1;
+
+ 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);
+ let nested_shape = match context.config.binop_separator() {
+ SeparatorPlace::Back => nested_shape.sub_width(nested_overhead)?,
+ SeparatorPlace::Front => nested_shape.offset_left(nested_overhead)?,
+ };
+
+ let opt_rewrites: Option<Vec<_>> = collect_binary_items(expr, op)
+ .iter()
+ .rev()
+ .map(|e| e.rewrite(context, nested_shape))
+ .collect();
+ if let Some(rewrites) = opt_rewrites {
+ if rewrites.iter().all(|e| ::utils::is_single_line(e)) {
+ let total_width = rewrites.iter().map(|s| s.len()).sum::<usize>()
+ + sep_overhead * (rewrites.len() - 1);
+
+ let sep_str = if total_width <= shape.width {
+ format!(" {} ", op_str)
+ } else {
+ let indent_str = nested_shape.indent.to_string_with_newline(context.config);
+ match context.config.binop_separator() {
+ SeparatorPlace::Back => format!(" {}{}", op_str.trim_right(), indent_str),
+ SeparatorPlace::Front => format!("{}{} ", indent_str, op_str.trim_left()),
+ }
+ };
+
+ return wrap_str(rewrites.join(&sep_str), context.config.max_width(), shape);
+ }
+ }
+
+ None
+}
+
#[derive(new, Clone, Copy)]
pub struct PairParts<'a> {
prefix: &'a str,
width: context.budget(lhs_overhead),
..shape
};
- let lhs_result = lhs.rewrite(context, lhs_shape)
+ let lhs_result = lhs
+ .rewrite(context, lhs_shape)
.map(|lhs_str| format!("{}{}", pp.prefix, lhs_str))?;
- // Try to the both lhs and rhs on the same line.
+ // Try to put both lhs and rhs on the same line.
let rhs_orig_result = shape
.offset_left(last_line_width(&lhs_result) + pp.infix.len())
.and_then(|s| s.sub_width(pp.suffix.len()))
.and_then(|rhs_shape| rhs.rewrite(context, rhs_shape));
if let Some(ref rhs_result) = rhs_orig_result {
- // If the rhs looks like block expression, we allow it to stay on the same line
- // with the lhs even if it is multi-lined.
- let allow_same_line = rhs_result
- .lines()
- .next()
- .map(|first_line| first_line.ends_with('{'))
- .unwrap_or(false);
+ // If the length of the lhs is equal to or shorter than the tab width or
+ // the rhs looks like block expression, we put the rhs on the same
+ // line with the lhs even if the rhs is multi-lined.
+ let allow_same_line = lhs_result.len() <= context.config.tab_spaces()
+ || rhs_result
+ .lines()
+ .next()
+ .map(|first_line| first_line.ends_with('{'))
+ .unwrap_or(false);
if !rhs_result.contains('\n') || allow_same_line {
- let one_line_width = last_line_width(&lhs_result) + pp.infix.len()
- + first_line_width(rhs_result) + pp.suffix.len();
+ let one_line_width = last_line_width(&lhs_result)
+ + pp.infix.len()
+ + first_line_width(rhs_result)
+ + pp.suffix.len();
if one_line_width <= shape.width {
return Some(format!(
"{}{}{}{}",
rhs_shape = rhs_shape.offset_left(infix.len())?;
}
let rhs_result = rhs.rewrite(context, rhs_shape)?;
- let indent_str = rhs_shape.indent.to_string(context.config);
+ let indent_str = rhs_shape.indent.to_string_with_newline(context.config);
let infix_with_sep = match separator_place {
- SeparatorPlace::Back => format!("{}\n{}", infix, indent_str),
- SeparatorPlace::Front => format!("\n{}{}", indent_str, infix),
+ SeparatorPlace::Back => format!("{}{}", infix, indent_str),
+ SeparatorPlace::Front => format!("{}{}", indent_str, infix),
};
Some(format!(
"{}{}{}{}",
}
pub fn rewrite_array<T: Rewrite + Spanned + ToExpr>(
+ name: &str,
exprs: &[&T],
span: Span,
context: &RewriteContext,
shape: Shape,
- trailing_comma: bool,
+ force_separator_tactic: Option<SeparatorTactic>,
+ delim_token: Option<DelimToken>,
) -> Option<String> {
- let bracket_size = if context.config.spaces_within_parens_and_brackets() {
- 2 // "[ "
- } else {
- 1 // "["
- };
-
- let nested_shape = match context.config.indent_style() {
- IndentStyle::Block => shape
- .block()
- .block_indent(context.config.tab_spaces())
- .with_max_width(context.config)
- .sub_width(1)?,
- IndentStyle::Visual => shape
- .visual_indent(bracket_size)
- .sub_width(bracket_size * 2)?,
- };
-
- let items = itemize_list(
- context.codemap,
- exprs.iter(),
- "]",
- ",",
- |item| item.span().lo(),
- |item| item.span().hi(),
- |item| item.rewrite(context, nested_shape),
- span.lo(),
- span.hi(),
- false,
- ).collect::<Vec<_>>();
-
- if items.is_empty() {
- if context.config.spaces_within_parens_and_brackets() {
- return Some("[ ]".to_string());
- } else {
- return Some("[]".to_string());
- }
- }
-
- let tactic = array_tactic(context, shape, nested_shape, exprs, &items, bracket_size);
- let ends_with_newline = tactic.ends_with_newline(context.config.indent_style());
-
- let fmt = ListFormatting {
- tactic: tactic,
- separator: ",",
- trailing_separator: if trailing_comma {
- SeparatorTactic::Always
- } else if context.inside_macro && !exprs.is_empty() {
- let ends_with_bracket = context.snippet(span).ends_with(']');
- let bracket_offset = if ends_with_bracket { 1 } else { 0 };
- let snippet = context.snippet(mk_sp(span.lo(), span.hi() - BytePos(bracket_offset)));
- let last_char_index = snippet.rfind(|c: char| !c.is_whitespace())?;
- if &snippet[last_char_index..last_char_index + 1] == "," {
- SeparatorTactic::Always
- } else {
- SeparatorTactic::Never
- }
- } else if context.config.indent_style() == IndentStyle::Visual {
- SeparatorTactic::Never
- } else {
- SeparatorTactic::Vertical
- },
- separator_place: SeparatorPlace::Back,
- shape: nested_shape,
- ends_with_newline: ends_with_newline,
- preserve_newline: false,
- config: context.config,
- };
- let list_str = write_list(&items, &fmt)?;
-
- let result = if context.config.indent_style() == IndentStyle::Visual
- || tactic == DefinitiveListTactic::Horizontal
- {
- if context.config.spaces_within_parens_and_brackets() && !list_str.is_empty() {
- format!("[ {} ]", list_str)
- } else {
- format!("[{}]", list_str)
- }
- } else {
- format!(
- "[\n{}{}\n{}]",
- nested_shape.indent.to_string(context.config),
- list_str,
- shape.block().indent.to_string(context.config)
- )
- };
-
- Some(result)
-}
-
-fn array_tactic<T: Rewrite + Spanned + ToExpr>(
- context: &RewriteContext,
- shape: Shape,
- nested_shape: Shape,
- exprs: &[&T],
- items: &[ListItem],
- bracket_size: usize,
-) -> DefinitiveListTactic {
- let has_long_item = items
- .iter()
- .any(|li| li.item.as_ref().map(|s| s.len() > 10).unwrap_or(false));
-
- match context.config.indent_style() {
- IndentStyle::Block => {
- let tactic = match shape.width.checked_sub(2 * bracket_size) {
- Some(width) => {
- let tactic = ListTactic::LimitedHorizontalVertical(
- context.config.width_heuristics().array_width,
- );
- definitive_tactic(items, tactic, Separator::Comma, width)
- }
- None => DefinitiveListTactic::Vertical,
- };
- if tactic == DefinitiveListTactic::Vertical && !has_long_item
- && is_every_args_simple(exprs)
- {
- DefinitiveListTactic::Mixed
- } else {
- tactic
- }
- }
- IndentStyle::Visual => {
- if has_long_item || items.iter().any(ListItem::is_multiline) {
- definitive_tactic(
- items,
- ListTactic::LimitedHorizontalVertical(
- context.config.width_heuristics().array_width,
- ),
- Separator::Comma,
- nested_shape.width,
- )
- } else {
- DefinitiveListTactic::Mixed
- }
- }
- }
-}
-
-fn nop_block_collapse(block_str: Option<String>, budget: usize) -> Option<String> {
- debug!("nop_block_collapse {:?} {}", block_str, budget);
- block_str.map(|block_str| {
- if block_str.starts_with('{') && budget >= 2
- && (block_str[1..].find(|c: char| !c.is_whitespace()).unwrap() == block_str.len() - 2)
- {
- "{}".to_owned()
- } else {
- block_str.to_owned()
- }
- })
+ overflow::rewrite_with_square_brackets(
+ context,
+ name,
+ exprs,
+ shape,
+ span,
+ force_separator_tactic,
+ delim_token,
+ )
}
fn rewrite_empty_block(
context: &RewriteContext,
block: &ast::Block,
+ attrs: Option<&[ast::Attribute]>,
+ prefix: &str,
shape: Shape,
) -> Option<String> {
+ if attrs.map_or(false, |a| !inner_attributes(a).is_empty()) {
+ return None;
+ }
+
if block.stmts.is_empty() && !block_contains_comment(block, context.codemap) && shape.width >= 2
{
- return Some("{}".to_owned());
+ return Some(format!("{}{{}}", prefix));
}
// If a block contains only a single-line comment, then leave it on one line.
