├── .gitignore ├── LICENSE ├── README.md ├── images ├── classhierarchy.png ├── legend.graphml ├── legend.png ├── scala-collection-immutable.graphml ├── scala-collection-immutable.png ├── scala-collection-mutable.graphml ├── scala-collection-mutable.png ├── scala-collection.graphml └── scala-collection.png ├── scala-cheat-sheet.pdf └── scala-cheat-sheet.tex /.gitignore: -------------------------------------------------------------------------------- 1 | *.acn 2 | *.acr 3 | *.alg 4 | *.aux 5 | *.bbl 6 | *.blg 7 | *.dvi 8 | *.fdb_latexmk 9 | *.glg 10 | *.glo 11 | *.gls 12 | *.idx 13 | *.ilg 14 | *.ind 15 | *.ist 16 | *.lof 17 | *.log 18 | *.lot 19 | *.maf 20 | *.mtc 21 | *.mtc0 22 | *.nav 23 | *.nlo 24 | *.out 25 | *.pdfsync 26 | *.ps 27 | *.snm 28 | *.synctex.gz 29 | *.toc 30 | *.vrb 31 | *.xdy 32 | *.tdo 33 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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Install [Tex Live 2013](http://www.tug.org/texlive/), then add its `bin` path for example `D:\texlive\2013\bin\win32` to he PATH environment variable. 9 | 2. Install [TeXstudio](http://texstudio.sourceforge.net/). 10 | 3. Configure TeXstudio. 11 | Run TeXstudio, click `Options-->Configure Texstudio-->Commands`, set `PdfLaTex` to `pdflatex.exe -synctex=1 -interaction=nonstopmode %.tex`. 12 | Click `Options-->Configure Texstudio-->Build`, 13 | set `Build & View` to `Compile & View`, 14 | set `Default Compiler` to `PdfLaTex`, 15 | set `PDF Viewer` to `Internal PDF Viewer(windowed)`, so that when previewing it will pop up a standalone window, which will be convenient. 16 | 4. Compile. Open `scala-cheat-sheet.tex` with TeXstudio，click the green arrow on the menu bar, then it will start to compile. 17 | In the messages window below we can see the compilation command that TeXstudio used is ` pdflatex.exe -synctex=1 -interaction=nonstopmode "scala-cheat-sheet".tex` 18 | -------------------------------------------------------------------------------- /images/classhierarchy.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/soulmachine/scala-cheat-sheet/778c8158b267976ba17334b1239fa9542f99563f/images/classhierarchy.png -------------------------------------------------------------------------------- /images/legend.graphml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | Trait 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | Class 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 | implemented by 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 | default implementation 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 | implemented by 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 | -------------------------------------------------------------------------------- /images/legend.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/soulmachine/scala-cheat-sheet/778c8158b267976ba17334b1239fa9542f99563f/images/legend.png -------------------------------------------------------------------------------- /images/scala-collection-immutable.graphml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | Traversable 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | Iterable 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | Set 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | Seq 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | Map 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 | 101 | 102 | 103 | IndexedSeq 104 | 105 | 106 | 107 | 108 | 109 | 110 | 111 | 112 | 113 | 114 | 115 | 116 | 117 | 118 | 119 | LinearSeq 120 | 121 | 122 | 123 | 124 | 125 | 126 | 127 | 128 | 129 | 130 | 131 | 132 | 133 | 134 | 135 | SortedSet 136 | 137 | 138 | 139 | 140 | 141 | 142 | 143 | 144 | 145 | 146 | 147 | 148 | 149 | 150 | 151 | SortedMap 152 | 153 | 154 | 155 | 156 | 157 | 158 | 159 | 160 | 161 | 162 | 163 | 164 | 165 | 166 | 167 | BitSet 168 | 169 | 170 | 171 | 172 | 173 | 174 | 175 | 176 | 177 | 178 | 179 | 180 | 181 | 182 | 183 | ListSet 184 | 185 | 186 | 187 | 188 | 189 | 190 | 191 | 192 | 193 | 194 | 195 | 196 | 197 | 198 | 199 | TreeSet 200 | 201 | 202 | 203 | 204 | 205 | 206 | 207 | 208 | 209 | 210 | 211 | 212 | 213 | 214 | 215 | HashSet 216 | 217 | 218 | 219 | 