use {Indent, Shape};
use codemap::SpanUtils;
use utils::{format_mutability, format_visibility, contains_skip, end_typaram, wrap_str,
last_line_width, format_unsafety, trim_newlines, stmt_expr, semicolon_for_expr,
trimmed_last_line_width, colon_spaces, mk_sp};
use lists::{write_list, itemize_list, ListItem, ListFormatting, SeparatorTactic,
DefinitiveListTactic, ListTactic, definitive_tactic};
use expr::{format_expr, is_empty_block, is_simple_block_stmt, rewrite_assign_rhs,
rewrite_call_inner, ExprType};
use comment::{FindUncommented, contains_comment, rewrite_comment, recover_comment_removed};
use visitor::FmtVisitor;
use rewrite::{Rewrite, RewriteContext};
use config::{Config, IndentStyle, Density, ReturnIndent, BraceStyle, Style};
use types::join_bounds;
use vertical::rewrite_with_alignment;
use syntax::{ast, abi, ptr, symbol};
use syntax::codemap::{Span, BytePos};
use syntax::ast::ImplItem;
fn type_annotation_separator(config: &Config) -> &str {
colon_spaces(
config.space_before_type_annotation(),
config.space_after_type_annotation_colon(),
)
}
impl Rewrite for ast::Local {
fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
debug!(
"Local::rewrite {:?} {} {:?}",
self,
shape.width,
shape.indent
);
let mut result = "let ".to_owned();
let pat_shape = try_opt!(shape.offset_left(4));
let pat_shape = try_opt!(pat_shape.sub_width(1));
let pat_str = try_opt!(self.pat.rewrite(&context, pat_shape));
result.push_str(&pat_str);
let infix = {
let mut infix = String::new();
if let Some(ref ty) = self.ty {
let separator = type_annotation_separator(context.config);
let indent = shape.indent + last_line_width(&result) + separator.len();
let budget = try_opt!(shape.width.checked_sub(indent.width() + 1));
let rewrite = try_opt!(ty.rewrite(context, Shape::legacy(budget, indent)));
infix.push_str(separator);
infix.push_str(&rewrite);
}
if self.init.is_some() {
infix.push_str(" =");
}
infix
};
result.push_str(&infix);
if let Some(ref ex) = self.init {
let nested_shape = try_opt!(shape.sub_width(1));
result = try_opt!(rewrite_assign_rhs(&context, result, ex, nested_shape));
}
result.push(';');
Some(result)
}
}
#[allow(dead_code)]
struct Item<'a> {
keyword: &'static str,
abi: String,
vis: Option<&'a ast::Visibility>,
body: Vec<BodyElement<'a>>,
span: Span,
}
impl<'a> Item<'a> {
fn from_foreign_mod(fm: &'a ast::ForeignMod, span: Span, config: &Config) -> Item<'a> {
let abi = if fm.abi == abi::Abi::C && !config.force_explicit_abi() {
"extern".into()
} else {
format!("extern {}", fm.abi)
};
Item {
keyword: "",
abi: abi,
vis: None,
body: fm.items
.iter()
.map(|i| BodyElement::ForeignItem(i))
.collect(),
span: span,
}
}
}
enum BodyElement<'a> {
ForeignItem(&'a ast::ForeignItem),
}
impl<'a> FmtVisitor<'a> {
fn format_item(&mut self, item: Item) {
self.buffer.push_str(&item.abi);
self.buffer.push_str(" ");
let snippet = self.snippet(item.span);
let brace_pos = snippet.find_uncommented("{").unwrap();
self.buffer.push_str("{");
if !item.body.is_empty() || contains_comment(&snippet[brace_pos..]) {
self.last_pos = item.span.lo + BytePos(brace_pos as u32 + 1);
self.block_indent = self.block_indent.block_indent(self.config);
if item.body.is_empty() {
self.format_missing_no_indent(item.span.hi - BytePos(1));
self.block_indent = self.block_indent.block_unindent(self.config);
self.buffer
.push_str(&self.block_indent.to_string(self.config));
} else {
for item in &item.body {
self.format_body_element(item);
}
self.block_indent = self.block_indent.block_unindent(self.config);
self.format_missing_with_indent(item.span.hi - BytePos(1));
}
}
self.buffer.push_str("}");
self.last_pos = item.span.hi;
}
fn format_body_element(&mut self, element: &BodyElement) {
match *element {
BodyElement::ForeignItem(ref item) => self.format_foreign_item(item),
}
}
pub fn format_foreign_mod(&mut self, fm: &ast::ForeignMod, span: Span) {
let item = Item::from_foreign_mod(fm, span, self.config);
self.format_item(item);
}
fn format_foreign_item(&mut self, item: &ast::ForeignItem) {
self.format_missing_with_indent(item.span.lo);
let span = mk_sp(item.span.lo, item.span.hi - BytePos(1));
match item.node {
ast::ForeignItemKind::Fn(ref fn_decl, ref generics) => {
let indent = self.block_indent;
let rewrite = rewrite_fn_base(
&self.get_context(),
indent,
item.ident,
fn_decl,
generics,
ast::Unsafety::Normal,
ast::Constness::NotConst,
ast::Defaultness::Final,
abi::Abi::Rust,
&item.vis,
span,
false,
false,
false,
);
match rewrite {
Some((new_fn, _)) => {
self.buffer.push_str(&new_fn);
self.buffer.push_str(";");
}
None => self.format_missing(item.span.hi),
}
}
ast::ForeignItemKind::Static(ref ty, is_mutable) => {
let vis = format_visibility(&item.vis);
let mut_str = if is_mutable { "mut " } else { "" };
let prefix = format!("{}static {}{}: ", vis, mut_str, item.ident);
let offset = self.block_indent + prefix.len();
let shape = Shape::indented(offset, self.config).sub_width(1).unwrap();
let rewrite = ty.rewrite(&self.get_context(), shape);
match rewrite {
Some(result) => {
self.buffer.push_str(&prefix);
self.buffer.push_str(&result);
self.buffer.push_str(";");
}
None => self.format_missing(item.span.hi),
}
}
}
self.last_pos = item.span.hi;
}
pub fn rewrite_fn(
&mut self,
indent: Indent,
ident: ast::Ident,
fd: &ast::FnDecl,
generics: &ast::Generics,
unsafety: ast::Unsafety,
constness: ast::Constness,
defaultness: ast::Defaultness,
abi: abi::Abi,
vis: &ast::Visibility,
span: Span,
block: &ast::Block,
) -> Option<String> {
let mut newline_brace = newline_for_brace(self.config, &generics.where_clause);
let context = self.get_context();
let block_snippet = self.snippet(mk_sp(block.span.lo, block.span.hi));
let has_body = !block_snippet[1..block_snippet.len() - 1].trim().is_empty() ||
!context.config.fn_empty_single_line();
let (mut result, force_newline_brace) = try_opt!(rewrite_fn_base(
&context,
indent,
ident,
fd,
generics,
unsafety,
constness,
defaultness,
abi,
vis,
span,
newline_brace,
has_body,
true,
));
if force_newline_brace {
newline_brace = true;
} else if self.config.fn_brace_style() != BraceStyle::AlwaysNextLine &&
!result.contains('\n')
{
newline_brace = false;
}
if newline_brace {
result.push('\n');
result.push_str(&indent.to_string(self.config));
} else {
result.push(' ');
}
self.single_line_fn(&result, block).or_else(|| Some(result))
}
pub fn rewrite_required_fn(
&mut self,
indent: Indent,
ident: ast::Ident,
sig: &ast::MethodSig,
span: Span,
) -> Option<String> {
let span = mk_sp(span.lo, span.hi - BytePos(1));
let context = self.get_context();
let (mut result, _) = try_opt!(rewrite_fn_base(
&context,
indent,
ident,
&sig.decl,
&sig.generics,
sig.unsafety,
sig.constness.node,
ast::Defaultness::Final,
sig.abi,
&ast::Visibility::Inherited,
span,
false,
false,
false,
));
result.push(';');
Some(result)
}
fn single_line_fn(&self, fn_str: &str, block: &ast::Block) -> Option<String> {
if fn_str.contains('\n') {
return None;
}
let codemap = self.get_context().codemap;
if self.config.fn_empty_single_line() && is_empty_block(block, codemap) &&
self.block_indent.width() + fn_str.len() + 2 <= self.config.max_width()
{
return Some(format!("{}{{}}", fn_str));
}
if self.config.fn_single_line() && is_simple_block_stmt(block, codemap) {
let rewrite = {
if let Some(ref stmt) = block.stmts.first() {
match stmt_expr(stmt) {
Some(e) => {
let suffix = if semicolon_for_expr(e) { ";" } else { "" };
format_expr(
&e,
ExprType::Statement,
&self.get_context(),
Shape::indented(self.block_indent, self.config),
).map(|s| s + suffix)
.or_else(|| Some(self.snippet(e.span)))
}
None => {
stmt.rewrite(
&self.get_context(),
Shape::indented(self.block_indent, self.config),
)
}
}
} else {
None
}
};
if let Some(res) = rewrite {
let width = self.block_indent.width() + fn_str.len() + res.len() + 4;
if !res.contains('\n') && width <= self.config.max_width() {
return Some(format!("{}{{ {} }}", fn_str, res));
}
}
