-
Notifications
You must be signed in to change notification settings - Fork 56
/
lists-elided.rs
355 lines (313 loc) · 9.78 KB
/
lists-elided.rs
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
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
// 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 std::cmp;
use std::iter::Peekable;
use syntax::codemap::{self, CodeMap, BytePos};
use Indent;
use comment::{FindUncommented, rewrite_comment, find_comment_end};
use config::Config;
/// Formatting tactic for lists. This will be cast down to a
/// DefinitiveListTactic depending on the number and length of the items and
/// their comments.
#[derive(Eq, PartialEq, Debug, Copy, Clone)]
pub enum ListTactic {
// One item per row.
Vertical,
// All items on one row.
Horizontal,
// Try Horizontal layout, if that fails then vertical.
HorizontalVertical,
// HorizontalVertical with a soft limit of n characters.
LimitedHorizontalVertical(usize),
// Pack as many items as possible per row over (possibly) many rows.
Mixed,
}
impl_enum_decodable!(ListTactic, Vertical, Horizontal, HorizontalVertical, Mixed);
#[derive(Eq, PartialEq, Debug, Copy, Clone)]
pub enum SeparatorTactic {
Always,
Never,
Vertical,
}
impl_enum_decodable!(SeparatorTactic, Always, Never, Vertical);
impl SeparatorTactic {
pub fn from_bool(b: bool) -> SeparatorTactic {
if b {
SeparatorTactic::Always
} else {
SeparatorTactic::Never
}
}
}
pub struct ListFormatting<'a> {
pub tactic: DefinitiveListTactic,
pub separator: &'a str,
pub trailing_separator: SeparatorTactic,
pub indent: Indent,
pub width: usize,
// Non-expressions, e.g. items, will have a new line at the end of the list.
// Important for comment styles.
pub ends_with_newline: bool,
pub config: &'a Config,
}
pub fn format_fn_args<I>(items: I, width: usize, offset: Indent, config: &Config) -> Option<String>
where
I: Iterator<Item = ListItem>,
{
// ...
}
pub fn format_item_list<I>(
items: I,
width: usize,
offset: Indent,
config: &Config,
) -> Option<String>
where
I: Iterator<Item = ListItem>,
{
list_helper(items, width, offset, config, ListTactic::HorizontalVertical)
}
pub fn list_helper<I>(
items: I,
width: usize,
offset: Indent,
config: &Config,
tactic: ListTactic,
) -> Option<String>
where
I: Iterator<Item = ListItem>,
{
let item_vec: Vec<_> = items.collect();
let tactic = definitive_tactic(&item_vec, tactic, width);
let fmt = ListFormatting {
tactic: tactic,
separator: ",",
trailing_separator: SeparatorTactic::Never,
indent: offset,
width: width,
ends_with_newline: false,
config: config,
};
write_list(&item_vec, &fmt)
}
impl AsRef<ListItem> for ListItem {
fn as_ref(&self) -> &ListItem {
self
}
}
pub struct ListItem {
// None for comments mean that they are not present.
pub pre_comment: Option<String>,
// Item should include attributes and doc comments. None indicates a failed
// rewrite.
pub item: Option<String>,
pub post_comment: Option<String>,
// Whether there is extra whitespace before this item.
pub new_lines: bool,
}
impl ListItem {
pub fn is_multiline(&self) -> bool {
// ...
}
pub fn has_line_pre_comment(&self) -> bool {
self.pre_comment.as_ref().map_or(false, |comment| comment.starts_with("//"))
}
pub fn from_str<S: Into<String>>(s: S) -> ListItem {
ListItem {
pre_comment: None,
item: Some(s.into()),
post_comment: None,
new_lines: false,
}
}
}
#[derive(Eq, PartialEq, Debug, Copy, Clone)]
/// The definitive formatting tactic for lists.
pub enum DefinitiveListTactic {
Vertical,
Horizontal,
Mixed,
}
pub fn definitive_tactic<I, T>(items: I, tactic: ListTactic, width: usize) -> DefinitiveListTactic
where
I: IntoIterator<Item = T> + Clone,
T: AsRef<ListItem>,
{
let pre_line_comments =
items.clone().into_iter().any(|item| item.as_ref().has_line_pre_comment());
let limit = match tactic {
_ if pre_line_comments => return DefinitiveListTactic::Vertical,
ListTactic::Mixed => return DefinitiveListTactic::Mixed,
ListTactic::Horizontal => return DefinitiveListTactic::Horizontal,
ListTactic::Vertical => return DefinitiveListTactic::Vertical,
ListTactic::LimitedHorizontalVertical(limit) => ::std::cmp::min(width, limit),
ListTactic::HorizontalVertical => width,
};
let (sep_count, total_width) = calculate_width(items.clone());
let sep_len = ", ".len(); // FIXME: make more generic?
let total_sep_len = sep_len * sep_count.checked_sub(1).unwrap_or(0);
let real_total = total_width + total_sep_len;
}
// Format a list of commented items into a string.