220 | 221 | 222 | 223 | 224 | 225 | 226 | 227 | 228 | 229 | 230 | 231 | HashMap 232 | 233 | 234 | 235 | 236 | 237 | 238 | 239 | 240 | 241 | 242 | 243 | 244 | 245 | 246 | 247 | ListMap 248 | 249 | 250 | 251 | 252 | 253 | 254 | 255 | 256 | 257 | 258 | 259 | 260 | 261 | 262 | 263 | TreeMap 264 | 265 | 266 | 267 | 268 | 269 | 270 | 271 | 272 | 273 | 274 | 275 | 276 | 277 | 278 | 279 | String 280 | 281 | 282 | 283 | 284 | 285 | 286 | 287 | 288 | 289 | 290 | 291 | 292 | 293 | 294 | 295 | Range 296 | 297 | 298 | 299 | 300 | 301 | 302 | 303 | 304 | 305 | 306 | 307 | 308 | 309 | 310 | 311 | NumericRange 312 | 313 | 314 | 315 | 316 | 317 | 318 | 319 | 320 | 321 | 322 | 323 | 324 | 325 | 326 | 327 | Vector 328 | 329 | 330 | 331 | 332 | 333 | 334 | 335 | 336 | 337 | 338 | 339 | 340 | 341 | 342 | 343 | List 344 | 345 | 346 | 347 | 348 | 349 | 350 | 351 | 352 | 353 | 354 | 355 | 356 | 357 | 358 | 359 | Stream 360 | 361 | 362 | 363 | 364 | 365 | 366 | 367 | 368 | 369 | 370 | 371 | 372 | 373 | 374 | 375 | Stack 376 | 377 | 378 | 379 | 380 | 381 | 382 | 383 | 384 | 385 | 386 | 387 | 388 | 389 | 390 | 391 | Queue 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 | -------------------------------------------------------------------------------- /images/scala-collection-immutable.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/soulmachine/scala-cheat-sheet/778c8158b267976ba17334b1239fa9542f99563f/images/scala-collection-immutable.png -------------------------------------------------------------------------------- /images/scala-collection-mutable.graphml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | Traversable 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | Iterable 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | Set 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | Seq 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | Map 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 | 101 | 102 | 103 | IndexedSeq 104 | 105 | 106 | 107 | 108 | 109 | 110 | 111 | 112 | 113 | 114 | 115 | 116 | 117 | 118 | 119 | LinearSeq 120 | 121 | 122 | 123 | 124 | 125 | 126 | 127 | 128 | 129 | 130 | 131 | 132 | 133 | 134 | 135 | SortedSet 136 | 137 | 138 | 139 | 140 | 141 | 142 | 143 | 144 | 145 | 146 | 147 | 148 | 149 | 150 | 151 | BitSet 152 | 153 | 154 | 155 | 156 | 157 | 158 | 159 | 160 | 161 | 162 | 163 | 164 | 165 | 166 | 167 | LinkedHashSet 168 | 169 | 170 | 171 | 172 | 173 | 174 | 175 | 176 | 177 | 178 | 179 | 180 | 181 | 182 | 183 | TreeSet 184 | 185 | 186 | 187 | 188 | 189 | 190 | 191 | 192 | 193 | 194 | 195 | 196 | 197 | 198 | 199 | HashSet 200 | 201 | 202 | 203 | 204 | 205 | 206 | 207 | 208 | 209 | 210 | 211 | 212 | 213 | 214 | 215 | HashMap 216 | 217 | 218 | 219 | 220 | 221 | 222 | 223 | 224 | 225 | 226 | 227 | 228 | 229 | 230 | 231 | ListMap 232 | 233 | 234 | 235 | 236 | 237 | 238 | 239 | 240 | 241 | 242 | 243 | 244 | 245 | 246 | 247 | ArraySeq 248 | 249 | 250 | 251 | 252 | 253 | 254 | 255 | 256 | 257 | 258 | 259 | 260 | 261 | 262 | 263 | Array 264 | 265 | 266 | 267 | 268 | 269 | 270 | 271 | 272 | 273 | 274 | 275 | 276 | 277 | 278 | 279 | StringBuilder 280 | 281 | 282 | 283 | 284 | 285 | 286 | 287 | 288 | 289 | 290 | 291 | 292 | 293 | 294 | 295 | ArrayBuffer 296 | 297 | 298 | 299 | 300 | 301 | 302 | 303 | 304 | 305 | 306 | 307 | 308 | 309 | 310 | 311 | MutableList 312 | 313 | 314 | 315 | 316 | 317 | 318 | 319 | 320 | 321 | 322 | 323 | 324 | 325 | 326 | 327 | LinkedList 328 | 329 | 330 | 331 | 332 | 333 | 334 | 335 | 336 | 337 | 338 | 339 | 340 | 341 | 342 | 343 | DoubledLinkedList 344 | 345 | 346 | 347 | 348 | 349 | 350 | 351 | 352 | 353 | 354 | 355 | 356 | 357 | 358 | 359 | ImmutableSetAdaptor 360 | 361 | 362 | 363 | 364 | 365 | 366 | 367 | 368 | 369 | 370 | 371 | 372 | 373 | 374 | 375 | ObservableSet 376 | 377 | 378 | 379 | 380 | 381 | 382 | 383 | 384 | 385 | 386 | 387 | 388 | 389 | 390 | 391 | SynchronizedSet 392 | 393 | 394 | 395 | 396 | 397 | 398 | 399 | 400 | 401 | 402 | 403 | 404 | 405 | 406 | 407 | LinkedHashMap 408 | 409 | 410 | 411 | 412 | 413 | 414 | 415 | 416 | 417 | 418 | 419 | 420 | 421 | 422 | 423 | WeakHashMap 424 | 425 | 426 | 427 | 428 | 429 | 430 | 431 | 432 | 433 | 434 | 435 | 436 | 437 | 438 | 439 | OpenHashMap 440 | 441 | 442 | 443 | 444 | 445 | 446 | 447 | 448 | 449 | 450 | 451 | 452 | 453 | 454 | 455 | MultiMap 456 | 457 | 458 | 459 | 460 | 461 | 462 | 463 | 464 | 465 | 466 | 467 | 468 | 469 | 470 | 471 | ObservableMap 472 | 473 | 474 | 475 | 476 | 477 | 478 | 479 | 480 | 481 | 482 | 483 | 484 | 485 | 486 | 487 | SynchronizedMap 488 | 489 | 490 | 491 | 492 | 493 | 494 | 495 | 496 | 497 | 498 | 499 | 500 | 501 | 502 | 503 | ImmutableMapAdaptor 504 | 505 | 506 | 507 | 508 | 509 | 510 | 511 | 512 | 513 | 514 | 515 | 516 | 517 | 518 | 519 | Buffer 520 | 521 | 522 | 523 | 524 | 525 | 526 | 527 | 528 | 529 | 530 | 531 | 532 | 533 | 534 | 535 | ListBuffer 536 | 537 | 538 | 539 | 540 | 541 | 542 | 543 | 544 | 545 | 546 | 547 | 548 | 549 | 550 | 551 | ObservableBuffer 552 | 553 | 554 | 555 | 556 | 557 | 558 | 559 | 560 | 561 | 562 | 563 | 564 | 565 | 566 | 567 | SynchronizedBuffer 568 | 569 | 570 | 571 | 572 | 573 | 574 | 575 | 576 | 577 | 578 | 579 | 580 | 581 | 582 | 583 | Stack 584 | 585 | 586 | 587 | 588 | 589 | 590 | 591 | 592 | 593 | 594 | 595 | 596 | 597 | 598 | 599 | ArrayStack 600 | 601 | 602 | 603 | 604 | 605 | 606 | 607 | 608 | 609 | 610 | 611 | 612 | 613 | 614 | 615 | PriorityQueue 616 | 617 | 618 | 619 | 620 | 621 | 622 | 623 | 624 | 625 | 626 | 627 | 628 | 629 | 630 | 631 | SynchronizedStack 632 | 633 | 634 | 635 | 636 | 637 | 638 | 639 | 640 | 641 | 642 | 643 | 644 | 645 | 646 | 647 | SynchronizedPriorityQueue 648 | 649 | 650 | 651 | 652 | 653 | 654 | 655 | 656 | 657 | 658 | 659 | 660 | 661 | 662 | 663 | Queue 664 | 665 | 666 | 667 | 668 | 669 | 670 | 671 | 672 | 673 | 674 | 675 | 676 | 677 | 678 | 679 | SynchronizedQueue 680 | 681 | 682 | 683 | 684 | 685 | 686 | 687 | 688 | 689 | 690 | 691 | 692 | 693 | 694 | 695 | 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122 | 123 | 124 | 125 | 126 | LinearSeq 127 | 128 | 129 | 130 | 131 | 132 | 133 | 134 | 135 | 136 | 137 | 138 | 139 | 140 | 141 | 142 | 143 | SortedSet 144 | 145 | 146 | 147 | 148 | 149 | 150 | 151 | 152 | 153 | 154 | 155 | 156 | 157 | 158 | 159 | 160 | BitSet 161 | 162 | 163 | 164 | 165 | 166 | 167 | 168 | 169 | 170 | 171 | 172 | 173 | 174 | 175 | 176 | 177 | SortedMap 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 | -------------------------------------------------------------------------------- /images/scala-collection.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/soulmachine/scala-cheat-sheet/778c8158b267976ba17334b1239fa9542f99563f/images/scala-collection.png -------------------------------------------------------------------------------- /scala-cheat-sheet.pdf: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/soulmachine/scala-cheat-sheet/778c8158b267976ba17334b1239fa9542f99563f/scala-cheat-sheet.pdf -------------------------------------------------------------------------------- /scala-cheat-sheet.tex: -------------------------------------------------------------------------------- 1 | \documentclass[a4paper,twoside,10pt,landscape]{article} 2 | \usepackage{multicol} 3 | \usepackage{calc} 4 | \usepackage{ifthen} 5 | \usepackage[landscape]{geometry} 6 | \usepackage{hyperref} 7 | \usepackage{graphicx} % standard LaTeX graphics tool when including figure files 8 | \graphicspath{{images/}} 9 | \usepackage[font={small}]{caption} 10 | \captionsetup{aboveskip=3pt} 11 | 12 | % To make this come out properly in landscape mode, do one of the following 13 | % 1. 14 | % pdflatex latexsheet.tex 15 | % 16 | % 2. 17 | % latex latexsheet.tex 18 | % dvips -P pdf -t landscape latexsheet.dvi 19 | % ps2pdf latexsheet.ps 20 | 21 | 22 | % If you're reading this, be prepared for confusion. Making this was 23 | % a learning experience for me, and it shows. Much of the placement 24 | % was hacked in; if you make it better, let me know... 25 | 26 | 27 | % 2008-04 28 | % Changed page margin code to use the geometry package. Also added code for 29 | % conditional page margins, depending on paper size. Thanks to Uwe Ziegenhagen 30 | % for the suggestions. 31 | 32 | % 2006-08 33 | % Made changes based on suggestions from Gene Cooperman. 