rust/src/imports.rs

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2015-04-21 21:01:19 +12:00
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use visitor::FmtVisitor;
use lists::{write_list, ListFormatting, SeparatorTactic, ListTactic};
use syntax::ast;
use syntax::codemap::Span;
use syntax::parse::token;
use syntax::print::pprust;
use IDEAL_WIDTH;
impl<'a> FmtVisitor<'a> {
// Basically just pretty prints a multi-item import.
pub fn rewrite_use_list(&mut self,
path: &ast::Path,
path_list: &[ast::PathListItem],
vp_span: Span) -> String {
// FIXME remove unused imports
// FIXME check indentation
let l_loc = self.codemap.lookup_char_pos(vp_span.lo);
let path_str = pprust::path_to_string(&path);
// 3 = :: + {
let indent = l_loc.col.0 + path_str.len() + 3;
let fmt = ListFormatting {
tactic: ListTactic::Mixed,
separator: ",",
trailing_separator: SeparatorTactic::Never,
indent: indent,
// 2 = } + ;
h_width: IDEAL_WIDTH - (indent + path_str.len() + 2),
v_width: IDEAL_WIDTH - (indent + path_str.len() + 2),
};
// TODO handle any comments inbetween items.
// If `self` is in the list, put it first.
let head = if path_list.iter().any(|vpi|
if let ast::PathListItem_::PathListMod{ .. } = vpi.node {
true
} else {
false
}
) {
Some(("self".to_string(), String::new()))
} else {
None
};
let items: Vec<_> = head.into_iter().chain(path_list.iter().filter_map(|vpi| {
match vpi.node {
ast::PathListItem_::PathListIdent{ name, .. } => {
Some((token::get_ident(name).to_string(), String::new()))
}
// Skip `self`, because we added it above.
ast::PathListItem_::PathListMod{ .. } => None,
}
})).collect();
format!("use {}::{{{}}};", path_str, write_list(&items, &fmt))
}
}