use std::iter::repeat;
use config::lists::*;
-use syntax::codemap::{BytePos, Span};
+use syntax::source_map::{BytePos, Span};
use syntax::{ast, ptr};
-use codemap::SpanUtils;
-use comment::combine_strs_with_missing_comments;
+use comment::{combine_strs_with_missing_comments, rewrite_comment};
use config::{Config, ControlBraceStyle, IndentStyle};
-use expr::{format_expr, is_empty_block, is_simple_block, is_unsafe_block, prefer_next_line,
- rewrite_multiple_patterns, ExprType, RhsTactics, ToExpr};
+use expr::{
+ format_expr, is_empty_block, is_simple_block, is_unsafe_block, prefer_next_line, rewrite_cond,
+ rewrite_multiple_patterns, ExprType, RhsTactics,
+};
use lists::{itemize_list, write_list, ListFormatting};
use rewrite::{Rewrite, RewriteContext};
use shape::Shape;
+use source_map::SpanUtils;
use spanned::Spanned;
-use utils::{contains_skip, extra_offset, first_line_width, inner_attributes, last_line_extendable,
- mk_sp, ptr_vec_to_ref_vec, trimmed_last_line_width};
+use utils::{
+ contains_skip, extra_offset, first_line_width, inner_attributes, last_line_extendable, mk_sp,
+ ptr_vec_to_ref_vec, trimmed_last_line_width,
+};
/// A simple wrapper type against `ast::Arm`. Used inside `write_list()`.
struct ArmWrapper<'a> {
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, self.beginning_vert)
+ rewrite_match_arm(context, self.arm, shape, self.is_last)
}
}
Some(context.snippet(span).to_owned())
}
} else {
+ let span_after_cond = mk_sp(cond.span.hi(), span.hi());
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)?,
+ rewrite_match_arms(context, arms, shape, span_after_cond, open_brace_pos)?,
shape.indent.to_string(context.config),
))
}
""
} else if config.match_block_trailing_comma() {
","
- } else if let ast::ExprKind::Block(ref block) = body.node {
+ } else if let ast::ExprKind::Block(ref block, _) = body.node {
if let ast::BlockCheckMode::Default = block.rules {
""
} else {
let arm_len = arms.len();
let is_last_iter = repeat(false)
- .take(arm_len.checked_sub(1).unwrap_or(0))
+ .take(arm_len.saturating_sub(1))
.chain(repeat(true));
let beginning_verts = collect_beginning_verts(context, arms, span);
let items = itemize_list(
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,
- };
+ // We will add/remove commas inside `arm.rewrite()`, and hence no separator here.
+ let fmt = ListFormatting::new(arm_shape, context.config)
+ .separator("")
+ .preserve_newline(true);
write_list(&arms_vec, &fmt)
}
arm: &ast::Arm,
shape: Shape,
is_last: bool,
- beginning_vert: Option<BytePos>,
) -> 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);
+ let (_, body) = flatten_arm_body(context, &arm.body, None);
// `arm.span()` does not include trailing comma, add it manually.