}
None
}
pub fn visit_enum(
&mut self,
ident: ast::Ident,
vis: &ast::Visibility,
enum_def: &ast::EnumDef,
generics: &ast::Generics,
span: Span,
) {
let enum_header = format_header("enum ", ident, vis);
self.buffer.push_str(&enum_header);
let enum_snippet = self.snippet(span);
let brace_pos = enum_snippet.find_uncommented("{").unwrap();
let body_start = span.lo + BytePos(brace_pos as u32 + 1);
let generics_str = format_generics(
&self.get_context(),
generics,
"{",
"{",
self.config.item_brace_style(),
enum_def.variants.is_empty(),
self.block_indent,
mk_sp(span.lo, body_start),
last_line_width(&enum_header),
).unwrap();
self.buffer.push_str(&generics_str);
self.last_pos = body_start;
self.block_indent = self.block_indent.block_indent(self.config);
let variant_list = self.format_variant_list(enum_def, body_start, span.hi - BytePos(1));
match variant_list {
Some(ref body_str) => self.buffer.push_str(body_str),
None => {
if contains_comment(&enum_snippet[brace_pos..]) {
self.format_missing_no_indent(span.hi - BytePos(1))
} else {
self.format_missing(span.hi - BytePos(1))
}
}
}
self.block_indent = self.block_indent.block_unindent(self.config);
if variant_list.is_some() || contains_comment(&enum_snippet[brace_pos..]) {
self.buffer
.push_str(&self.block_indent.to_string(self.config));
}
self.buffer.push_str("}");
self.last_pos = span.hi;
}
fn format_variant_list(
&self,
enum_def: &ast::EnumDef,
body_lo: BytePos,
body_hi: BytePos,
) -> Option<String> {
if enum_def.variants.is_empty() {
return None;
}
let mut result = String::with_capacity(1024);
result.push('\n');
let indentation = self.block_indent.to_string(self.config);
result.push_str(&indentation);
let items = itemize_list(
self.codemap,
enum_def.variants.iter(),
"}",
|f| if !f.node.attrs.is_empty() {
f.node.attrs[0].span.lo
} else {
f.span.lo
},
|f| f.span.hi,
|f| self.format_variant(f),
body_lo,
body_hi,
);
let shape = Shape::indented(self.block_indent, self.config)
.sub_width(2)
.unwrap();
let fmt = ListFormatting {
tactic: DefinitiveListTactic::Vertical,
separator: ",",
trailing_separator: self.config.trailing_comma(),
shape: shape,
ends_with_newline: true,
config: self.config,
};
let list = try_opt!(write_list(&items.collect::<Vec<_>>(), &fmt));
result.push_str(&list);
result.push('\n');
Some(result)
}
fn format_variant(&self, field: &ast::Variant) -> Option<String> {
if contains_skip(&field.node.attrs) {
let lo = field.node.attrs[0].span.lo;
let span = mk_sp(lo, field.span.hi);
return Some(self.snippet(span));
}
let context = self.get_context();
let indent = self.block_indent;
let mut result = try_opt!(
field
.node
.attrs
.rewrite(&context, Shape::indented(indent, self.config))
);
if !result.is_empty() {
let shape = Shape {
width: context.config.max_width(),
indent: self.block_indent,
offset: self.block_indent.alignment,
};
let missing_comment = rewrite_missing_comment_on_field(
&context,
shape,
field.node.attrs[field.node.attrs.len() - 1].span.hi,
field.span.lo,
&mut result,
).unwrap_or(String::new());
result.push_str(&missing_comment);
}
let variant_body = match field.node.data {
ast::VariantData::Tuple(..) | ast::VariantData::Struct(..) => {
format_struct(
&context,
"",
field.node.name,
&ast::Visibility::Inherited,
&field.node.data,
None,
field.span,
indent,
Some(self.config.struct_variant_width()),
)
}
ast::VariantData::Unit(..) => {
let tag = if let Some(ref expr) = field.node.disr_expr {
format!("{} = {}", field.node.name, self.snippet(expr.span))
} else {
field.node.name.to_string()
};
wrap_str(
tag,
self.config.max_width(),
Shape::indented(indent, self.config),
)
}
};
if let Some(variant_str) = variant_body {
result.push_str(&variant_str);
Some(result)
} else {
None
}
}
}
pub fn format_impl(
context: &RewriteContext,
item: &ast::Item,
offset: Indent,
where_span_end: Option<BytePos>,
) -> Option<String> {
if let ast::ItemKind::Impl(_, _, _, ref generics, _, _, ref items) = item.node {
let mut result = String::new();
let ref_and_type = try_opt!(format_impl_ref_and_type(context, item, offset));
result.push_str(&ref_and_type);
let where_budget = if result.contains('\n') {
context.config.max_width()
} else {
context
.config
.max_width()
.checked_sub(last_line_width(&result))
.unwrap_or(0)
};
let where_clause_str = try_opt!(rewrite_where_clause(
context,
&generics.where_clause,
context.config.item_brace_style(),
Shape::legacy(where_budget, offset.block_only()),
context.config.where_density(),
"{",
false,
last_line_width(&ref_and_type) == 1,
where_span_end,
));
if try_opt!(is_impl_single_line(
context,
&items,
&result,
&where_clause_str,
&item,
)) {
result.push_str(&where_clause_str);
if where_clause_str.contains('\n') {
let white_space = offset.to_string(context.config);
result.push_str(&format!("\n{}{{\n{}}}", &white_space, &white_space));
} else {
result.push_str(" {}");
}
return Some(result);
}
if !where_clause_str.is_empty() && !where_clause_str.contains('\n') {
result.push('\n');
let width = offset.block_indent + context.config.tab_spaces() - 1;
let where_indent = Indent::new(0, width);
result.push_str(&where_indent.to_string(context.config));
}
result.push_str(&where_clause_str);
match context.config.item_brace_style() {
BraceStyle::AlwaysNextLine => {
result.push('\n');
result.push_str(&offset.to_string(context.config));
}
BraceStyle::PreferSameLine => result.push(' '),
BraceStyle::SameLineWhere => {
if !where_clause_str.is_empty() {
result.push('\n');
result.push_str(&offset.to_string(context.config));
} else {
result.push(' ');
}
}
}
result.push('{');
let snippet = context.snippet(item.span);
let open_pos = try_opt!(snippet.find_uncommented("{")) + 1;
if !items.is_empty() || contains_comment(&snippet[open_pos..]) {
let mut visitor = FmtVisitor::from_codemap(context.parse_session, context.config);
visitor.block_indent = offset.block_only().block_indent(context.config);
visitor.last_pos = item.span.lo + BytePos(open_pos as u32);
for item in items {
visitor.visit_impl_item(item);
}
visitor.format_missing(item.span.hi - BytePos(1));
let inner_indent_str = visitor.block_indent.to_string(context.config);
let outer_indent_str = offset.block_only().to_string(context.config);
result.push('\n');
result.push_str(&inner_indent_str);
result.push_str(trim_newlines(visitor.buffer.to_string().trim()));
result.push('\n');
result.push_str(&outer_indent_str);
}
if result.chars().last().unwrap() == '{' {
result.push('\n');
result.push_str(&offset.to_string(context.config));
}
result.push('}');
Some(result)
} else {
unreachable!();
}
}
fn is_impl_single_line(
context: &RewriteContext,
items: &[ImplItem],
result: &str,
where_clause_str: &str,
item: &ast::Item,
) -> Option<bool> {
let snippet = context.snippet(item.span);
let open_pos = try_opt!(snippet.find_uncommented("{")) + 1;
Some(
context.config.impl_empty_single_line() && items.is_empty() &&
result.len() + where_clause_str.len() <= context.config.max_width() &&
!contains_comment(&snippet[open_pos..]),
)
}
fn format_impl_ref_and_type(
context: &RewriteContext,
item: &ast::Item,
offset: Indent,
) -> Option<String> {
if let ast::ItemKind::Impl(
unsafety,
polarity,
_,
ref generics,
ref trait_ref,
ref self_ty,
_,
) = item.node
{
let mut result = String::new();
result.push_str(&format_visibility(&item.vis));
result.push_str(format_unsafety(unsafety));
result.push_str("impl");
let lo = context.codemap.span_after(item.span, "impl");
let hi = match *trait_ref {
Some(ref tr) => tr.path.span.lo,
None => self_ty.span.lo,
};
let shape = try_opt!(generics_shape_from_config(
context.config,
Shape::indented(offset + last_line_width(&result), context.config),
0,
));
let one_line_budget = try_opt!(shape.width.checked_sub(last_line_width(&result) + 2));
let generics_str = try_opt!(rewrite_generics_inner(
context,
generics,
shape,
one_line_budget,
mk_sp(lo, hi),
));
let polarity_str = if polarity == ast::ImplPolarity::Negative {
"!"
