| 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.parser; |
| 17 | |
| 18 | |
| 19 | /** |
| 20 | * This class describes an term or logical operator. An operator is of either |
| 21 | * prefix, infix or postfix type and has a minimum and maximum number of operands. |
| 22 | * It has a symbol or token that enables to recognize it and a QEDEQ representation. |
| 23 | * Each instance of this class is unique so two instances with the same parameters are |
| 24 | * different from each other. |
| 25 | * |
| 26 | * @author Michael Meyling |
| 27 | */ |
| 28 | public final class Operator { |
| 29 | |
| 30 | /** Marks infix operator. */ |
| 31 | public static final int INFIX = 0; |
| 32 | |
| 33 | /** Marks prefix operator. */ |
| 34 | public static final int SIMPLE_PREFIX = 1; |
| 35 | |
| 36 | /** Marks postfix operator. */ |
| 37 | public static final int POSTFIX = 2; |
| 38 | |
| 39 | /** Marks function operator. */ |
| 40 | public static final int FUNCTION = 4; |
| 41 | |
| 42 | /** Prefix, function, infix or postfix. See {@link #SIMPLE_PREFIX}, {@link #FUNCTION}, |
| 43 | * {@link #INFIX} and {@link #POSTFIX}. */ |
| 44 | private final int type; |
| 45 | |
| 46 | /** Start symbol or token for this operator. */ |
| 47 | private final String startSymbol; |
| 48 | |
| 49 | /** Separator symbol or token for this operator. This could be a comma for example. */ |
| 50 | private final String separatorSymbol; |
| 51 | |
| 52 | /** End symbol or token for this operator. */ |
| 53 | private final String endSymbol; |
| 54 | |
| 55 | /** Operator priority. Highest is 0. */ |
| 56 | private final int priority; |
| 57 | |
| 58 | /** QEDEQ token for this operator. */ |
| 59 | private final String qedeq; |
| 60 | |
| 61 | /** First QEDEQ argument. Can be <code>null</code>. */ |
| 62 | private final String qedeqArgument; |
| 63 | |
| 64 | /** Minimum number of arguments. */ |
| 65 | private final int min; |
| 66 | |
| 67 | /** Maximum number of arguments. */ |
| 68 | private final int max; |
| 69 | |
| 70 | |
| 71 | /** |
| 72 | * Constructor. |
| 73 | * |
| 74 | * @param symbol Symbol or token for this operator. |
| 75 | * @param qedeq QEDEQ operator symbol. |
| 76 | * @param qedeqArgument First Argument in QEDEQ-Syntax - if any. |
| 77 | * @param priority Operator priority, highest is 0. |
| 78 | * @param type Prefix, infix or postfix. See {@link #SIMPLE_PREFIX}, {@link #FUNCTION}, |
| 79 | * {@link #INFIX} and {@link #POSTFIX}. |
| 80 | * @param min Minimum number of arguments for this operator. |
| 81 | */ |
| 82 | public Operator(final String symbol, |
| 83 | final String qedeq, |
| 84 | final String qedeqArgument, |
| 85 | final int priority, |
| 86 | final int type, |
| 87 | final int min) { |
| 88 | this(symbol, qedeq, qedeqArgument, priority, type, min, -1); |
| 89 | } |
| 90 | |
| 91 | /** |
| 92 | * Constructor. |
| 93 | * |
| 94 | * @param symbol Symbol or token for this operator. |
| 95 | * @param qedeq QEDEQ operator symbol. |
| 96 | * @param qedeqArgument First Argument in QEDEQ-Syntax - if any. |
| 97 | * @param priority Operator priority, highest is 0. |
| 98 | * @param type Prefix, infix or postfix. See {@link #SIMPLE_PREFIX}, |
| 99 | * {@link #FUNCTION}, |
| 100 | * {@link #INFIX} and {@link #POSTFIX}. |
| 101 | * @param min Minimum number of arguments for this operator. |
| 102 | * @param max Maximum number of arguments for this operator. |
| 103 | */ |
| 104 | public Operator(final String symbol, |
| 105 | final String qedeq, |
| 106 | final String qedeqArgument, |
| 107 | final int priority, |
| 108 | final int type, |
| 109 | final int min, |
| 110 | final int max) { |
| 111 | this(symbol, null, null, qedeq, qedeqArgument, priority, type, min, max); |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * Constructor for prefix operators like <code>{x | x > 0}</code>. |
| 116 | * |
| 117 | * @param startSymbol Starting symbol or token for this operator. |
