| 1 | /* This file is part of the project "Hilbert II" - http://www.qedeq.org |
| 2 | * |
| 3 | * Copyright 2000-2014, Michael Meyling <mime@qedeq.org>. |
| 4 | * |
| 5 | * "Hilbert II" is free software; you can redistribute |
| 6 | * it and/or modify it under the terms of the GNU General Public |
| 7 | * License as published by the Free Software Foundation; either |
| 8 | * version 2 of the License, or (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | */ |
| 15 | |
| 16 | package org.qedeq.kernel.bo.logic.wf; |
| 17 | |
| 18 | import org.qedeq.base.trace.Trace; |
| 19 | import org.qedeq.kernel.bo.logic.common.ExistenceChecker; |
| 20 | import org.qedeq.kernel.bo.logic.common.FormulaChecker; |
| 21 | import org.qedeq.kernel.bo.logic.common.FormulaUtility; |
| 22 | import org.qedeq.kernel.bo.logic.common.LogicalCheckExceptionList; |
| 23 | import org.qedeq.kernel.bo.logic.common.Operators; |
| 24 | import org.qedeq.kernel.se.base.list.Atom; |
| 25 | import org.qedeq.kernel.se.base.list.Element; |
| 26 | import org.qedeq.kernel.se.base.list.ElementList; |
| 27 | import org.qedeq.kernel.se.common.ModuleContext; |
| 28 | import org.qedeq.kernel.se.dto.list.ElementSet; |
| 29 | |
| 30 | |
| 31 | /** |
| 32 | * This class deals with {@link org.qedeq.kernel.se.base.list.Element}s which represent a |
| 33 | * formula. It has methods to check those elements for being well-formed. |
| 34 | * |
| 35 | * LATER mime 20070307: here are sometimes error messages that get concatenated with |
| 36 | * an {@link org.qedeq.kernel.se.base.list.ElementList#getOperator()} string. Perhaps these |
| 37 | * strings must be translated into the original input format and a mapping must be done. |
| 38 | * |
| 39 | * @author Michael Meyling |
| 40 | */ |
| 41 | public class FormulaCheckerImpl implements Operators, FormulaBasicErrors, FormulaChecker { |
| 42 | |
| 43 | /** This class. */ |
| 44 | private static final Class CLASS = FormulaCheckerImpl.class; |
| 45 | |
| 46 | /** Current context during creation. */ |
| 47 | private ModuleContext currentContext; |
| 48 | |
| 49 | /** Existence checker for operators. */ |
| 50 | private ExistenceChecker existenceChecker; |
| 51 | |
| 52 | /** All exceptions that occurred during checking. */ |
| 53 | private LogicalCheckExceptionList exceptions; |
| 54 | |
| 55 | |
| 56 | /** |
| 57 | * Constructor. |
| 58 | * |
| 59 | */ |
| 60 | public FormulaCheckerImpl() { |
| 61 | // nothing to do |
| 62 | } |
| 63 | |
| 64 | public final LogicalCheckExceptionList checkFormula(final Element element, |
| 65 | final ModuleContext context, final ExistenceChecker existenceChecker) { |
| 66 | if (existenceChecker.identityOperatorExists() |
| 67 | && !existenceChecker.predicateExists(existenceChecker.getIdentityOperator(), 2)) { |
| 68 | throw new IllegalArgumentException("identity predicate should exist, but it doesn't"); |
| 69 | } |
| 70 | this.existenceChecker = existenceChecker; |
| 71 | currentContext = new ModuleContext(context); |
| 72 | exceptions = new LogicalCheckExceptionList(); |
| 73 | checkFormula(element); |
| 74 | return exceptions; |
| 75 | } |
| 76 | |
| 77 | public final LogicalCheckExceptionList checkFormula(final Element element, |
| 78 | final ModuleContext context) { |
| 79 | return checkFormula(element, context, EverythingExists.getInstance()); |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Check if {@link Element} is a term. If there are any errors the returned list |
