601 lines
20 KiB
Rust
601 lines
20 KiB
Rust
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use std::cmp::Ordering;
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use syntax::ast;
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use syntax::codemap::{BytePos, Span};
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use codemap::SpanUtils;
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use comment::combine_strs_with_missing_comments;
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use config::IndentStyle;
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use lists::{definitive_tactic, itemize_list, write_list, DefinitiveListTactic, ListFormatting,
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ListItem, Separator, SeparatorPlace, SeparatorTactic};
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use rewrite::{Rewrite, RewriteContext};
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use shape::Shape;
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use spanned::Spanned;
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use types::{rewrite_path, PathContext};
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use utils::{format_visibility, mk_sp};
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use visitor::{rewrite_extern_crate, FmtVisitor};
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fn compare_path_segments(a: &ast::PathSegment, b: &ast::PathSegment) -> Ordering {
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a.identifier.name.as_str().cmp(&b.identifier.name.as_str())
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}
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fn compare_paths(a: &ast::Path, b: &ast::Path) -> Ordering {
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for segment in a.segments.iter().zip(b.segments.iter()) {
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let ord = compare_path_segments(segment.0, segment.1);
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if ord != Ordering::Equal {
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return ord;
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}
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}
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a.segments.len().cmp(&b.segments.len())
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}
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fn compare_use_trees(a: &ast::UseTree, b: &ast::UseTree, nested: bool) -> Ordering {
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use ast::UseTreeKind::*;
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// `use_nested_groups` is not yet supported, remove the `if !nested` when support will be
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// fully added
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if !nested {
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let paths_cmp = compare_paths(&a.prefix, &b.prefix);
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if paths_cmp != Ordering::Equal {
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return paths_cmp;
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}
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}
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match (&a.kind, &b.kind) {
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(&Simple(ident_a), &Simple(ident_b)) => {
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let name_a = &*path_to_imported_ident(&a.prefix).name.as_str();
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let name_b = &*path_to_imported_ident(&b.prefix).name.as_str();
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let name_ordering = if name_a == "self" {
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if name_b == "self" {
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Ordering::Equal
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} else {
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Ordering::Less
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}
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} else if name_b == "self" {
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Ordering::Greater
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} else {
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name_a.cmp(name_b)
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};
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if name_ordering == Ordering::Equal {
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if ident_a.name.as_str() != name_a {
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if ident_b.name.as_str() != name_b {
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ident_a.name.as_str().cmp(&ident_b.name.as_str())
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} else {
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Ordering::Greater
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}
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} else {
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Ordering::Less
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}
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} else {
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name_ordering
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}
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}
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(&Glob, &Glob) => Ordering::Equal,
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(&Simple(_), _) | (&Glob, &Nested(_)) => Ordering::Less,
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(&Nested(ref a_items), &Nested(ref b_items)) => {
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let mut a = a_items
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.iter()
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.map(|&(ref tree, _)| tree.clone())
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.collect::<Vec<_>>();
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let mut b = b_items
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.iter()
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.map(|&(ref tree, _)| tree.clone())
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.collect::<Vec<_>>();
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a.sort_by(|a, b| compare_use_trees(a, b, true));
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b.sort_by(|a, b| compare_use_trees(a, b, true));
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for comparison_pair in a.iter().zip(b.iter()) {
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let ord = compare_use_trees(comparison_pair.0, comparison_pair.1, true);
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if ord != Ordering::Equal {
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return ord;
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}
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}
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a.len().cmp(&b.len())
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}
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(&Glob, &Simple(_)) | (&Nested(_), _) => Ordering::Greater,
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}
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}
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fn compare_use_items(a: &ast::Item, b: &ast::Item) -> Ordering {
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match (&a.node, &b.node) {
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(&ast::ItemKind::Mod(..), &ast::ItemKind::Mod(..)) => {
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a.ident.name.as_str().cmp(&b.ident.name.as_str())
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}
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(&ast::ItemKind::Use(ref a_tree), &ast::ItemKind::Use(ref b_tree)) => {
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compare_use_trees(a_tree, b_tree, false)
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}
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(&ast::ItemKind::ExternCrate(ref a_name), &ast::ItemKind::ExternCrate(ref b_name)) => {
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// `extern crate foo as bar;`
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// ^^^ Comparing this.