return Some(format!(
"{}{}",
} else {
(mk_sp(arm.span().lo(), arm.span().lo()), String::new())
};
- let pats_str = rewrite_match_pattern(
+
+ // Patterns
+ // 5 = ` => {`
+ let pat_shape = shape.sub_width(5)?;
+ let pats_str = rewrite_multiple_patterns(context, &ptr_vec_to_ref_vec(&arm.pats), pat_shape)?;
+
+ // Guard
+ let block_like_pat = trimmed_last_line_width(&pats_str) <= context.config.tab_spaces();
+ let new_line_guard = pats_str.contains('\n') && !block_like_pat;
+ let guard_str = rewrite_guard(
context,
- &ptr_vec_to_ref_vec(&arm.pats),
&arm.guard,
- beginning_vert.is_some(),
shape,
- ).and_then(|pats_str| {
- combine_strs_with_missing_comments(
- context,
- &attrs_str,
- &pats_str,
- missing_span,
- shape,
- false,
- )
- })?;
+ trimmed_last_line_width(&pats_str),
+ new_line_guard,
+ )?;
+
+ let lhs_str = combine_strs_with_missing_comments(
+ context,
+ &attrs_str,
+ &format!("{}{}", pats_str, guard_str),
+ missing_span,
+ shape,
+ false,
+ )?;
+
+ let arrow_span = mk_sp(arm.pats.last().unwrap().span.hi(), arm.body.span.lo());
rewrite_match_body(
context,
&arm.body,
- &pats_str,
+ &lhs_str,
shape,
- arm.guard.is_some(),
+ guard_str.contains('\n'),
+ arrow_span,
is_last,
)
}
-fn rewrite_match_pattern(
+fn block_can_be_flattened<'a>(
context: &RewriteContext,
- pats: &[&ast::Pat],
- guard: &Option<ptr::P<ast::Expr>>,
- has_beginning_vert: bool,
- shape: Shape,
-) -> Option<String> {
- // Patterns
- // 5 = ` => {`
- // 2 = `| `
- let pat_shape = shape
- .sub_width(5)?
- .offset_left(if has_beginning_vert { 2 } else { 0 })?;
- let pats_str = rewrite_multiple_patterns(context, pats, pat_shape)?;
- let beginning_vert = if has_beginning_vert { "| " } else { "" };
-
- // Guard
- let guard_str = rewrite_guard(context, guard, shape, trimmed_last_line_width(&pats_str))?;
-
- Some(format!("{}{}{}", beginning_vert, pats_str, guard_str))
+ expr: &'a ast::Expr,
+) -> Option<&'a ast::Block> {
+ match expr.node {
+ ast::ExprKind::Block(ref block, _)
+ if !is_unsafe_block(block)
+ && is_simple_block(block, Some(&expr.attrs), context.source_map) =>
+ {
+ Some(&*block)
+ }
+ _ => None,
+ }
}
// (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, Some(&body.attrs), context.codemap) =>
- {
- if let ast::StmtKind::Expr(ref expr) = block.stmts[0].node {
- (
- !context.config.force_multiline_blocks() && can_flatten_block_around_this(expr),
- &*expr,
- )
+fn flatten_arm_body<'a>(
+ context: &'a RewriteContext,
+ body: &'a ast::Expr,
+ opt_shape: Option<Shape>,
+) -> (bool, &'a ast::Expr) {
+ let can_extend =
+ |expr| !context.config.force_multiline_blocks() && can_flatten_block_around_this(expr);
+
+ if let Some(ref block) = block_can_be_flattened(context, body) {
+ if let ast::StmtKind::Expr(ref expr) = block.stmts[0].node {
+ if let ast::ExprKind::Block(..) = expr.node {
+ flatten_arm_body(context, expr, None)
} else {
- (false, &*body)
+ let cond_becomes_muti_line = opt_shape
+ .and_then(|shape| rewrite_cond(context, expr, shape))
+ .map_or(false, |cond| cond.contains('\n'));
+ if cond_becomes_muti_line {
+ (false, &*body)
+ } else {
+ (can_extend(expr), &*expr)
+ }
}
+ } else {
+ (false, &*body)
}
- _ => (
- !context.config.force_multiline_blocks() && body.can_be_overflowed(context, 1),
- &*body,
- ),
+ } else {
+ (can_extend(body), &*body)
}
}
pats_str: &str,
shape: Shape,
has_guard: bool,
+ arrow_span: Span,
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 {
+ let (extend, body) = flatten_arm_body(
+ context,
+ body,
+ shape.offset_left(extra_offset(pats_str, shape) + 4),
+ );
+ let (is_block, is_empty_block) = if let ast::ExprKind::Block(ref block, _) = body.node {
(
true,
- is_empty_block(block, Some(&body.attrs), context.codemap),
+ is_empty_block(block, Some(&body.attrs), context.source_map),
)
} else {
(false, false)
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 forbid_same_line = has_guard && pats_str.contains('\n') && !is_empty_block;
+
+ // Look for comments between `=>` and the start of the body.