let user_str = user_str.trim();
if user_str.starts_with('{') && user_str.ends_with('}') {
let comment_str = user_str[1..user_str.len() - 1].trim();
- if block.stmts.is_empty() && !comment_str.contains('\n') && !comment_str.starts_with("//")
+ if block.stmts.is_empty()
+ && !comment_str.contains('\n')
+ && !comment_str.starts_with("//")
&& comment_str.len() + 4 <= shape.width
{
- return Some(format!("{{ {} }}", comment_str));
+ return Some(format!("{}{{ {} }}", prefix, comment_str));
}
}
context: &RewriteContext,
prefix: &str,
block: &ast::Block,
+ attrs: Option<&[ast::Attribute]>,
shape: Shape,
) -> Option<String> {
- if is_simple_block(block, context.codemap) {
+ if is_simple_block(block, attrs, context.codemap) {
let expr_shape = shape.offset_left(last_line_width(prefix))?;
let expr_str = block.stmts[0].rewrite(context, expr_shape)?;
let result = format!("{}{{ {} }}", prefix, expr_str);
context: &RewriteContext,
prefix: &str,
block: &ast::Block,
+ attrs: Option<&[ast::Attribute]>,
shape: Shape,
has_braces: bool,
) -> Option<String> {
- if let rw @ Some(_) = rewrite_empty_block(context, block, shape) {
+ if let rw @ Some(_) = rewrite_empty_block(context, block, attrs, prefix, shape) {
return rw;
}
let mut visitor = FmtVisitor::from_context(context);
visitor.block_indent = shape.indent;
- visitor.is_if_else_block = context.is_if_else_block;
+ visitor.is_if_else_block = context.is_if_else_block();
match block.rules {
ast::BlockCheckMode::Unsafe(..) => {
let snippet = context.snippet(block.span);
ast::BlockCheckMode::Default => visitor.last_pos = block.span.lo(),
}
- visitor.visit_block(block, None, has_braces);
+ let inner_attrs = attrs.map(inner_attributes);
+ visitor.visit_block(block, inner_attrs.as_ref().map(|a| &**a), has_braces);
Some(format!("{}{}", prefix, visitor.buffer))
}
impl Rewrite for ast::Block {
fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
- // shape.width is used only for the single line case: either the empty block `{}`,
- // or an unsafe expression `unsafe { e }`.
- if let rw @ Some(_) = rewrite_empty_block(context, self, shape) {
- return rw;
- }
+ rewrite_block(self, None, context, shape)
+ }
+}
- let prefix = block_prefix(context, self, shape)?;
+fn rewrite_block(
+ block: &ast::Block,
+ attrs: Option<&[ast::Attribute]>,
+ context: &RewriteContext,
+ shape: Shape,
+) -> Option<String> {
+ let prefix = block_prefix(context, block, shape)?;
- let result = rewrite_block_with_visitor(context, &prefix, self, shape, true);
- if let Some(ref result_str) = result {
- if result_str.lines().count() <= 3 {
- if let rw @ Some(_) = rewrite_single_line_block(context, &prefix, self, shape) {
- return rw;
- }
+ // shape.width is used only for the single line case: either the empty block `{}`,
+ // or an unsafe expression `unsafe { e }`.
+ if let rw @ Some(_) = rewrite_empty_block(context, block, attrs, &prefix, shape) {
+ return rw;
+ }
+
+ let result = rewrite_block_with_visitor(context, &prefix, block, attrs, shape, true);
+ if let Some(ref result_str) = result {
+ if result_str.lines().count() <= 3 {
+ if let rw @ Some(_) = rewrite_single_line_block(context, &prefix, block, attrs, shape) {
+ return rw;
}
}
-
- result
}
+
+ result
}
impl Rewrite for ast::Stmt {
cond: Option<&'a ast::Expr>,
block: &'a ast::Block,
else_block: Option<&'a ast::Expr>,
- label: Option<ast::SpannedIdent>,
- pat: Option<&'a ast::Pat>,
+ label: Option<ast::Label>,
+ pats: Vec<&'a ast::Pat>,
keyword: &'a str,
matcher: &'a str,
connector: &'a str,
match expr.node {
ast::ExprKind::If(ref cond, ref if_block, ref else_block) => Some(ControlFlow::new_if(
cond,
- None,
+ vec![],
if_block,
else_block.as_ref().map(|e| &**e),
expr_type == ExprType::SubExpression,
ast::ExprKind::IfLet(ref pat, ref cond, ref if_block, ref else_block) => {
Some(ControlFlow::new_if(
cond,
- Some(pat),
+ ptr_vec_to_ref_vec(pat),
if_block,
else_block.as_ref().map(|e| &**e),
expr_type == ExprType::SubExpression,
ast::ExprKind::Loop(ref block, label) => {
Some(ControlFlow::new_loop(block, label, expr.span))
}
- ast::ExprKind::While(ref cond, ref block, label) => {
- Some(ControlFlow::new_while(None, cond, block, label, expr.span))
- }
+ ast::ExprKind::While(ref cond, ref block, label) => Some(ControlFlow::new_while(
+ vec![],
+ cond,
+ block,
+ label,
+ expr.span,
+ )),
ast::ExprKind::WhileLet(ref pat, ref cond, ref block, label) => Some(
- ControlFlow::new_while(Some(pat), cond, block, label, expr.span),
+ ControlFlow::new_while(ptr_vec_to_ref_vec(pat), cond, block, label, expr.span),
),
_ => None,
}
}
+fn choose_matcher(pats: &[&ast::Pat]) -> &'static str {
+ if pats.is_empty() {
+ ""
+ } else {
+ "let"
+ }
+}
+
impl<'a> ControlFlow<'a> {
fn new_if(
cond: &'a ast::Expr,
- pat: Option<&'a ast::Pat>,
+ pats: Vec<&'a ast::Pat>,
block: &'a ast::Block,
else_block: Option<&'a ast::Expr>,
allow_single_line: bool,
nested_if: bool,
span: Span,
) -> ControlFlow<'a> {
+ let matcher = choose_matcher(&pats);
ControlFlow {
cond: Some(cond),
- block: block,
- else_block: else_block,
+ block,
+ else_block,
label: None,
- pat: pat,
+ pats,
keyword: "if",
- matcher: match pat {
- Some(..) => "let",
- None => "",
- },
+ matcher,
connector: " =",
- allow_single_line: allow_single_line,
- nested_if: nested_if,
- span: span,
+ allow_single_line,
+ nested_if,
+ span,
}
}
- fn new_loop(
- block: &'a ast::Block,
- label: Option<ast::SpannedIdent>,
- span: Span,
- ) -> ControlFlow<'a> {
+ fn new_loop(block: &'a ast::Block, label: Option<ast::Label>, span: Span) -> ControlFlow<'a> {
ControlFlow {
cond: None,
- block: block,
+ block,
else_block: None,
- label: label,
- pat: None,
+ label,
+ pats: vec![],
keyword: "loop",
matcher: "",
connector: "",
allow_single_line: false,
nested_if: false,
- span: span,
+ span,
}
}
fn new_while(
- pat: Option<&'a ast::Pat>,
+ pats: Vec<&'a ast::Pat>,
cond: &'a ast::Expr,
block: &'a ast::Block,
- label: Option<ast::SpannedIdent>,
+ label: Option<ast::Label>,
span: Span,
) -> ControlFlow<'a> {
+ let matcher = choose_matcher(&pats);
ControlFlow {
cond: Some(cond),
- block: block,
+ block,
else_block: None,
- label: label,
- pat: pat,
+ label,
+ pats,
keyword: "while",
- matcher: match pat {
- Some(..) => "let",
- None => "",
- },
+ matcher,
connector: " =",
allow_single_line: false,
nested_if: false,
- span: span,
+ span,
}
}
pat: &'a ast::Pat,
cond: &'a ast::Expr,
block: &'a ast::Block,
- label: Option<ast::SpannedIdent>,
+ label: Option<ast::Label>,
span: Span,
) -> ControlFlow<'a> {
ControlFlow {
cond: Some(cond),
- block: block,
+ block,
else_block: None,
- label: label,
- pat: Some(pat),
+ label,
+ pats: vec![pat],
keyword: "for",
matcher: "",
connector: " in",
allow_single_line: false,
nested_if: false,
- span: span,
+ span,
}
}
let else_block = self.else_block?;
let fixed_cost = self.keyword.len() + " { } else { }".len();
- if let ast::ExprKind::Block(ref else_node) = else_block.node {
- if !is_simple_block(self.block, context.codemap)
- || !is_simple_block(else_node, context.codemap)
+ if let ast::ExprKind::Block(ref else_node, _) = else_block.node {
+ if !is_simple_block(self.block, None, context.codemap)
+ || !is_simple_block(else_node, None, context.codemap)
|| pat_expr_str.contains('\n')
{
return None;
}
impl<'a> ControlFlow<'a> {
+ fn rewrite_pat_expr(
+ &self,
+ context: &RewriteContext,
+ expr: &ast::Expr,
+ shape: Shape,
+ offset: usize,
+ ) -> Option<String> {
+ debug!("rewrite_pat_expr {:?} {:?} {:?}", shape, self.pats, expr);
+
+ let cond_shape = shape.offset_left(offset)?;
+ if !self.pats.is_empty() {
+ let matcher = if self.matcher.is_empty() {
+ self.matcher.to_owned()
+ } else {
+ format!("{} ", self.matcher)
+ };
+ let pat_shape = cond_shape
+ .offset_left(matcher.len())?
+ .sub_width(self.connector.len())?;
+ let pat_string = rewrite_multiple_patterns(context, &self.pats, pat_shape)?;
+ let result = format!("{}{}{}", matcher, pat_string, self.connector);
+ return rewrite_assign_rhs(context, result, expr, cond_shape);
+ }
+
+ let expr_rw = expr.rewrite(context, cond_shape);
+ // The expression may (partially) fit on the current line.
+ // We do not allow splitting between `if` and condition.
+ if self.keyword == "if" || expr_rw.is_some() {
+ return expr_rw;
+ }
+
+ // The expression won't fit on the current line, jump to next.
+ let nested_shape = shape
+ .block_indent(context.config.tab_spaces())
+ .with_max_width(context.config);
+ let nested_indent_str = nested_shape.indent.to_string_with_newline(context.config);
+ expr.rewrite(context, nested_shape)
+ .map(|expr_rw| format!("{}{}", nested_indent_str, expr_rw))
+ }
+
fn rewrite_cond(
&self,
context: &RewriteContext,
) -> Option<(String, usize)> {
// Do not take the rhs overhead from the upper expressions into account
// when rewriting pattern.