34 | 35 | 36 | % To Do: 37 | % \listoffigures \listoftables 38 | % \setcounter{secnumdepth}{0} 39 | 40 | 41 | % This sets page margins to .5 inch if using letter paper, and to 1cm 42 | % if using A4 paper. (This probably isn't strictly necessary.) 43 | % If using another size paper, use default 1cm margins. 44 | \ifthenelse{\lengthtest { \paperwidth = 11in}} 45 | { \geometry{top=.5in,left=.5in,right=.5in,bottom=.5in} } 46 | {\ifthenelse{ \lengthtest{ \paperwidth = 297mm}} 47 | {\geometry{top=1cm,left=1cm,right=1cm,bottom=1cm} } 48 | {\geometry{top=1cm,left=1cm,right=1cm,bottom=1cm} } 49 | } 50 | 51 | % Turn off header and footer 52 | \pagestyle{empty} 53 | 54 | 55 | % Redefine section commands to use less space 56 | \makeatletter 57 | \renewcommand{\section}{\@startsection{section}{1}{0mm}% 58 | {-1ex plus -.5ex minus -.2ex}% 59 | {0.5ex plus .2ex}%x 60 | {\normalfont\large\bfseries}} 61 | \renewcommand{\subsection}{\@startsection{subsection}{2}{0mm}% 62 | {-1explus -.5ex minus -.2ex}% 63 | {0.5ex plus .2ex}% 64 | {\normalfont\normalsize\bfseries}} 65 | \renewcommand{\subsubsection}{\@startsection{subsubsection}{3}{0mm}% 66 | {-1ex plus -.5ex minus -.2ex}% 67 | {1ex plus .2ex}% 68 | {\normalfont\small\bfseries}} 69 | \makeatother 70 | 71 | % Define BibTeX command 72 | \def\BibTeX{{\rm B\kern-.05em{\sc i\kern-.025em b}\kern-.08em 73 | T\kern-.1667em\lower.7ex\hbox{E}\kern-.125emX}} 74 | 75 | % Don't print section numbers 76 | %\setcounter{secnumdepth}{0} 77 | 78 | 79 | \setlength{\parindent}{0pt} 80 | \setlength{\parskip}{0pt plus 0.5ex} 81 | 82 | 83 | % ----------------------------------------------------------------------- 84 | 85 | \begin{document} 86 | 87 | \raggedright 88 | \footnotesize 89 | \begin{multicols}{3} 90 | 91 | 92 | % multicol parameters 93 | % These lengths are set only within the two main columns 94 | %\setlength{\columnseprule}{0.25pt} 95 | \setlength{\premulticols}{1pt} 96 | \setlength{\postmulticols}{1pt} 97 | \setlength{\multicolsep}{1pt} 98 | \setlength{\columnsep}{2pt} 99 | 100 | \begin{center} 101 | \Large{\textbf{Scala Cheat Sheet}} \\ 102 | \end{center} 103 | 104 | 105 | \section{Scala Class Hierarchy} 106 | \begin{center} 107 | \includegraphics[scale=.69]{classhierarchy.png} 108 | \captionof{figure}{Scala class hierarchy, source: \url{http://www.scala-lang.org/old/node/128}} 109 | \label{fig:scala-class-hierarchy} 110 | \end{center} 111 | 112 | 113 | \section{Scala Collections} 114 | 115 | 116 | \subsection{Scala Collections Hierarchy} 117 | 118 | \begin{center} 119 | \includegraphics[scale=.50]{legend.png} 120 | \end{center} 121 | 122 | \begin{center} 123 | \includegraphics[scale=.50]{scala-collection.png} 124 | \captionof{figure}{scala.collection} 125 | \label{fig:scala-collection} 126 | \end{center} 127 | 128 | \begin{center} 129 | \includegraphics[scale=.70]{scala-collection-immutable.png} 130 | \captionof{figure}{scala.collection.immutable} 131 | \label{fig:scala-collection-immutable} 132 | \end{center} 133 | 134 | \begin{center} 135 | \includegraphics[scale=.68]{scala-collection-mutable.png} 136 | \captionof{figure}{scala.collection.mutable} 137 | \label{fig:scala-collection-mutable} 138 | \end{center} 139 | 140 | 141 | \subsection{Trait \texttt{Traversable}} 142 | \begin{center} 143 | \captionof{table}{Methods in \texttt{Traversable}} 144 | \begin{tabular}{@{}lp{6.5cm}@{}} 145 | \hline\noalign{\smallskip} 146 | \textbf{Category} & \textbf{Methods} \\ 147 | \noalign{\smallskip}\hline\noalign{\smallskip} 148 | \textbf{Abstract} & \texttt{xs foreach f}\\ 149 | \textbf{Addition} & \texttt{xs ++ ys}\\ 150 | \textbf{Maps} & \texttt{xs map f, xs flatMap f, xs collect f}\\ 151 | \textbf{Conversions} & \texttt{toArray, toList, toIterable, toSeq, toIndexedSeq, toStream, toSet, toMap}\\ 152 | \textbf{Size info} & \texttt{isEmpty, nonEmpty, size, hasDefiniteSize}\\ 153 | \textbf{Element} & \texttt{head, headOption, last, lastOption},\\ 154 | \textbf{Retrieval} & \texttt{xs find p}\\ 155 | \textbf{Sub-} & \texttt{xs.tail, xs.init, xs slice (from, to)},\\ 156 | \textbf{collection} & \texttt{xs take n, xs drop n, xs takeWhile p, xs dropWhile p, xs filter p, xs withFilter p, xs filterNot p}\\ 157 | \textbf{Subdivision} & \texttt{xs