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let a_orig_name =
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a_name.map_or_else(|| a.ident.name.as_str(), |symbol| symbol.as_str());
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let b_orig_name =
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b_name.map_or_else(|| b.ident.name.as_str(), |symbol| symbol.as_str());
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let result = a_orig_name.cmp(&b_orig_name);
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if result != Ordering::Equal {
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return result;
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}
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// `extern crate foo as bar;`
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// ^^^ Comparing this.
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match (a_name, b_name) {
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(Some(..), None) => Ordering::Greater,
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(None, Some(..)) => Ordering::Less,
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(None, None) => Ordering::Equal,
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(Some(..), Some(..)) => a.ident.name.as_str().cmp(&b.ident.name.as_str()),
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}
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}
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_ => unreachable!(),
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}
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}
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// TODO (some day) remove unused imports, expand globs, compress many single
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// imports into a list import.
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fn rewrite_prefix(path: &ast::Path, context: &RewriteContext, shape: Shape) -> Option<String> {
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if path.segments.len() > 1 && path_to_imported_ident(path).to_string() == "self" {
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let path = &ast::Path {
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span: path.span,
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segments: path.segments[..path.segments.len() - 1].to_owned(),
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};
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rewrite_path(context, PathContext::Import, None, path, shape)
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} else {
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rewrite_path(context, PathContext::Import, None, path, shape)
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}
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}
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impl Rewrite for ast::UseTree {
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fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
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match self.kind {
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ast::UseTreeKind::Nested(ref items) => {
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rewrite_nested_use_tree(shape, &self.prefix, items, self.span, context)
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}
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ast::UseTreeKind::Glob => {
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let prefix_shape = shape.sub_width(3)?;
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if !self.prefix.segments.is_empty() {
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let path_str = rewrite_prefix(&self.prefix, context, prefix_shape)?;
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Some(format!("{}::*", path_str))
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} else {
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Some("*".to_owned())
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}
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}
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ast::UseTreeKind::Simple(ident) => {
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let ident_str = ident.to_string();
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// 4 = " as ".len()
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let is_same_name_bind = path_to_imported_ident(&self.prefix) == ident;
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let prefix_shape = if is_same_name_bind {
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shape
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} else {
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shape.sub_width(ident_str.len() + 4)?
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};
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let path_str = rewrite_prefix(&self.prefix, context, prefix_shape)
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.unwrap_or_else(|| context.snippet(self.prefix.span).to_owned());
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if is_same_name_bind {
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Some(path_str)
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} else {
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Some(format!("{} as {}", path_str, ident_str))
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}
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}
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}
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}
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}
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fn is_unused_import(tree: &ast::UseTree, attrs: &[ast::Attribute]) -> bool {
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attrs.is_empty() && is_unused_import_inner(tree)
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}
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fn is_unused_import_inner(tree: &ast::UseTree) -> bool {
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match tree.kind {
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ast::UseTreeKind::Nested(ref items) => match items.len() {
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0 => true,
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1 => is_unused_import_inner(&items[0].0),
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_ => false,
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},
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_ => false,
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}
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}
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// Rewrite `use foo;` WITHOUT attributes.
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fn rewrite_import(
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context: &RewriteContext,
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vis: &ast::Visibility,
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tree: &ast::UseTree,
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attrs: &[ast::Attribute],
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shape: Shape,
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) -> Option<String> {
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let vis = format_visibility(vis);
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// 4 = `use `, 1 = `;`
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let rw = shape
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.offset_left(vis.len() + 4)
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.and_then(|shape| shape.sub_width(1))
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.and_then(|shape| {
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// If we have an empty nested group with no attributes, we erase it
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if is_unused_import(tree, attrs) {
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Some("".to_owned())
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} else {
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tree.rewrite(context, shape)
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}
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});
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match rw {
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Some(ref s) if !s.is_empty() => Some(format!("{}use {};", vis, s)),
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_ => rw,
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}
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}
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/// Rewrite an inline mod.