| 118 | * @param separatorSymbol Symbol or token that separates arguments for this operator. |
| 119 | * @param endSymbol End symbol or token for this operator. |
| 120 | * @param qedeq QEDEQ operator symbol. |
| 121 | * @param qedeqArgument First Argument in QEDEQ-Syntax - if any |
| 122 | * @param priority Operator priority, highest is 0. |
| 123 | * @param min Minimum number of arguments for this operator. |
| 124 | */ |
| 125 | public Operator(final String startSymbol, |
| 126 | final String separatorSymbol, |
| 127 | final String endSymbol, |
| 128 | final String qedeq, |
| 129 | final String qedeqArgument, |
| 130 | final int priority, |
| 131 | final int min) { |
| 132 | this(startSymbol, separatorSymbol, endSymbol, qedeq, qedeqArgument, priority, SIMPLE_PREFIX, |
| 133 | min, -1); |
| 134 | } |
| 135 | |
| 136 | /** |
| 137 | * Constructor for prefix operators like <code>{x, y, z}</code>. |
| 138 | * |
| 139 | * @param startSymbol Starting symbol or token for this operator. |
| 140 | * @param separatorSymbol Symbol or token that separates arguments for this operator. |
| 141 | * @param endSymbol End symbol or token for this operator. |
| 142 | * @param qedeq QEDEQ operator symbol. |
| 143 | * @param qedeqArgument First Argument in QEDEQ-Syntax - if any. |
| 144 | * @param priority Operator priority, highest is 0. |
| 145 | * @param min Minimum number of arguments for this operator. |
| 146 | * @param max Maximum number of arguments for this operator. |
| 147 | */ |
| 148 | public Operator(final String startSymbol, |
| 149 | final String separatorSymbol, |
| 150 | final String endSymbol, |
| 151 | final String qedeq, |
| 152 | final String qedeqArgument, |
| 153 | final int priority, |
| 154 | final int min, |
| 155 | final int max) { |
| 156 | this(startSymbol, separatorSymbol, endSymbol, qedeq, qedeqArgument, priority, SIMPLE_PREFIX, |
| 157 | min, max); |
| 158 | } |
| 159 | |
| 160 | /** |
| 161 | * Constructor. |
| 162 | * |
| 163 | * @param startSymbol Starting symbol or token for this operator. |
| 164 | * @param separatorSymbol Symbol or token that separates arguments for this operator. |
| 165 | * @param endSymbol End symbol or token for this operator. |
| 166 | * @param qedeq QEDEQ operator symbol. |
| 167 | * @param qedeqArgument First Argument in QEDEQ-Syntax - if any. |
| 168 | * @param priority Operator priority, highest is 0. |
| 169 | * @param type Prefix, infix or postfix. See {@link #SIMPLE_PREFIX}, |
| 170 | * {@link #FUNCTION}, {@link #INFIX} and {@link #POSTFIX}. |
| 171 | * @param min Minimum number of arguments for this operator. |
| 172 | * @param max Maximum number of arguments for this operator. |
| 173 | */ |
| 174 | public Operator(final String startSymbol, final String separatorSymbol, final String endSymbol, |
| 175 | final String qedeq, |
| 176 | final String qedeqArgument, |
| 177 | final int priority, |
| 178 | final int type, |
| 179 | final int min, |
| 180 | final int max) { |
| 181 | this.startSymbol = startSymbol; |
| 182 | this.separatorSymbol = separatorSymbol; |
| 183 | this.endSymbol = endSymbol; |
| 184 | this.type = type; |
| 185 | this.qedeq = qedeq; |
| 186 | this.qedeqArgument = qedeqArgument; |
| 187 | this.priority = priority; |
| 188 | this.min = min; |
| 189 | this.max = max; |
| 190 | switch (type) { |
| 191 | case INFIX: |
| 192 | case SIMPLE_PREFIX: |
| 193 | case FUNCTION: |
| 194 | case POSTFIX: |
| 195 | break; |
| 196 | default: |
| 197 | throw new IllegalArgumentException("unknown operator type: " |
| 198 | + type); |
| 199 | } |
| 200 | if (max != -1 && min > max) { |
| 201 | throw new IllegalArgumentException("Min greater than max: " + min + " > " + max); |
| 202 | } |
| 203 | if (isInfix() && min < 2) { |
| 204 | throw new IllegalArgumentException("Infix needs at least two arguments"); |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | /** |
| 209 | * Returns symbol or token to identify this operator. |
| 210 | * |