splitAt n, xs span p, xs partition p, xs groupBy f}\\ 158 | \textbf{Element} & \texttt{xs forall p, xs exists p, xs count p}\\ 159 | \textbf{Condition} & \\ 160 | \textbf{Fold} & \texttt{(z /: xs)(op), (xs :\ z)(op), xs.foldLeft(z)(op), xs.foldRight(z)(op), xs reduceLeft op, xs reduceRight op}\\ 161 | \textbf{Specific Fold} & \texttt{xs.sum, xs.product, xs.min, xs.max}\\ 162 | \textbf{String} & \texttt{xs addString (b, start, sep, end), xs mkString (start, sep, end), xs.stringPrefix}\\ 163 | \textbf{View} & \texttt{xs.view, xs view (from, to)}\\ 164 | \noalign{\smallskip}\hline 165 | \end{tabular} 166 | \raggedright{\tiny{Reference: \url{http://docs.scala-lang.org/overviews/collections/trait-traversable.html}}} 167 | \end{center} 168 | 169 | 170 | \subsection{Trait \texttt{Iterable}} 171 | All methods in this trait are defined in terms of an an abstract method, \texttt{iterator}, which yields the collection’s elements one by one. 172 | 173 | \begin{center} 174 | \captionof{table}{Methods in \texttt{Iterable}} 175 | \begin{tabular}{@{}lp{6cm}@{}} 176 | \hline\noalign{\smallskip} 177 | \textbf{Category} & \textbf{Methods} \\ 178 | \noalign{\smallskip}\hline\noalign{\smallskip} 179 | \textbf{Abstract} & \texttt{xs.iterator}\\ 180 | \textbf{Iterator} & \texttt{xs grouped n, xs sliding n}\\ 181 | \textbf{Subcollection} & \texttt{xs takeRight n, xs dropRight n}\\ 182 | \textbf{Zipper} & \texttt{xs zip ys, xs zipAll (ys, x, y), xs.zipWithIndex}\\ 183 | \textbf{Comparison} & \texttt{xs sameElements ys}\\ 184 | \noalign{\smallskip}\hline 185 | \end{tabular} 186 | \raggedright{\tiny{Reference: \url{http://docs.scala-lang.org/overviews/collections/trait-iterable.html}}} 187 | \end{center} 188 | 189 | In the inheritance hierarchy below \texttt{Iterable} you find three traits: \texttt{Seq}, \texttt{Set}, and \texttt{Map}. A common aspect of these three traits is that they all implement the \texttt{PartialFunction} trait with its \texttt{apply} and \texttt{isDefinedAt} methods. However, the way each trait implements \texttt{PartialFunction} differs. 190 | 191 | 192 | \subsection{Seq} 193 | 194 | \begin{center} 195 | \captionof{table}{Methods in \texttt{Seq}} 196 | \begin{tabular}{@{}lp{6.5cm}@{}} 197 | \hline\noalign{\smallskip} 198 | \textbf{Category} & \textbf{Methods} \\ 199 | \noalign{\smallskip}\hline\noalign{\smallskip} 200 | \textbf{Indexing and} & \texttt{xs(i), xs isDefinedAt i, xs.length,}\\ 201 | \textbf{Length} & \texttt{xs.lengthCompare ys, xs.indices}\\ 202 | \textbf{Index Search} & \texttt{xs indexOf x, xs lastIndexOf x, xs indexOfSlice ys, xs lastIndexOfSlice ys, xs indexWhere p, xs segmentLength (p, i), xs prefixLength p}\\ 203 | \textbf{Addition} & \texttt{x +: xs, xs :+ x, xs padTo (len, x)}\\ 204 | \textbf{Update} & \texttt{xs patch (i, ys, r), xs updated (i, x), xs(i) = x}(only available for \texttt{mutable.Seq}s)\\ 205 | \textbf{Sorting} & \texttt{xs.sorted, xs sortWith lt, xs sortBy f}\\ 206 | \textbf{Reversal} & \texttt{xs.reverse, xs.reverseIterator, xs reverseMap f}\\ 207 | \textbf{Comparison} & \texttt{xs startsWith ys, xs endsWith ys, xs contains x, xs containsSlice ys, (xs corresponds ys)(p)}\\ 208 | \textbf{Multiset} & \texttt{xs intersect ys, xs union ys, xs diff ys, xs.distinct}\\ 209 | \noalign{\smallskip}\hline 210 | \end{tabular} 211 | \raggedright{\tiny{Reference: \url{http://docs.scala-lang.org/overviews/collections/seqs.html}}} 212 | \end{center} 213 | 214 | \begin{center} 215 | \captionof{table}{Methods in \texttt{Buffer}} 216 | \begin{tabular}{@{}lp{6.5cm}@{}} 217 | \hline\noalign{\smallskip} 218 | \textbf{Category} & \textbf{Methods} \\ 219 | \noalign{\smallskip}\hline\noalign{\smallskip} 220 | \textbf{Addition} & \texttt{buf += x, buf += (x, y, z), buf ++= xs, x +=: buf, xs ++=: buf, buf insert (i, x), buf insertAll (i, xs)}\\ 221 | \textbf{Removal} & \texttt{buf -= x, buf remove i, buf remove (i, n), buf trimStart n, buf trimEnd n, buf.clear()}\\ 222 | \textbf{Cloning} & \texttt{buf.clone}\\ 223 | \noalign{\smallskip}\hline 224 | \end{tabular} 225 | \end{center} 226 | 227 | 228 | \subsection{Set} 229 | \begin{center} 230 | \captionof{table}{Methods in \texttt{Set}} 231 | \begin{tabular}{@{}lp{6.5cm}@{}} 232 | \hline\noalign{\smallskip} 233 | \textbf{Category} & \textbf{Methods} \\ 234 | \noalign{\smallskip}\hline\noalign{\smallskip} 235 | \textbf{Test} & \texttt{xs contains x, xs(x), xs subsetOf ys}\\ 236 | \textbf{Addition} & \texttt{xs + x, xs + (x, y, z), xs ++ ys}\\ 237 | \textbf{Removal} & \texttt{xs - x, xs - (x, y, z), xs -- ys, xs.empty}\\ 238 | \textbf{Set operation} & \texttt{xs \& ys, xs intersect ys, xs | ys, xs union ys, xs \&~ ys, xs diff ys}\\ 239 | \noalign{\smallskip}\hline 240 | \end{tabular} 241 | \raggedright{\tiny{Reference: \url{http://docs.scala-lang.org/overviews/collections/sets.html}}} 242 | \end{center} 243 | 244 | Mutable sets offer in addition methods to add, remove, or update elements, which are summarized in below. 245 | 246 | \begin{center} 247 | \captionof{table}{Methods in \texttt{mutable.Set}} 248 | \begin{tabular}{@{}lp{6.5cm}@{}} 249 | \hline\noalign{\smallskip} 250 | \textbf{Category} & \textbf{Methods} \\ 251 | \noalign{\smallskip}\hline\noalign{\smallskip} 252 | \textbf{Addition} & \texttt{xs += x, xs += (x, y, z), xs ++= ys, xs add x}\\ 253 | \textbf{Removal} & \texttt{xs -= x, xs -= (x, y, z), xs --= ys, xs remove x, xs retain p, xs.clear()}\\ 254 | \textbf{Update} & \texttt{xs(x) = b}\\ 255 | \textbf{Cloning} & \texttt{xs.clone}\\ 256 | \noalign{\smallskip}\hline 257 | \end{tabular} 258 | \end{center} 259 | 260 | 261 | \subsection{Map} 262 | \begin{center} 263 | \captionof{table}{Methods in \texttt{Map}} 264 | \begin{tabular}{@{}lp{6cm}@{}} 265 | \hline\noalign{\smallskip} 266 | \textbf{Category} & \textbf{Methods} \\ 267 | \noalign{\smallskip}\hline\noalign{\smallskip} 268 | \textbf{Lookup} & \texttt{ms get k, ms(k), ms getOrElse (k, d), ms contains k, ms isDefinedAt k}\\ 269 | \textbf{Addition} & \texttt{ms + (k -> v), ms + (k -> v, l -> w), ms ++ kvs}\\ 270 | \textbf{Removal} & \texttt{ms - k, ms - (k, 1, m), ms -- ks}\\ 271 | \textbf{Update} & \texttt{ms updated (k, v)}\\ 272 | \textbf{Subcollection} & \texttt{ms.keys, ms.keySet, ms.keyIterator, ms.values, ms.valuesIterator}\\ 273 | \textbf{Transformation} & \texttt{ms filterKeys p, ms mapValues f}\\ 274 | \noalign{\smallskip}\hline 275 | \end{tabular} 276 | \raggedright{\tiny{Reference: \url{http://docs.scala-lang.org/overviews/collections/maps.html}}} 277 | \end{center} 278 | 279 | \begin{center} 280 | \captionof{table}{Methods in \texttt{mutable.Map}} 281 | \begin{tabular}{@{}lp{6cm}@{}} 282 | \hline\noalign{\smallskip} 283 | \textbf{Category} & \textbf{Methods} \\ 284 | \noalign{\smallskip}\hline\noalign{\smallskip} 285 | \textbf{Addition} & \texttt{ms += (k -> v), ms += (k -> v, l -> w), ms ++= kvs, }\\ 286 | \textbf{Removal} & \texttt{ms -= k, ms -= (k, l, m), ms --= ks, ms remove k, ms retain p, ms.clear()}\\ 287 | \textbf{Update} & \texttt{ms(k) = v, ms put (k, v), ms getOrElseUpdate (k, d)}\\ 288 | \textbf{Transformation} & \texttt{ms transform f}\\ 289 | \textbf{Cloning} & \texttt{xs.clone}\\ 290 | \noalign{\smallskip}\hline 291 | \end{tabular} 292 | \end{center} 293 | 294 | 295 | \subsection{Performance Characteristics} 296 | \begingroup 297 | \setlength{\tabcolsep}{1pt} 298 | \begin{center} 299 | \captionof{table}{Performance characteristics of sequence types} 300 | %\begin{tabular}{@{}l@{\hskip 2pt}c@{\hskip 2pt}c@{\hskip 2pt}c@{\hskip 2pt}c@{\hskip 2pt}c@{\hskip 2pt}c@{\hskip 2pt}c@{}} 301 | \begin{tabular}{@{}lccccccc@{}} 302 | \hline\noalign{\smallskip} 303 | & \textbf{head} & \textbf{tail} & \textbf{apply} & \textbf{update} & \textbf{prepend} & \textbf{append} & \textbf{insert}\\ 304 | \noalign{\smallskip}\hline\noalign{\smallskip} 305 | \textbf{immutable} &&&&&&& \\ 306 | \texttt{List} & C & C & L & L & C & L & - \\ 307 | \texttt{Stream} & C & C & L & L & C & L & - \\ 308 | \texttt{Vector} & eC & eC & eC & eC & eC & eC & - \\ 309 | \texttt{Stack} & C & C & L & L & C & C & L \\ 310 | \texttt{Queue} & aC & aC & L & L & L & C & - \\ 311 | \texttt{Range} & C & C & C & - & - & - & - \\ 312 | \texttt{String} & C & L & C & L & L & L & - \\ 313 | \textbf{mutable} &&&&&&& \\ 314 | \texttt{ArrayBuffer} & C & L & C & C & L & aC & L \\ 315 | \texttt{ListBuffer} & C & L & L & L & C & C & L \\ 316 | \texttt{StringBuilder} & C & L & C & C & L & aC & L \\ 317 | \texttt{MutableList} & C & L & L & L & C & C & L \\ 318 | \texttt{Queue} & C & L & L & L & C & C & L \\ 319 | \texttt{ArraySeq} & C & L & C & C & - & - & - \\ 320 | \texttt{Stack} & C & L & L & L & C & L & L \\ 321 | \texttt{ArrayStack} & C & L & C & C & aC & L & L \\ 322 | \texttt{Array} & C & L & C & C & - & - & - \\ 323 | \noalign{\smallskip}\hline 324 | \end{tabular} 325 | \raggedright{\tiny{Reference: \url{http://docs.scala-lang.org/overviews/collections/performance-characteristics.html}}} 326 | \end{center} 327 | \endgroup 328 | 329 | \begin{center} 330 | \captionof{table}{Performance characteristics of set and map types} 331 | \begin{tabular}{@{}lcccc@{}} 332 | \hline\noalign{\smallskip} 333 | & \textbf{lookup} & \textbf{add} & \textbf{remove} & \textbf{min} \\ 334 | \noalign{\smallskip}\hline\noalign{\smallskip} 335 | \textbf{immutable} &&&& \\ 336 | \texttt{HashSet/HashMap} & eC & eC & eC & L \\ 337 | \texttt{TreeSet/TreeMap} & Log & Log & Log & Log \\ 338 | \texttt{BitSet} & C & L & L & $eC^1$ \\ 339 | \texttt{ListMap} & L & L & L & L \\ 340 | \textbf{mutable} &&&& \\ 341 | \texttt{HashSet/HashMap} & eC & eC & eC & L \\ 342 | \texttt{WeakHashMap} & eC & eC & eC & L \\ 343 | \texttt{BitSet} & C & aC & C & $eC^1$ \\ 344 | \texttt{TreeSet} & Log & Log & Log & Log \\ 345 | \noalign{\smallskip}\hline 346 | \multicolumn{5}{c}{\small{Footnote 1: Assuming bits are densely packed.}} 347 | \end{tabular} 348 | \end{center} 349 | 350 | The entries in these two tables are explained as follows: 351 | 352 | \begin{tabular}{@{}lp{7cm}@{}} 353 | C & The operation takes (fast) constant time. \\ 354 | eC & The operation takes effectively constant time, but this might depend on some assumptions such as maximum length of a vector or distribution of hash keys. \\ 355 | aC & The operation takes amortized constant time. Some invocations of the operation might take longer, but if many operations are performed on average only constant time per operation is taken. \\ 356 | Log & The operation takes time proportional to the logarithm of the collection size. \\ 357 | L & The operation is linear, that is it takes time proportional to the collection size. \\ 358 | - & The operation is not supported. 359 | \end{tabular} 360 | 361 | 362 | \section{Scala Parallel Collections} 363 | 364 | 365 | \subsection{Creating a Parallel Collection} 366 | Two ways to create a parallel collection: \texttt{new} and \texttt{par}. 367 | 368 | 369 | \subsection{Semantics} 370 | Conceptually, Scala’s parallel collections framework parallelizes an operation on a parallel collection by recursively “splitting” a given collection, applying an operation on each partition of the collection in parallel, and re-“combining” all of the results that were completed in parallel. 371 | 372 | These concurrent, and “out-of-order” semantics of parallel collections lead to the following two implications: 373 | \begin{enumerate} 374 | \item Side-effecting operations can lead to non-determinism 375 | \item Non-associative operations lead to non-determinism 376 | \end{enumerate} 377 | 378 | 379 | \subsection{Concrete Parallel Collection Classes} 380 | \texttt{mutable.ParArray}, \texttt{immutable.ParVector}, \texttt{immutable.ParRange}, 381 | 382 | \texttt{mutable.ParHashSet}, \texttt{mutable.ParHashMap}, \texttt{immutable.ParHashSet}, \texttt{immutable.ParHashMap}, 383 | 384 | \texttt{mutable.ParTrieMap} 385 | 386 | 387 | \subsection{Performance characteristics} 388 | \begingroup 389 | \setlength{\tabcolsep}{1pt} 390 | \begin{center} 391 | \captionof{table}{Performance characteristics of sequence types} 392 | \begin{tabular}{@{}lccccccc@{}} 393 | \hline\noalign{\smallskip} 394 | & \textbf{head} & \textbf{tail} & \textbf{apply} & \textbf{update} & \textbf{prepend} & \textbf{append} & \textbf{insert}\\ 395 | \noalign{\smallskip}\hline\noalign{\smallskip} 396 | \texttt{ParArray} & C & L & C & C & L & L & L \\ 397 | \texttt{ParVector} & eC & eC & eC & eC & eC & eC & - \\ 398 | \texttt{ParRange} & C & C & C & - & - & - & - \\ 399 | \noalign{\smallskip}\hline 400 | \end{tabular} 401 | \raggedright{\tiny{\url{http://docs.scala-lang.org/overviews/parallel-collections/concrete-parallel-collections.html}}} 402 | \end{center} 403 | \endgroup 404 | 405 | \begin{center} 406 | \captionof{table}{Performance characteristics of set and map types} 407 | \begin{tabular}{@{}lcccc@{}} 408 | \hline\noalign{\smallskip} 409 | & \textbf{lookup} & \textbf{add} & \textbf{remove} \\ 410 | \noalign{\smallskip}\hline\noalign{\smallskip} 411 | \textbf{immutable} &&& \\ 412 | \texttt{ParHashSet/ParHashMap} & eC & eC & eC \\ 413 | \textbf{mutable} &&& \\ 414 | \texttt{ParHashSet/ParHashMap} & C & C & C \\ 415 | \texttt{ParTrieMap} & eC & eC & eC \\ 416 | \noalign{\smallskip}\hline 417 | \end{tabular} 418 | \end{center} 419 | 420 | 421 | \subsection{Parallel Collection Conversions} 422 | Every sequential collection can be converted to its parallel variant using the \texttt{par} method. Certain sequential collections have a direct parallel counterpart. For these collections the conversion is efficient– it occurs in constant time, since both the sequential and the parallel collection have the same data-structural representation (one exception is mutable hash maps and hash sets which are slightly more expensive to convert the first time \texttt{par} is called, but subsequent invocations of par take constant time). It should be noted that for mutable collections, changes in the sequential collection are visible in its parallel counterpart if they share the underlying data-structure. 423 | 424 | \begin{center} 425 | \captionof{table}{Sequential collections and their direct parallel counterparts} 426 | \begin{tabular}{@{}ll@{}} 427 | \hline\noalign{\smallskip} 428 | \textbf{Sequential} & \textbf{Parallel} \\ 429 | \noalign{\smallskip}\hline\noalign{\smallskip} 430 | \textbf{mutable} & \\ 431 | \texttt{Array} & \texttt{ParArray} \\ 432 | \texttt{HashMap} & \texttt{ParHashMap} \\ 433 | \texttt{HashSet} & \texttt{ParHashSet} \\ 434 | \texttt{TrieMap} & \texttt{ParTrieMap} \\ 435 | \textbf{immutable} & \\ 436 | \texttt{Vector} & \texttt{ParVector} \\ 437 | \texttt{Range} & \texttt{ParRange} \\ 438 | \texttt{HashMap} & \texttt{ParHashMap} \\ 439 | \texttt{HashSet} & \texttt{ParHashSet} \\ 440 | \noalign{\smallskip}\hline 441 | \end{tabular} \\ 442 | \raggedright{\tiny{Source: \url{http://docs.scala-lang.org/overviews/parallel-collections/conversions.html}}} 443 | \end{center} 444 | 445 | Other collections, such as lists, queues or streams, are inherently sequential in the sense that the elements must be accessed one after the other. These collections are converted to their parallel variants by copying the elements into a similar parallel collection. For example, a functional list is converted into a standard immutable parallel sequence, which is a parallel vector. 446 | 447 | Every parallel collection can be converted to its sequential variant using the \texttt{seq} method. Converting a parallel collection to a sequential collection is always efficient– it takes constant time. Calling seq on a mutable parallel collection yields a sequential collection which is backed by the same store– updates to one collection will be visible in the other one. 448 | 449 | 450 | \subsection{Architecture of the Parallel Collections Library} 451 | Two core abstractions: \texttt{Splitter}s and \texttt{Combiner}s. 452 | 453 | \textbf{Splitter} 454 | \begin{verbatim} 455 | trait Splitter[T] extends Iterator[T] { 456 | def split: Seq[Splitter[T]] 457 | } 458 | \end{verbatim} 459 | 460 | \textbf{Combiner} 461 | \begin{verbatim} 462 | trait Combiner[Elem, To] extends Builder[Elem, To] { 463 | def combine(other: Combiner[Elem, To]): Combiner[Elem, To] 464 | } 465 | \end{verbatim} 466 | 467 | 468 | 469 | \rule{0.3\linewidth}{0.25pt} 470 | \scriptsize 471 | 472 | Copyright \copyright\ 2014 soulmachine 473 | 474 | Github: \url{https://github.com/soulmachine/scala-cheat-sheet} 475 | 476 | My blog: \url{http://www.soulmachine.me} 477 | 478 | Last update: \today 479 | 480 | 481 | \end{multicols} 482 | \end{document} 483 | --------------------------------------------------------------------------------