001//////////////////////////////////////////////////////////////////////////////// 002// checkstyle: Checks Java source code for adherence to a set of rules. 003// Copyright (C) 2001-2017 the original author or authors. 004// 005// This library is free software; you can redistribute it and/or 006// modify it under the terms of the GNU Lesser General Public 007// License as published by the Free Software Foundation; either 008// version 2.1 of the License, or (at your option) any later version. 009// 010// This library is distributed in the hope that it will be useful, 011// but WITHOUT ANY WARRANTY; without even the implied warranty of 012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 013// Lesser General Public License for more details. 014// 015// You should have received a copy of the GNU Lesser General Public 016// License along with this library; if not, write to the Free Software 017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 018//////////////////////////////////////////////////////////////////////////////// 019 020package com.puppycrawl.tools.checkstyle.checks.whitespace; 021 022import com.puppycrawl.tools.checkstyle.api.AbstractCheck; 023import com.puppycrawl.tools.checkstyle.api.DetailAST; 024import com.puppycrawl.tools.checkstyle.api.TokenTypes; 025import com.puppycrawl.tools.checkstyle.utils.CommonUtils; 026 027/** 028 * Checks that a token is surrounded by whitespace. 029 * 030 * <p>By default the check will check the following operators: 031 * {@link TokenTypes#LITERAL_ASSERT ASSERT}, 032 * {@link TokenTypes#ASSIGN ASSIGN}, 033 * {@link TokenTypes#BAND BAND}, 034 * {@link TokenTypes#BAND_ASSIGN BAND_ASSIGN}, 035 * {@link TokenTypes#BOR BOR}, 036 * {@link TokenTypes#BOR_ASSIGN BOR_ASSIGN}, 037 * {@link TokenTypes#BSR BSR}, 038 * {@link TokenTypes#BSR_ASSIGN BSR_ASSIGN}, 039 * {@link TokenTypes#BXOR BXOR}, 040 * {@link TokenTypes#BXOR_ASSIGN BXOR_ASSIGN}, 041 * {@link TokenTypes#COLON COLON}, 042 * {@link TokenTypes#DIV DIV}, 043 * {@link TokenTypes#DIV_ASSIGN DIV_ASSIGN}, 044 * {@link TokenTypes#DO_WHILE DO_WHILE}, 045 * {@link TokenTypes#EQUAL EQUAL}, 046 * {@link TokenTypes#GE GE}, 047 * {@link TokenTypes#GT GT}, 048 * {@link TokenTypes#LAND LAND}, 049 * {@link TokenTypes#LCURLY LCURLY}, 050 * {@link TokenTypes#LE LE}, 051 * {@link TokenTypes#LITERAL_CATCH LITERAL_CATCH}, 052 * {@link TokenTypes#LITERAL_DO LITERAL_DO}, 053 * {@link TokenTypes#LITERAL_ELSE LITERAL_ELSE}, 054 * {@link TokenTypes#LITERAL_FINALLY LITERAL_FINALLY}, 055 * {@link TokenTypes#LITERAL_FOR LITERAL_FOR}, 056 * {@link TokenTypes#LITERAL_IF LITERAL_IF}, 057 * {@link TokenTypes#LITERAL_RETURN LITERAL_RETURN}, 058 * {@link TokenTypes#LITERAL_SWITCH LITERAL_SWITCH}, 059 * {@link TokenTypes#LITERAL_SYNCHRONIZED LITERAL_SYNCHRONIZED}, 060 * {@link TokenTypes#LITERAL_TRY LITERAL_TRY}, 061 * {@link TokenTypes#LITERAL_WHILE LITERAL_WHILE}, 062 * {@link TokenTypes#LOR LOR}, 063 * {@link TokenTypes#LT LT}, 064 * {@link TokenTypes#MINUS MINUS}, 065 * {@link TokenTypes#MINUS_ASSIGN MINUS_ASSIGN}, 066 * {@link TokenTypes#MOD MOD}, 067 * {@link TokenTypes#MOD_ASSIGN MOD_ASSIGN}, 068 * {@link TokenTypes#NOT_EQUAL NOT_EQUAL}, 069 * {@link TokenTypes#PLUS PLUS}, 070 * {@link TokenTypes#PLUS_ASSIGN PLUS_ASSIGN}, 071 * {@link TokenTypes#QUESTION QUESTION}, 072 * {@link TokenTypes#RCURLY RCURLY}, 073 * {@link TokenTypes#SL SL}, 074 * {@link TokenTypes#SLIST SLIST}, 075 * {@link TokenTypes#SL_ASSIGN SL_ASSIGN}, 076 * {@link TokenTypes#SR SR}, 077 * {@link TokenTypes#SR_ASSIGN SR_ASSIGN}, 078 * {@link TokenTypes#STAR STAR}, 079 * {@link TokenTypes#STAR_ASSIGN STAR_ASSIGN}, 080 * {@link TokenTypes#LITERAL_ASSERT LITERAL_ASSERT}, 081 * {@link TokenTypes#TYPE_EXTENSION_AND TYPE_EXTENSION_AND}. 