} else {
""
};
if let Some(ref trait_ref) = *trait_ref {
let result_len = result.len();
if let Some(trait_ref_str) = rewrite_trait_ref(
context,
&trait_ref,
offset,
&generics_str,
true,
polarity_str,
result_len,
) {
result.push_str(&trait_ref_str);
} else {
let generics_str = try_opt!(rewrite_generics_inner(
context,
generics,
shape,
0,
mk_sp(lo, hi),
));
result.push_str(&try_opt!(rewrite_trait_ref(
context,
&trait_ref,
offset,
&generics_str,
false,
polarity_str,
result_len,
)));
}
} else {
result.push_str(&generics_str);
}
let trait_ref_overhead = if trait_ref.is_some() { 4 } else { 0 };
let curly_brace_overhead = if generics.where_clause.predicates.is_empty() {
match context.config.item_brace_style() {
BraceStyle::AlwaysNextLine => 0,
_ => 2,
}
} else {
0
};
let used_space = last_line_width(&result) + trait_ref_overhead + curly_brace_overhead;
let budget = context
.config
.max_width()
.checked_sub(used_space + 1)
.unwrap_or(0);
if let Some(self_ty_str) = self_ty.rewrite(context, Shape::legacy(budget, offset)) {
if !self_ty_str.contains('\n') {
if trait_ref.is_some() {
result.push_str(" for ");
} else {
result.push(' ');
}
result.push_str(&self_ty_str);
return Some(result);
}
}
result.push('\n');
let new_line_offset = offset.block_indent(context.config);
result.push_str(&new_line_offset.to_string(context.config));
if trait_ref.is_some() {
result.push_str("for ");
}
let budget = context.config.max_width() - last_line_width(&result);
let type_offset = match context.config.where_style() {
Style::Legacy => new_line_offset + trait_ref_overhead,
Style::Rfc => new_line_offset,
};
result.push_str(&*try_opt!(
self_ty.rewrite(context, Shape::legacy(budget, type_offset))
));
Some(result)
} else {
unreachable!();
}
}
fn rewrite_trait_ref(
context: &RewriteContext,
trait_ref: &ast::TraitRef,
offset: Indent,
generics_str: &str,
retry: bool,
polarity_str: &str,
result_len: usize,
) -> Option<String> {
let used_space = 1 + polarity_str.len() +
if generics_str.contains('\n') {
last_line_width(&generics_str)
} else {
result_len + generics_str.len()
};
let shape = Shape::indented(offset + used_space, context.config);
if let Some(trait_ref_str) = trait_ref.rewrite(context, shape) {
if !(retry && trait_ref_str.contains('\n')) {
return Some(format!(
"{} {}{}",
generics_str,
polarity_str,
&trait_ref_str
));
}
}
if !retry {
let offset = offset.block_indent(context.config);
let shape = Shape::indented(offset, context.config);
let trait_ref_str = try_opt!(trait_ref.rewrite(context, shape));
Some(format!(
"{}\n{}{}{}",
generics_str,
&offset.to_string(context.config),
polarity_str,
&trait_ref_str
))
} else {
None
}
}
pub fn format_struct(
context: &RewriteContext,
item_name: &str,
ident: ast::Ident,
vis: &ast::Visibility,
struct_def: &ast::VariantData,
generics: Option<&ast::Generics>,
span: Span,
offset: Indent,
one_line_width: Option<usize>,
) -> Option<String> {
match *struct_def {
ast::VariantData::Unit(..) => Some(format_unit_struct(item_name, ident, vis)),
ast::VariantData::Tuple(ref fields, _) => {
format_tuple_struct(
context,
item_name,
ident,
vis,
fields,
generics,
span,
offset,
)
}
ast::VariantData::Struct(ref fields, _) => {
format_struct_struct(
context,
item_name,
ident,
vis,
fields,
generics,
span,
offset,
one_line_width,
)
}
}
}
pub fn format_trait(context: &RewriteContext, item: &ast::Item, offset: Indent) -> Option<String> {
if let ast::ItemKind::Trait(unsafety, ref generics, ref type_param_bounds, ref trait_items) =
item.node
{
let mut result = String::new();
let header = format!(
"{}{}trait {}",
format_visibility(&item.vis),
format_unsafety(unsafety),
item.ident
);
result.push_str(&header);
let body_lo = context.codemap.span_after(item.span, "{");
let shape = Shape::indented(offset + last_line_width(&result), context.config);
let generics_str = try_opt!(rewrite_generics(
context,
generics,
shape,
mk_sp(item.span.lo, body_lo),
));
result.push_str(&generics_str);
let trait_bound_str = try_opt!(rewrite_trait_bounds(
context,
type_param_bounds,
Shape::indented(offset, context.config),
));
if offset.width() + last_line_width(&result) + trait_bound_str.len() >
context.config.comment_width()
{
result.push('\n');
let trait_indent = offset.block_only().block_indent(context.config);
result.push_str(&trait_indent.to_string(context.config));
}
result.push_str(&trait_bound_str);
let has_body = !trait_items.is_empty();
let where_density = if (context.config.where_density() == Density::Compressed &&
(!result.contains('\n') ||
context.config.fn_args_layout() == IndentStyle::Block)) ||
(context.config.fn_args_layout() == IndentStyle::Block && result.is_empty()) ||
(context.config.where_density() == Density::CompressedIfEmpty && !has_body &&
!result.contains('\n'))
{
Density::Compressed
} else {
Density::Tall
};
let where_budget = try_opt!(
context
.config
.max_width()
.checked_sub(last_line_width(&result))
);
let where_clause_str = try_opt!(rewrite_where_clause(
context,
&generics.where_clause,
context.config.item_brace_style(),
Shape::legacy(where_budget, offset.block_only()),
where_density,
"{",
!has_body,
trait_bound_str.is_empty() && last_line_width(&generics_str) == 1,
None,
));
if !where_clause_str.contains('\n') &&
last_line_width(&result) + where_clause_str.len() + offset.width() >
context.config.comment_width()
{
result.push('\n');
let width = offset.block_indent + context.config.tab_spaces() - 1;
let where_indent = Indent::new(0, width);
result.push_str(&where_indent.to_string(context.config));
}
result.push_str(&where_clause_str);
match context.config.item_brace_style() {
BraceStyle::AlwaysNextLine => {
result.push('\n');
result.push_str(&offset.to_string(context.config));
}
BraceStyle::PreferSameLine => result.push(' '),
BraceStyle::SameLineWhere => {
if !where_clause_str.is_empty() &&
(!trait_items.is_empty() || result.contains('\n'))
{
result.push('\n');
result.push_str(&offset.to_string(context.config));
} else {
result.push(' ');
}
}
}
result.push('{');
let snippet = context.snippet(item.span);
let open_pos = try_opt!(snippet.find_uncommented("{")) + 1;
if !trait_items.is_empty() || contains_comment(&snippet[open_pos..]) {
let mut visitor = FmtVisitor::from_codemap(context.parse_session, context.config);
visitor.block_indent = offset.block_only().block_indent(context.config);
visitor.last_pos = item.span.lo + BytePos(open_pos as u32);
for item in trait_items {
visitor.visit_trait_item(item);
}
visitor.format_missing(item.span.hi - BytePos(1));
let inner_indent_str = visitor.block_indent.to_string(context.config);
let outer_indent_str = offset.block_only().to_string(context.config);
result.push('\n');
result.push_str(&inner_indent_str);
result.push_str(trim_newlines(visitor.buffer.to_string().trim()));
result.push('\n');
result.push_str(&outer_indent_str);
} else if result.contains('\n') {
result.push('\n');
}
result.push('}');
Some(result)
} else {
unreachable!();
}
}
fn format_unit_struct(item_name: &str, ident: ast::Ident, vis: &ast::Visibility) -> String {
format!("{};", format_header(item_name, ident, vis))
}
fn format_struct_struct(
context: &RewriteContext,
item_name: &str,
ident: ast::Ident,
vis: &ast::Visibility,
fields: &[ast::StructField],
generics: Option<&ast::Generics>,
span: Span,
offset: Indent,
one_line_width: Option<usize>,
) -> Option<String> {
let mut result = String::with_capacity(1024);
