use config::lists::*;
use syntax::ast::{self, UseTreeKind};
-use syntax::codemap::{BytePos, Span};
+use syntax::codemap::{self, BytePos, Span, DUMMY_SP};
use codemap::SpanUtils;
+use comment::combine_strs_with_missing_comments;
use config::IndentStyle;
use lists::{definitive_tactic, itemize_list, write_list, ListFormatting, ListItem, Separator};
use rewrite::{Rewrite, RewriteContext};
use visitor::FmtVisitor;
use std::borrow::Cow;
+use std::fmt;
/// Returns a name imported by a `use` declaration. e.g. returns `Ordering`
/// for `std::cmp::Ordering` and `self` for `std::cmp::self`.
// sorting.
// FIXME we do a lot of allocation to make our own representation.
-#[derive(Debug, Clone, Eq, PartialEq)]
+#[derive(Clone, Eq, PartialEq)]
pub enum UseSegment {
Ident(String, Option<String>),
Slf(Option<String>),
List(Vec<UseTree>),
}
-#[derive(Debug, Clone)]
+#[derive(Clone)]
pub struct UseTree {
pub path: Vec<UseSegment>,
pub span: Span,
// Comment information within nested use tree.
- list_item: Option<ListItem>,
+ pub list_item: Option<ListItem>,
// Additional fields for top level use items.
// Should we have another struct for top-level use items rather than reusing this?
visibility: Option<ast::Visibility>,
}
}
-impl UseTree {
- // Rewrite use tree with `use ` and a trailing `;`.
- pub fn rewrite_top_level(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
- let mut result = String::with_capacity(256);
- if let Some(ref attrs) = self.attrs {
- result.push_str(&attrs.rewrite(context, shape)?);
- if !result.is_empty() {
- result.push_str(&shape.indent.to_string_with_newline(context.config));
+pub fn merge_use_trees(use_trees: Vec<UseTree>) -> Vec<UseTree> {
+ let mut result = Vec::with_capacity(use_trees.len());
+ for use_tree in use_trees {
+ if use_tree.has_comment() || use_tree.attrs.is_some() {
+ result.push(use_tree);
+ continue;
+ }
+
+ for flattened in use_tree.flatten() {
+ merge_use_trees_inner(&mut result, flattened);
+ }
+ }
+ result
+}
+
+fn merge_use_trees_inner(trees: &mut Vec<UseTree>, use_tree: UseTree) {
+ for tree in trees.iter_mut() {
+ if tree.share_prefix(&use_tree) {
+ tree.merge(use_tree);
+ return;
+ }
+ }
+
+ trees.push(use_tree);
+}
+
+impl fmt::Debug for UseTree {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ fmt::Display::fmt(self, f)
+ }
+}
+
+impl fmt::Debug for UseSegment {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ fmt::Display::fmt(self, f)
+ }
+}
+
+impl fmt::Display for UseSegment {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match *self {
+ UseSegment::Glob => write!(f, "*"),
+ UseSegment::Ident(ref s, _) => write!(f, "{}", s),
+ UseSegment::Slf(..) => write!(f, "self"),
+ UseSegment::Super(..) => write!(f, "super"),
+ UseSegment::List(ref list) => {
+ write!(f, "{{")?;
+ for (i, item) in list.iter().enumerate() {
+ let is_last = i == list.len() - 1;
+ write!(f, "{}", item)?;
+ if !is_last {
+ write!(f, ", ")?;
+ }
+ }
+ write!(f, "}}")
+ }
+ }
+ }
+}
+impl fmt::Display for UseTree {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ for (i, segment) in self.path.iter().enumerate() {
+ let is_last = i == self.path.len() - 1;
+ write!(f, "{}", segment)?;
+ if !is_last {
+ write!(f, "::")?;
}
}
+ write!(f, "")
+ }
+}
+impl UseTree {
+ // Rewrite use tree with `use ` and a trailing `;`.
+ pub fn rewrite_top_level(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
let vis = self.visibility
.as_ref()
.map_or(Cow::from(""), |vis| ::utils::format_visibility(&vis));
- result.push_str(&self.rewrite(context, shape.offset_left(vis.len())?)
+ let use_str = self.rewrite(context, shape.offset_left(vis.len())?)