082 * 083 * <p>An example of how to configure the check is: 084 * 085 * <pre> 086 * <module name="WhitespaceAround"/> 087 * </pre> 088 * 089 * <p>An example of how to configure the check for whitespace only around 090 * assignment operators is: 091 * 092 * <pre> 093 * <module name="WhitespaceAround"> 094 * <property name="tokens" 095 * value="ASSIGN,DIV_ASSIGN,PLUS_ASSIGN,MINUS_ASSIGN,STAR_ASSIGN, 096 * MOD_ASSIGN,SR_ASSIGN,BSR_ASSIGN,SL_ASSIGN,BXOR_ASSIGN, 097 * BOR_ASSIGN,BAND_ASSIGN"/> 098 * </module> 099 * </pre> 100 * 101 * <p>An example of how to configure the check for whitespace only around 102 * curly braces is: 103 * <pre> 104 * <module name="WhitespaceAround"> 105 * <property name="tokens" 106 * value="LCURLY,RCURLY"/> 107 * </module> 108 * </pre> 109 * 110 * <p>In addition, this check can be configured to allow empty methods, types, 111 * for, while, do-while loops, lambdas and constructor bodies. 112 * For example: 113 * 114 * <pre>{@code 115 * public MyClass() {} // empty constructor 116 * public void func() {} // empty method 117 * public interface Foo {} // empty interface 118 * public class Foo {} // empty class 119 * public enum Foo {} // empty enum 120 * MyClass c = new MyClass() {}; // empty anonymous class 121 * while (i = 1) {} // empty while loop 122 * for (int i = 1; i > 1; i++) {} // empty for loop 123 * do {} while (i = 1); // empty do-while loop 124 * Runnable noop = () -> {}; // empty lambda 125 * public @interface Beta {} // empty annotation type 126 * }</pre> 127 * 128 * <p>This check does not flag as violation double brace initialization like:</p> 129 * <pre> 130 * new Properties() {{ 131 * setProperty("key", "value"); 132 * }}; 133 * </pre> 134 * 135 * <p>To configure the check to allow empty method blocks use 136 * 137 * <pre> <property name="allowEmptyMethods" value="true" /></pre> 138 * 139 * <p>To configure the check to allow empty constructor blocks use 140 * 141 * <pre> <property name="allowEmptyConstructors" value="true" /></pre> 142 * 143 * <p>To configure the check to allow empty type blocks use 144 * 145 * <pre> <property name="allowEmptyTypes" value="true" /></pre> 146 * 147 * <p>To configure the check to allow empty loop blocks use 148 * 149 * <pre> <property name="allowEmptyLoops" value="true" /></pre> 150 * 151 * <p>To configure the check to allow empty lambdas blocks use 152 * 153 * <pre> <property name="allowEmptyLambdas" value="true" /></pre> 154 * 155 * <p>Also, this check can be configured to ignore the colon in an enhanced for 156 * loop. The colon in an enhanced for loop is ignored by default 157 * 158 * <p>To configure the check to ignore the colon 159 * 160 * <pre> <property name="ignoreEnhancedForColon" value="true" /></pre> 161 * 162 * @author Oliver Burn 163 * @author maxvetrenko 164 * @author Andrei Selkin 165 */ 166public class WhitespaceAroundCheck extends AbstractCheck { 167 168 /** 169 * A key is pointing to the warning message text in "messages.properties" 170 * file. 171 */ 172 public static final String MSG_WS_NOT_PRECEDED = "ws.notPreceded"; 173 174 /** 175 * A key is pointing to the warning message text in "messages.properties" 176 * file. 177 */ 178 public static final String MSG_WS_NOT_FOLLOWED = "ws.notFollowed"; 179 180 /** Whether or not empty