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 visitor::FmtVisitor;
12 use lists::{write_list, ListFormatting, SeparatorTactic, ListTactic};
15 use syntax::parse::token;
16 use syntax::print::pprust;
18 // TODO change import lists with one item to a single import
19 // remove empty lists (if they're even possible)
20 // TODO (some day) remove unused imports, expand globs, compress many single imports into a list import
22 impl<'a> FmtVisitor<'a> {
23 // Basically just pretty prints a multi-item import.
24 pub fn rewrite_use_list(&mut self,
26 one_line_budget: usize, // excluding indentation
27 multi_line_budget: usize,
29 path_list: &[ast::PathListItem],
30 visibility: ast::Visibility) -> String {
31 let path_str = pprust::path_to_string(&path);
33 let vis = match visibility {
34 ast::Public => "pub ",
39 let path_separation_w = if path_str.len() > 0 { 2 } else { 0 };
41 let indent = path_str.len() + 5 + path_separation_w + vis.len();
43 let used_width = indent + 2;
45 // Break as early as possible when we've blown our budget.
46 let remaining_line_budget = if used_width > one_line_budget {
49 one_line_budget - used_width
51 let remaining_multi_budget = if used_width > multi_line_budget {
54 multi_line_budget - used_width
57 let fmt = ListFormatting {
58 tactic: ListTactic::Mixed,
60 trailing_separator: SeparatorTactic::Never,
61 indent: block_indent + indent,
62 h_width: remaining_line_budget,
63 v_width: remaining_multi_budget,
66 // TODO handle any comments inbetween items.
67 // If `self` is in the list, put it first.
68 let head = if path_list.iter().any(|vpi|
69 if let ast::PathListItem_::PathListMod{ .. } = vpi.node {
75 Some(("self".to_owned(), String::new()))
80 let items: Vec<_> = head.into_iter().chain(path_list.iter().filter_map(|vpi| {
82 ast::PathListItem_::PathListIdent{ name, .. } => {
83 Some((token::get_ident(name).to_string(), String::new()))
85 // Skip `self`, because we added it above.
86 ast::PathListItem_::PathListMod{ .. } => None,
89 if path_str.len() == 0 {
90 format!("{}use {{{}}};", vis, write_list(&items, &fmt))
92 format!("{}use {}::{{{}}};", vis, path_str, write_list(&items, &fmt))