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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307
//! Array2D provides a fixed sized two-dimensional array. It is more efficient
//! and is easier to use than a vector of vectors, i.e. `Vec<Vec<T>>`.
//!
//! This is beneficial when using a grid-like structure, which is common in
//! image processing, game boards, and other situations. Array2D cannot be used
//! when rows or columns might have different lengths—all rows and columns must
//! be the same length.
//!
//! # How to use [`Array2D`]
//!
//! ## Creating an [`Array2D`]
//!
//! An [`Array2D`] can be created in many different ways. These include:
//! - Providing the rows or the columns, which must all be the same size (see
//! [`from_rows`] and [`from_columns`]).
//! - Providing a "flat" slice of elements in either [row major or column
//! major order] along with the dimensions, which must match the number of
//! elements in the slice (see [`from_row_major`] and
//! [`from_column_major`]).
//! - Providing a value to repeatedly put in every location (see
//! [`filled_with`]).
//! - Providing a generator function that is repeatedly called to produce
//! values to fill the array (see [`filled_by_row_major`] and
//! [`filled_by_column_major`]).
//! - Providing an iterator that is used to produce values to fill the array
//! (see [`from_iter_row_major`] and [`from_iter_column_major`]).
//!
//! ## Accessing data from an [`Array2D`]
//!
//! [`Array2D`] supports several forms of indexing:
//! - Using the indexing syntax (square brackets) with a tuple of [`(usize,
//! usize)`], which panics on out-of-bounds accesses.
//! - Using the [`get`], [`get_mut`], and [`set`] methods, which return an
//! [`Option`] or a [`Result`] on out-of-bounds accesses.
//! - Using the row major or column major version of these methods,
//! i.e. [`get_row_major`], [`get_mut_row_major`], [`set_row_major`],
//! [`get_column_major`], [`get_mut_column_major`],
//! [`set_column_major`]. These perform the same tasks as the non row/column
//! major methods, but take one index instead of two.
//!
//! [`Array2D`] also supports several forms of iteration. You can iterate
//! through:
//! - All of the elements, in either [row major or column major order] (see
//! [`elements_row_major_iter`] and [`elements_column_major_iter`]).
//! - Individual rows or columns (see [`row_iter`] and [`column_iter`]).
//! - All rows or all columns (see [`rows_iter`] and [`columns_iter`]).
//!
//! ## Extracting all data from an [`Array2D`]
//!
//! An [`Array2D`] can be converted back into a [`Vec`] through several
//! methods. You can extract the data as:
//! - A [`Vec`] of rows or columns (see [`as_rows`] and [`as_columns`]).
//! - A "flat" [`Vec`] of elements in either [row major or column major order]
//! (see [`as_row_major`] and [`as_column_major`]).
//!
//! # Examples
//!
//! ```rust
//! use array2d::{Array2D, Error};
//!
//! pub fn main() -> Result<(), Error> {
//! // Create an array filled with the same element.
//! let prefilled = Array2D::filled_with(42, 2, 3);
//! assert_eq!(prefilled.num_rows(), 2);
//! assert_eq!(prefilled.num_columns(), 3);
//! assert_eq!(prefilled[(0, 0)], 42);
//!
//! // Create an array from the given rows. You can also use columns
//! // with the `columns` function
//! let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
//! let from_rows = Array2D::from_rows(&rows)?;
//! assert_eq!(from_rows.num_rows(), 2);
//! assert_eq!(from_rows.num_columns(), 3);
//! assert_eq!(from_rows[(1, 1)], 5);
//!
//! // Create an array from a flat Vec of elements in row major or
//! // column major order.
//! let column_major = vec![1, 4, 2, 5, 3, 6];
//! let from_column_major =
//! Array2D::from_column_major(&column_major, 2, 3)?;
//! assert_eq!(from_column_major.num_rows(), 2);
//! assert_eq!(from_column_major.num_columns(), 3);
//! assert_eq!(from_column_major[(1, 1)], 5);
//!
//! // Implements `Eq` if the element type does.
//! assert_eq!(from_rows, from_column_major);
//!
//! // Index into an array using a tuple of usize to access or alter
//! // the array.
//! let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
//! let mut array = Array2D::from_rows(&rows)?;
//! array[(1, 1)] = 100;
//!
//! // Convert the array back into a nested Vec using `as_rows` or
//! // `as_columns`.
//! let array_rows = array.as_rows();
//! assert_eq!(array_rows, vec![vec![1, 2, 3], vec![4, 100, 6]]);
//!
//! // Convert the array back into a flat Vec using `as_row_major` or
//! // `as_column_major`.
//! let array_column_major = array.as_column_major();
//! assert_eq!(array_column_major, vec![1, 4, 2, 100, 3, 6]);
//!
//! // Iterate over a single row or column
//! println!("First column:");
//! for element in array.column_iter(0)? {
//! println!("{}", element);
//! }
//!
//! // Iterate over all rows or columns.
//! println!("All elements:");
//! for row_iter in array.rows_iter() {
//! for element in row_iter {
//! print!("{} ", element);
//! }
//! println!();
//! }
//!
