1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 use std::cmp::Ordering;
14 use syntax::codemap::{BytePos, Span};
17 use codemap::SpanUtils;
18 use comment::combine_strs_with_missing_comments;
19 use config::IndentStyle;
20 use lists::{definitive_tactic, itemize_list, write_list, DefinitiveListTactic, ListFormatting,
21 ListItem, Separator, SeparatorPlace, SeparatorTactic};
22 use rewrite::{Rewrite, RewriteContext};
24 use types::{rewrite_path, PathContext};
25 use utils::{format_visibility, mk_sp};
26 use visitor::{rewrite_extern_crate, FmtVisitor};
28 fn path_of(a: &ast::ViewPath_) -> &ast::Path {
30 ast::ViewPath_::ViewPathSimple(_, ref p) |
31 ast::ViewPath_::ViewPathGlob(ref p) |
32 ast::ViewPath_::ViewPathList(ref p, _) => p,
36 fn compare_path_segments(a: &ast::PathSegment, b: &ast::PathSegment) -> Ordering {
37 a.identifier.name.as_str().cmp(&b.identifier.name.as_str())
40 fn compare_paths(a: &ast::Path, b: &ast::Path) -> Ordering {
41 for segment in a.segments.iter().zip(b.segments.iter()) {
42 let ord = compare_path_segments(segment.0, segment.1);
43 if ord != Ordering::Equal {
47 a.segments.len().cmp(&b.segments.len())
50 fn compare_path_list_items(a: &ast::PathListItem, b: &ast::PathListItem) -> Ordering {
51 let a_name_str = &*a.node.name.name.as_str();
52 let b_name_str = &*b.node.name.name.as_str();
53 let name_ordering = if a_name_str == "self" {
54 if b_name_str == "self" {
59 } else if b_name_str == "self" {
62 a_name_str.cmp(b_name_str)
64 if name_ordering == Ordering::Equal {
66 Some(a_rename) => match b.node.rename {
67 Some(b_rename) => a_rename.name.as_str().cmp(&b_rename.name.as_str()),
68 None => Ordering::Greater,
70 None => Ordering::Less,
77 fn compare_path_list_item_lists(
78 a_items: &Vec<ast::PathListItem>,
79 b_items: &Vec<ast::PathListItem>,
81 let mut a = a_items.clone();
82 let mut b = b_items.clone();
83 a.sort_by(|a, b| compare_path_list_items(a, b));
84 b.sort_by(|a, b| compare_path_list_items(a, b));
85 for comparison_pair in a.iter().zip(b.iter()) {
86 let ord = compare_path_list_items(comparison_pair.0, comparison_pair.1);
87 if ord != Ordering::Equal {
94 fn compare_view_path_types(a: &ast::ViewPath_, b: &ast::ViewPath_) -> Ordering {
95 use syntax::ast::ViewPath_::*;
97 (&ViewPathSimple(..), &ViewPathSimple(..)) => Ordering::Equal,
98 (&ViewPathSimple(..), _) => Ordering::Less,
99 (&ViewPathGlob(_), &ViewPathSimple(..)) => Ordering::Greater,
100 (&ViewPathGlob(_), &ViewPathGlob(_)) => Ordering::Equal,
101 (&ViewPathGlob(_), &ViewPathList(..)) => Ordering::Less,
102 (&ViewPathList(_, ref a_items), &ViewPathList(_, ref b_items)) => {
103 compare_path_list_item_lists(a_items, b_items)
105 (&ViewPathList(..), _) => Ordering::Greater,
109 fn compare_view_paths(a: &ast::ViewPath_, b: &ast::ViewPath_) -> Ordering {
110 match compare_paths(path_of(a), path_of(b)) {
111 Ordering::Equal => compare_view_path_types(a, b),
116 fn compare_use_items(context: &RewriteContext, a: &ast::Item, b: &ast::Item) -> Option<Ordering> {
117 match (&a.node, &b.node) {
118 (&ast::ItemKind::Use(ref a_vp), &ast::ItemKind::Use(ref b_vp)) => {
119 Some(compare_view_paths(&a_vp.node, &b_vp.node))
121 (&ast::ItemKind::ExternCrate(..), &ast::ItemKind::ExternCrate(..)) => {
122 Some(context.snippet(a.span).cmp(&context.snippet(b.span)))
128 // TODO (some day) remove unused imports, expand globs, compress many single
129 // imports into a list import.
131 fn rewrite_view_path_prefix(
133 context: &RewriteContext,
135 ) -> Option<String> {
136 let path_str = if path.segments.last().unwrap().identifier.to_string() == "self"
137 && path.segments.len() > 1
139 let path = &ast::Path {
141 segments: path.segments[..path.segments.len() - 1].to_owned(),
143 try_opt!(rewrite_path(
151 try_opt!(rewrite_path(
162 impl Rewrite for ast::ViewPath {
163 fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
165 ast::ViewPath_::ViewPathList(ref path, ref path_list) => {
166 rewrite_use_list(shape, path, path_list, self.span, context)
168 ast::ViewPath_::ViewPathGlob(ref path) => {
170 let prefix_shape = try_opt!(shape.sub_width(3));
171 let path_str = try_opt!(rewrite_view_path_prefix(path, context, prefix_shape));
172 Some(format!("{}::*", path_str))
174 ast::ViewPath_::ViewPathSimple(ident, ref path) => {
175 let ident_str = ident.to_string();
177 let prefix_shape = try_opt!(shape.sub_width(ident_str.len() + 4));
178 let path_str = try_opt!(rewrite_view_path_prefix(path, context, prefix_shape));
180 Some(if path.segments.last().unwrap().identifier == ident {
183 format!("{} as {}", path_str, ident_str)
190 // Rewrite `use foo;` WITHOUT attributes.