let header_str = format_header(item_name, ident, vis);
result.push_str(&header_str);
let body_lo = context.codemap.span_after(span, "{");
let generics_str = match generics {
Some(g) => {
try_opt!(format_generics(
context,
g,
"{",
"{",
context.config.item_brace_style(),
fields.is_empty(),
offset,
mk_sp(span.lo, body_lo),
last_line_width(&result),
))
}
None => {
let overhead = if fields.is_empty() { 3 } else { 2 };
if (context.config.item_brace_style() == BraceStyle::AlwaysNextLine &&
!fields.is_empty()) ||
context
.config
.max_width()
.checked_sub(result.len())
.unwrap_or(0) < overhead
{
format!("\n{}{{", offset.block_only().to_string(context.config))
} else {
" {".to_owned()
}
}
};
let overhead = if fields.is_empty() { 1 } else { 0 };
let max_len = context.config.max_width() - offset.width();
if !generics_str.contains('\n') && result.len() + generics_str.len() + overhead > max_len {
result.push('\n');
result.push_str(&offset
.block_indent(context.config)
.to_string(context.config));
result.push_str(&generics_str.trim_left());
} else {
result.push_str(&generics_str);
}
if fields.is_empty() {
let snippet = context.snippet(mk_sp(body_lo, span.hi - BytePos(1)));
if snippet.trim().is_empty() {
} else if snippet.trim_right_matches(&[' ', '\t'][..]).ends_with('\n') {
result.push_str(&snippet.trim_right());
result.push('\n');
result.push_str(&offset.to_string(context.config));
} else {
result.push_str(&snippet);
}
result.push('}');
return Some(result);
}
let items_str = try_opt!(rewrite_with_alignment(
fields,
context,
Shape::indented(offset, context.config),
mk_sp(body_lo, span.hi),
one_line_width.unwrap_or(0),
));
if one_line_width.is_some() && !items_str.contains('\n') {
Some(format!("{} {} }}", result, items_str))
} else {
Some(format!(
"{}\n{}{}\n{}}}",
result,
offset
.block_indent(context.config)
.to_string(context.config),
items_str,
offset.to_string(context.config)
))
}
}
fn format_tuple_struct(
context: &RewriteContext,
item_name: &str,
ident: ast::Ident,
vis: &ast::Visibility,
fields: &[ast::StructField],
generics: Option<&ast::Generics>,
span: Span,
offset: Indent,
) -> Option<String> {
let mut result = String::with_capacity(1024);
let header_str = format_header(item_name, ident, vis);
result.push_str(&header_str);
let body_lo = if fields.is_empty() {
context.codemap.span_after(span, "(")
} else {
fields[0].span.lo
};
let where_clause_str = match generics {
Some(generics) => {
let budget = context.budget(last_line_width(&header_str));
let shape = Shape::legacy(budget, offset);
let g_span = mk_sp(span.lo, body_lo);
let generics_str = try_opt!(rewrite_generics(context, generics, shape, g_span));
result.push_str(&generics_str);
let where_budget = context.budget(last_line_width(&result));
try_opt!(rewrite_where_clause(
context,
&generics.where_clause,
context.config.item_brace_style(),
Shape::legacy(where_budget, offset.block_only()),
Density::Compressed,
";",
true,
false,
None,
))
}
None => "".to_owned(),
};
if fields.is_empty() {
let used_width = if result.contains('\n') {
last_line_width(&result) + 3
} else {
offset.width() + result.len() + 3
};
if used_width > context.config.max_width() {
result.push('\n');
result.push_str(&offset
.block_indent(context.config)
.to_string(context.config))
}
result.push('(');
let snippet = context.snippet(mk_sp(body_lo, context.codemap.span_before(span, ")")));
if snippet.is_empty() {
} else if snippet.trim_right_matches(&[' ', '\t'][..]).ends_with('\n') {
result.push_str(&snippet.trim_right());
result.push('\n');
result.push_str(&offset.to_string(context.config));
} else {
result.push_str(&snippet);
}
result.push(')');
} else {
let body = try_opt!(
rewrite_call_inner(
context,
"",
&fields.iter().map(|field| field).collect::<Vec<_>>()[..],
span,
Shape::legacy(context.budget(last_line_width(&result) + 3), offset),
context.config.fn_call_width(),
false,
).ok()
);
result.push_str(&body);
}
if !where_clause_str.is_empty() && !where_clause_str.contains('\n') &&
(result.contains('\n') ||
offset.block_indent + result.len() + where_clause_str.len() + 1 >
context.config.max_width())
{
result.push('\n');
result.push_str(&(offset.block_only() + (context.config.tab_spaces() - 1))
.to_string(context.config));
}
result.push_str(&where_clause_str);
Some(result)
}
pub fn rewrite_type_alias(
context: &RewriteContext,
indent: Indent,
ident: ast::Ident,
ty: &ast::Ty,
generics: &ast::Generics,
vis: &ast::Visibility,
span: Span,
) -> Option<String> {
let mut result = String::new();
result.push_str(&format_visibility(vis));
result.push_str("type ");
result.push_str(&ident.to_string());
let shape = try_opt!(Shape::indented(indent + result.len(), context.config).sub_width(2));
let g_span = mk_sp(context.codemap.span_after(span, "type"), ty.span.lo);
let generics_str = try_opt!(rewrite_generics(context, generics, shape, g_span));
result.push_str(&generics_str);
let where_budget = try_opt!(
context
.config
.max_width()
.checked_sub(last_line_width(&result))
);
let where_clause_str = try_opt!(rewrite_where_clause(
context,
&generics.where_clause,
context.config.item_brace_style(),
Shape::legacy(where_budget, indent),
context.config.where_density(),
"=",
true,
true,
Some(span.hi),
));
result.push_str(&where_clause_str);
result.push_str(" = ");
let line_width = last_line_width(&result);
let budget = context
.config
.max_width()
.checked_sub(indent.width() + line_width + ";".len())
.unwrap_or(0);
let type_indent = indent + line_width;
let ty_str = try_opt!(
ty.rewrite(context, Shape::legacy(budget, type_indent))
.or_else(|| {
result.pop();
let type_indent = indent.block_indent(context.config);
result.push('\n');
result.push_str(&type_indent.to_string(context.config));
let budget = try_opt!(
context
.config
.max_width()
.checked_sub(type_indent.width() + ";".len())
);
ty.rewrite(context, Shape::legacy(budget, type_indent))
})
);
result.push_str(&ty_str);
result.push_str(";");
Some(result)
}
fn type_annotation_spacing(config: &Config) -> (&str, &str) {
(
if config.space_before_type_annotation() {
" "
} else {
""
},
if config.space_after_type_annotation_colon() {
" "
} else {
""
},
)
}
fn rewrite_missing_comment_on_field(
context: &RewriteContext,
shape: Shape,
lo: BytePos,
hi: BytePos,
result: &mut String,
) -> Option<String> {
let possibly_comment_snippet = context.snippet(mk_sp(lo, hi));
let newline_index = possibly_comment_snippet.find('\n');
let comment_index = possibly_comment_snippet.find('/');
match (newline_index, comment_index) {
(Some(i), Some(j)) if i > j => result.push(' '),
_ => {
result.push('\n');
result.push_str(&shape.indent.to_string(context.config));
}
}
let trimmed = possibly_comment_snippet.trim();
if trimmed.is_empty() {
None
} else {
rewrite_comment(trimmed, false, shape, context.config).map(|s| {
format!("{}\n{}", s, shape.indent.to_string(context.config))
})
}
}
pub fn rewrite_struct_field_prefix(
context: &RewriteContext,
field: &ast::StructField,
shape: Shape,
) -> Option<String> {
let vis = format_visibility(&field.vis);
let mut attr_str = try_opt!(
field
.attrs
.rewrite(context, Shape::indented(shape.indent, context.config))
);
let missing_comment = if !field.attrs.is_empty() {
rewrite_missing_comment_on_field(
context,
shape,
field.attrs[field.attrs.len() - 1].span.hi,
field.span.lo,
&mut attr_str,
).unwrap_or(String::new())
} else {
String::new()
};
let type_annotation_spacing = type_annotation_spacing(context.config);