constructor bodies are allowed. */ 181 private boolean allowEmptyConstructors; 182 /** Whether or not empty method bodies are allowed. */ 183 private boolean allowEmptyMethods; 184 /** Whether or not empty classes, enums and interfaces are allowed. */ 185 private boolean allowEmptyTypes; 186 /** Whether or not empty loops are allowed. */ 187 private boolean allowEmptyLoops; 188 /** Whether or not empty lambda blocks are allowed. */ 189 private boolean allowEmptyLambdas; 190 /** Whether or not empty catch blocks are allowed. */ 191 private boolean allowEmptyCatches; 192 /** Whether or not to ignore a colon in a enhanced for loop. */ 193 private boolean ignoreEnhancedForColon = true; 194 195 @Override 196 public int[] getDefaultTokens() { 197 return new int[] { 198 TokenTypes.ASSIGN, 199 TokenTypes.BAND, 200 TokenTypes.BAND_ASSIGN, 201 TokenTypes.BOR, 202 TokenTypes.BOR_ASSIGN, 203 TokenTypes.BSR, 204 TokenTypes.BSR_ASSIGN, 205 TokenTypes.BXOR, 206 TokenTypes.BXOR_ASSIGN, 207 TokenTypes.COLON, 208 TokenTypes.DIV, 209 TokenTypes.DIV_ASSIGN, 210 TokenTypes.DO_WHILE, 211 TokenTypes.EQUAL, 212 TokenTypes.GE, 213 TokenTypes.GT, 214 TokenTypes.LAMBDA, 215 TokenTypes.LAND, 216 TokenTypes.LCURLY, 217 TokenTypes.LE, 218 TokenTypes.LITERAL_CATCH, 219 TokenTypes.LITERAL_DO, 220 TokenTypes.LITERAL_ELSE, 221 TokenTypes.LITERAL_FINALLY, 222 TokenTypes.LITERAL_FOR, 223 TokenTypes.LITERAL_IF, 224 TokenTypes.LITERAL_RETURN, 225 TokenTypes.LITERAL_SWITCH, 226 TokenTypes.LITERAL_SYNCHRONIZED, 227 TokenTypes.LITERAL_TRY, 228 TokenTypes.LITERAL_WHILE, 229 TokenTypes.LOR, 230 TokenTypes.LT, 231 TokenTypes.MINUS, 232 TokenTypes.MINUS_ASSIGN, 233 TokenTypes.MOD, 234 TokenTypes.MOD_ASSIGN, 235 TokenTypes.NOT_EQUAL, 236 TokenTypes.PLUS, 237 TokenTypes.PLUS_ASSIGN, 238 TokenTypes.QUESTION, 239 TokenTypes.RCURLY, 240 TokenTypes.SL, 241 TokenTypes.SLIST, 242 TokenTypes.SL_ASSIGN, 243 TokenTypes.SR, 244 TokenTypes.SR_ASSIGN, 245 TokenTypes.STAR, 246 TokenTypes.STAR_ASSIGN, 247 TokenTypes.LITERAL_ASSERT, 248 TokenTypes.TYPE_EXTENSION_AND, 249 }; 250 } 251 252 @Override 253 public int[] getAcceptableTokens() { 254 return new int[] { 255 TokenTypes.ASSIGN, 256 TokenTypes.ARRAY_INIT, 257 TokenTypes.BAND, 258 TokenTypes.BAND_ASSIGN, 259 TokenTypes.BOR, 260 TokenTypes.BOR_ASSIGN, 261 TokenTypes.BSR, 262 TokenTypes.BSR_ASSIGN, 263 TokenTypes.BXOR, 264 TokenTypes.BXOR_ASSIGN, 265 TokenTypes.COLON, 266 TokenTypes.DIV, 267 TokenTypes.DIV_ASSIGN, 268 TokenTypes.DO_WHILE, 269 TokenTypes.EQUAL, 270 TokenTypes.GE, 271 TokenTypes.GT, 272 TokenTypes.LAMBDA, 273 TokenTypes.LAND, 274 TokenTypes.LCURLY, 275 TokenTypes.LE, 276 TokenTypes.LITERAL_CATCH, 277 TokenTypes.LITERAL_DO, 278 TokenTypes.LITERAL_ELSE, 279 TokenTypes.LITERAL_FINALLY, 280 TokenTypes.LITERAL_FOR, 281 TokenTypes.LITERAL_IF, 282 TokenTypes.LITERAL_RETURN, 283 TokenTypes.LITERAL_SWITCH, 284 TokenTypes.LITERAL_SYNCHRONIZED, 285 TokenTypes.LITERAL_TRY, 286 TokenTypes.LITERAL_WHILE, 287 TokenTypes.LOR, 288 TokenTypes.LT, 289 TokenTypes.MINUS, 290 TokenTypes.MINUS_ASSIGN, 291 TokenTypes.MOD, 292 TokenTypes.MOD_ASSIGN, 293 TokenTypes.NOT_EQUAL, 294 TokenTypes.PLUS, 295 TokenTypes.PLUS_ASSIGN, 296 TokenTypes.QUESTION, 297 TokenTypes.RCURLY, 298 TokenTypes.SL, 299 TokenTypes.SLIST, 300 TokenTypes.SL_ASSIGN, 301 TokenTypes.SR, 302 TokenTypes.SR_ASSIGN, 303 TokenTypes.STAR, 304 TokenTypes.STAR_ASSIGN, 305 TokenTypes.LITERAL_ASSERT, 306 TokenTypes.TYPE_EXTENSION_AND, 307 TokenTypes.WILDCARD_TYPE, 308 TokenTypes.GENERIC_START, 309 TokenTypes.GENERIC_END, 310 }; 311 } 312 313 @Override 314 public int[] getRequiredTokens() { 315 return CommonUtils.EMPTY_INT_ARRAY; 316 } 317 318 /** 319 * Sets whether or not empty method bodies are allowed. 