192 context: &RewriteContext,
193 vis: &ast::Visibility,
195 attrs: &[ast::Attribute],
197 ) -> Option<String> {
198 let vis = format_visibility(vis);
199 // 4 = `use `, 1 = `;`
201 .offset_left(vis.len() + 4)
202 .and_then(|shape| shape.sub_width(1))
203 .and_then(|shape| match vp.node {
204 // If we have an empty path list with no attributes, we erase it
205 ast::ViewPath_::ViewPathList(_, ref path_list)
206 if path_list.is_empty() && attrs.is_empty() =>
210 _ => vp.rewrite(context, shape),
213 Some(ref s) if !s.is_empty() => Some(format!("{}use {};", vis, s)),
219 context: &RewriteContext,
220 use_items: &[&ast::Item],
223 ) -> Option<String> {
224 let items = itemize_list(
228 |item| item.span().lo(),
229 |item| item.span().hi(),
231 let attrs_str = try_opt!(item.attrs.rewrite(context, shape));
233 let missed_span = if item.attrs.is_empty() {
234 mk_sp(item.span.lo(), item.span.lo())
236 mk_sp(item.attrs.last().unwrap().span.hi(), item.span.lo())
239 let item_str = match item.node {
240 ast::ItemKind::Use(ref vp) => {
241 try_opt!(rewrite_import(context, &item.vis, vp, &item.attrs, shape))
243 ast::ItemKind::ExternCrate(..) => try_opt!(rewrite_extern_crate(context, item)),
247 combine_strs_with_missing_comments(
260 let mut item_pair_vec: Vec<_> = items.zip(use_items.iter()).collect();
261 item_pair_vec.sort_by(|a, b| compare_use_items(context, a.1, b.1).unwrap());
262 let item_vec: Vec<_> = item_pair_vec.into_iter().map(|pair| pair.0).collect();
264 let fmt = ListFormatting {
265 tactic: DefinitiveListTactic::Vertical,
267 trailing_separator: SeparatorTactic::Never,
268 separator_place: SeparatorPlace::Back,
270 ends_with_newline: true,
271 preserve_newline: false,
272 config: context.config,
275 write_list(&item_vec, &fmt)
278 impl<'a> FmtVisitor<'a> {
279 pub fn format_imports(&mut self, use_items: &[&ast::Item]) {
280 if use_items.is_empty() {
284 let lo = use_items.first().unwrap().span().lo();
285 let hi = use_items.last().unwrap().span().hi();
286 let span = mk_sp(lo, hi);
287 let rw = rewrite_imports(&self.get_context(), use_items, self.shape(), span);
288 self.push_rewrite(span, rw);
291 pub fn format_import(&mut self, item: &ast::Item, vp: &ast::ViewPath) {
292 let span = item.span;
293 let shape = self.shape();
294 let rw = rewrite_import(&self.get_context(), &item.vis, vp, &item.attrs, shape);
296 Some(ref s) if s.is_empty() => {
297 // Format up to last newline
298 let prev_span = mk_sp(self.last_pos, source!(self, span).lo());
299 let span_end = match self.snippet(prev_span).rfind('\n') {
300 Some(offset) => self.last_pos + BytePos(offset as u32),
301 None => source!(self, span).lo(),
303 self.format_missing(span_end);
304 self.last_pos = source!(self, span).hi();
307 self.format_missing_with_indent(source!(self, span).lo());
308 self.buffer.push_str(&s);
309 self.last_pos = source!(self, span).hi();
312 self.format_missing_with_indent(source!(self, span).lo());
313 self.format_missing(source!(self, span).hi());
319 fn rewrite_single_use_list(path_str: String, vpi: &ast::PathListItem) -> String {
320 let mut item_str = vpi.node.name.to_string();
321 if item_str == "self" {
322 item_str = "".to_owned();
324 let path_item_str = if path_str.is_empty() {
325 if item_str.is_empty() {
330 } else if item_str.is_empty() {
333 format!("{}::{}", path_str, item_str)
335 append_alias(path_item_str, vpi)
338 fn rewrite_path_item(vpi: &&ast::PathListItem) -> Option<String> {
339 Some(append_alias(vpi.node.name.to_string(), vpi))
342 fn append_alias(path_item_str: String, vpi: &ast::PathListItem) -> String {
343 match vpi.node.rename {
344 Some(rename) => format!("{} as {}", path_item_str, rename),
345 None => path_item_str,
349 #[derive(Eq, PartialEq)]
350 enum ImportItem<'a> {
351 // `self` or `self as a`
353 // name_one, name_two, ...