.map(|s| {
if s.is_empty() {
s.to_owned()
} else {
format!("{}use {};", vis, s)
}
- })?);
- Some(result)
+ })?;
+ if let Some(ref attrs) = self.attrs {
+ let attr_str = attrs.rewrite(context, shape)?;
+ let lo = attrs.last().as_ref()?.span().hi();
+ let hi = self.span.lo();
+ let span = mk_sp(lo, hi);
+ combine_strs_with_missing_comments(context, &attr_str, &use_str, span, shape, false)
+ } else {
+ Some(use_str)
+ }
+ }
+
+ // FIXME: Use correct span?
+ // The given span is essentially incorrect, since we are reconstructing
+ // use statements. This should not be a problem, though, since we have
+ // already tried to extract comment and observed that there are no comment
+ // around the given use item, and the span will not be used afterward.
+ fn from_path(path: Vec<UseSegment>, span: Span) -> UseTree {
+ UseTree {
+ path,
+ span,
+ list_item: None,
+ visibility: None,
+ attrs: None,
+ }
}
pub fn from_ast_with_normalization(
// Normalise foo::self -> foo.
if let UseSegment::Slf(None) = last {
- if self.path.len() > 0 {
+ if !self.path.is_empty() {
return self;
}
}
self.path.push(last);
self
}
+
+ fn has_comment(&self) -> bool {
+ self.list_item.as_ref().map_or(false, ListItem::has_comment)
+ }
+
+ fn same_visibility(&self, other: &UseTree) -> bool {
+ match (&self.visibility, &other.visibility) {
+ (
+ Some(codemap::Spanned {
+ node: ast::VisibilityKind::Inherited,
+ ..
+ }),
+ None,
+ )
+ | (
+ None,
+ Some(codemap::Spanned {
+ node: ast::VisibilityKind::Inherited,
+ ..
+ }),
+ )
+ | (None, None) => true,
+ (
+ Some(codemap::Spanned { node: lnode, .. }),
+ Some(codemap::Spanned { node: rnode, .. }),
+ ) => lnode == rnode,
+ _ => false,
+ }
+ }
+
+ fn share_prefix(&self, other: &UseTree) -> bool {
+ if self.path.is_empty() || other.path.is_empty() || self.attrs.is_some()
+ || !self.same_visibility(other)
+ {
+ false
+ } else {
+ self.path[0] == other.path[0]
+ }
+ }
+
+ fn flatten(self) -> Vec<UseTree> {
+ if self.path.is_empty() {
+ return vec![self];
+ }
+ match self.path.clone().last().unwrap() {
+ UseSegment::List(list) => {
+ let prefix = &self.path[..self.path.len() - 1];
+ let mut result = vec![];
+ for nested_use_tree in list {
+ for mut flattend in &mut nested_use_tree.clone().flatten() {
+ let mut new_path = prefix.to_vec();
+ new_path.append(&mut flattend.path);
+ result.push(UseTree {
+ path: new_path,
+ span: self.span,
+ list_item: None,
+ visibility: self.visibility.clone(),
+ attrs: None,
+ });
+ }
+ }
+
+ result
+ }
+ _ => vec![self],
+ }
+ }
+
+ fn merge(&mut self, other: UseTree) {
+ let mut new_path = vec![];
+ for (mut a, b) in self.path
+ .clone()
+ .iter_mut()
+ .zip(other.path.clone().into_iter())
+ {
+ if *a == b {
+ new_path.push(b);
+ } else {
+ break;
+ }
+ }
+ if let Some(merged) = merge_rest(&self.path, &other.path, new_path.len()) {
+ new_path.push(merged);
+ self.span = self.span.to(other.span);
+ }
+ self.path = new_path;
+ }
+}
+
+fn merge_rest(a: &[UseSegment], b: &[UseSegment], len: usize) -> Option<UseSegment> {
+ let a_rest = &a[len..];
+ let b_rest = &b[len..];
+ if a_rest.is_empty() && b_rest.is_empty() {