320 * @param allow {@code true} to allow empty method bodies. 321 */ 322 public void setAllowEmptyMethods(boolean allow) { 323 allowEmptyMethods = allow; 324 } 325 326 /** 327 * Sets whether or not empty constructor bodies are allowed. 328 * @param allow {@code true} to allow empty constructor bodies. 329 */ 330 public void setAllowEmptyConstructors(boolean allow) { 331 allowEmptyConstructors = allow; 332 } 333 334 /** 335 * Sets whether or not to ignore the whitespace around the 336 * colon in an enhanced for loop. 337 * @param ignore {@code true} to ignore enhanced for colon. 338 */ 339 public void setIgnoreEnhancedForColon(boolean ignore) { 340 ignoreEnhancedForColon = ignore; 341 } 342 343 /** 344 * Sets whether or not empty type bodies are allowed. 345 * @param allow {@code true} to allow empty type bodies. 346 */ 347 public void setAllowEmptyTypes(boolean allow) { 348 allowEmptyTypes = allow; 349 } 350 351 /** 352 * Sets whether or not empty loop bodies are allowed. 353 * @param allow {@code true} to allow empty loops bodies. 354 */ 355 public void setAllowEmptyLoops(boolean allow) { 356 allowEmptyLoops = allow; 357 } 358 359 /** 360 * Sets whether or not empty lambdas bodies are allowed. 361 * @param allow {@code true} to allow empty lambda expressions. 362 */ 363 public void setAllowEmptyLambdas(boolean allow) { 364 allowEmptyLambdas = allow; 365 } 366 367 /** 368 * Sets whether or not empty catch blocks are allowed. 369 * @param allow {@code true} to allow empty catch blocks. 370 */ 371 public void setAllowEmptyCatches(boolean allow) { 372 allowEmptyCatches = allow; 373 } 374 375 @Override 376 public void visitToken(DetailAST ast) { 377 final int currentType = ast.getType(); 378 if (!isNotRelevantSituation(ast, currentType)) { 379 final String line = getLine(ast.getLineNo() - 1); 380 final int before = ast.getColumnNo() - 1; 381 final int after = ast.getColumnNo() + ast.getText().length(); 382 383 if (before >= 0) { 384 final char prevChar = line.charAt(before); 385 if (shouldCheckSeparationFromPreviousToken(ast) 386 && !Character.isWhitespace(prevChar)) { 387 log(ast.getLineNo(), ast.getColumnNo(), 388 MSG_WS_NOT_PRECEDED, ast.getText()); 389 } 390 } 391 392 if (after < line.length()) { 393 final char nextChar = line.charAt(after); 394 if (shouldCheckSeparationFromNextToken(ast, nextChar) 395 && !Character.isWhitespace(nextChar)) { 396 log(ast.getLineNo(), ast.getColumnNo() + ast.getText().length(), 397 MSG_WS_NOT_FOLLOWED, ast.getText()); 398 } 399 } 400 } 401 } 402 403 /** 404 * Is ast not a target of Check. 405 * @param ast ast 406 * @param currentType type of ast 407 * @return true is ok to skip validation 408 */ 409 private boolean isNotRelevantSituation(DetailAST ast, int currentType) { 410 final int parentType = ast.getParent().getType(); 411 final boolean starImport = currentType == TokenTypes.STAR 412 && parentType == TokenTypes.DOT; 413 final boolean slistInsideCaseGroup = currentType == TokenTypes.SLIST 414 && parentType == TokenTypes.CASE_GROUP; 415 416 final boolean starImportOrSlistInsideCaseGroup = starImport || slistInsideCaseGroup; 417 final boolean colonOfCaseOrDefaultOrForEach = 418 isColonOfCaseOrDefault(currentType, parentType) 419 || isColonOfForEach(currentType, parentType); 420 final boolean emptyBlockOrType = 421 isEmptyBlock(ast, parentType) 422 || allowEmptyTypes && isEmptyType(ast); 423 424 return starImportOrSlistInsideCaseGroup 425 || colonOfCaseOrDefaultOrForEach 426 || emptyBlockOrType 427 || isArrayInitialization(currentType, parentType); 428 } 429 430 /** 431 * Check if it should be checked if previous token is separated from current by 432 * whitespace. 