Some(match field.ident {
Some(name) => {
format!(
"{}{}{}{}{}:",
attr_str,
missing_comment,
vis,
name,
type_annotation_spacing.0
)
}
None => format!("{}{}{}", attr_str, missing_comment, vis),
})
}
fn rewrite_struct_field_type(
context: &RewriteContext,
last_line_width: usize,
field: &ast::StructField,
spacing: &str,
shape: Shape,
) -> Option<String> {
let ty_shape = try_opt!(shape.offset_left(last_line_width + spacing.len()));
field
.ty
.rewrite(context, ty_shape)
.map(|ty| format!("{}{}", spacing, ty))
}
impl Rewrite for ast::StructField {
fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
rewrite_struct_field(context, self, shape, 0)
}
}
pub fn rewrite_struct_field(
context: &RewriteContext,
field: &ast::StructField,
shape: Shape,
lhs_max_width: usize,
) -> Option<String> {
if contains_skip(&field.attrs) {
let span = context.snippet(mk_sp(field.attrs[0].span.lo, field.span.hi));
return wrap_str(span, context.config.max_width(), shape);
}
let type_annotation_spacing = type_annotation_spacing(context.config);
let prefix = try_opt!(rewrite_struct_field_prefix(context, field, shape));
let last_line_width = last_line_width(&prefix);
let mut spacing = String::from(if field.ident.is_some() {
type_annotation_spacing.1
} else {
""
});
let lhs_offset = lhs_max_width.checked_sub(last_line_width).unwrap_or(0);
for _ in 0..lhs_offset {
spacing.push(' ');
}
let ty_rewritten = rewrite_struct_field_type(context, last_line_width, field, &spacing, shape);
if let Some(ref ty) = ty_rewritten {
if !ty.contains('\n') {
return Some(prefix + &ty);
}
}
let type_offset = shape.indent.block_indent(context.config);
let rewrite_type_in_next_line = || {
field
.ty
.rewrite(context, Shape::indented(type_offset, context.config))
};
match ty_rewritten {
Some(ref ty) => {
match rewrite_type_in_next_line() {
Some(ref new_ty) if !new_ty.contains('\n') => {
Some(format!(
"{}\n{}{}",
prefix,
type_offset.to_string(&context.config),
&new_ty
))
}
_ => Some(prefix + &ty),
}
}
_ => {
let ty = try_opt!(rewrite_type_in_next_line());
Some(format!(
"{}\n{}{}",
prefix,
type_offset.to_string(&context.config),
&ty
))
}
}
}
pub fn rewrite_static(
prefix: &str,
vis: &ast::Visibility,
ident: ast::Ident,
ty: &ast::Ty,
mutability: ast::Mutability,
expr_opt: Option<&ptr::P<ast::Expr>>,
offset: Indent,
span: Span,
context: &RewriteContext,
) -> Option<String> {
let colon = colon_spaces(
context.config.space_before_type_annotation(),
context.config.space_after_type_annotation_colon(),
);
let prefix = format!(
"{}{} {}{}{}",
format_visibility(vis),
prefix,
format_mutability(mutability),
ident,
colon,
);
let ty_str = try_opt!(ty.rewrite(
context,
try_opt!(
Shape::indented(offset.block_only(), context.config).offset_left(prefix.len() + 2)
),
));
if let Some(expr) = expr_opt {
let lhs = format!("{}{} =", prefix, ty_str);
let remaining_width = context.config.max_width() - offset.block_indent - 1;
rewrite_assign_rhs(
context,
lhs,
expr,
Shape::legacy(remaining_width, offset.block_only()),
).and_then(|res| {
recover_comment_removed(res, span, context, Shape::indented(offset, context.config))
})
.map(|s| if s.ends_with(';') { s } else { s + ";" })
} else {
Some(format!("{}{};", prefix, ty_str))
}
}
pub fn rewrite_associated_type(
ident: ast::Ident,
ty_opt: Option<&ptr::P<ast::Ty>>,
ty_param_bounds_opt: Option<&ast::TyParamBounds>,
context: &RewriteContext,
indent: Indent,
) -> Option<String> {
let prefix = format!("type {}", ident);
let type_bounds_str = if let Some(ty_param_bounds) = ty_param_bounds_opt {
let shape = Shape::indented(indent, context.config);
let bounds: &[_] = ty_param_bounds;
let bound_str = try_opt!(
bounds
.iter()
.map(|ty_bound| ty_bound.rewrite(context, shape))
.collect::<Option<Vec<_>>>()
);
if bounds.len() > 0 {
format!(": {}", join_bounds(context, shape, &bound_str))
} else {
String::new()
}
} else {
String::new()
};
if let Some(ty) = ty_opt {
let ty_str = try_opt!(ty.rewrite(
context,
Shape::legacy(
context.config.max_width() - indent.block_indent - prefix.len() - 2,
indent.block_only(),
),
));
Some(format!("{} = {};", prefix, ty_str))
} else {
Some(format!("{}{};", prefix, type_bounds_str))
}
}
pub fn rewrite_associated_impl_type(
ident: ast::Ident,
defaultness: ast::Defaultness,
ty_opt: Option<&ptr::P<ast::Ty>>,
ty_param_bounds_opt: Option<&ast::TyParamBounds>,
context: &RewriteContext,
indent: Indent,
) -> Option<String> {
let result = try_opt!(rewrite_associated_type(
ident,
ty_opt,
ty_param_bounds_opt,
context,
indent,
));
match defaultness {
ast::Defaultness::Default => Some(format!("default {}", result)),
_ => Some(result),
}
}
impl Rewrite for ast::FunctionRetTy {
fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
match *self {
ast::FunctionRetTy::Default(_) => Some(String::new()),
ast::FunctionRetTy::Ty(ref ty) => {
let inner_width = try_opt!(shape.width.checked_sub(3));
ty.rewrite(context, Shape::legacy(inner_width, shape.indent + 3))
.map(|r| format!("-> {}", r))
}
}
}
}
fn is_empty_infer(context: &RewriteContext, ty: &ast::Ty) -> bool {
match ty.node {
ast::TyKind::Infer => {
let original = context.snippet(ty.span);
original != "_"
}
_ => false,
}
}
impl Rewrite for ast::Arg {
fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
if is_named_arg(self) {
let mut result = try_opt!(
self.pat
.rewrite(context, Shape::legacy(shape.width, shape.indent))
);
if !is_empty_infer(context, &*self.ty) {
if context.config.space_before_type_annotation() {
result.push_str(" ");
}
result.push_str(":");
if context.config.space_after_type_annotation_colon() {
result.push_str(" ");
}
let max_width = try_opt!(shape.width.checked_sub(result.len()));
let ty_str = try_opt!(self.ty.rewrite(
context,
Shape::legacy(max_width, shape.indent + result.len()),
));
result.push_str(&ty_str);
}
Some(result)
} else {
self.ty.rewrite(context, shape)
}
}
}
fn rewrite_explicit_self(
explicit_self: &ast::ExplicitSelf,
args: &[ast::Arg],
context: &RewriteContext,
) -> Option<String> {
match explicit_self.node {
ast::SelfKind::Region(lt, m) => {
let mut_str = format_mutability(m);
match lt {
Some(ref l) => {
let lifetime_str = try_opt!(l.rewrite(
context,
Shape::legacy(context.config.max_width(), Indent::empty()),
));
Some(format!("&{} {}self", lifetime_str, mut_str))
}
None => Some(format!("&{}self", mut_str)),
}
}
ast::SelfKind::Explicit(ref ty, _) => {
assert!(!args.is_empty(), "&[ast::Arg] shouldn't be empty.");
let mutability = explicit_self_mutability(&args[0]);
let type_str = try_opt!(ty.rewrite(
context,
Shape::legacy(context.config.max_width(), Indent::empty()),
));
Some(format!(
"{}self: {}",
format_mutability(mutability),
type_str
))
}
ast::SelfKind::Value(_) => {
assert!(!args.is_empty(), "&[ast::Arg] shouldn't be empty.");
let mutability = explicit_self_mutability(&args[0]);
Some(format!("{}self", format_mutability(mutability)))
}
}
}
fn explicit_self_mutability(arg: &ast::Arg) -> ast::Mutability {
if let ast::PatKind::Ident(ast::BindingMode::ByValue(mutability), _, _) = arg.pat.node {
mutability
} else {
unreachable!()
}
}
pub fn span_lo_for_arg(arg: &ast::Arg) -> BytePos {
if is_named_arg(arg) {
arg.pat.span.lo
} else {
arg.ty.span.lo
}
}
pub fn span_hi_for_arg(context: &RewriteContext, arg: &ast::Arg) -> BytePos {
match arg.ty.node {
ast::TyKind::Infer if context.snippet(arg.ty.span) == "_" => arg.ty.span.hi,
