1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
use ra_syntax::{ast, AstNode, TextRange};
use crate::{Name, AsName};
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct Path {
pub kind: PathKind,
pub segments: Vec<Name>,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum PathKind {
Plain,
Self_,
Super,
Crate,
}
impl Path {
/// Calls `cb` with all paths, represented by this use item.
pub fn expand_use_item(item: &ast::UseItem, mut cb: impl FnMut(Path, Option<TextRange>)) {
if let Some(tree) = item.use_tree() {
expand_use_tree(None, tree, &mut cb);
}
}
/// Converts an `ast::Path` to `Path`. Works with use trees.
pub fn from_ast(mut path: &ast::Path) -> Option<Path> {
let mut kind = PathKind::Plain;
let mut segments = Vec::new();
loop {
let segment = path.segment()?;
match segment.kind()? {
ast::PathSegmentKind::Name(name) => segments.push(name.as_name()),
ast::PathSegmentKind::CrateKw => {
kind = PathKind::Crate;
break;
}
ast::PathSegmentKind::SelfKw => {
kind = PathKind::Self_;
break;
}
ast::PathSegmentKind::SuperKw => {
kind = PathKind::Super;
break;
}
}
path = match qualifier(path) {
Some(it) => it,
None => break,
};
}
segments.reverse();
return Some(Path { kind, segments });
fn qualifier(path: &ast::Path) -> Option<&ast::Path> {
if let Some(q) = path.qualifier() {
return Some(q);
}
// TODO: this bottom up traversal is not too precise.
// Should we handle do a top-down analysiss, recording results?
let use_tree_list = path.syntax().ancestors().find_map(ast::UseTreeList::cast)?;
let use_tree = use_tree_list.parent_use_tree();
use_tree.path()
}
}
/// Converts an `ast::NameRef` into a single-identifier `Path`.
pub fn from_name_ref(name_ref: &ast::NameRef) -> Path {
name_ref.as_name().into()
}
/// `true` is this path is a single identifier, like `foo`
pub fn is_ident(&self) -> bool {
self.kind == PathKind::Plain && self.segments.len() == 1
}
/// `true` if this path is just a standalone `self`
pub fn is_self(&self) -> bool {
self.kind == PathKind::Self_ && self.segments.len() == 0
}
/// If this path is a single identifier, like `foo`, return its name.
pub fn as_ident(&self) -> Option<&Name> {
if self.kind != PathKind::Plain || self.segments.len() > 1 {
return None;
}
self.segments.first()
}
}
impl From<Name> for Path {
fn from(name: Name) -> Path {
Path {
kind: PathKind::Plain,
segments: vec![name],
}
}
}
fn expand_use_tree(
prefix: Option<Path>,
tree: &ast::UseTree,
cb: &mut impl FnMut(Path, Option<TextRange>),
) {
if let Some(use_tree_list) = tree.use_tree_list() {
let prefix = match tree.path() {
// E.g. use something::{{{inner}}};
None => prefix,
// E.g. `use something::{inner}` (prefix is `None`, path is `something`)
// or `use something::{path::{inner::{innerer}}}` (prefix is `something::path`, path is `inner`)
Some(path) => match convert_path(prefix, path) {
Some(it) => Some(it),
None => return, // TODO: report errors somewhere
},
};
for child_tree in use_tree_list.use_trees() {
expand_use_tree(prefix.clone(), child_tree, cb);
}
} else {
if let Some(ast_path) = tree.path() {
// Handle self in a path.
// E.g. `use something::{self, <...>}`
if ast_path.qualifier().is_none() {
if let Some(segment) = ast_path.segment() {
if segment.kind() == Some(ast::PathSegmentKind::SelfKw) {
if let Some(prefix) = prefix {
cb(prefix, Some(segment.syntax().range()));
return;
}
}
}
}
if let Some(path) = convert_path(prefix, ast_path) {
let range = if tree.has_star() {
None
} else {
let range = ast_path.segment().unwrap().syntax().range();
Some(range)
};
cb(path, range)
}
// TODO: report errors somewhere
// We get here if we do
}
}
}
fn convert_path(prefix: Option<Path>, path: &ast::Path) -> Option<Path> {
let prefix = if let Some(qual) = path.qualifier() {
Some(convert_path(prefix, qual)?)
} else {
prefix
};
let segment = path.segment()?;
let res = match segment.kind()? {
ast::PathSegmentKind::Name(name) => {
let mut res = prefix.unwrap_or_else(|| Path {
kind: PathKind::Plain,
segments: Vec::with_capacity(1),
});
res.segments.push(name.as_name());
res
}
ast::PathSegmentKind::CrateKw => {
if prefix.is_some() {
return None;
}
Path {
kind: PathKind::Crate,
segments: Vec::new(),
}
}
ast::PathSegmentKind::SelfKw => {
if prefix.is_some() {
return None;
}
Path {
kind: PathKind::Self_,
segments: Vec::new(),
}
}
ast::PathSegmentKind::SuperKw => {
if prefix.is_some() {
return None;
}
Path {
kind: PathKind::Super,
segments: Vec::new(),
}
}
};
Some(res)
}
|