355 // NameOne, NameTwo, ...
357 // NAME_ONE, NAME_TWO, ...
359 // Failed to format the import item
363 impl<'a> ImportItem<'a> {
364 fn from_str(s: &str) -> ImportItem {
365 if s == "self" || s.starts_with("self as") {
366 ImportItem::SelfImport(s)
367 } else if s.chars().all(|c| c.is_lowercase() || c == '_' || c == ' ') {
368 ImportItem::SnakeCase(s)
369 } else if s.chars().all(|c| c.is_uppercase() || c == '_' || c == ' ') {
370 ImportItem::AllCaps(s)
372 ImportItem::CamelCase(s)
376 fn from_opt_str(s: Option<&String>) -> ImportItem {
377 s.map_or(ImportItem::Invalid, |s| ImportItem::from_str(s))
380 fn to_str(&self) -> Option<&str> {
382 ImportItem::SelfImport(s) |
383 ImportItem::SnakeCase(s) |
384 ImportItem::CamelCase(s) |
385 ImportItem::AllCaps(s) => Some(s),
386 ImportItem::Invalid => None,
390 fn to_u32(&self) -> u32 {
392 ImportItem::SelfImport(..) => 0,
393 ImportItem::SnakeCase(..) => 1,
394 ImportItem::CamelCase(..) => 2,
395 ImportItem::AllCaps(..) => 3,
396 ImportItem::Invalid => 4,
401 impl<'a> PartialOrd for ImportItem<'a> {
402 fn partial_cmp(&self, other: &ImportItem<'a>) -> Option<Ordering> {
403 Some(self.cmp(other))
407 impl<'a> Ord for ImportItem<'a> {
408 fn cmp(&self, other: &ImportItem<'a>) -> Ordering {
409 let res = self.to_u32().cmp(&other.to_u32());
410 if res != Ordering::Equal {
413 self.to_str().map_or(Ordering::Greater, |self_str| {
416 .map_or(Ordering::Less, |other_str| self_str.cmp(other_str))
421 // Pretty prints a multi-item import.
422 // If the path list is empty, it leaves the braces empty.
426 path_list: &[ast::PathListItem],
428 context: &RewriteContext,
429 ) -> Option<String> {
430 // Returns a different option to distinguish `::foo` and `foo`
431 let path_str = try_opt!(rewrite_path(
439 match path_list.len() {
441 return rewrite_path(context, PathContext::Import, None, path, shape)
442 .map(|path_str| format!("{}::{{}}", path_str));
444 1 => return Some(rewrite_single_use_list(path_str, &path_list[0])),
448 let path_str = if path_str.is_empty() {
451 format!("{}::", path_str)
455 let remaining_width = shape.width.checked_sub(path_str.len() + 2).unwrap_or(0);
458 // Dummy value, see explanation below.
459 let mut items = vec![ListItem::from_str("")];
460 let iter = itemize_list(
467 context.codemap.span_after(span, "{"),
475 // We prefixed the item list with a dummy value so that we can
476 // potentially move "self" to the front of the vector without touching
477 // the rest of the items.
478 let has_self = move_self_to_front(&mut items);
479 let first_index = if has_self { 0 } else { 1 };
481 if context.config.reorder_imported_names() {
482 items[1..].sort_by(|a, b| {
483 let a = ImportItem::from_opt_str(a.item.as_ref());
484 let b = ImportItem::from_opt_str(b.item.as_ref());
489 let tactic = definitive_tactic(
490 &items[first_index..],
491 context.config.imports_layout(),
496 let nested_indent = match context.config.imports_indent() {
497 IndentStyle::Block => shape.indent.block_indent(context.config),
499 IndentStyle::Visual => shape.visual_indent(path_str.len() + 1).indent,
502 let nested_shape = match context.config.imports_indent() {
503 IndentStyle::Block => Shape::indented(nested_indent, context.config),
504 IndentStyle::Visual => Shape::legacy(remaining_width, nested_indent),
507 let ends_with_newline = context.config.imports_indent() == IndentStyle::Block
508 && tactic != DefinitiveListTactic::Horizontal;
510 let fmt = ListFormatting {
513 trailing_separator: if ends_with_newline {
514 context.config.trailing_comma()
516 SeparatorTactic::Never
518 separator_place: SeparatorPlace::Back,
520 ends_with_newline: ends_with_newline,
521 preserve_newline: true,
522 config: context.config,
524 let list_str = try_opt!(write_list(&items[first_index..], &fmt));
526 let result = if list_str.contains('\n') && context.config.imports_indent() == IndentStyle::Block
531 nested_shape.indent.to_string(context.config),
533 shape.indent.to_string(context.config)
536 format!("{}{{{}}}", path_str, list_str)
541 // Returns true when self item was found.
542 fn move_self_to_front(items: &mut Vec<ListItem>) -> bool {
545 .position(|item| item.item.as_ref().map(|x| &x[..]) == Some("self"))
548 items[0] = items.remove(pos);