| 211 | * @return Symbol or token to identify a start of this operator. |
| 212 | */ |
| 213 | public final String getStartSymbol() { |
| 214 | return startSymbol; |
| 215 | } |
| 216 | |
| 217 | /** |
| 218 | * Returns symbol or token to separate different arguments for this operator. Can only be |
| 219 | * different from <code>null</code> if this is a prefix operator. |
| 220 | * |
| 221 | * @return Symbol or token to identify the start of a new argument of this operator. |
| 222 | */ |
| 223 | public String getSeparatorSymbol() { |
| 224 | return separatorSymbol; |
| 225 | } |
| 226 | |
| 227 | /** |
| 228 | * Returns symbol or token to identify the end of this operator. Can only be different from |
| 229 | * <code>null</code> if this is a prefix operator. |
| 230 | * |
| 231 | * @return Symbol or token to identify the end of this operator. Maybe <code>null</code>. |
| 232 | */ |
| 233 | public String getEndSymbol() { |
| 234 | return endSymbol; |
| 235 | } |
| 236 | |
| 237 | /** |
| 238 | * Is this an infix operator? |
| 239 | * |
| 240 | * @return Is this an infix operator? |
| 241 | */ |
| 242 | public final boolean isInfix() { |
| 243 | return type == INFIX; |
| 244 | } |
| 245 | |
| 246 | /** |
| 247 | * Is this a prefix operator? |
| 248 | * |
| 249 | * @return Is this a prefix operator? |
| 250 | */ |
| 251 | public final boolean isPrefix() { |
| 252 | return type == SIMPLE_PREFIX || type == FUNCTION; |
| 253 | } |
| 254 | |
| 255 | /** |
| 256 | * Is this a function operator? |
| 257 | * |
| 258 | * @return Is this a function operator? |
| 259 | */ |
| 260 | public final boolean isFunction() { |
| 261 | return type == FUNCTION; |
| 262 | } |
| 263 | |
| 264 | /** |
| 265 | * Is this a postfix operator? |
| 266 | * |
| 267 | * @return Is this a postfix operator? |
| 268 | */ |
| 269 | public final boolean isPostfix() { |
| 270 | return type == POSTFIX; |
| 271 | } |
| 272 | |
| 273 | /** |
| 274 | * Get operator priority. 0 is the highest priority. |
| 275 | * |
| 276 | * @return Priority. |
| 277 | */ |
| 278 | public final int getPriority() { |
| 279 | return this.priority; |
| 280 | } |
| 281 | |
| 282 | /** |
| 283 | * Get minimum argument number. |
| 284 | * |
| 285 | * @return Minimum argument number. |
| 286 | */ |
| 287 | public final int getMin() { |
| 288 | return this.min; |
| 289 | } |
| 290 | |
| 291 | /** |
| 292 | * Get maximum argument number. |
| 293 | * |
| 294 | * @return Maximum argument number. |
| 295 | */ |
| 296 | public final int getMax() { |
| 297 | return max; |
| 298 | } |
| 299 | |
| 300 | /** |
| 301 | * Get QEDEQ operator name. |
| 302 | * |
| 303 | * @return QEDEQ operator name. |
| 304 | */ |
| 305 | public final String getQedeq() { |
| 306 | return qedeq; |
| 307 | } |
| 308 | |
| 309 | /** |
| 310 | * Get first QEDEQ argument. |
| 311 | * |
| 312 | * @return First QEDEQ argument. Can be <code>null</code>. |
| 313 | */ |
| 314 | public final String getQedeqArgument() { |
| 315 | return qedeqArgument; |
| 316 | } |
| 317 | |
| 318 | public final String toString() { |
| 319 | final StringBuffer buffer = new StringBuffer(getStartSymbol()); |
| 320 | buffer.append("[" + getMin() + ", "); |
| 321 | if (getMax() == -1) { |
| 322 | buffer.append(".."); |
| 323 | } else { |
| 324 | buffer.append(getMax()); |
| 325 | } |
| 326 | buffer.append("]"); |
| 327 | if (getSeparatorSymbol() != null) { |
| 328 | buffer.append(" ").append(getSeparatorSymbol()); |
| 329 | } |
| 330 | if (getEndSymbol() != null) { |
| 331 | buffer.append(" ").append(getEndSymbol()); |
| 332 | } |
| 333 | if (isFunction()) { |
| 334 | buffer.append(", is function"); |
| 335 | } |
| 336 | if (isPrefix()) { |
| 337 | buffer.append(", is prefix"); |
| 338 | } |
| 339 | if (isInfix()) { |
| 340 | buffer.append(", is infix"); |
| 341 | } |
| 342 | if (isPostfix()) { |
| 343 | buffer.append(", is postfix"); |
| 344 | } |
| 345 | return buffer.toString(); |
| 346 | } |
| 347 | |
| 348 | } |
| 349 | |