- let new_width = context
- .config
- .max_width()
- .checked_sub(shape.used_width())
- .unwrap_or(0);
+ let new_width = context.budget(shape.used_width());
let fresh_shape = Shape {
width: new_width,
..shape
let offset = self.keyword.len() + label_string.len() + 1;
let pat_expr_string = match self.cond {
- Some(cond) => rewrite_pat_expr(
- context,
- self.pat,
- cond,
- self.matcher,
- self.connector,
- self.keyword,
- constr_shape,
- offset,
- )?,
+ Some(cond) => self.rewrite_pat_expr(context, cond, constr_shape, offset)?,
None => String::new(),
};
let one_line_budget = context
.config
.max_width()
- .checked_sub(constr_shape.used_width() + offset + brace_overhead)
- .unwrap_or(0);
+ .saturating_sub(constr_shape.used_width() + offset + brace_overhead);
let force_newline_brace = (pat_expr_string.contains('\n')
|| pat_expr_string.len() > one_line_budget)
&& !last_line_extendable(&pat_expr_string);
// `for event in event`
// Do not include label in the span.
- let lo = self.label.map_or(self.span.lo(), |label| label.span.hi());
+ let lo = self
+ .label
+ .map_or(self.span.lo(), |label| label.ident.span.hi());
let between_kwd_cond = mk_sp(
context
- .codemap
+ .snippet_provider
.span_after(mk_sp(lo, self.span.hi()), self.keyword.trim()),
- self.pat.map_or(cond_span.lo(), |p| {
- if self.matcher.is_empty() {
- p.span.lo()
- } else {
- context.codemap.span_before(self.span, self.matcher.trim())
- }
- }),
+ if self.pats.is_empty() {
+ cond_span.lo()
+ } else if self.matcher.is_empty() {
+ self.pats[0].span.lo()
+ } else {
+ context
+ .snippet_provider
+ .span_before(self.span, self.matcher.trim())
+ },
);
let between_kwd_cond_comment = extract_comment(between_kwd_cond, context, shape);
fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
debug!("ControlFlow::rewrite {:?} {:?}", self, shape);
- let alt_block_sep = String::from("\n") + &shape.indent.to_string(context.config);
- let (cond_str, used_width) = self.rewrite_cond(context, shape, &alt_block_sep)?;
+ let alt_block_sep = &shape.indent.to_string_with_newline(context.config);
+ let (cond_str, used_width) = self.rewrite_cond(context, shape, alt_block_sep)?;
// If `used_width` is 0, it indicates that whole control flow is written in a single line.
if used_width == 0 {
return Some(cond_str);
}
- let block_width = shape.width.checked_sub(used_width).unwrap_or(0);
+ let block_width = shape.width.saturating_sub(used_width);
// This is used only for the empty block case: `{}`. So, we use 1 if we know
// we should avoid the single line case.
let block_width = if self.else_block.is_some() || self.nested_if {
width: block_width,
..shape
};
- let mut block_context = context.clone();
- block_context.is_if_else_block = self.else_block.is_some();
- let block_str =
- rewrite_block_with_visitor(&block_context, "", self.block, block_shape, true)?;
+ let block_str = {
+ let old_val = context.is_if_else_block.replace(self.else_block.is_some());
+ let result =
+ rewrite_block_with_visitor(context, "", self.block, None, block_shape, true);
+ context.is_if_else_block.replace(old_val);
+ result?
+ };
let mut result = format!("{}{}", cond_str, block_str);
ast::ExprKind::IfLet(ref pat, ref cond, ref if_block, ref next_else_block) => {
ControlFlow::new_if(
cond,
- Some(pat),
+ ptr_vec_to_ref_vec(pat),
if_block,
next_else_block.as_ref().map(|e| &**e),
false,
ast::ExprKind::If(ref cond, ref if_block, ref next_else_block) => {
ControlFlow::new_if(
cond,
- None,
+ vec![],
if_block,
next_else_block.as_ref().map(|e| &**e),
false,
let between_kwd_else_block = mk_sp(
self.block.span.hi(),
context
- .codemap
+ .snippet_provider
.span_before(mk_sp(self.block.span.hi(), else_block.span.lo()), "else"),
);
let between_kwd_else_block_comment =
let after_else = mk_sp(
context
- .codemap
+ .snippet_provider
.span_after(mk_sp(self.block.span.hi(), else_block.span.lo()), "else"),
else_block.span.lo(),
);
}
}
-fn rewrite_label(label: Option<ast::SpannedIdent>) -> Cow<'static, str> {
- match label {
- Some(ident) => Cow::from(format!("{}: ", ident.node)),
+fn rewrite_label(opt_label: Option<ast::Label>) -> Cow<'static, str> {
+ match opt_label {
+ Some(label) => Cow::from(format!("{}: ", label.ident)),
None => Cow::from(""),
}
}
fn extract_comment(span: Span, context: &RewriteContext, shape: Shape) -> Option<String> {
match rewrite_missing_comment(span, shape, context) {
Some(ref comment) if !comment.is_empty() => Some(format!(
- "\n{indent}{}\n{indent}",
+ "{indent}{}{indent}",
comment,
- indent = shape.indent.to_string(context.config)
+ indent = shape.indent.to_string_with_newline(context.config)
)),
_ => None,
}
contains_comment(&snippet)
}
-// Checks that a block contains no statements, an expression and no comments.
+// Checks that a block contains no statements, an expression and no comments or
+// attributes.
// FIXME: incorrectly returns false when comment is contained completely within
// the expression.
-pub fn is_simple_block(block: &ast::Block, codemap: &CodeMap) -> bool {
- (block.stmts.len() == 1 && stmt_is_expr(&block.stmts[0])
- && !block_contains_comment(block, codemap))
-}
-
-/// Checks whether a block contains at most one statement or expression, and no comments.
-pub fn is_simple_block_stmt(block: &ast::Block, codemap: &CodeMap) -> bool {
- block.stmts.len() <= 1 && !block_contains_comment(block, codemap)
+pub fn is_simple_block(
+ block: &ast::Block,
+ attrs: Option<&[ast::Attribute]>,
+ codemap: &CodeMap,
+) -> bool {
+ (block.stmts.len() == 1
+ && stmt_is_expr(&block.stmts[0])
+ && !block_contains_comment(block, codemap)
+ && attrs.map_or(true, |a| a.is_empty()))
+}
+
+/// Checks whether a block contains at most one statement or expression, and no
+/// comments or attributes.
+pub fn is_simple_block_stmt(
+ block: &ast::Block,
+ attrs: Option<&[ast::Attribute]>,
+ codemap: &CodeMap,
+) -> bool {
+ block.stmts.len() <= 1
+ && !block_contains_comment(block, codemap)
+ && attrs.map_or(true, |a| a.is_empty())
}
-/// Checks whether a block contains no statements, expressions, or comments.
-pub fn is_empty_block(block: &ast::Block, codemap: &CodeMap) -> bool {
- block.stmts.is_empty() && !block_contains_comment(block, codemap)
+/// Checks whether a block contains no statements, expressions, comments, or
+/// inner attributes.
+pub fn is_empty_block(
+ block: &ast::Block,
+ attrs: Option<&[ast::Attribute]>,
+ codemap: &CodeMap,
+) -> bool {
+ block.stmts.is_empty()
+ && !block_contains_comment(block, codemap)
+ && attrs.map_or(true, |a| inner_attributes(a).is_empty())
}
pub fn stmt_is_expr(stmt: &ast::Stmt) -> bool {
}
}
-// A simple wrapper type against ast::Arm. Used inside write_list().
-struct ArmWrapper<'a> {
- pub arm: &'a ast::Arm,
- // True if the arm is the last one in match expression. Used to decide on whether we should add
- // trailing comma to the match arm when `config.trailing_comma() == Never`.
- pub is_last: bool,
-}
-
-impl<'a> ArmWrapper<'a> {
- pub fn new(arm: &'a ast::Arm, is_last: bool) -> ArmWrapper<'a> {
- ArmWrapper { arm, is_last }
- }
-}
-
-impl<'a> Rewrite for ArmWrapper<'a> {
- fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
- rewrite_match_arm(context, self.arm, shape, self.is_last)
- }
-}
-
-fn rewrite_match(
+pub fn rewrite_multiple_patterns(
context: &RewriteContext,
- cond: &ast::Expr,
- arms: &[ast::Arm],
+ pats: &[&ast::Pat],
shape: Shape,
- span: Span,
- attrs: &[ast::Attribute],
) -> Option<String> {
- // Do not take the rhs overhead from the upper expressions into account
- // when rewriting match condition.
- let cond_shape = Shape {
- width: context.budget(shape.used_width()),
- ..shape
- };
- // 6 = `match `
- let cond_shape = match context.config.indent_style() {
- IndentStyle::Visual => cond_shape.shrink_left(6)?,
- IndentStyle::Block => cond_shape.offset_left(6)?,
- };
- let cond_str = cond.rewrite(context, cond_shape)?;
- let alt_block_sep = String::from("\n") + &shape.indent.to_string(context.config);
- let block_sep = match context.config.control_brace_style() {
- ControlBraceStyle::AlwaysNextLine => &alt_block_sep,
- _ if last_line_extendable(&cond_str) => " ",
- // 2 = ` {`
- _ if cond_str.contains('\n') || cond_str.len() + 2 > cond_shape.width => &alt_block_sep,
- _ => " ",
- };
+ let pat_strs = pats
+ .iter()
+ .map(|p| p.rewrite(context, shape))
+ .collect::<Option<Vec<_>>>()?;
- let nested_indent_str = shape
- .indent
- .block_indent(context.config)
- .to_string(context.config);
- // Inner attributes.