433 * This function is needed to recognise double brace initialization as valid, 434 * unfortunately its not possible to implement this functionality 435 * in isNotRelevantSituation method, because in this method when we return 436 * true(is not relevant) ast is later doesn't check at all. For example: 437 * new Properties() {{setProperty("double curly braces", "are not a style error"); 438 * }}; 439 * For second left curly brace in first line when we would return true from 440 * isNotRelevantSituation it wouldn't later check that the next token(setProperty) 441 * is not separated from previous token. 442 * @param ast current AST. 443 * @return true if it should be checked if previous token is separated by whitespace, 444 * false otherwise. 445 */ 446 private static boolean shouldCheckSeparationFromPreviousToken(DetailAST ast) { 447 return !isPartOfDoubleBraceInitializerForPreviousToken(ast); 448 } 449 450 /** 451 * Check if it should be checked if next token is separated from current by 452 * whitespace. Explanation why this method is needed is identical to one 453 * included in shouldCheckSeparationFromPreviousToken method. 454 * @param ast current AST. 455 * @param nextChar next character. 456 * @return true if it should be checked if next token is separated by whitespace, 457 * false otherwise. 458 */ 459 private static boolean shouldCheckSeparationFromNextToken(DetailAST ast, char nextChar) { 460 return !(ast.getType() == TokenTypes.LITERAL_RETURN 461 && ast.getFirstChild().getType() == TokenTypes.SEMI) 462 && ast.getType() != TokenTypes.ARRAY_INIT 463 && !isAnonymousInnerClassEnd(ast.getType(), nextChar) 464 && !isPartOfDoubleBraceInitializerForNextToken(ast); 465 } 466 467 /** 468 * Check for "})" or "};" or "},". Happens with anon-inners 469 * @param currentType token 470 * @param nextChar next symbol 471 * @return true is that is end of anon inner class 472 */ 473 private static boolean isAnonymousInnerClassEnd(int currentType, char nextChar) { 474 return currentType == TokenTypes.RCURLY 475 && (nextChar == ')' 476 || nextChar == ';' 477 || nextChar == ',' 478 || nextChar == '.'); 479 } 480 481 /** 482 * Is empty block. 483 * @param ast ast 484 * @param parentType parent 485 * @return true is block is empty 486 */ 487 private boolean isEmptyBlock(DetailAST ast, int parentType) { 488 return isEmptyMethodBlock(ast, parentType) 489 || isEmptyCtorBlock(ast, parentType) 490 || isEmptyLoop(ast, parentType) 491 || isEmptyLambda(ast, parentType) 492 || isEmptyCatch(ast, parentType); 493 } 494 495 /** 496 * Tests if a given {@code DetailAST} is part of an empty block. 497 * An example empty block might look like the following 498 * <p> 499 * <pre> public void myMethod(int val) {}</pre> 500 * </p> 501 * In the above, the method body is an empty block ("{}"). 502 * 503 * @param ast the {@code DetailAST} to test. 504 * @param parentType the token type of {@code ast}'s parent. 505 * @param match the parent token type we're looking to match. 