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fn rewrite_mod(item: &ast::Item) -> String {
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let mut result = String::with_capacity(32);
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result.push_str(&*format_visibility(&item.vis));
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result.push_str("mod ");
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result.push_str(&item.ident.to_string());
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result.push(';');
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result
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}
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fn rewrite_imports(
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context: &RewriteContext,
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use_items: &[&ast::Item],
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shape: Shape,
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span: Span,
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) -> Option<String> {
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let items = itemize_list(
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context.codemap,
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use_items.iter(),
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"",
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";",
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|item| item.span().lo(),
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|item| item.span().hi(),
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|item| {
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let attrs = ::visitor::filter_inline_attrs(&item.attrs, item.span());
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let attrs_str = attrs.rewrite(context, shape)?;
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let missed_span = if attrs.is_empty() {
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mk_sp(item.span.lo(), item.span.lo())
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} else {
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mk_sp(attrs.last().unwrap().span.hi(), item.span.lo())
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};
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let item_str = match item.node {
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ast::ItemKind::Use(ref tree) => {
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rewrite_import(context, &item.vis, tree, &item.attrs, shape)?
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}
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ast::ItemKind::ExternCrate(..) => rewrite_extern_crate(context, item)?,
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ast::ItemKind::Mod(..) => rewrite_mod(item),
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_ => return None,
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};
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combine_strs_with_missing_comments(
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context,
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&attrs_str,
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&item_str,
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missed_span,
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shape,
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false,
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)
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},
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span.lo(),
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span.hi(),
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false,
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);
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let mut item_pair_vec: Vec<_> = items.zip(use_items.iter()).collect();
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item_pair_vec.sort_by(|a, b| compare_use_items(a.1, b.1));
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let item_vec: Vec<_> = item_pair_vec.into_iter().map(|pair| pair.0).collect();
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let fmt = ListFormatting {
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tactic: DefinitiveListTactic::Vertical,
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separator: "",
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trailing_separator: SeparatorTactic::Never,
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separator_place: SeparatorPlace::Back,
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shape,
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ends_with_newline: true,
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preserve_newline: false,
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config: context.config,
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};
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write_list(&item_vec, &fmt)
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}
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impl<'a> FmtVisitor<'a> {
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pub fn format_imports(&mut self, use_items: &[&ast::Item]) {
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if use_items.is_empty() {
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return;
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}
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let lo = use_items.first().unwrap().span().lo();
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let hi = use_items.last().unwrap().span().hi();
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let span = mk_sp(lo, hi);
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let rw = rewrite_imports(&self.get_context(), use_items, self.shape(), span);
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self.push_rewrite(span, rw);
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}
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pub fn format_import(&mut self, item: &ast::Item, tree: &ast::UseTree) {
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let span = item.span;
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let shape = self.shape();
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let rw = rewrite_import(&self.get_context(), &item.vis, tree, &item.attrs, shape);
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match rw {
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Some(ref s) if s.is_empty() => {
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// Format up to last newline
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let prev_span = mk_sp(self.last_pos, source!(self, span).lo());
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let trimmed_snippet = self.snippet(prev_span).trim_right();
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let span_end = self.last_pos + BytePos(trimmed_snippet.len() as u32);
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self.format_missing(span_end);
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// We have an excessive newline from the removed import.