- let inner_attrs = &inner_attributes(attrs);
- let inner_attrs_str = if inner_attrs.is_empty() {
- String::new()
+ let use_mixed_layout = pats
+ .iter()
+ .zip(pat_strs.iter())
+ .all(|(pat, pat_str)| is_short_pattern(pat, pat_str));
+ let items: Vec<_> = pat_strs.into_iter().map(ListItem::from_str).collect();
+ let tactic = if use_mixed_layout {
+ DefinitiveListTactic::Mixed
} else {
- inner_attrs
- .rewrite(context, shape)
- .map(|s| format!("{}{}\n", nested_indent_str, s))?
+ definitive_tactic(
+ &items,
+ ListTactic::HorizontalVertical,
+ Separator::VerticalBar,
+ shape.width,
+ )
};
-
- let open_brace_pos = if inner_attrs.is_empty() {
- let hi = if arms.is_empty() {
- span.hi()
- } else {
- arms[0].span().lo()
- };
- context.codemap.span_after(mk_sp(cond.span.hi(), hi), "{")
- } else {
- inner_attrs[inner_attrs.len() - 1].span().hi()
+ let fmt = ListFormatting {
+ tactic,
+ separator: " |",
+ trailing_separator: SeparatorTactic::Never,
+ separator_place: context.config.binop_separator(),
+ shape,
+ ends_with_newline: false,
+ preserve_newline: false,
+ config: context.config,
};
-
- if arms.is_empty() {
- let snippet = context.snippet(mk_sp(open_brace_pos, span.hi() - BytePos(1)));
- if snippet.trim().is_empty() {
- Some(format!("match {} {{}}", cond_str))
- } else {
- // Empty match with comments or inner attributes? We are not going to bother, sorry ;)
- Some(context.snippet(span).to_owned())
- }
- } else {
- Some(format!(
- "match {}{}{{\n{}{}{}\n{}}}",
- cond_str,
- block_sep,
- inner_attrs_str,
- nested_indent_str,
- rewrite_match_arms(context, arms, shape, span, open_brace_pos)?,
- shape.indent.to_string(context.config),
- ))
- }
+ write_list(&items, &fmt)
}
-fn arm_comma(config: &Config, body: &ast::Expr, is_last: bool) -> &'static str {
- if is_last && config.trailing_comma() == SeparatorTactic::Never {
- ""
- } else if config.match_block_trailing_comma() {
- ","
- } else if let ast::ExprKind::Block(ref block) = body.node {
- if let ast::BlockCheckMode::Default = block.rules {
- ""
- } else {
- ","
- }
- } else {
- ","
- }
-}
-
-fn rewrite_match_arms(
- context: &RewriteContext,
- arms: &[ast::Arm],
- shape: Shape,
- span: Span,
- open_brace_pos: BytePos,
-) -> Option<String> {
- let arm_shape = shape
- .block_indent(context.config.tab_spaces())
- .with_max_width(context.config);
-
- let arm_len = arms.len();
- let is_last_iter = repeat(false)
- .take(arm_len.checked_sub(1).unwrap_or(0))
- .chain(repeat(true));
- let items = itemize_list(
- context.codemap,
- arms.iter()
- .zip(is_last_iter)
- .map(|(arm, is_last)| ArmWrapper::new(arm, is_last)),
- "}",
- "|",
- |arm| arm.arm.span().lo(),
- |arm| arm.arm.span().hi(),
- |arm| arm.rewrite(context, arm_shape),
- open_brace_pos,
- span.hi(),
- false,
- );
- let arms_vec: Vec<_> = items.collect();
- let fmt = ListFormatting {
- tactic: DefinitiveListTactic::Vertical,
- // We will add/remove commas inside `arm.rewrite()`, and hence no separator here.
- separator: "",
- trailing_separator: SeparatorTactic::Never,
- separator_place: SeparatorPlace::Back,
- shape: arm_shape,
- ends_with_newline: true,
- preserve_newline: true,
- config: context.config,
- };
-
- write_list(&arms_vec, &fmt)
-}
-
-fn rewrite_match_arm(
- context: &RewriteContext,
- arm: &ast::Arm,
- shape: Shape,
- is_last: bool,
-) -> Option<String> {
- let (missing_span, attrs_str) = if !arm.attrs.is_empty() {
- if contains_skip(&arm.attrs) {
- let (_, body) = flatten_arm_body(context, &arm.body);
- // `arm.span()` does not include trailing comma, add it manually.
- return Some(format!(
- "{}{}",
- context.snippet(arm.span()),
- arm_comma(context.config, body, is_last),
- ));
- }
- let missing_span = mk_sp(
- arm.attrs[arm.attrs.len() - 1].span.hi(),
- arm.pats[0].span.lo(),
- );
- (missing_span, arm.attrs.rewrite(context, shape)?)
- } else {
- (mk_sp(arm.span().lo(), arm.span().lo()), String::new())
- };
- let pats_str =
- rewrite_match_pattern(context, &arm.pats, &arm.guard, shape).and_then(|pats_str| {
- combine_strs_with_missing_comments(
- context,
- &attrs_str,
- &pats_str,
- missing_span,
- shape,
- false,
- )
- })?;
- rewrite_match_body(
- context,
- &arm.body,
- &pats_str,
- shape,
- arm.guard.is_some(),
- is_last,
- )
-}
-
-/// Returns true if the given pattern is short. A short pattern is defined by the following grammer:
-///
-/// [small, ntp]:
-/// - single token
-/// - `&[single-line, ntp]`
-///
-/// [small]:
-/// - `[small, ntp]`
-/// - unary tuple constructor `([small, ntp])`
-/// - `&[small]`
-fn is_short_pattern(pat: &ast::Pat, pat_str: &str) -> bool {
- // We also require that the pattern is reasonably 'small' with its literal width.
- pat_str.len() <= 20 && !pat_str.contains('\n') && is_short_pattern_inner(pat)
-}
-
-fn is_short_pattern_inner(pat: &ast::Pat) -> bool {
- match pat.node {
- ast::PatKind::Wild | ast::PatKind::Lit(_) => true,
- ast::PatKind::Ident(_, _, ref pat) => pat.is_none(),
- ast::PatKind::Struct(..)
- | ast::PatKind::Mac(..)
- | ast::PatKind::Slice(..)
- | ast::PatKind::Path(..)
- | ast::PatKind::Range(..) => false,
- ast::PatKind::Tuple(ref subpats, _) => subpats.len() <= 1,
- ast::PatKind::TupleStruct(ref path, ref subpats, _) => {
- path.segments.len() <= 1 && subpats.len() <= 1
- }
- ast::PatKind::Box(ref p) | ast::PatKind::Ref(ref p, _) => is_short_pattern_inner(&*p),
- }
-}
-
-fn rewrite_match_pattern(
- context: &RewriteContext,
- pats: &[ptr::P<ast::Pat>],
- guard: &Option<ptr::P<ast::Expr>>,
- shape: Shape,
-) -> Option<String> {
- // Patterns
- // 5 = ` => {`
- let pat_shape = shape.sub_width(5)?;
-
- let pat_strs = pats.iter()
- .map(|p| p.rewrite(context, pat_shape))
- .collect::<Option<Vec<_>>>()?;
-
- let use_mixed_layout = pats.iter()
- .zip(pat_strs.iter())
- .all(|(pat, pat_str)| is_short_pattern(pat, pat_str));
- let items: Vec<_> = pat_strs.into_iter().map(ListItem::from_str).collect();
- let tactic = if use_mixed_layout {
- DefinitiveListTactic::Mixed
- } else {
- definitive_tactic(
- &items,
- ListTactic::HorizontalVertical,
- Separator::VerticalBar,
- pat_shape.width,
- )
- };
- let fmt = ListFormatting {
- tactic: tactic,
- separator: " |",
- trailing_separator: SeparatorTactic::Never,
- separator_place: context.config.binop_separator(),
- shape: pat_shape,
- ends_with_newline: false,
- preserve_newline: false,
- config: context.config,
- };
- let pats_str = write_list(&items, &fmt)?;
-
- // Guard
- let guard_str = rewrite_guard(context, guard, shape, trimmed_last_line_width(&pats_str))?;
-
- Some(format!("{}{}", pats_str, guard_str))
-}
-
-// (extend, body)
-// @extend: true if the arm body can be put next to `=>`
-// @body: flattened body, if the body is block with a single expression
-fn flatten_arm_body<'a>(context: &'a RewriteContext, body: &'a ast::Expr) -> (bool, &'a ast::Expr) {
- match body.node {
- ast::ExprKind::Block(ref block)
- if !is_unsafe_block(block) && is_simple_block(block, context.codemap) =>
- {
- if let ast::StmtKind::Expr(ref expr) = block.stmts[0].node {
- (
- !context.config.force_multiline_blocks() && can_extend_match_arm_body(expr),
- &*expr,
- )
- } else {
- (false, &*body)
- }
- }
- _ => (
- !context.config.force_multiline_blocks() && body.can_be_overflowed(context, 1),
- &*body,
- ),
- }
-}
-
-fn rewrite_match_body(
- context: &RewriteContext,
- body: &ptr::P<ast::Expr>,
- pats_str: &str,
- shape: Shape,
- has_guard: bool,
- is_last: bool,
-) -> Option<String> {
- let (extend, body) = flatten_arm_body(context, body);
- let (is_block, is_empty_block) = if let ast::ExprKind::Block(ref block) = body.node {
- (true, is_empty_block(block, context.codemap))
- } else {
- (false, false)
- };
-
- let comma = arm_comma(context.config, body, is_last);
- let alt_block_sep = String::from("\n") + &shape.indent.to_string(context.config);
- let alt_block_sep = alt_block_sep.as_str();
-
- let combine_orig_body = |body_str: &str| {
- let block_sep = match context.config.control_brace_style() {
- ControlBraceStyle::AlwaysNextLine if is_block => alt_block_sep,
- _ => " ",
- };
-
- Some(format!("{} =>{}{}{}", pats_str, block_sep, body_str, comma))
- };
-
- let forbid_same_line = has_guard && pats_str.contains('\n') && !is_empty_block;
- let next_line_indent = if !is_block || is_empty_block {
- shape.indent.block_indent(context.config)
- } else {
- shape.indent
- };
- let combine_next_line_body = |body_str: &str| {
- if is_block {
- return Some(format!(
- "{} =>\n{}{}",
- pats_str,
- next_line_indent.to_string(context.config),
- body_str
- ));
- }
-
- let indent_str = shape.indent.to_string(context.config);
- let nested_indent_str = next_line_indent.to_string(context.config);
- let (body_prefix, body_suffix) = if context.config.match_arm_blocks() {
- let comma = if context.config.match_block_trailing_comma() {
- ","
- } else {
- ""
- };
- ("{", format!("\n{}}}{}", indent_str, comma))
- } else {
- ("", String::from(","))
- };
-
- let block_sep = match context.config.control_brace_style() {
- ControlBraceStyle::AlwaysNextLine => format!("{}{}\n", alt_block_sep, body_prefix),
- _ if body_prefix.is_empty() => "\n".to_owned(),
- _ if forbid_same_line => format!("{}{}\n", alt_block_sep, body_prefix),
- _ => format!(" {}\n", body_prefix),
- } + &nested_indent_str;
-
- Some(format!(
- "{} =>{}{}{}",
- pats_str, block_sep, body_str, body_suffix
- ))
- };
-
- // Let's try and get the arm body on the same line as the condition.