| 84 | * (which is always not <code>null</code>) has a size greater zero. |
| 85 | * |
| 86 | * @param element Check this element. |
| 87 | * @param context For location information. Important for locating errors. |
| 88 | * @param existenceChecker Existence checker for operators. |
| 89 | * @return Collected errors if there are any. Not <code>null</code>. |
| 90 | */ |
| 91 | public final LogicalCheckExceptionList checkTerm(final Element element, |
| 92 | final ModuleContext context, final ExistenceChecker existenceChecker) { |
| 93 | if (existenceChecker.identityOperatorExists() |
| 94 | && !existenceChecker.predicateExists(existenceChecker.getIdentityOperator(), 2)) { |
| 95 | throw new IllegalArgumentException("identity predicate should exist, but it doesn't"); |
| 96 | } |
| 97 | this.existenceChecker = existenceChecker; |
| 98 | currentContext = new ModuleContext(context); |
| 99 | exceptions = new LogicalCheckExceptionList(); |
| 100 | checkTerm(element); |
| 101 | return exceptions; |
| 102 | } |
| 103 | |
| 104 | /** |
| 105 | * Check if {@link Element} is a term. If there are any errors the returned list |
| 106 | * (which is always not <code>null</code>) has a size greater zero. |
| 107 | * If the existence context is known you should use |
| 108 | * {@link #checkTerm(Element, ModuleContext, ExistenceChecker)}. |
| 109 | * |
| 110 | * @param element Check this element. |
| 111 | * @param context For location information. Important for locating errors. |
| 112 | * @return Collected errors if there are any. Not <code>null</code>. |
| 113 | */ |
| 114 | public final LogicalCheckExceptionList checkTerm(final Element element, |
| 115 | final ModuleContext context) { |
| 116 | return checkTerm(element, context, EverythingExists.getInstance()); |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | * Is {@link Element} a formula? |
| 121 | * |
| 122 | * @param element Check this element. |
| 123 | */ |
| 124 | private final void checkFormula(final Element element) { |
| 125 | final String method = "checkFormula"; |
| 126 | Trace.begin(CLASS, this, method); |
| 127 | Trace.param(CLASS, this, method, "element", element); |
| 128 | final String context = getCurrentContext().getLocationWithinModule(); |
| 129 | Trace.param(CLASS, this, method, "context", context); |
| 130 | if (!checkList(element)) { |
| 131 | return; |
| 132 | } |
| 133 | final ElementList list = element.getList(); |
| 134 | final String listContext = context + ".getList()"; |
| 135 | setLocationWithinModule(listContext); |
| 136 | final String operator = list.getOperator(); |
| 137 | if (operator.equals(CONJUNCTION_OPERATOR) |
| 138 | || operator.equals(DISJUNCTION_OPERATOR) |
| 139 | || operator.equals(IMPLICATION_OPERATOR) |
| 140 | || operator.equals(EQUIVALENCE_OPERATOR)) { |
| 141 | Trace.trace(CLASS, this, method, |
| 142 | "one of (and, or, implication, equivalence) operator found"); |
| 143 | if (list.size() <= 1) { |
| 144 | handleFormulaCheckException(MORE_THAN_ONE_ARGUMENT_EXPECTED, |
| 145 | MORE_THAN_ONE_ARGUMENT_EXPECTED_TEXT + "\"" |
| 146 | + operator + "\"", element, getCurrentContext()); |
| 147 | return; |
| 148 | } |
| 149 | if (operator.equals(IMPLICATION_OPERATOR) && list.size() != 2) { |
| 150 | handleFormulaCheckException(EXACTLY_TWO_ARGUMENTS_EXPECTED, |
| 151 | EXACTLY_TWO_ARGUMENTS_EXPECTED_TEXT + "\"" |
| 152 | + operator + "\"", element, getCurrentContext()); |
| 153 | return; |
| 154 | } |
| 155 | for (int i = 0; i < list.size(); i++) { |