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if self.buffer.ends_with('\n') {
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self.buffer.pop();
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self.line_number -= 1;
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}
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self.last_pos = source!(self, span).hi();
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}
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Some(ref s) => {
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self.format_missing_with_indent(source!(self, span).lo());
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self.push_str(s);
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self.last_pos = source!(self, span).hi();
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}
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None => {
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self.format_missing_with_indent(source!(self, span).lo());
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self.format_missing(source!(self, span).hi());
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}
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}
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}
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}
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fn rewrite_nested_use_tree_single(
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context: &RewriteContext,
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path_str: &str,
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tree: &ast::UseTree,
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shape: Shape,
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) -> Option<String> {
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match tree.kind {
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ast::UseTreeKind::Simple(rename) => {
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let ident = path_to_imported_ident(&tree.prefix);
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let mut item_str = rewrite_prefix(&tree.prefix, context, shape)?;
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if item_str == "self" {
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item_str = "".to_owned();
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}
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let path_item_str = if path_str.is_empty() {
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if item_str.is_empty() {
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"self".to_owned()
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} else {
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item_str
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}
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} else if item_str.is_empty() {
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path_str.to_owned()
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} else {
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format!("{}::{}", path_str, item_str)
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};
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Some(if ident == rename {
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path_item_str
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} else {
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format!("{} as {}", path_item_str, rename)
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})
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}
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ast::UseTreeKind::Glob | ast::UseTreeKind::Nested(..) => {
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// 2 = "::"
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let nested_shape = shape.offset_left(path_str.len() + 2)?;
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tree.rewrite(context, nested_shape)
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.map(|item| format!("{}::{}", path_str, item))
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}
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}
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}
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#[derive(Eq, PartialEq)]
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enum ImportItem<'a> {
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// `self` or `self as a`
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SelfImport(&'a str),
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// name_one, name_two, ...
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SnakeCase(&'a str),
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// NameOne, NameTwo, ...
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CamelCase(&'a str),
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// NAME_ONE, NAME_TWO, ...
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AllCaps(&'a str),
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// Failed to format the import item
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Invalid,
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}
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impl<'a> ImportItem<'a> {
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fn from_str(s: &str) -> ImportItem {
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if s == "self" || s.starts_with("self as") {
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ImportItem::SelfImport(s)
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} else if s.chars().all(|c| c.is_lowercase() || c == '_' || c == ' ') {
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ImportItem::SnakeCase(s)
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} else if s.chars().all(|c| c.is_uppercase() || c == '_' || c == ' ') {
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ImportItem::AllCaps(s)
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} else {
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ImportItem::CamelCase(s)
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}
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}
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fn from_opt_str(s: Option<&String>) -> ImportItem {
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s.map_or(ImportItem::Invalid, |s| ImportItem::from_str(s))
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}
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fn to_str(&self) -> Option<&str> {
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match *self {
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ImportItem::SelfImport(s)
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| ImportItem::SnakeCase(s)
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| ImportItem::CamelCase(s)
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| ImportItem::AllCaps(s) => Some(s),
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ImportItem::Invalid => None,
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}
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}
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fn to_u32(&self) -> u32 {
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match *self {
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ImportItem::SelfImport(..) => 0,
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ImportItem::SnakeCase(..) => 1,
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ImportItem::CamelCase(..) => 2,
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ImportItem::AllCaps(..) => 3,
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ImportItem::Invalid => 4,
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}
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}
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}
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impl<'a> PartialOrd for ImportItem<'a> {
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fn partial_cmp(&self, other: &ImportItem<'a>) -> Option<Ordering> {
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Some(self.cmp(other))
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}
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}
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impl<'a> Ord for ImportItem<'a> {
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fn cmp(&self, other: &ImportItem<'a>) -> Ordering {
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let res = self.to_u32().cmp(&other.to_u32());
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if res != Ordering::Equal {
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return res;
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}
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self.to_str().map_or(Ordering::Greater, |self_str| {
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other
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.to_str()
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.map_or(Ordering::Less, |other_str| self_str.cmp(other_str))
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})
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}
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}
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// Pretty prints a multi-item import.
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// If the path list is empty, it leaves the braces empty.