- // 4 = ` => `.len()
- let orig_body_shape = shape
- .offset_left(extra_offset(pats_str, shape) + 4)
- .and_then(|shape| shape.sub_width(comma.len()));
- let orig_body = if let Some(body_shape) = orig_body_shape {
- let rewrite = nop_block_collapse(
- format_expr(body, ExprType::Statement, context, body_shape),
- body_shape.width,
- );
-
- match rewrite {
- Some(ref body_str)
- if !forbid_same_line
- && (is_block
- || (!body_str.contains('\n') && body_str.len() <= body_shape.width)) =>
- {
- return combine_orig_body(body_str);
- }
- _ => rewrite,
- }
- } else {
- None
- };
- let orig_budget = orig_body_shape.map_or(0, |shape| shape.width);
-
- // Try putting body on the next line and see if it looks better.
- let next_line_body_shape = Shape::indented(next_line_indent, context.config);
- let next_line_body = nop_block_collapse(
- format_expr(body, ExprType::Statement, context, next_line_body_shape),
- next_line_body_shape.width,
- );
- match (orig_body, next_line_body) {
- (Some(ref orig_str), Some(ref next_line_str))
- if forbid_same_line || prefer_next_line(orig_str, next_line_str) =>
- {
- combine_next_line_body(next_line_str)
- }
- (Some(ref orig_str), _) if extend && first_line_width(orig_str) <= orig_budget => {
- combine_orig_body(orig_str)
- }
- (Some(ref orig_str), Some(ref next_line_str)) if orig_str.contains('\n') => {
- combine_next_line_body(next_line_str)
- }
- (None, Some(ref next_line_str)) => combine_next_line_body(next_line_str),
- (None, None) => None,
- (Some(ref orig_str), _) => combine_orig_body(orig_str),
- }
-}
-
-// The `if ...` guard on a match arm.
-fn rewrite_guard(
- context: &RewriteContext,
- guard: &Option<ptr::P<ast::Expr>>,
- shape: Shape,
- // The amount of space used up on this line for the pattern in
- // the arm (excludes offset).
- pattern_width: usize,
-) -> Option<String> {
- if let Some(ref guard) = *guard {
- // First try to fit the guard string on the same line as the pattern.
- // 4 = ` if `, 5 = ` => {`
- let cond_shape = shape
- .offset_left(pattern_width + 4)
- .and_then(|s| s.sub_width(5));
- if let Some(cond_shape) = cond_shape {
- if let Some(cond_str) = guard.rewrite(context, cond_shape) {
- if !cond_str.contains('\n') || pattern_width <= context.config.tab_spaces() {
- return Some(format!(" if {}", cond_str));
- }
- }
- }
-
- // Not enough space to put the guard after the pattern, try a newline.
- // 3 = `if `, 5 = ` => {`
- let cond_shape = Shape::indented(shape.indent.block_indent(context.config), context.config)
- .offset_left(3)
- .and_then(|s| s.sub_width(5));
- if let Some(cond_shape) = cond_shape {
- if let Some(cond_str) = guard.rewrite(context, cond_shape) {
- return Some(format!(
- "\n{}if {}",
- cond_shape.indent.to_string(context.config),
- cond_str
- ));
- }
- }
-
- None
- } else {
- Some(String::new())
- }
-}
-
-fn rewrite_pat_expr(
- context: &RewriteContext,
- pat: Option<&ast::Pat>,
- expr: &ast::Expr,
- matcher: &str,
- // Connecting piece between pattern and expression,
- // *without* trailing space.
- connector: &str,
- keyword: &str,
- shape: Shape,
- offset: usize,
-) -> Option<String> {
- debug!("rewrite_pat_expr {:?} {:?} {:?}", shape, pat, expr);
- let cond_shape = shape.offset_left(offset)?;
- if let Some(pat) = pat {
- let matcher = if matcher.is_empty() {
- matcher.to_owned()
- } else {
- format!("{} ", matcher)
- };
- let pat_shape = cond_shape
- .offset_left(matcher.len())?
- .sub_width(connector.len())?;
- let pat_string = pat.rewrite(context, pat_shape)?;
- let result = format!("{}{}{}", matcher, pat_string, connector);
- return rewrite_assign_rhs(context, result, expr, cond_shape);
- }
-
- let expr_rw = expr.rewrite(context, cond_shape);
- // The expression may (partially) fit on the current line.
- // We do not allow splitting between `if` and condition.
- if keyword == "if" || expr_rw.is_some() {
- return expr_rw;
- }
-
- // The expression won't fit on the current line, jump to next.
- let nested_shape = shape
- .block_indent(context.config.tab_spaces())
- .with_max_width(context.config);
- let nested_indent_str = nested_shape.indent.to_string(context.config);
- expr.rewrite(context, nested_shape)
- .map(|expr_rw| format!("\n{}{}", nested_indent_str, expr_rw))
-}
-
-fn can_extend_match_arm_body(body: &ast::Expr) -> bool {
- match body.node {
- // We do not allow `if` to stay on the same line, since we could easily mistake
- // `pat => if cond { ... }` and `pat if cond => { ... }`.
- ast::ExprKind::If(..) | ast::ExprKind::IfLet(..) => false,
- ast::ExprKind::ForLoop(..)
- | ast::ExprKind::Loop(..)
- | ast::ExprKind::While(..)
- | ast::ExprKind::WhileLet(..)
- | ast::ExprKind::Match(..)
- | ast::ExprKind::Block(..)
- | ast::ExprKind::Closure(..)
- | ast::ExprKind::Array(..)
- | ast::ExprKind::Call(..)
- | ast::ExprKind::MethodCall(..)
- | ast::ExprKind::Mac(..)
- | ast::ExprKind::Struct(..)
- | ast::ExprKind::Tup(..) => true,
- ast::ExprKind::AddrOf(_, ref expr)
- | ast::ExprKind::Box(ref expr)
- | ast::ExprKind::Try(ref expr)
- | ast::ExprKind::Unary(_, ref expr)
- | ast::ExprKind::Cast(ref expr, _) => can_extend_match_arm_body(expr),
- _ => false,
- }
-}
-
-pub fn rewrite_literal(context: &RewriteContext, l: &ast::Lit, shape: Shape) -> Option<String> {
- match l.node {
- ast::LitKind::Str(_, ast::StrStyle::Cooked) => rewrite_string_lit(context, l.span, shape),
- _ => wrap_str(
- context.snippet(l.span).to_owned(),
- context.config.max_width(),
- shape,
- ),
+pub fn rewrite_literal(context: &RewriteContext, l: &ast::Lit, shape: Shape) -> Option<String> {
+ match l.node {
+ ast::LitKind::Str(_, ast::StrStyle::Cooked) => rewrite_string_lit(context, l.span, shape),
+ _ => wrap_str(
+ context.snippet(l.span).to_owned(),
+ context.config.max_width(),
+ shape,
+ ),
}
}
)
}
+/// In case special-case style is required, returns an offset from which we start horizontal layout.
+pub fn maybe_get_args_offset<T: ToExpr>(callee_str: &str, args: &[&T]) -> Option<(bool, usize)> {
+ if let Some(&(_, num_args_before)) = SPECIAL_MACRO_WHITELIST
+ .iter()
+ .find(|&&(s, _)| s == callee_str)
+ {
+ let all_simple = args.len() > num_args_before && is_every_expr_simple(args);
+
+ Some((all_simple, num_args_before))
+ } else {
+ None
+ }
+}
+
/// A list of `format!`-like macros, that take a long format string and a list of arguments to
/// format.
///
("debug_assert_ne!", 2),
];
+fn choose_separator_tactic(context: &RewriteContext, span: Span) -> Option<SeparatorTactic> {
+ if context.inside_macro() {
+ if span_ends_with_comma(context, span) {
+ Some(SeparatorTactic::Always)
+ } else {
+ Some(SeparatorTactic::Never)
+ }
+ } else {
+ None
+ }
+}
+
pub fn rewrite_call(
context: &RewriteContext,
callee: &str,
span: Span,
shape: Shape,
) -> Option<String> {
- let force_trailing_comma = if context.inside_macro {
- span_ends_with_comma(context, span)
- } else {
- false
- };
- rewrite_call_inner(
+ overflow::rewrite_with_parens(
context,
callee,
&ptr_vec_to_ref_vec(args),
- span,
shape,
+ span,
context.config.width_heuristics().fn_call_width,
- force_trailing_comma,
+ choose_separator_tactic(context, span),
)
}
-pub fn rewrite_call_inner<'a, T>(
- context: &RewriteContext,
- callee_str: &str,
- args: &[&T],
- span: Span,
- shape: Shape,
- args_max_width: usize,
- force_trailing_comma: bool,
-) -> Option<String>
-where
- T: Rewrite + Spanned + ToExpr + 'a,
-{
- // 2 = `( `, 1 = `(`
- let paren_overhead = if context.config.spaces_within_parens_and_brackets() {
- 2
- } else {
- 1
- };
- let used_width = extra_offset(callee_str, shape);
- let one_line_width = shape.width.checked_sub(used_width + 2 * paren_overhead)?;
-
- // 1 = "(" or ")"
- let one_line_shape = shape
- .offset_left(last_line_width(callee_str) + 1)?