//! Ok(())
//! }
//! ```
//!
//! [`Array2D`]: struct.Array2D.html
//! [`from_rows`]: struct.Array2D.html#method.from_rows
//! [`from_columns`]: struct.Array2D.html#method.from_columns
//! [`from_row_major`]: struct.Array2D.html#method.from_row_major
//! [`from_column_major`]: struct.Array2D.html#method.from_column_major
//! [`filled_with`]: struct.Array2D.html#method.filled_with
//! [`filled_by_row_major`]: struct.Array2D.html#method.filled_by_row_major
//! [`filled_by_column_major`]: struct.Array2D.html#method.filled_by_column_major
//! [`from_iter_row_major`]: struct.Array2D.html#method.from_iter_row_major
//! [`from_iter_column_major`]: struct.Array2D.html#method.from_iter_column_major
//! [`get`]: struct.Array2D.html#method.get
//! [`get_mut`]: struct.Array2D.html#method.get_mut
//! [`set`]: struct.Array2D.html#method.set
//! [`get_row_major`]: struct.Array2D.html#method.get_row_major
//! [`get_mut_row_major`]: struct.Array2D.html#method.get_mut_row_major
//! [`set_row_major`]: struct.Array2D.html#method.set_row_major
//! [`get_column_major`]: struct.Array2D.html#method.get_column_major
//! [`get_mut_column_major`]: struct.Array2D.html#method.get_mut_column_major
//! [`set_column_major`]: struct.Array2D.html#method.set_column_major
//! [`elements_row_major_iter`]: struct.Array2D.html#method.elements_row_major_iter
//! [`elements_column_major_iter`]: struct.Array2D.html#method.elements_column_major_iter
//! [`row_iter`]: struct.Array2D.html#method.row_iter
//! [`column_iter`]: struct.Array2D.html#method.column_iter
//! [`rows_iter`]: struct.Array2D.html#method.rows_iter
//! [`columns_iter`]: struct.Array2D.html#method.columns_iter
//! [`as_rows`]: struct.Array2D.html#method.as_rows
//! [`as_columns`]: struct.Array2D.html#method.as_columns
//! [`as_row_major`]: struct.Array2D.html#method.as_row_major
//! [`as_column_major`]: struct.Array2D.html#method.as_column_major
//! [`Vec`]: https://doc.rust-lang.org/std/vec/struct.Vec.html
//! [`Option`]: https://doc.rust-lang.org/std/option/
//! [`Result`]: https://doc.rust-lang.org/std/result/
//! [`(usize, usize)`]: https://doc.rust-lang.org/std/primitive.usize.html
//! [row major or column major order]: https://en.wikipedia.org/wiki/Row-_and_column-major_order
#![deny(missing_docs)]
use std::fmt::{Display, Formatter};
use std::ops::{Index, IndexMut};
#[cfg(feature = "serde")]
use serde::{Deserialize, Serialize};
/// A fixed sized two-dimensional array.
#[derive(Debug, Clone, Eq, PartialEq, Hash)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
pub struct Array2D<T> {
array: Vec<T>,
num_rows: usize,
num_columns: usize,
}
/// An error that can arise during the use of an [`Array2D`].
///
/// [`Array2D`]: struct.Array2D.html
#[derive(Debug, Eq, PartialEq)]
pub enum Error {
/// The given indices were out of bounds.
IndicesOutOfBounds(usize, usize),
/// The given index in row or column major order was out of bounds.
IndexOutOfBounds(usize),
/// The dimensions given did not match the elements provided
DimensionMismatch,
/// There were not enough elements to fill the array.
NotEnoughElements,
}
impl Display for Error {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
match self {
Error::IndicesOutOfBounds(row, column) => write!(f, "indices ({row}, {column}) out of bounds"),
Error::IndexOutOfBounds(index) => write!(f, "index {index} out of bounds"),
Error::DimensionMismatch => write!(f, "dimension mismatch"),
Error::NotEnoughElements => write!(f, "not enough elements"),
}
}
}
impl std::error::Error for Error {}
impl<T> Array2D<T> {
/// Creates a new [`Array2D`] from a slice of rows, each of which is a
/// [`Vec`] of elements.
///
/// Returns an error if the rows are not all the same size.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// assert_eq!(array[(1, 2)], 6);
/// assert_eq!(array.as_rows(), rows);
/// # Ok(())
/// # }
/// ```
///
/// [`Array2D`]: struct.Array2D.html
/// [`Vec`]: https://doc.rust-lang.org/std/vec/struct.Vec.html
pub fn from_rows(elements: &[Vec<T>]) -> Result<Self, Error>
where
T: Clone,
{
let row_len = elements.get(0).map(Vec::len).unwrap_or(0);
if !elements.iter().all(|row| row.len() == row_len) {
return Err(Error::DimensionMismatch);
}
Ok(Array2D {
array: flatten(elements),
num_rows: elements.len(),
num_columns: row_len,
})
}
/// Creates a new [`Array2D`] from a slice of columns, each of which
/// contains a [`Vec`] of elements.
