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
356
357
358
359
360
361
362
363
364
365
366
367
// Copyright 2012 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 fmt;

/// An unbounded range. Use `..` (two dots) for its shorthand.
///
/// Its primary use case is slicing index. It cannot serve as an iterator
/// because it doesn't have a starting point.
///
/// # Examples
///
/// The `..` syntax is a `RangeFull`:
///
/// ```
/// assert_eq!((..), std::ops::RangeFull);
/// ```
///
/// It does not have an `IntoIterator` implementation, so you can't use it in a
/// `for` loop directly. This won't compile:
///
/// ```compile_fail,E0277
/// for i in .. {
///    // ...
/// }
/// ```
///
/// Used as a slicing index, `RangeFull` produces the full array as a slice.
///
/// ```
/// let arr = [0, 1, 2, 3];
/// assert_eq!(arr[ .. ], [0,1,2,3]);  // RangeFull
/// assert_eq!(arr[ ..3], [0,1,2  ]);
/// assert_eq!(arr[1.. ], [  1,2,3]);
/// assert_eq!(arr[1..3], [  1,2  ]);
/// ```
#[derive(Copy, Clone, PartialEq, Eq, Hash)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct RangeFull;

#[stable(feature = "rust1", since = "1.0.0")]
impl fmt::Debug for RangeFull {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        write!(fmt, "..")
    }
}

/// A (half-open) range which is bounded at both ends: { x | start <= x < end }.
/// Use `start..end` (two dots) for its shorthand.
///
/// See the [`contains`](#method.contains) method for its characterization.
///
/// # Examples
///
/// ```
/// fn main() {
///     assert_eq!((3..5), std::ops::Range{ start: 3, end: 5 });
///     assert_eq!(3+4+5, (3..6).sum());
///
///     let arr = [0, 1, 2, 3];
///     assert_eq!(arr[ .. ], [0,1,2,3]);
///     assert_eq!(arr[ ..3], [0,1,2  ]);
///     assert_eq!(arr[1.. ], [  1,2,3]);
///     assert_eq!(arr[1..3], [  1,2  ]);  // Range
/// }
/// ```
#[derive(Clone, PartialEq, Eq, Hash)]  // not Copy -- see #27186
#[stable(feature = "rust1", since = "1.0.0")]
pub struct Range<Idx> {
    /// The lower bound of the range (inclusive).
    #[stable(feature = "rust1", since = "1.0.0")]
    pub start: Idx,
    /// The upper bound of the range (exclusive).
    #[stable(feature = "rust1", since = "1.0.0")]
    pub end: Idx,
}

#[stable(feature = "rust1", since = "1.0.0")]
impl<Idx: fmt::Debug> fmt::Debug for Range<Idx> {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        write!(fmt, "{:?}..{:?}", self.start, self.end)
    }
}

#[unstable(feature = "range_contains", reason = "recently added as per RFC", issue = "32311")]
impl<Idx: PartialOrd<Idx>> Range<Idx> {
    /// # Examples
    ///
    /// ```
    /// #![feature(range_contains)]
    /// fn main() {
    ///     assert!( ! (3..5).contains(2));
    ///     assert!(   (3..5).contains(3));
    ///     assert!(   (3..5).contains(4));
    ///     assert!( ! (3..5).contains(5));
    ///
    ///     assert!( ! (3..3).contains(3));
    ///     assert!( ! (3..2).contains(3));
    /// }
    /// ```
    pub fn contains(&self, item: Idx) -> bool {
        (self.start <= item) && (item < self.end)
    }
}