- .sub_width(1)?;
- let nested_shape = shape_from_indent_style(
- context,
- shape,
- used_width + 2 * paren_overhead,
- used_width + paren_overhead,
- )?;
-
- let span_lo = context.codemap.span_after(span, "(");
- let args_span = mk_sp(span_lo, span.hi());
-
- let (extendable, list_str) = rewrite_call_args(
- context,
- args,
- args_span,
- one_line_shape,
- nested_shape,
- one_line_width,
- args_max_width,
- force_trailing_comma,
- callee_str,
- )?;
-
- if !context.use_block_indent() && need_block_indent(&list_str, nested_shape) && !extendable {
- let mut new_context = context.clone();
- new_context.use_block = true;
- return rewrite_call_inner(
- &new_context,
- callee_str,
- args,
- span,
- shape,
- args_max_width,
- force_trailing_comma,
- );
- }
-
- let args_shape = shape.sub_width(last_line_width(callee_str))?;
- Some(format!(
- "{}{}",
- callee_str,
- wrap_args_with_parens(context, &list_str, extendable, args_shape, nested_shape)
- ))
-}
-
-fn need_block_indent(s: &str, shape: Shape) -> bool {
- s.lines().skip(1).any(|s| {
- s.find(|c| !char::is_whitespace(c))
- .map_or(false, |w| w + 1 < shape.indent.width())
- })
-}
-
-fn rewrite_call_args<'a, T>(
- context: &RewriteContext,
- args: &[&T],
- span: Span,
- one_line_shape: Shape,
- nested_shape: Shape,
- one_line_width: usize,
- args_max_width: usize,
- force_trailing_comma: bool,
- callee_str: &str,
-) -> Option<(bool, String)>
-where
- T: Rewrite + Spanned + ToExpr + 'a,
-{
- let items = itemize_list(
- context.codemap,
- args.iter(),
- ")",
- ",",
- |item| item.span().lo(),
- |item| item.span().hi(),
- |item| item.rewrite(context, nested_shape),
- span.lo(),
- span.hi(),
- true,
- );
- let mut item_vec: Vec<_> = items.collect();
-
- // Try letting the last argument overflow to the next line with block
- // indentation. If its first line fits on one line with the other arguments,
- // we format the function arguments horizontally.
- let tactic = try_overflow_last_arg(
- context,
- &mut item_vec,
- &args[..],
- one_line_shape,
- nested_shape,
- one_line_width,
- args_max_width,
- callee_str,
- );
-
- let fmt = ListFormatting {
- tactic: tactic,
- separator: ",",
- trailing_separator: if force_trailing_comma {
- SeparatorTactic::Always
- } else if context.inside_macro || !context.use_block_indent() {
- SeparatorTactic::Never
- } else {
- context.config.trailing_comma()
- },
- separator_place: SeparatorPlace::Back,
- shape: nested_shape,
- ends_with_newline: context.use_block_indent() && tactic == DefinitiveListTactic::Vertical,
- preserve_newline: false,
- config: context.config,
- };
-
- write_list(&item_vec, &fmt)
- .map(|args_str| (tactic == DefinitiveListTactic::Horizontal, args_str))
-}
-
-fn try_overflow_last_arg<'a, T>(
- context: &RewriteContext,
- item_vec: &mut Vec<ListItem>,
- args: &[&T],
- one_line_shape: Shape,
- nested_shape: Shape,
- one_line_width: usize,
- args_max_width: usize,
- callee_str: &str,
-) -> DefinitiveListTactic
-where
- T: Rewrite + Spanned + ToExpr + 'a,
-{
- // 1 = "("
- let combine_arg_with_callee =
- callee_str.len() + 1 <= context.config.tab_spaces() && args.len() == 1;
- let overflow_last = combine_arg_with_callee || can_be_overflowed(context, args);
-
- // Replace the last item with its first line to see if it fits with
- // first arguments.
- let placeholder = if overflow_last {
- let mut context = context.clone();
- if !combine_arg_with_callee {
- if let Some(expr) = args[args.len() - 1].to_expr() {
- if let ast::ExprKind::MethodCall(..) = expr.node {
- context.force_one_line_chain = true;
- }
- }
- }
- last_arg_shape(args, item_vec, one_line_shape, args_max_width).and_then(|arg_shape| {
- rewrite_last_arg_with_overflow(&context, args, &mut item_vec[args.len() - 1], arg_shape)
- })
- } else {
- None
- };
-
- let mut tactic = definitive_tactic(
- &*item_vec,
- ListTactic::LimitedHorizontalVertical(args_max_width),
- Separator::Comma,
- one_line_width,
- );
-
- // Replace the stub with the full overflowing last argument if the rewrite
- // succeeded and its first line fits with the other arguments.
- match (overflow_last, tactic, placeholder) {
- (true, DefinitiveListTactic::Horizontal, Some(ref overflowed)) if args.len() == 1 => {
- // When we are rewriting a nested function call, we restrict the
- // bugdet for the inner function to avoid them being deeply nested.
- // However, when the inner function has a prefix or a suffix
- // (e.g. `foo() as u32`), this budget reduction may produce poorly
- // formatted code, where a prefix or a suffix being left on its own
- // line. Here we explicitlly check those cases.
- if count_newlines(overflowed) == 1 {
- let rw = args.last()
- .and_then(|last_arg| last_arg.rewrite(context, nested_shape));
- let no_newline = rw.as_ref().map_or(false, |s| !s.contains('\n'));
- if no_newline {
- item_vec[args.len() - 1].item = rw;
- } else {
- item_vec[args.len() - 1].item = Some(overflowed.to_owned());
- }
- } else {
- item_vec[args.len() - 1].item = Some(overflowed.to_owned());
- }
- }
- (true, DefinitiveListTactic::Horizontal, placeholder @ Some(..)) => {
- item_vec[args.len() - 1].item = placeholder;
- }
- _ if args.len() >= 1 => {
- item_vec[args.len() - 1].item = args.last()
- .and_then(|last_arg| last_arg.rewrite(context, nested_shape));
-
- let default_tactic = || {
- definitive_tactic(
- &*item_vec,
- ListTactic::LimitedHorizontalVertical(args_max_width),
- Separator::Comma,
- one_line_width,
- )
- };
-
- // Use horizontal layout for a function with a single argument as long as
- // everything fits in a single line.
- if args.len() == 1
- && args_max_width != 0 // Vertical layout is forced.
- && !item_vec[0].has_comment()
- && !item_vec[0].inner_as_ref().contains('\n')
- && ::lists::total_item_width(&item_vec[0]) <= one_line_width
- {
- tactic = DefinitiveListTactic::Horizontal;
- } else {
- tactic = default_tactic();
-
- if tactic == DefinitiveListTactic::Vertical {
- if let Some((all_simple, num_args_before)) =
- maybe_get_args_offset(callee_str, args)
- {
- let one_line = all_simple
- && definitive_tactic(
- &item_vec[..num_args_before],
- ListTactic::HorizontalVertical,
- Separator::Comma,
- nested_shape.width,
- ) == DefinitiveListTactic::Horizontal
- && definitive_tactic(
- &item_vec[num_args_before + 1..],
- ListTactic::HorizontalVertical,
- Separator::Comma,
- nested_shape.width,
- ) == DefinitiveListTactic::Horizontal;
-
- if one_line {
- tactic = DefinitiveListTactic::SpecialMacro(num_args_before);
- };
- }
- }
- }
- }
- _ => (),
- }
-
- tactic
-}
-
-fn is_simple_arg(expr: &ast::Expr) -> bool {
+fn is_simple_expr(expr: &ast::Expr) -> bool {
match expr.node {
ast::ExprKind::Lit(..) => true,
ast::ExprKind::Path(ref qself, ref path) => qself.is_none() && path.segments.len() <= 1,
| ast::ExprKind::Cast(ref expr, _)
| ast::ExprKind::Field(ref expr, _)
| ast::ExprKind::Try(ref expr)
- | ast::ExprKind::TupField(ref expr, _)
- | ast::ExprKind::Unary(_, ref expr) => is_simple_arg(expr),
+ | ast::ExprKind::Unary(_, ref expr) => is_simple_expr(expr),
ast::ExprKind::Index(ref lhs, ref rhs) | ast::ExprKind::Repeat(ref lhs, ref rhs) => {
- is_simple_arg(lhs) && is_simple_arg(rhs)
+ is_simple_expr(lhs) && is_simple_expr(rhs)
}
_ => false,
}
}
-fn is_every_args_simple<T: ToExpr>(lists: &[&T]) -> bool {
+pub fn is_every_expr_simple<T: ToExpr>(lists: &[&T]) -> bool {
lists
.iter()
- .all(|arg| arg.to_expr().map_or(false, is_simple_arg))
-}
-
-/// In case special-case style is required, returns an offset from which we start horizontal layout.
-fn maybe_get_args_offset<T: ToExpr>(callee_str: &str, args: &[&T]) -> Option<(bool, usize)> {
- if let Some(&(_, num_args_before)) = SPECIAL_MACRO_WHITELIST
- .iter()
- .find(|&&(s, _)| s == callee_str)
- {
- let all_simple = args.len() >= num_args_before && is_every_args_simple(args);
-
- Some((all_simple, num_args_before))
- } else {
- None
- }
-}
-
-/// Returns a shape for the last argument which is going to be overflowed.