| 156 | setLocationWithinModule(listContext + ".getElement(" + i + ")"); |
| 157 | checkFormula(list.getElement(i)); |
| 158 | } |
| 159 | setLocationWithinModule(listContext); |
| 160 | checkFreeAndBoundDisjunct(0, list); |
| 161 | } else if (operator.equals(NEGATION_OPERATOR)) { |
| 162 | Trace.trace(CLASS, this, method, "negation operator found"); |
| 163 | setLocationWithinModule(listContext); |
| 164 | if (list.size() != 1) { |
| 165 | handleFormulaCheckException(EXACTLY_ONE_ARGUMENT_EXPECTED, |
| 166 | EXACTLY_ONE_ARGUMENT_EXPECTED_TEXT + "\"" + operator + "\"", |
| 167 | element, getCurrentContext()); |
| 168 | return; |
| 169 | } |
| 170 | setLocationWithinModule(listContext + ".getElement(0)"); |
| 171 | checkFormula(list.getElement(0)); |
| 172 | } else if (operator.equals(PREDICATE_VARIABLE) |
| 173 | || operator.equals(PREDICATE_CONSTANT)) { |
| 174 | Trace.trace(CLASS, this, method, "predicate operator found"); |
| 175 | setLocationWithinModule(listContext); |
| 176 | if (list.size() < 1) { |
| 177 | handleFormulaCheckException(AT_LEAST_ONE_ARGUMENT_EXPECTED, |
| 178 | AT_LEAST_ONE_ARGUMENT_EXPECTED_TEXT + "\"" + operator + "\"", |
| 179 | element, getCurrentContext()); |
| 180 | return; |
| 181 | } |
| 182 | // check if first argument is an atom |
| 183 | setLocationWithinModule(listContext + ".getElement(0)"); |
| 184 | if (!checkAtomFirst(list.getElement(0))) { |
| 185 | return; |
| 186 | } |
| 187 | |
| 188 | // check if rest arguments are terms |
| 189 | for (int i = 1; i < list.size(); i++) { |
| 190 | setLocationWithinModule(listContext + ".getElement(" + i + ")"); |
| 191 | checkTerm(list.getElement(i)); |
| 192 | } |
| 193 | |
| 194 | setLocationWithinModule(listContext); |
| 195 | checkFreeAndBoundDisjunct(1, list); |
| 196 | |
| 197 | // check if predicate is known |
| 198 | if (PREDICATE_CONSTANT.equals(operator) && !existenceChecker.predicateExists( |
| 199 | list.getElement(0).getAtom().getString(), list.size() - 1)) { |
| 200 | setLocationWithinModule(listContext + ".getElement(0)"); |
| 201 | handleFormulaCheckException(UNKNOWN_PREDICATE_CONSTANT, |
| 202 | UNKNOWN_PREDICATE_CONSTANT_TEXT + "\"" |
| 203 | + list.getElement(0).getAtom().getString() + "\" [" + (list.size() - 1) + "]", |
| 204 | element, getCurrentContext()); |
| 205 | } |
| 206 | |
| 207 | } else if (operator.equals(EXISTENTIAL_QUANTIFIER_OPERATOR) |
| 208 | || operator.equals(UNIQUE_EXISTENTIAL_QUANTIFIER_OPERATOR) |
| 209 | || operator.equals(UNIVERSAL_QUANTIFIER_OPERATOR)) { |
| 210 | Trace.trace(CLASS, this, method, "quantifier found"); |
| 211 | setLocationWithinModule(context); |
| 212 | checkQuantifier(element); |
| 213 | } else { |
| 214 | setLocationWithinModule(listContext + ".getOperator()"); |
| 215 | handleFormulaCheckException(UNKNOWN_LOGICAL_OPERATOR, |
| 216 | UNKNOWN_LOGICAL_OPERATOR_TEXT + "\"" + operator + "\"", |
| 217 | element, getCurrentContext()); |
| 218 | } |
| 219 | // restore context |
| 220 | setLocationWithinModule(context); |
| 221 | Trace.end(CLASS, this, method); |
| 222 | } |
| 223 | |
| 224 | /** |
| 225 | * Check quantifier element. |
| 226 | * |
| 227 | * @param element Check this element. Must be a quantifier element. |
| 228 | * @throws IllegalArgumentException <code>element.getList().getOperator()</code> is no |
| 229 | * quantifier operator. |
| 230 | */ |
| 231 | private void checkQuantifier(final Element element) { |
| 232 | final String method = "checkQuantifier"; |
| 233 | Trace.begin(CLASS, this, method); |