506 * @return {@code true} if {@code ast} makes up part of an 507 * empty block contained under a {@code match} token type 508 * node. 509 */ 510 private static boolean isEmptyBlock(DetailAST ast, int parentType, int match) { 511 final boolean result; 512 final int type = ast.getType(); 513 if (type == TokenTypes.RCURLY) { 514 final DetailAST parent = ast.getParent(); 515 final DetailAST grandParent = ast.getParent().getParent(); 516 result = parentType == TokenTypes.SLIST 517 && parent.getFirstChild().getType() == TokenTypes.RCURLY 518 && grandParent.getType() == match; 519 } 520 else { 521 result = type == TokenTypes.SLIST 522 && parentType == match 523 && ast.getFirstChild().getType() == TokenTypes.RCURLY; 524 } 525 return result; 526 } 527 528 /** 529 * Whether colon belongs to cases or defaults. 530 * @param currentType current 531 * @param parentType parent 532 * @return true if current token in colon of case or default tokens 533 */ 534 private static boolean isColonOfCaseOrDefault(int currentType, int parentType) { 535 return currentType == TokenTypes.COLON 536 && (parentType == TokenTypes.LITERAL_DEFAULT 537 || parentType == TokenTypes.LITERAL_CASE); 538 } 539 540 /** 541 * Whether colon belongs to for-each. 542 * @param currentType current 543 * @param parentType parent 544 * @return true if current token in colon of for-each token 545 */ 546 private boolean isColonOfForEach(int currentType, int parentType) { 547 return currentType == TokenTypes.COLON 548 && parentType == TokenTypes.FOR_EACH_CLAUSE 549 && ignoreEnhancedForColon; 550 } 551 552 /** 553 * Is array initialization. 554 * @param currentType current token 555 * @param parentType parent token 556 * @return true is current token inside array initialization 557 */ 558 private static boolean isArrayInitialization(int currentType, int parentType) { 559 return (currentType == TokenTypes.RCURLY || currentType == TokenTypes.LCURLY) 560 && (parentType == TokenTypes.ARRAY_INIT 561 || parentType == TokenTypes.ANNOTATION_ARRAY_INIT); 562 } 563 564 /** 565 * Test if the given {@code DetailAST} is part of an allowed empty 566 * method block. 567 * @param ast the {@code DetailAST} to test. 568 * @param parentType the token type of {@code ast}'s parent. 569 * @return {@code true} if {@code ast} makes up part of an 570 * allowed empty method block. 571 */ 572 private boolean isEmptyMethodBlock(DetailAST ast, int parentType) { 573 return allowEmptyMethods 574 && isEmptyBlock(ast, parentType, TokenTypes.METHOD_DEF); 575 } 576 577 /** 578 * Test if the given {@code DetailAST} is part of an allowed empty 579 * constructor (ctor) block. 580 * @param ast the {@code DetailAST} to test. 581 * @param parentType the token type of {@code ast}'s parent. 582 * @return {@code true} if {@code ast} makes up part of an 583 * allowed empty constructor block. 584 */ 585 private boolean isEmptyCtorBlock(DetailAST ast, int parentType) { 586 return allowEmptyConstructors 587 && isEmptyBlock(ast, parentType, TokenTypes.CTOR_DEF); 588 } 589 590 /** 591 * Checks if loop is empty. 592 * @param ast ast the {@code DetailAST} to test. 593 * @param parentType the token type of {@code ast}'s parent. 594 * @return {@code true} if {@code ast} makes up part of an 595 * allowed empty loop block. 596 */ 597 private boolean isEmptyLoop(DetailAST ast, int parentType) { 598 return allowEmptyLoops 599 && (isEmptyBlock(ast, parentType, TokenTypes.LITERAL_FOR) 600 || isEmptyBlock(ast, parentType, TokenTypes.LITERAL_WHILE) 601 || isEmptyBlock(ast, parentType, TokenTypes.LITERAL_DO)); 602 } 603 604 /** 605 * Test if the given {@code DetailAST} is part of an allowed empty 606 * lambda block. 