-fn last_arg_shape<T>(
- lists: &[&T],
- items: &[ListItem],
- shape: Shape,
- args_max_width: usize,
-) -> Option<Shape>
-where
- T: Rewrite + Spanned + ToExpr,
-{
- let is_nested_call = lists
- .iter()
- .next()
- .and_then(|item| item.to_expr())
- .map_or(false, is_nested_call);
- if items.len() == 1 && !is_nested_call {
- return Some(shape);
- }
- let offset = items.iter().rev().skip(1).fold(0, |acc, i| {
- // 2 = ", "
- acc + 2 + i.inner_as_ref().len()
- });
- Shape {
- width: min(args_max_width, shape.width),
- ..shape
- }.offset_left(offset)
-}
-
-fn rewrite_last_arg_with_overflow<'a, T>(
- context: &RewriteContext,
- args: &[&T],
- last_item: &mut ListItem,
- shape: Shape,
-) -> Option<String>
-where
- T: Rewrite + Spanned + ToExpr + 'a,
-{
- let last_arg = args[args.len() - 1];
- let rewrite = if let Some(expr) = last_arg.to_expr() {
- match expr.node {
- // When overflowing the closure which consists of a single control flow expression,
- // force to use block if its condition uses multi line.
- ast::ExprKind::Closure(..) => {
- // If the argument consists of multiple closures, we do not overflow
- // the last closure.
- if closures::args_have_many_closure(args) {
- None
- } else {
- closures::rewrite_last_closure(context, expr, shape)
- }
- }
- _ => expr.rewrite(context, shape),
- }
- } else {
- last_arg.rewrite(context, shape)
- };
-
- if let Some(rewrite) = rewrite {
- let rewrite_first_line = Some(rewrite[..first_line_width(&rewrite)].to_owned());
- last_item.item = rewrite_first_line;
- Some(rewrite)
- } else {
- None
- }
-}
-
-fn can_be_overflowed<'a, T>(context: &RewriteContext, args: &[&T]) -> bool
-where
- T: Rewrite + Spanned + ToExpr + 'a,
-{
- args.last()
- .map_or(false, |x| x.can_be_overflowed(context, args.len()))
+ .all(|arg| arg.to_expr().map_or(false, is_simple_expr))
}
pub fn can_be_overflowed_expr(context: &RewriteContext, expr: &ast::Expr, args_len: usize) -> bool {
}
}
-fn is_nested_call(expr: &ast::Expr) -> bool {
+pub fn is_nested_call(expr: &ast::Expr) -> bool {
match expr.node {
ast::ExprKind::Call(..) | ast::ExprKind::Mac(..) => true,
ast::ExprKind::AddrOf(_, ref expr)
}
}
-pub fn wrap_args_with_parens(
- context: &RewriteContext,
- args_str: &str,
- is_extendable: bool,
- shape: Shape,
- nested_shape: Shape,
-) -> String {
- if !context.use_block_indent()
- || (context.inside_macro && !args_str.contains('\n')
- && args_str.len() + paren_overhead(context) <= shape.width) || is_extendable
- {
- if context.config.spaces_within_parens_and_brackets() && !args_str.is_empty() {
- format!("( {} )", args_str)
- } else {
- format!("({})", args_str)
- }
- } else {
- format!(
- "(\n{}{}\n{})",
- nested_shape.indent.to_string(context.config),
- args_str,
- shape.block().indent.to_string(context.config)
- )
- }
-}
-
/// Return true if a function call or a method call represented by the given span ends with a
/// trailing comma. This function is used when rewriting macro, as adding or removing a trailing
/// comma from macro can potentially break the code.
-fn span_ends_with_comma(context: &RewriteContext, span: Span) -> bool {
- let mut encountered_closing_paren = false;
- for c in context.snippet(span).chars().rev() {
+pub fn span_ends_with_comma(context: &RewriteContext, span: Span) -> bool {
+ let mut result: bool = Default::default();
+ let mut prev_char: char = Default::default();
+ let closing_delimiters = &[')', '}', ']'];
+
+ for (kind, c) in CharClasses::new(context.snippet(span).chars()) {
match c {
- ',' => return true,
- ')' => if encountered_closing_paren {
- return false;
- } else {
- encountered_closing_paren = true;
- },
- _ if c.is_whitespace() => continue,
- _ => return false,
+ _ if kind.is_comment() || c.is_whitespace() => continue,
+ c if closing_delimiters.contains(&c) => {
+ result &= !closing_delimiters.contains(&prev_char);
+ }
+ ',' => result = true,
+ _ => result = false,
}
+ prev_char = c;
}
- false
+
+ result
}
-fn rewrite_paren(context: &RewriteContext, subexpr: &ast::Expr, shape: Shape) -> Option<String> {
+fn rewrite_paren(
+ context: &RewriteContext,
+ mut subexpr: &ast::Expr,
+ shape: Shape,
+ mut span: Span,
+) -> Option<String> {
debug!("rewrite_paren, shape: {:?}", shape);
- let total_paren_overhead = paren_overhead(context);
- let paren_overhead = total_paren_overhead / 2;
- let sub_shape = shape
- .offset_left(paren_overhead)
- .and_then(|s| s.sub_width(paren_overhead))?;
-
- let paren_wrapper = |s: &str| {
- if context.config.spaces_within_parens_and_brackets() && !s.is_empty() {
- format!("( {} )", s)
- } else {
- format!("({})", s)
+
+ // Extract comments within parens.
+ let mut pre_comment;
+ let mut post_comment;
+ let remove_nested_parens = context.config.remove_nested_parens();
+ loop {
+ // 1 = "(" or ")"
+ let pre_span = mk_sp(span.lo() + BytePos(1), subexpr.span.lo());
+ let post_span = mk_sp(subexpr.span.hi(), span.hi() - BytePos(1));
+ pre_comment = rewrite_missing_comment(pre_span, shape, context)?;
+ post_comment = rewrite_missing_comment(post_span, shape, context)?;
+
+ // Remove nested parens if there are no comments.
+ if let ast::ExprKind::Paren(ref subsubexpr) = subexpr.node {
+ if remove_nested_parens && pre_comment.is_empty() && post_comment.is_empty() {
+ span = subexpr.span;
+ subexpr = subsubexpr;
+ continue;
+ }
}
- };
+
+ break;
+ }
+
+ // 1 `(`
+ let sub_shape = shape.offset_left(1).and_then(|s| s.sub_width(1))?;
let subexpr_str = subexpr.rewrite(context, sub_shape)?;
debug!("rewrite_paren, subexpr_str: `{:?}`", subexpr_str);
- if subexpr_str.contains('\n')
- || first_line_width(&subexpr_str) + total_paren_overhead <= shape.width
- {
- Some(paren_wrapper(&subexpr_str))
+ // 2 = `()`
+ if subexpr_str.contains('\n') || first_line_width(&subexpr_str) + 2 <= shape.width {
+ Some(format!("({}{}{})", pre_comment, &subexpr_str, post_comment))
} else {
None
}
) -> Option<String> {
let expr_str = expr.rewrite(context, shape)?;
- let (lbr, rbr) = if context.config.spaces_within_parens_and_brackets() {
- ("[ ", " ]")
- } else {
- ("[", "]")
- };
-
- let offset = last_line_width(&expr_str) + lbr.len();
+ let offset = last_line_width(&expr_str) + 1;
let rhs_overhead = shape.rhs_overhead(context.config);
let index_shape = if expr_str.contains('\n') {
Shape::legacy(context.config.max_width(), shape.indent)
.offset_left(offset)
- .and_then(|shape| shape.sub_width(rbr.len() + rhs_overhead))
+ .and_then(|shape| shape.sub_width(1 + rhs_overhead))
} else {
- shape.visual_indent(offset).sub_width(offset + rbr.len())
+ shape.visual_indent(offset).sub_width(offset + 1)
};
let orig_index_rw = index_shape.and_then(|s| index.rewrite(context, s));
// Return if index fits in a single line.
match orig_index_rw {
Some(ref index_str) if !index_str.contains('\n') => {
- return Some(format!("{}{}{}{}", expr_str, lbr, index_str, rbr));
+ return Some(format!("{}[{}]", expr_str, index_str));
}
_ => (),
}
// Try putting index on the next line and see if it fits in a single line.
let indent = shape.indent.block_indent(context.config);
- let index_shape = Shape::indented(indent, context.config).offset_left(lbr.len())?;
- let index_shape = index_shape.sub_width(rbr.len() + rhs_overhead)?;
+ let index_shape = Shape::indented(indent, context.config).offset_left(1)?;
+ let index_shape = index_shape.sub_width(1 + rhs_overhead)?;
let new_index_rw = index.rewrite(context, index_shape);
match (orig_index_rw, new_index_rw) {
(_, Some(ref new_index_str)) if !new_index_str.contains('\n') => Some(format!(
- "{}\n{}{}{}{}",
+ "{}{}[{}]",
expr_str,
- indent.to_string(context.config),
- lbr,
+ indent.to_string_with_newline(context.config),
new_index_str,
- rbr
)),
(None, Some(ref new_index_str)) => Some(format!(
- "{}\n{}{}{}{}",
+ "{}{}[{}]",
expr_str,
- indent.to_string(context.config),
- lbr,
+ indent.to_string_with_newline(context.config),
new_index_str,
- rbr
)),
- (Some(ref index_str), _) => Some(format!("{}{}{}{}", expr_str, lbr, index_str, rbr)),
+ (Some(ref index_str), _) => Some(format!("{}[{}]", expr_str, index_str)),
_ => None,
}
}
let (h_shape, v_shape) = struct_lit_shape(shape, context, path_str.len() + 3, 2)?;
let one_line_width = h_shape.map_or(0, |shape| shape.width);
- let body_lo = context.codemap.span_after(span, "{");
+ let body_lo = context.snippet_provider.span_after(span, "{");
let fields_str = if struct_lit_can_be_aligned(fields, &base)
&& context.config.struct_field_align_threshold() > 0
{
};
let items = itemize_list(
- context.codemap,
+ context.snippet_provider,
field_iter,
"}",
",",
let tactic = struct_lit_tactic(h_shape, context, &item_vec);
let nested_shape = shape_for_tactic(tactic, h_shape, v_shape);
- let fmt = struct_lit_formatting(nested_shape, tactic, context, base.is_some());
+
+ let ends_with_comma = span_ends_with_comma(context, span);
+ let force_no_trailing_comma = context.inside_macro() && !ends_with_comma;
+
+ let fmt = struct_lit_formatting(
+ nested_shape,
+ tactic,
+ context,
+ force_no_trailing_comma || base.is_some(),
+ );
write_list(&item_vec, &fmt)?