// TODO: add unit tests
pub fn write_list<I, T>(items: I, formatting: &ListFormatting) -> Option<String>
where
I: IntoIterator<Item = T>,
T: AsRef<ListItem>,
{
let tactic = formatting.tactic;
let sep_len = formatting.separator.len();
// Now that we know how we will layout, we can decide for sure if there
// will be a trailing separator.
let trailing_separator = needs_trailing_separator(formatting.trailing_separator, tactic);
let mut result = String::new();
let mut iter = items.into_iter().enumerate().peekable();
let mut line_len = 0;
let indent_str = &formatting.indent.to_string(formatting.config);
while let Some((i, item)) = iter.next() {
let item = item.as_ref();
let inner_item = try_opt!(item.item.as_ref());
let first = i == 0;
let last = iter.peek().is_none();
let separate = !last || trailing_separator;
let item_sep_len = if separate { sep_len } else { 0 };
// Item string may be multi-line. Its length (used for block comment alignment)
// Should be only the length of the last line.
let item_last_line = if item.is_multiline() {
inner_item.lines().last().unwrap_or("")
} else {
inner_item.as_ref()
};
let mut item_last_line_width = item_last_line.len() + item_sep_len;
if item_last_line.starts_with(indent_str) {
item_last_line_width -= indent_str.len();
}
match tactic {
DefinitiveListTactic::Horizontal if !first => {
result.push(' ');
}
DefinitiveListTactic::Vertical if !first => {
result.push('\n');
result.push_str(indent_str);
}
DefinitiveListTactic::Mixed => {
let total_width = total_item_width(item) + item_sep_len;
// 1 is space between separator and item.
if line_len > 0 && line_len + 1 + total_width > formatting.width {
result.push('\n');
result.push_str(indent_str);
line_len = 0;
}
if line_len > 0 {
result.push(' ');
line_len += 1;
}
line_len += total_width;
}
_ => {}
}
result.push_str(&inner_item[..]);
if separate {
result.push_str(formatting.separator);
}
if !last && tactic == DefinitiveListTactic::Vertical && item.new_lines {
result.push('\n');
}
}
Some(result)
}
pub struct ListItems<'a, I, F1, F2, F3>
where
I: Iterator,
{
codemap: &'a CodeMap,
inner: Peekable<I>,
get_lo: F1,
get_hi: F2,
get_item_string: F3,
prev_span_end: BytePos,
next_span_start: BytePos,
terminator: &'a str,
}
impl<'a, T, I, F1, F2, F3> Iterator for ListItems<'a, I, F1, F2, F3>
where
I: Iterator<Item = T>,
F1: Fn(&T) -> BytePos,
F2: Fn(&T) -> BytePos,
F3: Fn(&T) -> Option<String>,
{
type Item = ListItem;
fn next(&mut self) -> Option<Self::Item> {
// ...
}
}
// Creates an iterator over a list's items with associated comments.
pub fn itemize_list<'a, T, I, F1, F2, F3>(
codemap: &'a CodeMap,
inner: I,
terminator: &'a str,
get_lo: F1,
get_hi: F2,
get_item_string: F3,
prev_span_end: BytePos,
next_span_start: BytePos,
) -> ListItems<'a, I, F1, F2, F3>
where
I: Iterator<Item = T>,
F1: Fn(&T) -> BytePos,
F2: Fn(&T) -> BytePos,
F3: Fn(&T) -> Option<String>,
{
ListItems {
codemap: codemap,
inner: inner.peekable(),
get_lo: get_lo,
get_hi: get_hi,
get_item_string: get_item_string,
prev_span_end: prev_span_end,
next_span_start: next_span_start,
terminator: terminator,
}
}
fn needs_trailing_separator(
separator_tactic: SeparatorTactic,
list_tactic: DefinitiveListTactic,
) -> bool {
match separator_tactic {
SeparatorTactic::Always => true,
SeparatorTactic::Vertical => list_tactic == DefinitiveListTactic::Vertical,
SeparatorTactic::Never => false,
}
}
/// Returns the count and total width of the list items.
fn calculate_width<I, T>(items: I) -> (usize, usize)
where
I: IntoIterator<Item = T>,
T: AsRef<ListItem>,
{
// ...
}
fn total_item_width(item: &ListItem) -> usize {
// ...
}
fn comment_len(comment: Option<&str>) -> usize {
match comment {
Some(s) => {
let text_len = s.trim().len();
if text_len > 0 {
// We'll put " /*" before and " */" after inline comments.
text_len + 6
} else {
text_len
}
}
None => 0,
}
}