///
/// Returns an error if the columns are not all the same size.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let columns = vec![vec![1, 4], vec![2, 5], vec![3, 6]];
/// let array = Array2D::from_columns(&columns)?;
/// assert_eq!(array[(1, 2)], 6);
/// assert_eq!(array.as_rows(), vec![vec![1, 2, 3], vec![4, 5, 6]]);
/// # Ok(())
/// # }
/// ```
///
/// [`Array2D`]: struct.Array2D.html
/// [`Vec`]: https://doc.rust-lang.org/std/vec/struct.Vec.html
pub fn from_columns(elements: &[Vec<T>]) -> Result<Self, Error>
where
T: Clone,
{
let column_len = elements.get(0).map(Vec::len).unwrap_or(0);
if !elements.iter().all(|column| column.len() == column_len) {
return Err(Error::DimensionMismatch);
}
let num_rows = column_len;
let num_columns = elements.len();
let array = indices_row_major(num_rows, num_columns)
.map(|(row, column)| elements[column][row].clone())
.collect();
Ok(Array2D {
array,
num_rows,
num_columns,
})
}
/// Creates a new [`Array2D`] from the given flat slice in [row major
/// order].
///
/// Returns an error if the number of elements in `elements` is not the
/// product of `num_rows` and `num_columns`, i.e. the dimensions do not
/// match.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let row_major = vec![1, 2, 3, 4, 5, 6];
/// let array = Array2D::from_row_major(&row_major, 2, 3)?;
/// assert_eq!(array[(1, 2)], 6);
/// assert_eq!(array.as_rows(), vec![vec![1, 2, 3], vec![4, 5, 6]]);
/// # Ok(())
/// # }
/// ```
///
/// [`Array2D`]: struct.Array2D.html
/// [row major order]: https://en.wikipedia.org/wiki/Row-_and_column-major_order
pub fn from_row_major(
elements: &[T],
num_rows: usize,
num_columns: usize,
) -> Result<Self, Error>
where
T: Clone,
{
let total_len = num_rows * num_columns;
if total_len != elements.len() {
return Err(Error::DimensionMismatch);
}
Ok(Array2D {
array: elements.to_vec(),
num_rows,
num_columns,
})
}
/// Creates a new [`Array2D`] from the given flat slice in [column major
/// order].
///
/// Return an error if the number of elements in `elements` is not the
/// product of `num_rows` and `num_columns`, i.e. the dimensions do not
/// match.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let column_major = vec![1, 4, 2, 5, 3, 6];
/// let array = Array2D::from_column_major(&column_major, 2, 3)?;
/// assert_eq!(array[(1, 2)], 6);
/// assert_eq!(array.as_rows(), vec![vec![1, 2, 3], vec![4, 5, 6]]);
/// # Ok(())
/// # }
/// ```
///
/// [`Array2D`]: struct.Array2D.html
/// [column major order]: https://en.wikipedia.org/wiki/Row-_and_column-major_order
pub fn from_column_major(
elements: &[T],
num_rows: usize,
num_columns: usize,
) -> Result<Self, Error>
where
T: Clone,
{
let total_len = num_rows * num_columns;
if total_len != elements.len() {
return Err(Error::DimensionMismatch);
}
let indices_row_major =
(0..num_rows).flat_map(move |row| (0..num_columns).map(move |column| (row, column)));
let array = indices_row_major
.map(|(row, column)| {
let index = column * num_rows + row;
elements[index].clone()
})
.collect();
Ok(Array2D {
array,
num_rows,
num_columns,
})
}
/// Creates a new [`Array2D`] with the specified number of rows and columns
/// that contains `element` in every location.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// let array = Array2D::filled_with(42, 2, 3);
/// assert_eq!(array.as_rows(), vec![vec![42, 42, 42], vec![42, 42, 42]]);
/// ```
///
/// [`Array2D`]: struct.Array2D.html
pub fn filled_with(element: T, num_rows: usize, num_columns: usize) -> Self
where
T: Clone,
{
let total_len = num_rows * num_columns;
let array = vec![element; total_len];
Array2D {
array,
num_rows,
num_columns,
}
}
#[deprecated(since = "0.2.0", note = "Renamed to filled_with")]
/// Renamed to filled_with.