};
one_line_width: usize,
) -> String {
if context.config.indent_style() == IndentStyle::Block
- && (fields_str.contains('\n') || !context.config.struct_lit_single_line()
+ && (fields_str.contains('\n')
+ || !context.config.struct_lit_single_line()
|| fields_str.len() > one_line_width)
{
format!(
- "\n{}{}\n{}",
- nested_shape.indent.to_string(context.config),
+ "{}{}{}",
+ nested_shape.indent.to_string_with_newline(context.config),
fields_str,
- shape.indent.to_string(context.config)
+ shape.indent.to_string_with_newline(context.config)
)
} else {
// One liner or visual indent.
if contains_skip(&field.attrs) {
return Some(context.snippet(field.span()).to_owned());
}
- let name = &field.ident.node.to_string();
+ let mut attrs_str = field.attrs.rewrite(context, shape)?;
+ if !attrs_str.is_empty() {
+ attrs_str.push_str(&shape.indent.to_string_with_newline(context.config));
+ };
+ let name = &field.ident.name.to_string();
if field.is_shorthand {
- Some(name.to_string())
+ Some(attrs_str + &name)
} else {
let mut separator = String::from(struct_lit_field_separator(context.config));
- for _ in 0..prefix_max_width.checked_sub(name.len()).unwrap_or(0) {
+ for _ in 0..prefix_max_width.saturating_sub(name.len()) {
separator.push(' ');
}
let overhead = name.len() + separator.len();
let expr_shape = shape.offset_left(overhead)?;
let expr = field.expr.rewrite(context, expr_shape);
- let mut attrs_str = field.attrs.rewrite(context, shape)?;
- if !attrs_str.is_empty() {
- attrs_str.push_str(&format!("\n{}", shape.indent.to_string(context.config)));
- };
-
match expr {
+ Some(ref e) if e.as_str() == name && context.config.use_field_init_shorthand() => {
+ Some(attrs_str + &name)
+ }
Some(e) => Some(format!("{}{}{}{}", attrs_str, name, separator, e)),
None => {
let expr_offset = shape.indent.block_indent(context.config);
}
}
-fn shape_from_indent_style(
- context: &RewriteContext,
- shape: Shape,
- overhead: usize,
- offset: usize,
-) -> Option<Shape> {
- if context.use_block_indent() {
- // 1 = ","
- shape
- .block()
- .block_indent(context.config.tab_spaces())
- .with_max_width(context.config)
- .sub_width(1)
- } else {
- shape.visual_indent(offset).sub_width(overhead)
- }
-}
-
fn rewrite_tuple_in_visual_indent_style<'a, T>(
context: &RewriteContext,
items: &[&T],
.next()
.unwrap()
.rewrite(context, nested_shape)
- .map(|s| {
- if context.config.spaces_within_parens_and_brackets() {
- format!("( {}, )", s)
- } else {
- format!("({},)", s)
- }
- });
+ .map(|s| format!("({},)", s));
}
- let list_lo = context.codemap.span_after(span, "(");
+ let list_lo = context.snippet_provider.span_after(span, "(");
let nested_shape = shape.sub_width(2)?.visual_indent(1);
let items = itemize_list(
- context.codemap,
+ context.snippet_provider,
items,
")",
",",
nested_shape.width,
);
let fmt = ListFormatting {
- tactic: tactic,
+ tactic,
separator: ",",
trailing_separator: SeparatorTactic::Never,
separator_place: SeparatorPlace::Back,
- shape: shape,
+ shape,
ends_with_newline: false,
preserve_newline: false,
config: context.config,
};
let list_str = write_list(&item_vec, &fmt)?;
- if context.config.spaces_within_parens_and_brackets() && !list_str.is_empty() {
- Some(format!("( {} )", list_str))
- } else {
- Some(format!("({})", list_str))
- }
+ Some(format!("({})", list_str))
}
pub fn rewrite_tuple<'a, T>(
debug!("rewrite_tuple {:?}", shape);
if context.use_block_indent() {
// We use the same rule as function calls for rewriting tuples.
- let force_trailing_comma = if context.inside_macro {
- span_ends_with_comma(context, span)
+ let force_tactic = if context.inside_macro() {
+ if span_ends_with_comma(context, span) {
+ Some(SeparatorTactic::Always)
+ } else {
+ Some(SeparatorTactic::Never)
+ }
+ } else if items.len() == 1 {
+ Some(SeparatorTactic::Always)
} else {
- items.len() == 1
+ None
};
- rewrite_call_inner(
+ overflow::rewrite_with_parens(
context,
- &String::new(),
+ "",
items,
- span,
shape,
+ span,
context.config.width_heuristics().fn_call_width,
- force_trailing_comma,
+ force_tactic,
)
} else {
rewrite_tuple_in_visual_indent_style(context, items, span, shape)
rewrite_assign_rhs(context, lhs_str, rhs, shape)
}
+/// Controls where to put the rhs.
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub enum RhsTactics {
+ /// Use heuristics.
+ Default,
+ /// Put the rhs on the next line if it uses multiple line.
+ ForceNextLine,
+}
+
// The left hand side must contain everything up to, and including, the
// assignment operator.
pub fn rewrite_assign_rhs<S: Into<String>, R: Rewrite>(
lhs: S,
ex: &R,
shape: Shape,
+) -> Option<String> {
+ rewrite_assign_rhs_with(context, lhs, ex, shape, RhsTactics::Default)
+}
+
+pub fn rewrite_assign_rhs_with<S: Into<String>, R: Rewrite>(
+ context: &RewriteContext,
+ lhs: S,
+ ex: &R,
+ shape: Shape,
+ rhs_tactics: RhsTactics,
) -> Option<String> {
let lhs = lhs.into();
- let last_line_width = last_line_width(&lhs)
- .checked_sub(if lhs.contains('\n') {
- shape.indent.width()
- } else {
- 0
- })
- .unwrap_or(0);
+ let last_line_width = last_line_width(&lhs).saturating_sub(if lhs.contains('\n') {
+ shape.indent.width()
+ } else {
+ 0
+ });
// 1 = space between operator and rhs.
let orig_shape = shape.offset_left(last_line_width + 1).unwrap_or(Shape {
width: 0,
offset: shape.offset + last_line_width + 1,
..shape
});
- let rhs = choose_rhs(context, ex, orig_shape, ex.rewrite(context, orig_shape))?;
+ let rhs = choose_rhs(
+ context,
+ ex,
+ orig_shape,
+ ex.rewrite(context, orig_shape),
+ rhs_tactics,
+ )?;
Some(lhs + &rhs)
}
-pub fn choose_rhs<R: Rewrite>(
+fn choose_rhs<R: Rewrite>(
context: &RewriteContext,
expr: &R,
shape: Shape,
orig_rhs: Option<String>,
+ rhs_tactics: RhsTactics,
) -> Option<String> {
match orig_rhs {
Some(ref new_str) if !new_str.contains('\n') && new_str.len() <= shape.width => {
Shape::indented(shape.indent.block_indent(context.config), context.config)
.sub_width(shape.rhs_overhead(context.config))?;
let new_rhs = expr.rewrite(context, new_shape);
- let new_indent_str = &new_shape.indent.to_string(context.config);
+ let new_indent_str = &new_shape.indent.to_string_with_newline(context.config);
match (orig_rhs, new_rhs) {
(Some(ref orig_rhs), Some(ref new_rhs))
{
Some(format!(" {}", orig_rhs))
}
- (Some(ref orig_rhs), Some(ref new_rhs)) if prefer_next_line(orig_rhs, new_rhs) => {
- Some(format!("\n{}{}", new_indent_str, new_rhs))
+ (Some(ref orig_rhs), Some(ref new_rhs))
+ if prefer_next_line(orig_rhs, new_rhs, rhs_tactics) =>
+ {
+ Some(format!("{}{}", new_indent_str, new_rhs))
}
- (None, Some(ref new_rhs)) => Some(format!("\n{}{}", new_indent_str, new_rhs)),
+ (None, Some(ref new_rhs)) => Some(format!("{}{}", new_indent_str, new_rhs)),
(None, None) => None,
(Some(ref orig_rhs), _) => Some(format!(" {}", orig_rhs)),
}
}
}
-fn prefer_next_line(orig_rhs: &str, next_line_rhs: &str) -> bool {
- !next_line_rhs.contains('\n') || count_newlines(orig_rhs) > count_newlines(next_line_rhs) + 1
+pub fn prefer_next_line(orig_rhs: &str, next_line_rhs: &str, rhs_tactics: RhsTactics) -> bool {
+ rhs_tactics == RhsTactics::ForceNextLine
+ || !next_line_rhs.contains('\n')
+ || count_newlines(orig_rhs) > count_newlines(next_line_rhs) + 1
}
fn rewrite_expr_addrof(
MacroArg::Expr(ref expr) => can_be_overflowed_expr(context, expr, len),
MacroArg::Ty(ref ty) => can_be_overflowed_type(context, ty, len),
MacroArg::Pat(..) => false,
+ MacroArg::Item(..) => len == 1,
}
}
}
+
+impl ToExpr for ast::GenericParam {
+ fn to_expr(&self) -> Option<&ast::Expr> {
+ None
+ }
+
+ fn can_be_overflowed(&self, _: &RewriteContext, _: usize) -> bool {
+ false
+ }
+}
projects / rust.git / blobdiff