| 234 | Trace.param(CLASS, this, method, "element", element); |
| 235 | // save context |
| 236 | final String context = getCurrentContext().getLocationWithinModule(); |
| 237 | Trace.param(CLASS, this, method, "context", context); |
| 238 | checkList(element); |
| 239 | final ElementList list = element.getList(); |
| 240 | final String listContext = context + ".getList()"; |
| 241 | setLocationWithinModule(listContext); |
| 242 | final String operator = list.getOperator(); |
| 243 | if (!operator.equals(EXISTENTIAL_QUANTIFIER_OPERATOR) |
| 244 | && operator.equals(UNIQUE_EXISTENTIAL_QUANTIFIER_OPERATOR) |
| 245 | && operator.equals(UNIVERSAL_QUANTIFIER_OPERATOR)) { |
| 246 | throw new IllegalArgumentException("quantifier element expected but found: " |
| 247 | + element.toString()); |
| 248 | } |
| 249 | if (list.size() < 2 || list.size() > 3) { |
| 250 | handleFormulaCheckException(EXACTLY_TWO_OR_THREE_ARGUMENTS_EXPECTED, |
| 251 | EXACTLY_TWO_OR_THREE_ARGUMENTS_EXPECTED_TEXT, element, getCurrentContext()); |
| 252 | return; |
| 253 | } |
| 254 | |
| 255 | // check if unique existential operator could be used |
| 256 | if (operator.equals(UNIQUE_EXISTENTIAL_QUANTIFIER_OPERATOR) |
| 257 | && !existenceChecker.identityOperatorExists()) { |
| 258 | setLocationWithinModule(listContext + ".getOperator()"); |
| 259 | handleFormulaCheckException(EQUALITY_PREDICATE_NOT_YET_DEFINED, |
| 260 | EQUALITY_PREDICATE_NOT_YET_DEFINED_TEXT, element, getCurrentContext()); |
| 261 | } |
| 262 | |
| 263 | // check if first argument is subject variable |
| 264 | setLocationWithinModule(listContext + ".getElement(" + 0 + ")"); |
| 265 | checkSubjectVariable(list.getElement(0)); |
| 266 | |
| 267 | // check if second argument is a formula |
| 268 | setLocationWithinModule(listContext + ".getElement(" + 1 + ")"); |
| 269 | checkFormula(list.getElement(1)); |
| 270 | |
| 271 | setLocationWithinModule(listContext); |
| 272 | // check if subject variable is not already bound in formula |
| 273 | if (FormulaUtility.getBoundSubjectVariables(list.getElement(1)).contains( |
| 274 | list.getElement(0))) { |
| 275 | handleFormulaCheckException(SUBJECT_VARIABLE_ALREADY_BOUND_IN_FORMULA, |
| 276 | SUBJECT_VARIABLE_ALREADY_BOUND_IN_FORMULA_TEXT, list.getElement(1), |
| 277 | getCurrentContext()); |
| 278 | } |
| 279 | if (list.size() > 3) { |
| 280 | handleFormulaCheckException(EXACTLY_TWO_OR_THREE_ARGUMENTS_EXPECTED, |
| 281 | EXACTLY_TWO_OR_THREE_ARGUMENTS_EXPECTED_TEXT, list, |
| 282 | getCurrentContext()); |
| 283 | return; |
| 284 | } |
| 285 | if (list.size() > 2) { |
| 286 | // check if third argument is a formula |
| 287 | setLocationWithinModule(listContext + ".getElement(" + 2 + ")"); |
| 288 | checkFormula(list.getElement(2)); |
| 289 | |
| 290 | // check if subject variable is not bound in formula |
| 291 | setLocationWithinModule(listContext); |
| 292 | if (FormulaUtility.getBoundSubjectVariables(list.getElement(2)).contains( |
| 293 | list.getElement(0))) { |
| 294 | handleFormulaCheckException(SUBJECT_VARIABLE_ALREADY_BOUND_IN_FORMULA, |
| 295 | SUBJECT_VARIABLE_ALREADY_BOUND_IN_FORMULA_TEXT, list.getElement(2), |
| 296 | getCurrentContext()); |
| 297 | return; |
| 298 | } |
| 299 | setLocationWithinModule(listContext); |
| 300 | checkFreeAndBoundDisjunct(1, list); |
| 301 | } |
| 302 | // restore context |
| 303 | setLocationWithinModule(context); |
| 304 | Trace.end(CLASS, this, method); |
| 305 | } |
| 306 | |
| 307 | /** |