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fn rewrite_nested_use_tree(
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shape: Shape,
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path: &ast::Path,
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trees: &[(ast::UseTree, ast::NodeId)],
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span: Span,
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context: &RewriteContext,
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) -> Option<String> {
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// Returns a different option to distinguish `::foo` and `foo`
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let path_str = rewrite_path(context, PathContext::Import, None, path, shape)?;
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match trees.len() {
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0 => {
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let shape = shape.offset_left(path_str.len() + 3)?;
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return rewrite_path(context, PathContext::Import, None, path, shape)
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.map(|path_str| format!("{}::{{}}", path_str));
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}
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1 => {
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return rewrite_nested_use_tree_single(context, &path_str, &trees[0].0, shape);
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}
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_ => (),
|
|
}
|
|
|
|
let path_str = if path_str.is_empty() {
|
|
path_str
|
|
} else {
|
|
format!("{}::", path_str)
|
|
};
|
|
|
|
// 2 = "{}"
|
|
let remaining_width = shape.width.checked_sub(path_str.len() + 2).unwrap_or(0);
|
|
let nested_indent = match context.config.imports_indent() {
|
|
IndentStyle::Block => shape.indent.block_indent(context.config),
|
|
// 1 = `{`
|
|
IndentStyle::Visual => shape.visual_indent(path_str.len() + 1).indent,
|
|
};
|
|
|
|
let nested_shape = match context.config.imports_indent() {
|
|
IndentStyle::Block => Shape::indented(nested_indent, context.config).sub_width(1)?,
|
|
IndentStyle::Visual => Shape::legacy(remaining_width, nested_indent),
|
|
};
|
|
|
|
let mut items = {
|
|
// Dummy value, see explanation below.
|
|
let mut items = vec![ListItem::from_str("")];
|
|
let iter = itemize_list(
|
|
context.codemap,
|
|
trees.iter().map(|tree| &tree.0),
|
|
"}",
|
|
",",
|
|
|tree| tree.span.lo(),
|
|
|tree| tree.span.hi(),
|
|
|tree| tree.rewrite(context, nested_shape),
|
|
context.codemap.span_after(span, "{"),
|
|
span.hi(),
|
|
false,
|
|
);
|
|
items.extend(iter);
|
|
items
|
|
};
|
|
|
|
// We prefixed the item list with a dummy value so that we can
|
|
// potentially move "self" to the front of the vector without touching
|
|
// the rest of the items.
|
|
let has_self = move_self_to_front(&mut items);
|
|
let first_index = if has_self { 0 } else { 1 };
|
|
|
|
if context.config.reorder_imported_names() {
|
|
items[1..].sort_by(|a, b| {
|
|
let a = ImportItem::from_opt_str(a.item.as_ref());
|
|
let b = ImportItem::from_opt_str(b.item.as_ref());
|
|
a.cmp(&b)
|
|
});
|
|
}
|
|
|
|
let tactic = definitive_tactic(
|
|
&items[first_index..],
|
|
context.config.imports_layout(),
|
|
Separator::Comma,
|
|
remaining_width,
|
|
);
|
|
|
|
let ends_with_newline = context.config.imports_indent() == IndentStyle::Block
|
|
&& tactic != DefinitiveListTactic::Horizontal;
|
|
|
|
let fmt = ListFormatting {
|
|
tactic,
|
|
separator: ",",
|
|
trailing_separator: if ends_with_newline {
|
|
context.config.trailing_comma()
|
|
} else {
|
|
SeparatorTactic::Never
|
|
},
|
|
separator_place: SeparatorPlace::Back,
|
|
shape: nested_shape,
|
|
ends_with_newline,
|
|
preserve_newline: true,
|
|
config: context.config,
|
|
};
|
|
let list_str = write_list(&items[first_index..], &fmt)?;
|
|
|
|
let result = if list_str.contains('\n') && context.config.imports_indent() == IndentStyle::Block
|
|
{
|
|
format!(
|
|
"{}{{\n{}{}\n{}}}",
|
|
path_str,
|
|
nested_shape.indent.to_string(context.config),
|
|
list_str,
|
|
shape.indent.to_string(context.config)
|
|
)
|
|
} else {
|
|
format!("{}{{{}}}", path_str, list_str)
|
|
};
|
|
Some(result)
|
|
}
|
|
|
|
// Returns true when self item was found.
|
|
fn move_self_to_front(items: &mut Vec<ListItem>) -> bool {
|
|
match items
|
|
.iter()
|
|
.position(|item| item.item.as_ref().map(|x| &x[..]) == Some("self"))
|
|
{
|
|
Some(pos) => {
|
|
items[0] = items.remove(pos);
|
|
true
|
|
}
|
|
None => false,
|
|
}
|
|
}
|
|
|
|
fn path_to_imported_ident(path: &ast::Path) -> ast::Ident {
|
|
path.segments.last().unwrap().identifier
|
|
}
|