pub fn fill_with(element: T, num_rows: usize, num_columns: usize) -> Self
where
T: Clone,
{
Array2D::filled_with(element, num_rows, num_columns)
}
/// Creates a new [`Array2D`] with the specified number of rows and columns
/// and fills each element with the result of calling the given
/// function. The function is called once for every location going in
/// row major order.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// let mut counter = 1;
/// let increment = || {
/// let tmp = counter;
/// counter += 1;
/// tmp
/// };
/// let array = Array2D::filled_by_row_major(increment, 2, 3);
/// assert_eq!(array.as_rows(), vec![vec![1, 2, 3], vec![4, 5, 6]]);
/// ```
///
/// [`Array2D`]: struct.Array2D.html
pub fn filled_by_row_major<F>(mut generator: F, num_rows: usize, num_columns: usize) -> Self
where
F: FnMut() -> T,
{
let total_len = num_rows * num_columns;
let array = (0..total_len).map(|_| generator()).collect();
Array2D {
array,
num_rows,
num_columns,
}
}
/// Creates a new [`Array2D`] with the specified number of rows and columns
/// and fills each element with the result of calling the given
/// function. The function is called once for every location going in
/// column major order.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// let mut counter = 1;
/// let increment = || {
/// let tmp = counter;
/// counter += 1;
/// tmp
/// };
/// let array = Array2D::filled_by_column_major(increment, 2, 3);
/// assert_eq!(array.as_columns(), vec![vec![1, 2], vec![3, 4], vec![5, 6]]);
/// ```
///
/// [`Array2D`]: struct.Array2D.html
pub fn filled_by_column_major<F>(mut generator: F, num_rows: usize, num_columns: usize) -> Self
where
F: FnMut() -> T,
T: Clone,
{
let total_len = num_rows * num_columns;
let array_column_major = (0..total_len).map(|_| generator()).collect::<Vec<_>>();
Array2D::from_column_major(&array_column_major, num_rows, num_columns)
.expect("Filled by should never fail")
}
/// Creates a new [`Array2D`] with the specified number of rows and columns
/// and fills each element with the elements produced from the provided
/// iterator. If the iterator produces more than enough elements, the
/// remaining are unused. Returns an error if the iterator does not produce
/// enough elements.
///
/// The elements are inserted into the array in [row major order].
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let iterator = (1..);
/// let array = Array2D::from_iter_row_major(iterator, 2, 3)?;
/// assert_eq!(array.as_rows(), vec![vec![1, 2, 3], vec![4, 5, 6]]);
/// # Ok(())
/// # }
/// ```
///
/// [`Array2D`]: struct.Array2D.html
/// [row major order]: https://en.wikipedia.org/wiki/Row-_and_column-major_order
pub fn from_iter_row_major<I>(
iterator: I,
num_rows: usize,
num_columns: usize,
) -> Result<Self, Error>
where
I: Iterator<Item = T>,
{
let total_len = num_rows * num_columns;
let array = iterator.take(total_len).collect::<Vec<_>>();
if array.len() != total_len {
return Err(Error::NotEnoughElements);
}
Ok(Array2D {
array,
num_rows,
num_columns,
})
}
/// Creates a new [`Array2D`] with the specified number of rows and columns
/// and fills each element with the elements produced from the provided
/// iterator. If the iterator produces more than enough elements, the
/// remaining are unused. Returns an error if the iterator does not produce
/// enough elements.
///
/// The elements are inserted into the array in [column major order].
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let iterator = (1..);
/// let array = Array2D::from_iter_column_major(iterator, 2, 3)?;
/// assert_eq!(array.as_rows(), vec![vec![1, 3, 5], vec![2, 4, 6]]);
/// # Ok(())
/// # }
/// ```
///
/// [`Array2D`]: struct.Array2D.html
/// [column major order]: https://en.wikipedia.org/wiki/Row-_and_column-major_order
pub fn from_iter_column_major<I>(
iterator: I,
num_rows: usize,
num_columns: usize,
) -> Result<Self, Error>
where
I: Iterator<Item = T>,
T: Clone,
{
let total_len = num_rows * num_columns;
let array_column_major = iterator.take(total_len).collect::<Vec<_>>();
Array2D::from_column_major(&array_column_major, num_rows, num_columns)
.map_err(|_| Error::NotEnoughElements)
}
/// The number of rows.
pub fn num_rows(&self) -> usize {
self.num_rows
}
/// The number of columns.
pub fn num_columns(&self) -> usize {
self.num_columns
}
/// The total number of elements, i.e. the product of `num_rows` and
/// `num_columns`.
pub fn num_elements(&self) -> usize {
self.num_rows * self.num_columns
}
/// The number of elements in each row, i.e. the number of columns.
pub fn row_len(&self) -> usize {
self.num_columns
}
/// The number of elements in each column, i.e. the number of rows.