+ return None;
+ }
+ if a_rest.is_empty() {
+ return Some(UseSegment::List(vec![
+ UseTree::from_path(vec![UseSegment::Slf(None)], DUMMY_SP),
+ UseTree::from_path(b_rest.to_vec(), DUMMY_SP),
+ ]));
+ }
+ if b_rest.is_empty() {
+ return Some(UseSegment::List(vec![
+ UseTree::from_path(vec![UseSegment::Slf(None)], DUMMY_SP),
+ UseTree::from_path(a_rest.to_vec(), DUMMY_SP),
+ ]));
+ }
+ if let UseSegment::List(mut list) = a_rest[0].clone() {
+ merge_use_trees_inner(&mut list, UseTree::from_path(b_rest.to_vec(), DUMMY_SP));
+ list.sort();
+ return Some(UseSegment::List(list.clone()));
+ }
+ let mut list = vec![
+ UseTree::from_path(a_rest.to_vec(), DUMMY_SP),
+ UseTree::from_path(b_rest.to_vec(), DUMMY_SP),
+ ];
+ list.sort();
+ Some(UseSegment::List(list))
}
impl PartialOrd for UseSegment {
IndentStyle::Visual => shape.visual_indent(0),
};
for use_tree in use_tree_list {
- let mut list_item = use_tree.list_item.clone()?;
- list_item.item = use_tree.rewrite(context, nested_shape);
- list_items.push(list_item);
+ if let Some(mut list_item) = use_tree.list_item.clone() {
+ list_item.item = use_tree.rewrite(context, nested_shape);
+ list_items.push(list_item);
+ } else {
+ list_items.push(ListItem::from_str(use_tree.rewrite(context, nested_shape)?));
+ }
}
- let (tactic, remaining_width) = if use_tree_list.iter().any(|use_segment| {
+ let has_nested_list = use_tree_list.iter().any(|use_segment| {
use_segment
.path
.last()
UseSegment::List(..) => true,
_ => false,
})
- }) {
+ });
+ let (tactic, remaining_width) = if has_nested_list {
(DefinitiveListTactic::Vertical, 0)
} else {
let remaining_width = shape.width.checked_sub(2).unwrap_or(0);
parser.parse_in_list()
}
+ macro parse_use_trees($($s:expr),* $(,)*) {
+ vec![
+ $(parse_use_tree($s),)*
+ ]
+ }
+
+ #[test]
+ fn test_use_tree_merge() {
+ macro test_merge([$($input:expr),* $(,)*], [$($output:expr),* $(,)*]) {
+ assert_eq!(
+ merge_use_trees(parse_use_trees!($($input,)*)),
+ parse_use_trees!($($output,)*),
+ );
+ }
+
+ test_merge!(["a::b::{c, d}", "a::b::{e, f}"], ["a::b::{c, d, e, f}"]);
+ test_merge!(["a::b::c", "a::b"], ["a::b::{self, c}"]);
+ test_merge!(["a::b", "a::b"], ["a::b"]);
+ test_merge!(["a", "a::b", "a::b::c"], ["a::{self, b::{self, c}}"]);
+ test_merge!(
+ ["a::{b::{self, c}, d::e}", "a::d::f"],
+ ["a::{b::{self, c}, d::{e, f}}"]
+ );
+ test_merge!(
+ ["a::d::f", "a::{b::{self, c}, d::e}"],
+ ["a::{b::{self, c}, d::{e, f}}"]
+ );
+ test_merge!(
+ ["a::{c, d, b}", "a::{d, e, b, a, f}", "a::{f, g, c}"],
+ ["a::{a, b, c, d, e, f, g}"]
+ );
+ }
+
+ #[test]
+ fn test_use_tree_flatten() {
+ assert_eq!(
+ parse_use_tree("a::b::{c, d, e, f}").flatten(),
+ parse_use_trees!("a::b::c", "a::b::d", "a::b::e", "a::b::f",)
+ );
+
+ assert_eq!(
+ parse_use_tree("a::b::{c::{d, e, f}, g, h::{i, j, k}}").flatten(),
+ parse_use_trees![
+ "a::b::c::d",
+ "a::b::c::e",
+ "a::b::c::f",
+ "a::b::g",
+ "a::b::h::i",
+ "a::b::h::j",
+ "a::b::h::k",
+ ]
+ );
+ }
+
#[test]
fn test_use_tree_normalize() {
assert_eq!(parse_use_tree("a::self").normalize(), parse_use_tree("a"));
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