| 308 | * Is {@link Element} a term? |
| 309 | * |
| 310 | * @param element Check this element. |
| 311 | */ |
| 312 | private void checkTerm(final Element element) { |
| 313 | final String method = "checkTerm"; |
| 314 | Trace.begin(CLASS, this, method); |
| 315 | Trace.param(CLASS, this, method, "element", element); |
| 316 | // save current context |
| 317 | final String context = getCurrentContext().getLocationWithinModule(); |
| 318 | Trace.param(CLASS, this, method, "context", context); |
| 319 | if (!checkList(element)) { |
| 320 | return; |
| 321 | } |
| 322 | final ElementList list = element.getList(); |
| 323 | final String listContext = context + ".getList()"; |
| 324 | setLocationWithinModule(listContext); |
| 325 | final String operator = list.getOperator(); |
| 326 | if (operator.equals(SUBJECT_VARIABLE)) { |
| 327 | checkSubjectVariable(element); |
| 328 | } else if (operator.equals(FUNCTION_CONSTANT) |
| 329 | || operator.equals(FUNCTION_VARIABLE)) { |
| 330 | |
| 331 | // function constants must have at least a function name |
| 332 | if (operator.equals(FUNCTION_CONSTANT) && list.size() < 1) { |
| 333 | handleTermCheckException(AT_LEAST_ONE_ARGUMENT_EXPECTED, |
| 334 | AT_LEAST_ONE_ARGUMENT_EXPECTED_TEXT, element, getCurrentContext()); |
| 335 | return; |
| 336 | } |
| 337 | |
| 338 | // function variables must have at least a function name and at least one argument |
| 339 | if (operator.equals(FUNCTION_VARIABLE) && list.size() < 2) { |
| 340 | handleTermCheckException(MORE_THAN_ONE_ARGUMENT_EXPECTED, |
| 341 | MORE_THAN_ONE_ARGUMENT_EXPECTED_TEXT, element, getCurrentContext()); |
| 342 | return; |
| 343 | } |
| 344 | |
| 345 | // check if first argument is an atom |
| 346 | setLocationWithinModule(listContext + ".getElement(0)"); |
| 347 | if (!checkAtomFirst(list.getElement(0))) { |
| 348 | return; |
| 349 | } |
| 350 | |
| 351 | // check if all arguments are terms |
| 352 | setLocationWithinModule(listContext); |
| 353 | for (int i = 1; i < list.size(); i++) { |
| 354 | setLocationWithinModule(listContext + ".getElement(" + i + ")"); |
| 355 | checkTerm(list.getElement(i)); |
| 356 | } |
| 357 | |
| 358 | setLocationWithinModule(listContext); |
| 359 | checkFreeAndBoundDisjunct(1, list); |
| 360 | |
| 361 | // check if function is known |
| 362 | setLocationWithinModule(listContext); |
| 363 | if (FUNCTION_CONSTANT.equals(operator) && !existenceChecker.functionExists( |
| 364 | list.getElement(0).getAtom().getString(), list.size() - 1)) { |
| 365 | handleFormulaCheckException(UNKNOWN_FUNCTION_CONSTANT, |
| 366 | UNKNOWN_FUNCTION_CONSTANT_TEXT + "\"" |
| 367 | + list.getElement(0).getAtom().getString() + "\"", element, |
| 368 | getCurrentContext()); |
| 369 | } |
| 370 | |
| 371 | } else if (operator.equals(CLASS_OP)) { |
| 372 | |
| 373 | if (list.size() != 2) { |
| 374 | handleTermCheckException(EXACTLY_TWO_ARGUMENTS_EXPECTED, |
| 375 | EXACTLY_TWO_ARGUMENTS_EXPECTED_TEXT, element, getCurrentContext()); |
| 376 | return; |
| 377 | } |
| 378 | // check if first argument is a subject variable |
| 379 | setLocationWithinModule(listContext + ".getElement(" + 0 + ")"); |
| 380 | if (!FormulaUtility.isSubjectVariable(list.getElement(0))) { |
| 381 | handleTermCheckException(SUBJECT_VARIABLE_EXPECTED, |
| 382 | SUBJECT_VARIABLE_EXPECTED_TEXT, element, getCurrentContext()); |
| 383 | } |
| 384 | |
| 385 | // check if the second argument is a formula |
| 386 | setLocationWithinModule(listContext + ".getElement(" + 1 + ")"); |