pub fn column_len(&self) -> usize {
self.num_rows
}
/// Returns a reference to the element at the given `row` and `column` if the
/// index is in bounds (wrapped in [`Some`]). Returns [`None`] if the index
/// is out of bounds.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// let array = Array2D::filled_with(42, 2, 3);
/// assert_eq!(array.get(0, 0), Some(&42));
/// assert_eq!(array.get(10, 10), None);
/// ```
///
/// [`Some`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.Some
/// [`None`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.None
pub fn get(&self, row: usize, column: usize) -> Option<&T> {
self.get_index(row, column).map(|index| &self.array[index])
}
/// Returns a reference to the element at the given index in row major
/// order. Returns [`None`] if the index is out of bounds.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// assert_eq!(array.get_row_major(2), Some(&3));
/// assert_eq!(array.get_row_major(4), Some(&5));
/// assert_eq!(array.get_row_major(10), None);
/// # Ok(())
/// # }
/// ```
///
/// [`None`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.None
pub fn get_row_major(&self, index: usize) -> Option<&T> {
self.array.get(index)
}
/// Returns a reference to the element at the given index in column major
/// order. Returns [`None`] if the index is out of bounds.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// assert_eq!(array.get_column_major(2), Some(&2));
/// assert_eq!(array.get_column_major(4), Some(&3));
/// assert_eq!(array.get_column_major(10), None);
/// # Ok(())
/// # }
/// ```
///
/// [`None`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.None
pub fn get_column_major(&self, index: usize) -> Option<&T> {
let column = dbg!(dbg!(index) / self.num_rows);
let row = dbg!(index % self.num_rows);
self.get(row, column)
}
/// Returns a mutable reference to the element at the given `row` and
/// `column` if the index is in bounds (wrapped in [`Some`]). Returns
/// [`None`] if the index is out of bounds.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// let mut array = Array2D::filled_with(42, 2, 3);
///
/// assert_eq!(array.get_mut(0, 0), Some(&mut 42));
/// assert_eq!(array.get_mut(10, 10), None);
///
/// array.get_mut(0, 0).map(|x| *x = 100);
/// assert_eq!(array.get(0, 0), Some(&100));
///
/// array.get_mut(10, 10).map(|x| *x = 200);
/// assert_eq!(array.get(10, 10), None);
/// ```
///
/// [`Some`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.Some
/// [`None`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.None
pub fn get_mut(&mut self, row: usize, column: usize) -> Option<&mut T> {
self.get_index(row, column)
.map(move |index| &mut self.array[index])
}
/// Returns a mutable reference to the element at the given index in row
/// major order. Returns [`None`] if the index is out of bounds.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let mut array = Array2D::from_rows(&rows)?;
///
/// assert_eq!(array.get_mut_row_major(1), Some(&mut 2));
/// assert_eq!(array.get_mut_row_major(10), None);
///
/// array.get_mut_row_major(3).map(|x| *x = 100);
/// assert_eq!(array.get(1, 0), Some(&100));
///
/// array.get_mut_row_major(10).map(|x| *x = 200);
/// assert_eq!(array.get(10, 10), None);
/// # Ok(())
/// # }
/// ```
///
/// [`None`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.None
pub fn get_mut_row_major(&mut self, index: usize) -> Option<&mut T> {
self.array.get_mut(index)
}
/// Returns a mutable reference to the element at the given index in row
/// major order. Returns [`None`] if the index is out of bounds.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let mut array = Array2D::from_rows(&rows)?;
///
/// assert_eq!(array.get_mut_column_major(1), Some(&mut 4));
/// assert_eq!(array.get_mut_column_major(10), None);
///
/// array.get_mut_column_major(4).map(|x| *x = 100);
/// assert_eq!(array.get(0, 2), Some(&100));
///
/// array.get_mut_column_major(10).map(|x| *x = 200);
/// assert_eq!(array.get(10, 10), None);
/// # Ok(())
/// # }
/// ```
///
/// [`None`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.None
pub fn get_mut_column_major(&mut self, index: usize) -> Option<&mut T> {
let column = index / self.num_rows;
let row = index % self.num_rows;
self.get_mut(row, column)
}
/// Changes the element at given `row` and `column` to `element`. Returns
/// [`Ok(())`] if the indices were in bounds and returns an [`Err`]
/// otherwise.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// let mut array = Array2D::filled_with(42, 2, 3);
///
/// let result = array.set(0, 0, 100);
/// assert_eq!(result, Ok(()));
/// assert_eq!(array.get(0, 0), Some(&100));
///
/// let result = array.set(10, 20, 200);
/// assert_eq!(result, Err(Error::IndicesOutOfBounds(10, 20)));
/// ```
///
/// [`Ok(())`]: https://doc.rust-lang.org/std/result/enum.Result.html#variant.Ok
/// [array2d::Error]: enum.Error.html
/// [`Err`]: https://doc.rust-lang.org/std/result/enum.Result.html#variant.Err
/// [`array2d::Error`]: enum.Error.html
pub fn set(&mut self, row: usize, column: usize, element: T) -> Result<(), Error> {
self.get_mut(row, column)
.map(|location| {
*location = element;
})
.ok_or(Error::IndicesOutOfBounds(row, column))
}
/// Changes the element at the given `index` to `element`, in row major
/// order. Returns [`Ok(())`] if the index is in bounds and returns an
/// [`Err`] otherwise.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// let mut array = Array2D::filled_with(42, 2, 3);
///
/// let result = array.set_row_major(4, 100);
/// assert_eq!(result, Ok(()));
/// assert_eq!(array.get(1, 1), Some(&100));
///
/// let result = array.set_row_major(10, 200);
/// assert_eq!(result, Err(Error::IndexOutOfBounds(10)));
/// ```
///
/// [`Ok(())`]: https://doc.rust-lang.org/std/result/enum.Result.html#variant.Ok
/// [array2d::Error]: enum.Error.html
/// [`Err`]: https://doc.rust-lang.org/std/result/enum.Result.html#variant.Err
/// [`array2d::Error`]: enum.Error.html
pub fn set_row_major(&mut self, index: usize, element: T) -> Result<(), Error> {
self.get_mut_row_major(index)
.map(|location| {
*location = element;
})
.ok_or(Error::IndexOutOfBounds(index))
}
/// Changes the element at the given `index` to `element`, in column major
/// order. Returns [`Ok(())`] if the index is in bounds and returns an
/// [`Err`] otherwise.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// let mut array = Array2D::filled_with(42, 2, 3);
///
/// let result = array.set_column_major(4, 100);
/// assert_eq!(result, Ok(()));
/// assert_eq!(array.get(0, 2), Some(&100));
///
/// let result = array.set_column_major(10, 200);
/// assert_eq!(result, Err(Error::IndexOutOfBounds(10)));
/// ```
///
/// [`Ok(())`]: https://doc.rust-lang.org/std/result/enum.Result.html#variant.Ok
/// [array2d::Error]: enum.Error.html
/// [`Err`]: https://doc.rust-lang.org/std/result/enum.Result.html#variant.Err
/// [`array2d::Error`]: enum.Error.html
pub fn set_column_major(&mut self, index: usize, element: T) -> Result<(), Error> {
self.get_mut_column_major(index)
.map(|location| {
*location = element;
})
.ok_or(Error::IndexOutOfBounds(index))
}
/// Returns an [`Iterator`] over references to all elements in [row major
/// order].