ast::TyKind::Infer if is_named_arg(arg) => arg.pat.span.hi,
_ => arg.ty.span.hi,
}
}
pub fn is_named_arg(arg: &ast::Arg) -> bool {
if let ast::PatKind::Ident(_, ident, _) = arg.pat.node {
ident.node != symbol::keywords::Invalid.ident()
} else {
true
}
}
fn span_for_return(ret: &ast::FunctionRetTy) -> Span {
match *ret {
ast::FunctionRetTy::Default(ref span) => span.clone(),
ast::FunctionRetTy::Ty(ref ty) => ty.span,
}
}
fn span_for_ty_param(ty: &ast::TyParam) -> Span {
let lo = if ty.attrs.is_empty() {
ty.span.lo
} else {
ty.attrs[0].span.lo
};
if let Some(ref def) = ty.default {
return mk_sp(lo, def.span.hi);
}
if ty.bounds.is_empty() {
return mk_sp(lo, ty.span.hi);
}
let hi = match ty.bounds[ty.bounds.len() - 1] {
ast::TyParamBound::TraitTyParamBound(ref ptr, _) => ptr.span.hi,
ast::TyParamBound::RegionTyParamBound(ref l) => l.span.hi,
};
mk_sp(lo, hi)
}
fn span_for_where_pred(pred: &ast::WherePredicate) -> Span {
match *pred {
ast::WherePredicate::BoundPredicate(ref p) => p.span,
ast::WherePredicate::RegionPredicate(ref p) => p.span,
ast::WherePredicate::EqPredicate(ref p) => p.span,
}
}
fn rewrite_fn_base(
context: &RewriteContext,
indent: Indent,
ident: ast::Ident,
fd: &ast::FnDecl,
generics: &ast::Generics,
unsafety: ast::Unsafety,
constness: ast::Constness,
defaultness: ast::Defaultness,
abi: abi::Abi,
vis: &ast::Visibility,
span: Span,
newline_brace: bool,
has_body: bool,
has_braces: bool,
) -> Option<(String, bool)> {
let mut force_new_line_for_brace = false;
let where_clause = &generics.where_clause;
let mut result = String::with_capacity(1024);
result.push_str(&*format_visibility(vis));
if let ast::Defaultness::Default = defaultness {
result.push_str("default ");
}
if let ast::Constness::Const = constness {
result.push_str("const ");
}
result.push_str(::utils::format_unsafety(unsafety));
if abi != abi::Abi::Rust {
result.push_str(&::utils::format_abi(
abi,
context.config.force_explicit_abi(),
));
}
result.push_str("fn ");
result.push_str(&ident.to_string());
let overhead = if has_braces && !newline_brace {
4
} else {
2
};
let shape = try_opt!(
Shape::indented(indent + last_line_width(&result), context.config).sub_width(overhead)
);
let g_span = mk_sp(span.lo, span_for_return(&fd.output).lo);
let generics_str = try_opt!(rewrite_generics(context, generics, shape, g_span));
result.push_str(&generics_str);
let snuggle_angle_bracket = generics_str
.lines()
.last()
.map_or(false, |l| l.trim_left().len() == 1);
let ret_str = try_opt!(
fd.output
.rewrite(&context, Shape::indented(indent, context.config))
);
let multi_line_ret_str = ret_str.contains('\n');
let ret_str_len = if multi_line_ret_str { 0 } else { ret_str.len() };
let (mut one_line_budget, mut multi_line_budget, mut arg_indent) =
try_opt!(compute_budgets_for_args(
context,
&result,
indent,
ret_str_len,
newline_brace,
has_braces,
));
if context.config.fn_args_layout() == IndentStyle::Block {
arg_indent = indent.block_indent(context.config);
multi_line_budget = context.config.max_width() - (arg_indent.width() + 1);
}
debug!(
"rewrite_fn_base: one_line_budget: {}, multi_line_budget: {}, arg_indent: {:?}",
one_line_budget,
multi_line_budget,
arg_indent
);
if one_line_budget == 0 {
if snuggle_angle_bracket {
result.push('(');
} else {
if context.config.fn_args_paren_newline() {
result.push('\n');
result.push_str(&arg_indent.to_string(context.config));
if context.config.fn_args_layout() == IndentStyle::Visual {
arg_indent = arg_indent + 1; }
result.push('(');
} else {
result.push_str("(");
if context.config.fn_args_layout() == IndentStyle::Visual {
result.push('\n');
result.push_str(&arg_indent.to_string(context.config));
}
}
}
} else {
result.push('(');
}
if context.config.spaces_within_parens() && fd.inputs.len() > 0 && result.ends_with('(') {
result.push(' ')
}
if multi_line_ret_str {
one_line_budget = 0;
}
let args_start = generics
.ty_params
.last()
.map_or(span.lo, |tp| end_typaram(tp));
let args_span = mk_sp(
context.codemap.span_after(mk_sp(args_start, span.hi), "("),
span_for_return(&fd.output).lo,
);
let arg_str = try_opt!(rewrite_args(
context,
&fd.inputs,
fd.get_self().as_ref(),
one_line_budget,
multi_line_budget,
indent,
arg_indent,
args_span,
fd.variadic,
generics_str.contains('\n'),
));
let multi_line_arg_str =
arg_str.contains('\n') || arg_str.chars().last().map_or(false, |c| c == ',');
let put_args_in_block = match context.config.fn_args_layout() {
IndentStyle::Block => multi_line_arg_str || generics_str.contains('\n'),
_ => false,
} && !fd.inputs.is_empty();
let mut args_last_line_contains_comment = false;
if put_args_in_block {
arg_indent = indent.block_indent(context.config);
result.push('\n');
result.push_str(&arg_indent.to_string(context.config));
result.push_str(&arg_str);
result.push('\n');
result.push_str(&indent.to_string(context.config));
result.push(')');
} else {
result.push_str(&arg_str);
if context.config.spaces_within_parens() && fd.inputs.len() > 0 {
result.push(' ')
}
if arg_str
.lines()
.last()
.map_or(false, |last_line| last_line.contains("//"))
{
args_last_line_contains_comment = true;
result.push('\n');
result.push_str(&arg_indent.to_string(context.config));
}
result.push(')');
}
if !ret_str.is_empty() {
let ret_should_indent = match context.config.fn_args_layout() {
IndentStyle::Block if put_args_in_block => false,
_ => {
let mut sig_length = result.len() + indent.width() + ret_str_len + 1;
if where_clause.predicates.is_empty() {
sig_length += 2;
}
let overlong_sig = sig_length > context.config.max_width();
(!args_last_line_contains_comment) &&
(result.contains('\n') || multi_line_ret_str || overlong_sig)
}
};
let ret_indent = if ret_should_indent {
let indent = match context.config.fn_return_indent() {
ReturnIndent::WithWhereClause => indent + 4,
_ if arg_str.is_empty() => {
force_new_line_for_brace = true;
indent + 4
}
_ => arg_indent,
};
result.push('\n');
result.push_str(&indent.to_string(context.config));
indent
} else {
result.push(' ');
Indent::new(indent.block_indent, last_line_width(&result))
};
if multi_line_ret_str || ret_should_indent {
let ret_str = try_opt!(
fd.output
.rewrite(context, Shape::indented(ret_indent, context.config))
);
result.push_str(&ret_str);
} else {
result.push_str(&ret_str);
}
let snippet_lo = fd.output.span().hi;
if where_clause.predicates.is_empty() {
let snippet_hi = span.hi;
let snippet = context.snippet(mk_sp(snippet_lo, snippet_hi));
let original_starts_with_newline = snippet
.find(|c| c != ' ')
.map_or(false, |i| snippet[i..].starts_with('\n'));
let original_ends_with_newline = snippet
.rfind(|c| c != ' ')
.map_or(false, |i| snippet[i..].ends_with('\n'));
let snippet = snippet.trim();
if !snippet.is_empty() {
result.push(if original_starts_with_newline {
'\n'
} else {
' '
});
result.push_str(snippet);
if original_ends_with_newline {
force_new_line_for_brace = true;
}
}
} else {
}
}
let should_compress_where = match context.config.where_density() {
Density::Compressed => !result.contains('\n') || put_args_in_block,
Density::CompressedIfEmpty => !has_body && !result.contains('\n'),
_ => false,
} || (put_args_in_block && ret_str.is_empty());
if where_clause.predicates.len() == 1 && should_compress_where {
let budget = try_opt!(
context
.config
.max_width()
.checked_sub(last_line_width(&result))
);
if let Some(where_clause_str) = rewrite_where_clause(
context,
where_clause,
context.config.fn_brace_style(),