| 387 | checkFormula(list.getElement(1)); |
| 388 | |
| 389 | // check if class operator is allowed |
| 390 | setLocationWithinModule(listContext); |
| 391 | if (!existenceChecker.classOperatorExists()) { |
| 392 | handleFormulaCheckException(CLASS_OPERATOR_STILL_UNKNOWN, |
| 393 | CLASS_OPERATOR_STILL_UNKNOWN_TEXT, element, getCurrentContext()); |
| 394 | } |
| 395 | |
| 396 | // check if subject variable is not bound in formula |
| 397 | setLocationWithinModule(listContext + ".getElement(" + 0 + ")"); |
| 398 | if (FormulaUtility.getBoundSubjectVariables(list.getElement(1)).contains( |
| 399 | list.getElement(0))) { |
| 400 | handleTermCheckException(SUBJECT_VARIABLE_ALREADY_BOUND_IN_FORMULA, |
| 401 | SUBJECT_VARIABLE_ALREADY_BOUND_IN_FORMULA_TEXT, list.getElement(0), |
| 402 | getCurrentContext()); |
| 403 | } |
| 404 | |
| 405 | } else { |
| 406 | setLocationWithinModule(listContext + ".getOperator()"); |
| 407 | handleTermCheckException(UNKNOWN_TERM_OPERATOR, |
| 408 | UNKNOWN_TERM_OPERATOR_TEXT + "\"" + operator + "\"", element, getCurrentContext()); |
| 409 | } |
| 410 | // restore context |
| 411 | setLocationWithinModule(context); |
| 412 | Trace.end(CLASS, this, method); |
| 413 | } |
| 414 | |
| 415 | /** |
| 416 | * Check if no bound variables are free and vice versa. |
| 417 | * The current context must be at the list element. |
| 418 | * |
| 419 | * @param start Start check with this list position. Beginning with 0. |
| 420 | * @param list List element to check. |
| 421 | */ |
| 422 | private void checkFreeAndBoundDisjunct(final int start, |
| 423 | final ElementList list) { |
| 424 | // save current context |
| 425 | final String context = getCurrentContext().getLocationWithinModule(); |
| 426 | final ElementSet free = new ElementSet(); |
| 427 | final ElementSet bound = new ElementSet(); |
| 428 | for (int i = start; i < list.size(); i++) { |
| 429 | setLocationWithinModule(context + ".getElement(" + i + ")"); |
| 430 | final ElementSet newFree |
| 431 | = FormulaUtility.getFreeSubjectVariables(list.getElement(i)); |
| 432 | final ElementSet newBound |
| 433 | = FormulaUtility.getBoundSubjectVariables(list.getElement(i)); |
| 434 | final ElementSet interBound = newFree.newIntersection(bound); |
| 435 | if (!interBound.isEmpty()) { |
| 436 | handleFormulaCheckException(FREE_VARIABLE_ALREADY_BOUND, |
| 437 | FREE_VARIABLE_ALREADY_BOUND_TEXT |
| 438 | + interBound, list.getElement(i), getCurrentContext()); |
| 439 | } |
| 440 | final ElementSet interFree = newBound.newIntersection(free); |
| 441 | if (!interFree.isEmpty()) { |
| 442 | handleFormulaCheckException(BOUND_VARIABLE_ALREADY_FREE, |
| 443 | BOUND_VARIABLE_ALREADY_FREE_TEXT |
| 444 | + interFree, list.getElement(i), getCurrentContext()); |
| 445 | } |
| 446 | bound.union(newBound); |
| 447 | free.union(newFree); |
| 448 | } |
| 449 | // restore context |
| 450 | setLocationWithinModule(context); |
| 451 | } |
| 452 | |
| 453 | /** |
| 454 | * Check if {@link Element} is a subject variable. |
| 455 | * |
| 456 | * @param element Check this element. |
| 457 | * @return Is it a subject variable? |
| 458 | */ |
| 459 | private boolean checkSubjectVariable(final Element element) { |
| 460 | // throws LogicalCheckException { |
| 461 | // save current context |
| 462 | final String context = getCurrentContext().getLocationWithinModule(); |
| 463 | if (!checkList(element)) { |
| 464 | return false; |
| 465 | } |
| 466 | setLocationWithinModule(context + ".getList()"); |