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let elements = vec![1, 2, 3, 4, 5, 6];
/// let array = Array2D::from_rows(&rows)?;
/// let row_major = array.elements_row_major_iter();
/// assert_eq!(row_major.cloned().collect::<Vec<_>>(), elements);
/// # Ok(())
/// # }
/// ```
///
/// [`Iterator`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html
/// [row major order]: https://en.wikipedia.org/wiki/Row-_and_column-major_order
pub fn elements_row_major_iter(&self) -> impl DoubleEndedIterator<Item = &T> + Clone {
self.array.iter()
}
/// Returns an [`Iterator`] over references to all elements in [column major
/// order].
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let elements = vec![1, 4, 2, 5, 3, 6];
/// let array = Array2D::from_rows(&rows)?;
/// let column_major = array.elements_column_major_iter();
/// assert_eq!(column_major.cloned().collect::<Vec<_>>(), elements);
/// # Ok(())
/// # }
/// ```
///
/// [`Iterator`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html
/// [column major order]: https://en.wikipedia.org/wiki/Row-_and_column-major_order
pub fn elements_column_major_iter(&self) -> impl DoubleEndedIterator<Item = &T> + Clone {
self.indices_column_major().map(move |i| &self[i])
}
/// Returns an [`Iterator`] over references to all elements in the given
/// row. Returns an error if the index is out of bounds.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// let mut row_iter = array.row_iter(1)?;
/// assert_eq!(row_iter.next(), Some(&4));
/// assert_eq!(row_iter.next(), Some(&5));
/// assert_eq!(row_iter.next(), Some(&6));
/// assert_eq!(row_iter.next(), None);
/// # Ok(())
/// # }
/// ```
///
/// [`Iterator`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html
pub fn row_iter(&self, row_index: usize) -> Result<impl DoubleEndedIterator<Item = &T> + Clone, Error> {
let start = self
.get_index(row_index, 0)
.ok_or(Error::IndicesOutOfBounds(row_index, 0))?;
let end = start + self.row_len();
Ok(self.array[start..end].iter())
}
/// Returns an [`Iterator`] over references to all elements in the given
/// column. Returns an error if the index is out of bounds.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// let mut column_iter = array.column_iter(1)?;
/// assert_eq!(column_iter.next(), Some(&2));
/// assert_eq!(column_iter.next(), Some(&5));
/// assert_eq!(column_iter.next(), None);
/// # Ok(())
/// # }
/// ```
///
/// [`Iterator`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html
pub fn column_iter(
&self,
column_index: usize,
) -> Result<impl DoubleEndedIterator<Item = &T> + Clone, Error> {
if column_index >= self.num_columns {
return Err(Error::IndicesOutOfBounds(0, column_index));
}
Ok((0..self.column_len()).map(move |row_index| &self[(row_index, column_index)]))
}
/// Returns an [`Iterator`] over all rows. Each [`Item`] is itself another
/// [`Iterator`] over references to the elements in that row.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// for row_iter in array.rows_iter() {
/// for element in row_iter {
/// print!("{} ", element);
/// }
/// println!();
/// }
///
/// let mut rows_iter = array.rows_iter();
///
/// let mut first_row_iter = rows_iter.next().unwrap();
/// assert_eq!(first_row_iter.next(), Some(&1));
/// assert_eq!(first_row_iter.next(), Some(&2));
/// assert_eq!(first_row_iter.next(), Some(&3));
/// assert_eq!(first_row_iter.next(), None);
///
/// let mut second_row_iter = rows_iter.next().unwrap();
/// assert_eq!(second_row_iter.next(), Some(&4));
/// assert_eq!(second_row_iter.next(), Some(&5));
/// assert_eq!(second_row_iter.next(), Some(&6));
/// assert_eq!(second_row_iter.next(), None);
///
/// assert!(rows_iter.next().is_none());
/// # Ok(())
/// # }
/// ```
///
/// [`Iterator`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html
/// [`Item`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#associatedtype.Item
pub fn rows_iter(
&self,
) -> impl DoubleEndedIterator<Item = impl DoubleEndedIterator<Item = &T> + Clone> + Clone {
(0..self.num_rows()).map(move |row_index| {
self.row_iter(row_index)
.expect("rows_iter should never fail")
})
}
/// Returns an [`Iterator`] over all columns. Each [`Item`] is itself