Shape::legacy(budget, indent),
Density::Compressed,
"{",
!has_braces,
put_args_in_block && ret_str.is_empty(),
Some(span.hi),
) {
if !where_clause_str.contains('\n') {
if last_line_width(&result) + where_clause_str.len() > context.config.max_width() {
result.push('\n');
}
result.push_str(&where_clause_str);
force_new_line_for_brace |= last_line_contains_single_line_comment(&result);
return Some((result, force_new_line_for_brace));
}
}
}
let where_clause_str = try_opt!(rewrite_where_clause(
context,
where_clause,
context.config.fn_brace_style(),
Shape::indented(indent, context.config),
Density::Tall,
"{",
!has_braces,
put_args_in_block && ret_str.is_empty(),
Some(span.hi),
));
result.push_str(&where_clause_str);
force_new_line_for_brace |= last_line_contains_single_line_comment(&result);
return Some((result, force_new_line_for_brace));
}
fn last_line_contains_single_line_comment(s: &str) -> bool {
s.lines().last().map_or(false, |l| l.contains("//"))
}
fn rewrite_args(
context: &RewriteContext,
args: &[ast::Arg],
explicit_self: Option<&ast::ExplicitSelf>,
one_line_budget: usize,
multi_line_budget: usize,
indent: Indent,
arg_indent: Indent,
span: Span,
variadic: bool,
generics_str_contains_newline: bool,
) -> Option<String> {
let mut arg_item_strs = try_opt!(
args.iter()
.map(|arg| {
arg.rewrite(&context, Shape::legacy(multi_line_budget, arg_indent))
})
.collect::<Option<Vec<_>>>()
);
let min_args = explicit_self
.and_then(|explicit_self| {
rewrite_explicit_self(explicit_self, args, context)
})
.map_or(1, |self_str| {
arg_item_strs[0] = self_str;
2
});
let mut arg_items = Vec::new();
if min_args == 2 {
arg_items.push(ListItem::from_str(""));
}
if args.len() >= min_args || variadic {
let comment_span_start = if min_args == 2 {
let second_arg_start = if arg_has_pattern(&args[1]) {
args[1].pat.span.lo
} else {
args[1].ty.span.lo
};
let reduced_span = mk_sp(span.lo, second_arg_start);
context.codemap.span_after_last(reduced_span, ",")
} else {
span.lo
};
enum ArgumentKind<'a> {
Regular(&'a ast::Arg),
Variadic(BytePos),
}
let variadic_arg = if variadic {
let variadic_span = mk_sp(args.last().unwrap().ty.span.hi, span.hi);
let variadic_start = context.codemap.span_after(variadic_span, "...") - BytePos(3);
Some(ArgumentKind::Variadic(variadic_start))
} else {
None
};
let more_items = itemize_list(
context.codemap,
args[min_args - 1..]
.iter()
.map(ArgumentKind::Regular)
.chain(variadic_arg),
")",
|arg| match *arg {
ArgumentKind::Regular(arg) => span_lo_for_arg(arg),
ArgumentKind::Variadic(start) => start,
},
|arg| match *arg {
ArgumentKind::Regular(arg) => arg.ty.span.hi,
ArgumentKind::Variadic(start) => start + BytePos(3),
},
|arg| match *arg {
ArgumentKind::Regular(..) => None,
ArgumentKind::Variadic(..) => Some("...".to_owned()),
},
comment_span_start,
span.hi,
);
arg_items.extend(more_items);
}
let fits_in_one_line = !generics_str_contains_newline &&
(arg_items.len() == 0 || arg_items.len() == 1 && arg_item_strs[0].len() <= one_line_budget);
for (item, arg) in arg_items.iter_mut().zip(arg_item_strs) {
item.item = Some(arg);
}
let last_line_ends_with_comment = arg_items
.iter()
.last()
.and_then(|item| item.post_comment.as_ref())
.map_or(false, |s| s.trim().starts_with("//"));
let (indent, trailing_comma, end_with_newline) = match context.config.fn_args_layout() {
IndentStyle::Block if fits_in_one_line => {
(
indent.block_indent(context.config),
SeparatorTactic::Never,
true,
)
}
IndentStyle::Block => {
(
indent.block_indent(context.config),
context.config.trailing_comma(),
true,
)
}
IndentStyle::Visual if last_line_ends_with_comment => {
(arg_indent, context.config.trailing_comma(), true)
}
IndentStyle::Visual => (arg_indent, SeparatorTactic::Never, false),
};
let tactic = definitive_tactic(
&arg_items,
context.config.fn_args_density().to_list_tactic(),
one_line_budget,
);
let budget = match tactic {
DefinitiveListTactic::Horizontal => one_line_budget,
_ => multi_line_budget,
};
debug!("rewrite_args: budget: {}, tactic: {:?}", budget, tactic);
let fmt = ListFormatting {
tactic: tactic,
separator: ",",
trailing_separator: if variadic {
SeparatorTactic::Never
} else {
trailing_comma
},
shape: Shape::legacy(budget, indent),
ends_with_newline: end_with_newline,
config: context.config,
};
write_list(&arg_items, &fmt)
}
fn arg_has_pattern(arg: &ast::Arg) -> bool {
if let ast::PatKind::Ident(_, ident, _) = arg.pat.node {
ident.node != symbol::keywords::Invalid.ident()
} else {
true
}
}
fn compute_budgets_for_args(
context: &RewriteContext,
result: &str,
indent: Indent,
ret_str_len: usize,
newline_brace: bool,
has_braces: bool,
) -> Option<((usize, usize, Indent))> {
debug!(
"compute_budgets_for_args {} {:?}, {}, {}",
result.len(),
indent,
ret_str_len,
newline_brace
);
if !result.contains('\n') {
let overhead = if ret_str_len == 0 { 2 } else { 3 };
let mut used_space = indent.width() + result.len() + ret_str_len + overhead;
if has_braces {
if !newline_brace {
used_space += 2;
}
} else {
used_space += 1;
}
let one_line_budget = context
.config
.max_width()
.checked_sub(used_space)
.unwrap_or(0);
if one_line_budget > 0 {
let multi_line_overhead =
indent.width() + result.len() + if newline_brace { 2 } else { 4 };
let multi_line_budget =
try_opt!(context.config.max_width().checked_sub(multi_line_overhead));
return Some((
one_line_budget,
multi_line_budget,
indent + result.len() + 1,
));
}
}
let new_indent = indent.block_indent(context.config);
let used_space = new_indent.width() + if ret_str_len == 0 { 1 } else { 3 };
let max_space = try_opt!(context.config.max_width().checked_sub(used_space));
Some((0, max_space, new_indent))
}
fn newline_for_brace(config: &Config, where_clause: &ast::WhereClause) -> bool {
match config.fn_brace_style() {
BraceStyle::AlwaysNextLine => true,
BraceStyle::SameLineWhere if !where_clause.predicates.is_empty() => true,
_ => false,
}
}
fn rewrite_generics(
context: &RewriteContext,
generics: &ast::Generics,
shape: Shape,
span: Span,
) -> Option<String> {
let g_shape = try_opt!(generics_shape_from_config(context.config, shape, 0));
let one_line_width = shape.width.checked_sub(2).unwrap_or(0);
rewrite_generics_inner(context, generics, g_shape, one_line_width, span).or_else(|| {
rewrite_generics_inner(context, generics, g_shape, 0, span)
})
}
fn rewrite_generics_inner(
context: &RewriteContext,
generics: &ast::Generics,
shape: Shape,
one_line_width: usize,
span: Span,
) -> Option<String> {
let lifetimes: &[_] = &generics.lifetimes;
let tys: &[_] = &generics.ty_params;
if lifetimes.is_empty() && tys.is_empty() {
return Some(String::new());
}
let lt_strs = lifetimes.iter().map(|lt| lt.rewrite(context, shape));
let ty_strs = tys.iter().map(|ty_param| ty_param.rewrite(context, shape));
let lt_spans = lifetimes.iter().map(|l| {
let hi = if l.bounds.is_empty() {
l.lifetime.span.hi
} else {
l.bounds[l.bounds.len() - 1].span.hi
};
mk_sp(l.lifetime.span.lo, hi)
});
let ty_spans = tys.iter().map(span_for_ty_param);
let items = itemize_list(
context.codemap,
lt_spans.chain(ty_spans).zip(lt_strs.chain(ty_strs)),
">",
|&(sp, _)| sp.lo,
|&(sp, _)| sp.hi,
|&(_, ref str)| str.clone(),
context.codemap.span_after(span, "<"),
span.hi,
);
format_generics_item_list(context, items, shape, one_line_width)
}
pub fn generics_shape_from_config(config: &Config, shape: Shape, offset: usize) -> Option<Shape> {
match config.generics_indent() {