| 467 | if (element.getList().getOperator().equals(SUBJECT_VARIABLE)) { |
| 468 | if (element.getList().size() != 1) { |
| 469 | handleFormulaCheckException(EXACTLY_ONE_ARGUMENT_EXPECTED, |
| 470 | EXACTLY_ONE_ARGUMENT_EXPECTED_TEXT, element.getList(), getCurrentContext()); |
| 471 | return false; |
| 472 | } |
| 473 | // check if first argument is an atom |
| 474 | setLocationWithinModule(context + ".getList().getElement(0)"); |
| 475 | if (checkAtomFirst(element.getList().getElement(0))) { |
| 476 | return false; |
| 477 | } |
| 478 | } else { |
| 479 | setLocationWithinModule(context + ".getList().getOperator()"); |
| 480 | handleFormulaCheckException(SUBJECT_VARIABLE_EXPECTED, |
| 481 | SUBJECT_VARIABLE_EXPECTED_TEXT, element, getCurrentContext()); |
| 482 | return false; |
| 483 | } |
| 484 | // restore context |
| 485 | setLocationWithinModule(context); |
| 486 | return true; |
| 487 | } |
| 488 | |
| 489 | /** |
| 490 | * Check common requirements for list elements that are checked for being a term or formula. |
| 491 | * That includes: is the element a true list, has the operator a non zero size. |
| 492 | * |
| 493 | * @param element List element. |
| 494 | * @return Are the requirements fulfilled? |
| 495 | */ |
| 496 | private boolean checkList(final Element element) { |
| 497 | // save current context |
| 498 | final String context = getCurrentContext().getLocationWithinModule(); |
| 499 | if (element == null) { |
| 500 | handleElementCheckException(ELEMENT_MUST_NOT_BE_NULL, |
| 501 | ELEMENT_MUST_NOT_BE_NULL_TEXT, null, getCurrentContext()); |
| 502 | return false; |
| 503 | } |
| 504 | if (!element.isList()) { |
| 505 | handleElementCheckException(LIST_EXPECTED, |
| 506 | LIST_EXPECTED_TEXT, element, getCurrentContext()); |
| 507 | return false; |
| 508 | } |
| 509 | final ElementList list = element.getList(); |
| 510 | setLocationWithinModule(context + ".getList()"); |
| 511 | if (list == null) { |
| 512 | handleElementCheckException(LIST_MUST_NOT_BE_NULL, |
| 513 | LIST_MUST_NOT_BE_NULL_TEXT, element, getCurrentContext()); |
| 514 | return false; |
| 515 | } |
| 516 | final String operator = list.getOperator(); |
| 517 | setLocationWithinModule(context + ".getList().getOperator()"); |
| 518 | if (operator == null) { |
| 519 | handleElementCheckException(OPERATOR_CONTENT_MUST_NOT_BE_NULL, |
| 520 | OPERATOR_CONTENT_MUST_NOT_BE_NULL_TEXT , element, |
| 521 | getCurrentContext()); |
| 522 | return false; |
| 523 | } |
| 524 | if (operator.length() == 0) { |
| 525 | handleElementCheckException(OPERATOR_CONTENT_MUST_NOT_BE_EMPTY, |
| 526 | OPERATOR_CONTENT_MUST_NOT_BE_EMPTY_TEXT + "\"" |
| 527 | + operator + "\"", element, getCurrentContext()); |
| 528 | return false; |
| 529 | } |
| 530 | // restore context |
| 531 | setLocationWithinModule(context); |
| 532 | return true; |
| 533 | } |
| 534 | |
| 535 | /** |
| 536 | * Check if element is an atom and has valid content. It is assumed, that this element is the |
| 537 | * first of a list. |
| 538 | * |
| 539 | * @param element Check this for an atom. |
| 540 | * @return Is the content valid? |
| 541 | */ |
| 542 | private boolean checkAtomFirst(final Element element) { |
| 543 | // save current context |
| 544 | final String context = getCurrentContext().getLocationWithinModule(); |
| 545 | if (element == null) { |
| 546 | handleElementCheckException(ELEMENT_MUST_NOT_BE_NULL, |
| 547 | ELEMENT_MUST_NOT_BE_NULL_TEXT, null, getCurrentContext()); |