607 * @param ast the {@code DetailAST} to test. 608 * @param parentType the token type of {@code ast}'s parent. 609 * @return {@code true} if {@code ast} makes up part of an 610 * allowed empty lambda block. 611 */ 612 private boolean isEmptyLambda(DetailAST ast, int parentType) { 613 return allowEmptyLambdas && isEmptyBlock(ast, parentType, TokenTypes.LAMBDA); 614 } 615 616 /** 617 * Tests if the given {@code DetailAst} is part of an allowed empty 618 * catch block. 619 * @param ast the {@code DetailAst} to test. 620 * @param parentType the token type of {@code ast}'s parent 621 * @return {@code true} if {@code ast} makes up part of an 622 * allowed empty catch block. 623 */ 624 private boolean isEmptyCatch(DetailAST ast, int parentType) { 625 return allowEmptyCatches && isEmptyBlock(ast, parentType, TokenTypes.LITERAL_CATCH); 626 } 627 628 /** 629 * Test if the given {@code DetailAST} is part of an empty block. 630 * An example empty block might look like the following 631 * <p> 632 * <pre> class Foo {}</pre> 633 * </p> 634 * 635 * @param ast ast the {@code DetailAST} to test. 636 * @return {@code true} if {@code ast} makes up part of an 637 * empty block contained under a {@code match} token type 638 * node. 639 */ 640 private static boolean isEmptyType(DetailAST ast) { 641 final int type = ast.getType(); 642 final DetailAST nextSibling = ast.getNextSibling(); 643 final DetailAST previousSibling = ast.getPreviousSibling(); 644 return type == TokenTypes.LCURLY 645 && nextSibling.getType() == TokenTypes.RCURLY 646 || type == TokenTypes.RCURLY 647 && previousSibling != null 648 && previousSibling.getType() == TokenTypes.LCURLY; 649 } 650 651 /** 652 * Check if given ast is part of double brace initializer and if it 653 * should omit checking if previous token is separated by whitespace. 654 * @param ast ast to check 655 * @return true if it should omit checking for previous token, false otherwise 656 */ 657 private static boolean isPartOfDoubleBraceInitializerForPreviousToken(DetailAST ast) { 658 final boolean initializerBeginsAfterClassBegins = ast.getType() == TokenTypes.SLIST 659 && ast.getParent().getType() == TokenTypes.INSTANCE_INIT; 660 final boolean classEndsAfterInitializerEnds = ast.getType() == TokenTypes.RCURLY 661 && ast.getPreviousSibling() != null 662 && ast.getPreviousSibling().getType() == TokenTypes.INSTANCE_INIT; 663 return initializerBeginsAfterClassBegins || classEndsAfterInitializerEnds; 664 } 665 666 /** 667 * Check if given ast is part of double brace initializer and if it 668 * should omit checking if next token is separated by whitespace. 669 * See <a href="https://github.com/checkstyle/checkstyle/pull/2845"> 670 * PR#2845</a> for more information why this function was needed. 671 * @param ast ast to check 672 * @return true if it should omit checking for next token, false otherwise 673 */ 674 private static boolean isPartOfDoubleBraceInitializerForNextToken(DetailAST ast) { 675 final boolean classBeginBeforeInitializerBegin = ast.getType() == TokenTypes.LCURLY 676 && ast.getNextSibling().getType() == TokenTypes.INSTANCE_INIT; 677 final boolean initalizerEndsBeforeClassEnds = ast.getType() == TokenTypes.RCURLY 678 && ast.getParent().getType() == TokenTypes.SLIST 679 && ast.getParent().getParent().getType() == TokenTypes.INSTANCE_INIT 680 && ast.getParent().getParent().getNextSibling().getType() == TokenTypes.RCURLY; 681 return classBeginBeforeInitializerBegin || initalizerEndsBeforeClassEnds; 682 } 683}