IndentStyle::Visual => shape.visual_indent(1 + offset).sub_width(offset + 2),
IndentStyle::Block => {
shape
.block()
.block_indent(config.tab_spaces())
.with_max_width(config)
.sub_width(1)
}
}
}
pub fn format_generics_item_list<I>(
context: &RewriteContext,
items: I,
shape: Shape,
one_line_budget: usize,
) -> Option<String>
where
I: Iterator<Item = ListItem>,
{
let item_vec = items.collect::<Vec<_>>();
let tactic = definitive_tactic(&item_vec, ListTactic::HorizontalVertical, one_line_budget);
let ends_with_newline = context.config.generics_indent() == IndentStyle::Block &&
tactic == DefinitiveListTactic::Vertical;
let fmt = ListFormatting {
tactic: tactic,
separator: ",",
trailing_separator: if context.config.generics_indent() == IndentStyle::Visual {
SeparatorTactic::Never
} else {
context.config.trailing_comma()
},
shape: shape,
ends_with_newline: ends_with_newline,
config: context.config,
};
let list_str = try_opt!(write_list(&item_vec, &fmt));
Some(wrap_generics_with_angle_brackets(
context,
&list_str,
shape.indent,
))
}
pub fn wrap_generics_with_angle_brackets(
context: &RewriteContext,
list_str: &str,
list_offset: Indent,
) -> String {
if context.config.generics_indent() == IndentStyle::Block &&
(list_str.contains('\n') || list_str.ends_with(','))
{
format!(
"<\n{}{}\n{}>",
list_offset.to_string(context.config),
list_str,
list_offset
.block_unindent(context.config)
.to_string(context.config)
)
} else if context.config.spaces_within_angle_brackets() {
format!("< {} >", list_str)
} else {
format!("<{}>", list_str)
}
}
fn rewrite_trait_bounds(
context: &RewriteContext,
type_param_bounds: &ast::TyParamBounds,
shape: Shape,
) -> Option<String> {
let bounds: &[_] = type_param_bounds;
if bounds.is_empty() {
return Some(String::new());
}
let bound_str = try_opt!(
bounds
.iter()
.map(|ty_bound| ty_bound.rewrite(&context, shape))
.collect::<Option<Vec<_>>>()
);
Some(format!(": {}", join_bounds(context, shape, &bound_str)))
}
fn rewrite_where_clause_rfc_style(
context: &RewriteContext,
where_clause: &ast::WhereClause,
shape: Shape,
terminator: &str,
suppress_comma: bool,
snuggle: bool,
span_end: Option<BytePos>,
) -> Option<String> {
let block_shape = shape.block().with_max_width(context.config);
let starting_newline = if snuggle {
" ".to_owned()
} else {
"\n".to_owned() + &block_shape.indent.to_string(context.config)
};
let clause_shape = block_shape.block_indent(context.config.tab_spaces());
let span_start = span_for_where_pred(&where_clause.predicates[0]).lo;
let len = where_clause.predicates.len();
let end_of_preds = span_for_where_pred(&where_clause.predicates[len - 1]).hi;
let span_end = span_end.unwrap_or(end_of_preds);
let items = itemize_list(
context.codemap,
where_clause.predicates.iter(),
terminator,
|pred| span_for_where_pred(pred).lo,
|pred| span_for_where_pred(pred).hi,
|pred| pred.rewrite(context, block_shape),
span_start,
span_end,
);
let comma_tactic = if suppress_comma {
SeparatorTactic::Never
} else {
context.config.trailing_comma()
};
let fmt = ListFormatting {
tactic: DefinitiveListTactic::Vertical,
separator: ",",
trailing_separator: comma_tactic,
shape: clause_shape,
ends_with_newline: true,
config: context.config,
};
let preds_str = try_opt!(write_list(&items.collect::<Vec<_>>(), &fmt));
Some(format!(
"{}where\n{}{}",
starting_newline,
clause_shape.indent.to_string(context.config),
preds_str
))
}
fn rewrite_where_clause(
context: &RewriteContext,
where_clause: &ast::WhereClause,
brace_style: BraceStyle,
shape: Shape,
density: Density,
terminator: &str,
suppress_comma: bool,
snuggle: bool,
span_end: Option<BytePos>,
) -> Option<String> {
if where_clause.predicates.is_empty() {
return Some(String::new());
}
if context.config.where_style() == Style::Rfc {
return rewrite_where_clause_rfc_style(
context,
where_clause,
shape,
terminator,
suppress_comma,
snuggle,
span_end,
);
}
let extra_indent = Indent::new(context.config.tab_spaces(), 0);
let offset = match context.config.where_pred_indent() {
IndentStyle::Block => shape.indent + extra_indent.block_indent(context.config),
IndentStyle::Visual => shape.indent + extra_indent + 6,
};
let budget = context.config.max_width() - offset.width();
let span_start = span_for_where_pred(&where_clause.predicates[0]).lo;
let len = where_clause.predicates.len();
let end_of_preds = span_for_where_pred(&where_clause.predicates[len - 1]).hi;
let span_end = span_end.unwrap_or(end_of_preds);
let items = itemize_list(
context.codemap,
where_clause.predicates.iter(),
terminator,
|pred| span_for_where_pred(pred).lo,
|pred| span_for_where_pred(pred).hi,
|pred| pred.rewrite(context, Shape::legacy(budget, offset)),
span_start,
span_end,
);
let item_vec = items.collect::<Vec<_>>();
let tactic = definitive_tactic(&item_vec, context.config.where_layout(), budget);
let mut comma_tactic = context.config.trailing_comma();
if comma_tactic == SeparatorTactic::Vertical || suppress_comma {
comma_tactic = SeparatorTactic::Never;
}
let fmt = ListFormatting {
tactic: tactic,
separator: ",",
trailing_separator: comma_tactic,
shape: Shape::legacy(budget, offset),
ends_with_newline: true,
config: context.config,
};
let preds_str = try_opt!(write_list(&item_vec, &fmt));
let end_length = if terminator == "{" {
match brace_style {
BraceStyle::AlwaysNextLine | BraceStyle::SameLineWhere => 0,
BraceStyle::PreferSameLine => 2,
}
} else if terminator == "=" {
2
} else {
terminator.len()
};
if density == Density::Tall || preds_str.contains('\n') ||
shape.indent.width() + " where ".len() + preds_str.len() + end_length > shape.width
{
Some(format!(
"\n{}where {}",
(shape.indent + extra_indent).to_string(context.config),
preds_str
))
} else {
Some(format!(" where {}", preds_str))
}
}
fn format_header(item_name: &str, ident: ast::Ident, vis: &ast::Visibility) -> String {
format!("{}{}{}", format_visibility(vis), item_name, ident)
}
fn format_generics(
context: &RewriteContext,
generics: &ast::Generics,
opener: &str,
terminator: &str,
brace_style: BraceStyle,
force_same_line_brace: bool,
offset: Indent,
span: Span,
used_width: usize,
) -> Option<String> {
let shape = Shape::legacy(context.budget(used_width + offset.width()), offset);
let mut result = try_opt!(rewrite_generics(context, generics, shape, span));
if !generics.where_clause.predicates.is_empty() || result.contains('\n') {
let budget = try_opt!(
context
.config
.max_width()
.checked_sub(last_line_width(&result))
);
let where_clause_str = try_opt!(rewrite_where_clause(
context,
&generics.where_clause,
brace_style,
Shape::legacy(budget, offset.block_only()),
Density::Tall,
terminator,
false,
trimmed_last_line_width(&result) == 1,
Some(span.hi),
));
result.push_str(&where_clause_str);
let same_line_brace = force_same_line_brace ||
(generics.where_clause.predicates.is_empty() && trimmed_last_line_width(&result) == 1);
if !same_line_brace &&
(brace_style == BraceStyle::SameLineWhere ||
brace_style == BraceStyle::AlwaysNextLine)
{
result.push('\n');
result.push_str(&offset.block_only().to_string(context.config));
} else {
result.push(' ');
}
result.push_str(opener);
} else {
if force_same_line_brace || trimmed_last_line_width(&result) == 1 ||
brace_style != BraceStyle::AlwaysNextLine
{
result.push(' ');
} else {
result.push('\n');
result.push_str(&offset.block_only().to_string(context.config));
}
result.push_str(opener);
}
Some(result)
}