| 548 | return false; |
| 549 | } |
| 550 | if (!element.isAtom()) { // TODO mime 20061126: this is special? |
| 551 | handleElementCheckException(FIRST_ARGUMENT_MUST_BE_AN_ATOM, |
| 552 | FIRST_ARGUMENT_MUST_BE_AN_ATOM_TEXT, element, getCurrentContext()); |
| 553 | return false; |
| 554 | } |
| 555 | final Atom atom = element.getAtom(); |
| 556 | setLocationWithinModule(context + ".getAtom()"); |
| 557 | if (atom == null) { |
| 558 | handleElementCheckException(ATOM_MUST_NOT_BE_NULL, |
| 559 | ATOM_MUST_NOT_BE_NULL_TEXT, element, getCurrentContext()); |
| 560 | return false; |
| 561 | } |
| 562 | if (atom.getString() == null) { |
| 563 | handleElementCheckException(ATOM_CONTENT_MUST_NOT_BE_NULL, |
| 564 | ATOM_CONTENT_MUST_NOT_BE_NULL_TEXT, element, getCurrentContext()); |
| 565 | return false; |
| 566 | } |
| 567 | if (atom.getString().length() == 0) { |
| 568 | handleElementCheckException(ATOM_CONTENT_MUST_NOT_BE_EMPTY, |
| 569 | ATOM_CONTENT_MUST_NOT_BE_EMPTY_TEXT, element, getCurrentContext()); |
| 570 | return false; |
| 571 | } |
| 572 | // restore context |
| 573 | setLocationWithinModule(context); |
| 574 | return true; |
| 575 | } |
| 576 | |
| 577 | /** |
| 578 | * Add new {@link FormulaCheckException} to exception list. |
| 579 | * |
| 580 | * @param code Error code. |
| 581 | * @param msg Error message. |
| 582 | * @param element Element with error. |
| 583 | * @param context Error context. |
| 584 | */ |
| 585 | private void handleFormulaCheckException(final int code, final String msg, |
| 586 | final Element element, final ModuleContext context) { |
| 587 | final FormulaCheckException ex = new FormulaCheckException(code, msg, element, context); |
| 588 | exceptions.add(ex); |
| 589 | } |
| 590 | |
| 591 | /** |
| 592 | * Add new {@link TermCheckException} to exception list. |
| 593 | * |
| 594 | * @param code Error code. |
| 595 | * @param msg Error message. |
| 596 | * @param element Element with error. |
| 597 | * @param context Error context. |
| 598 | */ |
| 599 | private void handleTermCheckException(final int code, final String msg, |
| 600 | final Element element, final ModuleContext context) { |
| 601 | final TermCheckException ex = new TermCheckException(code, msg, element, context); |
| 602 | exceptions.add(ex); |
| 603 | } |
| 604 | |
| 605 | /** |
| 606 | * Add new {@link ElementCheckException} to exception list. |
| 607 | * |
| 608 | * @param code Error code. |
| 609 | * @param msg Error message. |
| 610 | * @param element Element with error. |
| 611 | * @param context Error context. |
| 612 | */ |
| 613 | private void handleElementCheckException(final int code, final String msg, |
| 614 | final Element element, final ModuleContext context) { |
| 615 | final ElementCheckException ex = new ElementCheckException(code, msg, element, context); |
| 616 | exceptions.add(ex); |
| 617 | } |
| 618 | |
| 619 | /** |
| 620 | * Set location information where are we within the original module. |
| 621 | * |
| 622 | * @param locationWithinModule Location within module. |
| 623 | */ |
| 624 | protected void setLocationWithinModule(final String locationWithinModule) { |
| 625 | getCurrentContext().setLocationWithinModule(locationWithinModule); |
| 626 | } |
| 627 | |
| 628 | /** |
| 629 | * Get current context within original. |
| 630 | * |
| 631 | * @return Current context. |
| 632 | */ |
| 633 | protected final ModuleContext getCurrentContext() { |
| 634 | return currentContext; |
| 635 | } |
| 636 | |
| 637 | } |