/// another [`Iterator`] over references to the elements in that column.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// for column_iter in array.columns_iter() {
/// for element in column_iter {
/// print!("{} ", element);
/// }
/// println!();
/// }
///
/// let mut columns_iter = array.columns_iter();
///
/// let mut first_column_iter = columns_iter.next().unwrap();
/// assert_eq!(first_column_iter.next(), Some(&1));
/// assert_eq!(first_column_iter.next(), Some(&4));
/// assert_eq!(first_column_iter.next(), None);
///
/// let mut second_column_iter = columns_iter.next().unwrap();
/// assert_eq!(second_column_iter.next(), Some(&2));
/// assert_eq!(second_column_iter.next(), Some(&5));
/// assert_eq!(second_column_iter.next(), None);
///
/// let mut third_column_iter = columns_iter.next().unwrap();
/// assert_eq!(third_column_iter.next(), Some(&3));
/// assert_eq!(third_column_iter.next(), Some(&6));
/// assert_eq!(third_column_iter.next(), None);
///
/// assert!(columns_iter.next().is_none());
/// # Ok(())
/// # }
/// ```
///
/// [`Iterator`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html
/// [`Item`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#associatedtype.Item
pub fn columns_iter(
&self,
) -> impl DoubleEndedIterator<Item = impl DoubleEndedIterator<Item = &T> + Clone> + Clone {
(0..self.num_columns).map(move |column_index| {
self.column_iter(column_index)
.expect("columns_iter should never fail")
})
}
/// Collects the [`Array2D`] into a [`Vec`] of rows, each of which contains
/// a [`Vec`] of elements.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// assert_eq!(array.as_rows(), rows);
/// # Ok(())
/// # }
/// ```
///
/// [`Array2D`]: struct.Array2D.html
/// [`Vec`]: https://doc.rust-lang.org/std/vec/struct.Vec.html
pub fn as_rows(&self) -> Vec<Vec<T>>
where
T: Clone,
{
self.rows_iter()
.map(|row_iter| row_iter.cloned().collect())
.collect()
}
/// Collects the [`Array2D`] into a [`Vec`] of columns, each of which
/// contains a [`Vec`] of elements.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let columns = vec![vec![1, 4], vec![2, 5], vec![3, 6]];
/// let array = Array2D::from_columns(&columns)?;
/// assert_eq!(array.as_columns(), columns);
/// # Ok(())
/// # }
/// ```
///
/// [`Array2D`]: struct.Array2D.html
/// [`Vec`]: https://doc.rust-lang.org/std/vec/struct.Vec.html
pub fn as_columns(&self) -> Vec<Vec<T>>
where
T: Clone,
{
self.columns_iter()
.map(|column_iter| column_iter.cloned().collect())
.collect()
}
/// Collects the [`Array2D`] into a [`Vec`] of elements in [row major
/// order].
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// assert_eq!(array.as_row_major(), vec![1, 2, 3, 4, 5, 6]);
/// # Ok(())
/// # }
/// ```
///
/// [`Array2D`]: struct.Array2D.html
/// [`Vec`]: https://doc.rust-lang.org/std/vec/struct.Vec.html
/// [row major order]: https://en.wikipedia.org/wiki/Row-_and_column-major_order
pub fn as_row_major(&self) -> Vec<T>
where
T: Clone,
{
self.elements_row_major_iter().cloned().collect()
}
/// Collects the [`Array2D`] into a [`Vec`] of elements in [column major
/// order].
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// assert_eq!(array.as_column_major(), vec![1, 4, 2, 5, 3, 6]);
/// # Ok(())
/// # }
/// ```
///
/// [`Array2D`]: struct.Array2D.html
/// [`Vec`]: https://doc.rust-lang.org/std/vec/struct.Vec.html
/// [column major order]: https://en.wikipedia.org/wiki/Row-_and_column-major_order
pub fn as_column_major(&self) -> Vec<T>
where
T: Clone,
{
self.elements_column_major_iter().cloned().collect()
}
/// Returns the indices of the array in row major order. Each index is a tuple of [`usize`].
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// let indices_row_major = array.indices_row_major().collect::<Vec<_>>();
/// assert_eq!(
/// indices_row_major,
/// vec![(0, 0), (0, 1), (0, 2), (1, 0), (1, 1), (1, 2)]
/// );
/// # Ok(())
/// # }
/// ```
///
/// [`usize`]: https://doc.rust-lang.org/std/primitive.usize.html
pub fn indices_row_major(&self) -> impl DoubleEndedIterator<Item = (usize, usize)> + Clone {
indices_row_major(self.num_rows, self.num_columns)
}
/// Returns the indices of the array in column major order. Each index is a tuple of [`usize`].