/// A range which is only bounded below: { x | start <= x }.
/// Use `start..` for its shorthand.
///
/// See the [`contains`](#method.contains) method for its characterization.
///
/// Note: Currently, no overflow checking is done for the iterator
/// implementation; if you use an integer range and the integer overflows, it
/// might panic in debug mode or create an endless loop in release mode. This
/// overflow behavior might change in the future.
///
/// # Examples
///
/// ```
/// fn main() {
///     assert_eq!((2..), std::ops::RangeFrom{ start: 2 });
///     assert_eq!(2+3+4, (2..).take(3).sum());
///
///     let arr = [0, 1, 2, 3];
///     assert_eq!(arr[ .. ], [0,1,2,3]);
///     assert_eq!(arr[ ..3], [0,1,2  ]);
///     assert_eq!(arr[1.. ], [  1,2,3]);  // RangeFrom
///     assert_eq!(arr[1..3], [  1,2  ]);
/// }
/// ```
#[derive(Clone, PartialEq, Eq, Hash)]  // not Copy -- see #27186
#[stable(feature = "rust1", since = "1.0.0")]
pub struct RangeFrom<Idx> {
    /// The lower bound of the range (inclusive).
    #[stable(feature = "rust1", since = "1.0.0")]
    pub start: Idx,
}

#[stable(feature = "rust1", since = "1.0.0")]
impl<Idx: fmt::Debug> fmt::Debug for RangeFrom<Idx> {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        write!(fmt, "{:?}..", self.start)
    }
}

#[unstable(feature = "range_contains", reason = "recently added as per RFC", issue = "32311")]
impl<Idx: PartialOrd<Idx>> RangeFrom<Idx> {
    /// # Examples
    ///
    /// ```
    /// #![feature(range_contains)]
    /// fn main() {
    ///     assert!( ! (3..).contains(2));
    ///     assert!(   (3..).contains(3));
    ///     assert!(   (3..).contains(1_000_000_000));
    /// }
    /// ```
    pub fn contains(&self, item: Idx) -> bool {
        (self.start <= item)
    }
}

/// A range which is only bounded above: { x | x < end }.
/// Use `..end` (two dots) for its shorthand.
///
/// See the [`contains`](#method.contains) method for its characterization.
///
/// It cannot serve as an iterator because it doesn't have a starting point.
///
/// # Examples
///
/// The `..{integer}` syntax is a `RangeTo`:
///
/// ```
/// assert_eq!((..5), std::ops::RangeTo{ end: 5 });
/// ```
///
/// It does not have an `IntoIterator` implementation, so you can't use it in a
/// `for` loop directly. This won't compile:
///
/// ```compile_fail,E0277
/// for i in ..5 {
///     // ...
/// }
/// ```
///
/// When used as a slicing index, `RangeTo` produces a slice of all array
/// elements before the index indicated by `end`.
///
/// ```
/// let arr = [0, 1, 2, 3];
/// assert_eq!(arr[ .. ], [0,1,2,3]);
/// assert_eq!(arr[ ..3], [0,1,2  ]);  // RangeTo
/// assert_eq!(arr[1.. ], [  1,2,3]);
/// assert_eq!(arr[1..3], [  1,2  ]);
/// ```
#[derive(Copy, Clone, PartialEq, Eq, Hash)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct RangeTo<Idx> {
    /// The upper bound of the range (exclusive).
    #[stable(feature = "rust1", since = "1.0.0")]
    pub end: Idx,
}

#[stable(feature = "rust1", since = "1.0.0")]
impl<Idx: fmt::Debug> fmt::Debug for RangeTo<Idx> {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        write!(fmt, "..{:?}", self.end)
    }
}

#[unstable(feature = "range_contains", reason = "recently added as per RFC", issue = "32311")]
impl<Idx: PartialOrd<Idx>> RangeTo<Idx> {
    /// # Examples
    ///
    /// ```
    /// #![feature(range_contains)]
    /// fn main() {
    ///     assert!(   (..5).contains(-1_000_000_000));
    ///     assert!(   (..5).contains(4));
    ///     assert!( ! (..5).contains(5));
    /// }
    /// ```
    pub fn contains(&self, item: Idx) -> bool {
        (item < self.end)
    }
}

