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
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
|
use rustc_ast::ptr::P;
use rustc_ast::Expr;
use rustc_data_structures::fx::FxHashMap;
use rustc_span::symbol::{Ident, Symbol};
use rustc_span::Span;
// Definitions:
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └──────────────────────────────────────────────┘
// FormatArgs
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └─────────┘
// argument
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └───────────────────┘
// template
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └────┘└─────────┘└┘
// pieces
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └────┘ └┘
// literal pieces
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └─────────┘
// placeholder
//
// format_args!("hello {abc:.xyz$}!!", abc="world");
// └─┘ └─┘
// positions (could be names, numbers, empty, or `*`)
/// (Parsed) format args.
///
/// Basically the "AST" for a complete `format_args!()`.
///
/// E.g., `format_args!("hello {name}");`.
#[derive(Clone, Debug)]
pub struct FormatArgs {
pub span: Span,
pub template: Vec<FormatArgsPiece>,
pub arguments: FormatArguments,
}
/// A piece of a format template string.
///
/// E.g. "hello" or "{name}".
#[derive(Clone, Debug)]
pub enum FormatArgsPiece {
Literal(Symbol),
Placeholder(FormatPlaceholder),
}
/// The arguments to format_args!().
///
/// E.g. `1, 2, name="ferris", n=3`,
/// but also implicit captured arguments like `x` in `format_args!("{x}")`.
#[derive(Clone, Debug)]
pub struct FormatArguments {
arguments: Vec<FormatArgument>,
num_unnamed_args: usize,
num_explicit_args: usize,
names: FxHashMap<Symbol, usize>,
}
impl FormatArguments {
pub fn new() -> Self {
Self {
arguments: Vec::new(),
names: FxHashMap::default(),
num_unnamed_args: 0,
num_explicit_args: 0,
}
}
pub fn add(&mut self, arg: FormatArgument) -> usize {
let index = self.arguments.len();
if let Some(name) = arg.kind.ident() {
self.names.insert(name.name, index);
} else if self.names.is_empty() {
// Only count the unnamed args before the first named arg.
// (Any later ones are errors.)
self.num_unnamed_args += 1;
}
if !matches!(arg.kind, FormatArgumentKind::Captured(..)) {
// This is an explicit argument.
// Make sure that all arguments so far are explcit.
assert_eq!(
self.num_explicit_args,
self.arguments.len(),
"captured arguments must be added last"
);
self.num_explicit_args += 1;
}
self.arguments.push(arg);
index
}
pub fn by_name(&self, name: Symbol) -> Option<(usize, &FormatArgument)> {
let i = *self.names.get(&name)?;
Some((i, &self.arguments[i]))
}
pub fn by_index(&self, i: usize) -> Option<&FormatArgument> {
(i < self.num_explicit_args).then(|| &self.arguments[i])
}
pub fn unnamed_args(&self) -> &[FormatArgument] {
&self.arguments[..self.num_unnamed_args]
}
pub fn named_args(&self) -> &[FormatArgument] {
&self.arguments[self.num_unnamed_args..self.num_explicit_args]
}
pub fn explicit_args(&self) -> &[FormatArgument] {
&self.arguments[..self.num_explicit_args]
}
pub fn into_vec(self) -> Vec<FormatArgument> {
self.arguments
}
}
#[derive(Clone, Debug)]
pub struct FormatArgument {
pub kind: FormatArgumentKind,
pub expr: P<Expr>,
}
#[derive(Clone, Debug)]
pub enum FormatArgumentKind {
/// `format_args(…, arg)`
Normal,
/// `format_args(…, arg = 1)`
Named(Ident),
/// `format_args("… {arg} …")`
Captured(Ident),
}
impl FormatArgumentKind {
pub fn ident(&self) -> Option<Ident> {
match self {
&Self::Normal => None,
&Self::Named(id) => Some(id),
&Self::Captured(id) => Some(id),
}
}
}
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct FormatPlaceholder {
/// Index into [`FormatArgs::arguments`].
pub argument: FormatArgPosition,
/// The span inside the format string for the full `{…}` placeholder.
pub span: Option<Span>,
/// `{}`, `{:?}`, or `{:x}`, etc.
pub format_trait: FormatTrait,
/// `{}` or `{:.5}` or `{:-^20}`, etc.
pub format_options: FormatOptions,
}
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct FormatArgPosition {
/// Which argument this position refers to (Ok),
/// or would've referred to if it existed (Err).
pub index: Result<usize, usize>,
/// What kind of position this is. See [`FormatArgPositionKind`].
pub kind: FormatArgPositionKind,
/// The span of the name or number.
pub span: Option<Span>,
}
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub enum FormatArgPositionKind {
/// `{}` or `{:.*}`
Implicit,
/// `{1}` or `{:1$}` or `{:.1$}`
Number,
/// `{a}` or `{:a$}` or `{:.a$}`
Named,
}
#[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
pub enum FormatTrait {
/// `{}`
Display,
/// `{:?}`
Debug,
/// `{:e}`
LowerExp,
/// `{:E}`
UpperExp,
/// `{:o}`
Octal,
/// `{:p}`
Pointer,
/// `{:b}`
Binary,
/// `{:x}`
LowerHex,
/// `{:X}`
UpperHex,
}
#[derive(Clone, Debug, Default, PartialEq, Eq)]
pub struct FormatOptions {
/// The width. E.g. `{:5}` or `{:width$}`.
pub width: Option<FormatCount>,
/// The precision. E.g. `{:.5}` or `{:.precision$}`.
pub precision: Option<FormatCount>,
/// The alignment. E.g. `{:>}` or `{:<}` or `{:^}`.
pub alignment: Option<FormatAlignment>,
/// The fill character. E.g. the `.` in `{:.>10}`.
pub fill: Option<char>,
/// The `+`, `-`, `0`, `#`, `x?` and `X?` flags.
pub flags: u32,
}
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum FormatAlignment {
/// `{:<}`
Left,
/// `{:>}`
Right,
/// `{:^}`
Center,
}
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum FormatCount {
/// `{:5}` or `{:.5}`
Literal(usize),
/// `{:.*}`, `{:.5$}`, or `{:a$}`, etc.
Argument(FormatArgPosition),
}
|