+ let arrow_comment = {
+ let arrow_snippet = context.snippet(arrow_span).trim();
+ // search for the arrow starting from the end of the snippet since there may be a match
+ // expression within the guard
+ let arrow_index = arrow_snippet.rfind("=>").unwrap();
+ // 2 = `=>`
+ let comment_str = arrow_snippet[arrow_index + 2..].trim();
+ if comment_str.is_empty() {
+ String::new()
+ } else {
+ rewrite_comment(comment_str, false, shape, &context.config)?
+ }
+ };
+
let combine_next_line_body = |body_str: &str| {
+ let nested_indent_str = next_line_indent.to_string_with_newline(context.config);
+
if is_block {
- return Some(format!(
- "{} =>{}{}",
- pats_str,
- next_line_indent.to_string_with_newline(context.config),
- body_str
- ));
+ let mut result = pats_str.to_owned();
+ result.push_str(" =>");
+ if !arrow_comment.is_empty() {
+ result.push_str(&nested_indent_str);
+ result.push_str(&arrow_comment);
+ }
+ result.push_str(&nested_indent_str);
+ result.push_str(&body_str);
+ return Some(result);
}
let indent_str = shape.indent.to_string_with_newline(context.config);
- let nested_indent_str = next_line_indent.to_string_with_newline(context.config);
let (body_prefix, body_suffix) = if context.config.match_arm_blocks() {
let comma = if context.config.match_block_trailing_comma() {
","
let block_sep = match context.config.control_brace_style() {
ControlBraceStyle::AlwaysNextLine => format!("{}{}", alt_block_sep, body_prefix),
_ if body_prefix.is_empty() => "".to_owned(),
- _ if forbid_same_line => format!("{}{}", alt_block_sep, body_prefix),
+ _ if forbid_same_line || !arrow_comment.is_empty() => {
+ format!("{}{}", alt_block_sep, body_prefix)
+ }
_ => format!(" {}", body_prefix),
} + &nested_indent_str;
- Some(format!(
- "{} =>{}{}{}",
- pats_str, block_sep, body_str, body_suffix
- ))
+ let mut result = pats_str.to_owned();
+ result.push_str(" =>");
+ if !arrow_comment.is_empty() {
+ result.push_str(&indent_str);
+ result.push_str(&arrow_comment);
+ }
+ result.push_str(&block_sep);
+ result.push_str(&body_str);
+ result.push_str(&body_suffix);
+ Some(result)
};
// Let's try and get the arm body on the same line as the condition.
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 orig_body = if forbid_same_line || !arrow_comment.is_empty() {
+ None
+ } else 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)) =>
+ if is_block || (!body_str.contains('\n') && body_str.len() <= body_shape.width) =>
{
return combine_orig_body(body_str);
}
);
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, RhsTactics::Default) =>
+ if prefer_next_line(orig_str, next_line_str, RhsTactics::Default) =>
{
combine_next_line_body(next_line_str)
}
}
}
+impl Rewrite for ast::Guard {
+ fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
+ match self {
+ ast::Guard::If(ref expr) => expr.rewrite(context, shape),
+ }
+ }
+}
+
// The `if ...` guard on a match arm.
fn rewrite_guard(
context: &RewriteContext,
- guard: &Option<ptr::P<ast::Expr>>,
+ guard: &Option<ast::Guard>,
shape: Shape,
// The amount of space used up on this line for the pattern in
// the arm (excludes offset).
pattern_width: usize,
+ multiline_pattern: bool,
) -> Option<String> {
if let Some(ref guard) = *guard {
// First try to fit the guard string on the same line as the pattern.
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));
+ if !multiline_pattern {
+ 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));
+ }
}
}
}
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
+ if block_str.starts_with('{')
+ && budget >= 2
&& (block_str[1..].find(|c: char| !c.is_whitespace()).unwrap() == block_str.len() - 2)
{
- "{}".to_owned()
+ String::from("{}")
} else {
- block_str.to_owned()
+ block_str
}
})
}
projects / rust.git / blobdiff