/// An inclusive range which is bounded at both ends: { x | start <= x <= end }.
/// Use `start...end` (three dots) for its shorthand.
///
/// See the [`contains`](#method.contains) method for its characterization.
///
/// # Examples
///
/// ```
/// #![feature(inclusive_range,inclusive_range_syntax)]
/// fn main() {
///     assert_eq!((3...5), std::ops::RangeInclusive{ start: 3, end: 5 });
///     assert_eq!(3+4+5, (3...5).sum());
///
///     let arr = [0, 1, 2, 3];
///     assert_eq!(arr[ ...2], [0,1,2  ]);
///     assert_eq!(arr[1...2], [  1,2  ]);  // RangeInclusive
/// }
/// ```
#[derive(Clone, PartialEq, Eq, Hash)]  // not Copy -- see #27186
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
pub struct RangeInclusive<Idx> {
    /// The lower bound of the range (inclusive).
    #[unstable(feature = "inclusive_range",
               reason = "recently added, follows RFC",
               issue = "28237")]
    pub start: Idx,
    /// The upper bound of the range (inclusive).
    #[unstable(feature = "inclusive_range",
               reason = "recently added, follows RFC",
               issue = "28237")]
    pub end: Idx,
}

#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
impl<Idx: fmt::Debug> fmt::Debug for RangeInclusive<Idx> {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        write!(fmt, "{:?}...{:?}", self.start, self.end)
    }
}

#[unstable(feature = "range_contains", reason = "recently added as per RFC", issue = "32311")]
impl<Idx: PartialOrd<Idx>> RangeInclusive<Idx> {
    /// # Examples
    ///
    /// ```
    /// #![feature(range_contains,inclusive_range_syntax)]
    /// fn main() {
    ///     assert!( ! (3...5).contains(2));
    ///     assert!(   (3...5).contains(3));
    ///     assert!(   (3...5).contains(4));
    ///     assert!(   (3...5).contains(5));
    ///     assert!( ! (3...5).contains(6));
    ///
    ///     assert!(   (3...3).contains(3));
    ///     assert!( ! (3...2).contains(3));
    /// }
    /// ```
    pub fn contains(&self, item: Idx) -> bool {
        self.start <= item && item <= self.end
    }
}

/// An inclusive range which is only bounded above: { x | x <= end }.
/// Use `...end` (three dots) for its shorthand.
///
/// See the [`contains`](#method.contains) method for its characterization.
///
/// It cannot serve as an iterator because it doesn't have a starting point.
///
/// # Examples
///
/// The `...{integer}` syntax is a `RangeToInclusive`:
///
/// ```
/// #![feature(inclusive_range,inclusive_range_syntax)]
/// assert_eq!((...5), std::ops::RangeToInclusive{ end: 5 });
/// ```
///
/// It does not have an `IntoIterator` implementation, so you can't use it in a
/// `for` loop directly. This won't compile:
///
/// ```compile_fail,E0277
/// #![feature(inclusive_range_syntax)]
/// for i in ...5 {
///     // ...
/// }
/// ```
///
/// When used as a slicing index, `RangeToInclusive` produces a slice of all
/// array elements up to and including the index indicated by `end`.
///
/// ```
/// #![feature(inclusive_range_syntax)]
/// let arr = [0, 1, 2, 3];
/// assert_eq!(arr[ ...2], [0,1,2  ]);  // RangeToInclusive
/// assert_eq!(arr[1...2], [  1,2  ]);
/// ```
#[derive(Copy, Clone, PartialEq, Eq, Hash)]
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
pub struct RangeToInclusive<Idx> {
    /// The upper bound of the range (inclusive)
    #[unstable(feature = "inclusive_range",
               reason = "recently added, follows RFC",
               issue = "28237")]
    pub end: Idx,
}

#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
impl<Idx: fmt::Debug> fmt::Debug for RangeToInclusive<Idx> {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        write!(fmt, "...{:?}", self.end)
    }
}

#[unstable(feature = "range_contains", reason = "recently added as per RFC", issue = "32311")]
impl<Idx: PartialOrd<Idx>> RangeToInclusive<Idx> {
    /// # Examples
    ///
    /// ```
    /// #![feature(range_contains,inclusive_range_syntax)]
    /// fn main() {
    ///     assert!(   (...5).contains(-1_000_000_000));
    ///     assert!(   (...5).contains(5));
    ///     assert!( ! (...5).contains(6));
    /// }
    /// ```
    pub fn contains(&self, item: Idx) -> bool {
        (item <= self.end)
    }
}

// RangeToInclusive<Idx> cannot impl From<RangeTo<Idx>>
// because underflow would be possible with (..0).into()