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// let indices_column_major = array.indices_column_major().collect::<Vec<_>>();
/// assert_eq!(
/// indices_column_major,
/// vec![(0, 0), (1, 0), (0, 1), (1, 1), (0, 2), (1, 2)]
/// );
/// # Ok(())
/// # }
/// ```
///
/// [`usize`]: https://doc.rust-lang.org/std/primitive.usize.html
pub fn indices_column_major(&self) -> impl DoubleEndedIterator<Item = (usize, usize)> + Clone {
indices_column_major(self.num_rows, self.num_columns)
}
/// Iterate through the array in row major order along with the corresponding indices. Each
/// index is a tuple of [`usize`].
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// let enumerate_row_major = array.enumerate_row_major().collect::<Vec<_>>();
/// assert_eq!(
/// enumerate_row_major,
/// vec![
/// ((0, 0), &1),
/// ((0, 1), &2),
/// ((0, 2), &3),
/// ((1, 0), &4),
/// ((1, 1), &5),
/// ((1, 2), &6)
/// ]
/// );
/// # Ok(())
/// # }
/// ```
///
/// [`usize`]: https://doc.rust-lang.org/std/primitive.usize.html
pub fn enumerate_row_major(
&self,
) -> impl DoubleEndedIterator<Item = ((usize, usize), &T)> + Clone {
self.indices_row_major().map(move |i| (i, &self[i]))
}
/// Iterate through the array in column major order along with the corresponding indices. Each
/// index is a tuple of [`usize`].
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// # fn main() -> Result<(), Error> {
/// let rows = vec![vec![1, 2, 3], vec![4, 5, 6]];
/// let array = Array2D::from_rows(&rows)?;
/// let enumerate_column_major = array.enumerate_column_major().collect::<Vec<_>>();
/// assert_eq!(
/// enumerate_column_major,
/// vec![
/// ((0, 0), &1),
/// ((1, 0), &4),
/// ((0, 1), &2),
/// ((1, 1), &5),
/// ((0, 2), &3),
/// ((1, 2), &6)
/// ]
/// );
/// # Ok(())
/// # }
/// ```
///
/// [`usize`]: https://doc.rust-lang.org/std/primitive.usize.html
pub fn enumerate_column_major(
&self,
) -> impl DoubleEndedIterator<Item = ((usize, usize), &T)> + Clone {
self.indices_column_major().map(move |i| (i, &self[i]))
}
fn get_index(&self, row: usize, column: usize) -> Option<usize> {
if row < self.num_rows && column < self.num_columns {
Some(row * self.row_len() + column)
} else {
None
}
}
}
impl<T> Index<(usize, usize)> for Array2D<T> {
type Output = T;
/// Returns the element at the given indices, given as `(row, column)`.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// let array = Array2D::filled_with(42, 2, 3);
/// assert_eq!(array[(0, 0)], 42);
/// ```
///
/// # Panics
///
/// Panics if the indices are out of bounds.
///
/// ```rust,should_panic
/// # use array2d::Array2D;
/// let array = Array2D::filled_with(42, 2, 3);
/// let element = array[(10, 10)];
/// ```
fn index(&self, (row, column): (usize, usize)) -> &Self::Output {
self.get(row, column)
.unwrap_or_else(|| panic!("Index indices {}, {} out of bounds", row, column))
}
}
impl<T> IndexMut<(usize, usize)> for Array2D<T> {
/// Returns a mutable version of the element at the given indices, given as
/// `(row, column)`.
///
/// # Examples
///
/// ```
/// # use array2d::{Array2D, Error};
/// let mut array = Array2D::filled_with(42, 2, 3);
/// array[(0, 0)] = 100;
/// assert_eq!(array[(0, 0)], 100);
/// ```
///
/// # Panics
///
/// Panics if the indices are out of bounds.
///
/// ```rust,should_panic
/// # use array2d::Array2D;
/// let mut array = Array2D::filled_with(42, 2, 3);
/// array[(10, 10)] = 7;
/// ```
fn index_mut(&mut self, (row, column): (usize, usize)) -> &mut Self::Output {
self.get_mut(row, column)
.unwrap_or_else(|| panic!("Index mut indices {}, {} out of bounds", row, column))
}
}
fn flatten<T: Clone>(nested: &[Vec<T>]) -> Vec<T> {
nested.iter().flat_map(|row| row.clone()).collect()
}
fn indices_row_major(
num_rows: usize,
num_columns: usize,
) -> impl DoubleEndedIterator<Item = (usize, usize)> + Clone {
(0..num_rows).flat_map(move |row| (0..num_columns).map(move |column| (row, column)))
}
fn indices_column_major(
num_rows: usize,
num_columns: usize,
) -> impl DoubleEndedIterator<Item = (usize, usize)> + Clone {
(0..num_columns).flat_map(move |column| (0..num_rows).map(move |row| (row, column)))
}