/*-*-c++-*- * $Id$ * * This file is part of plptools. * * Copyright (C) 2000 Henner Zeller * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #ifndef _ENUM_H_ #define _ENUM_H_ #ifdef HAVE_CONFIG_H #include #endif #ifdef HAVE_LIBINTL_H #include #endif #include #include /** * the Base for the Enum template. * currently, only purpose is to provide a class type for mapping * integer enum values to strings in the Enumeration class. * The mapping is done basically with a STL-multimap. * * @author Henner Zeller */ class EnumBase { protected: /** * maps integers (typically: enumeration values) to * Strings. Takes care of the fact, that an Integer may map * to multiple strings (sometimes multiple enumeration values * represent the same integer). * * Provides a means to get the string representation of an * integer and vice versa. * * @author Henner Zeller */ class i2sMapper { private: /** * there can be one value, mapping to multiple * strings. Therefore, we need a multimap. */ typedef multimap i2s_map_t; /** * just for the record. Mapping back a string to the * Integer value in question. Since Symbols must be unique, * there is only a 1:1 relation as opposed to i2s_map_t. So * we can use a normal map here. * * Since in the usual application, mapping a string back * to its value is not important performance wise (typically * in a frontend), so it is implemented as exhaustive search, * not as extra map. Saves some bits of memrory .. */ //typedef map s2i_map_t; i2s_map_t stringMap; public: /** * adds a new int -> string mapping * Does NOT take over responsibility for the * pointer (i.e. it is not freed), so it is save * to add constant strings provided in the program code. */ void add(long, const char*); /** * returns the string representation for this integer. * If there are multiple strings for this integer, * return a comma delimited list. */ string lookup(long) const; /** * returns the integer associated with the * given string or -1 if the value * is not found (XXX: this should throw * an exception). */ long lookup (const char *) const; /** * returns true, if we have an representation for * the given integer. */ bool inRange(long) const; }; }; /** * Wrapper class featuring range-checking and string * representation of enumerated values. * * The string representation capability is needed to provide a * generic input frontend for any Enumeration because text labels * are needed in GUIs, and, of course, aids debugging, because you * can provide a readable presentation of an entry if something * goes wrong. * * NOTE, that wrapping an enumeration with this class * does not mean any performance overhead at all since the * compiler optimizes the member calls away. Nor does an instance of * this class use more memory than the use of an usual Enumeration. * (i.e. sizeof(E) == sizeof(Enum)). * * Besides that, it provides a great opportunity to check the * code and make it bug free, esp. if you've to read the * Enumeration from some dubious integer source * (.. to make the dubious integer source bug free ;-) * * So there is no reason, not to use this class. * Alas, you've to provide a StringRepresentation for it, which may * be tedious for large enumerations. To make the Definition easier * and more readable, an ENUM_DEFINITION() macro is provided. * * @see #ENUM_DEFINITION * @author Henner Zeller */ template class Enum : private EnumBase { private: struct sdata { /** * The constructor of the static data part. * You've to provide a constructor for each Enumeration * you want to wrap with this class. Initializes * the string Representation map, the readable name * of this Enumeration and a default value. * * The constructor is called automatically on definition, * so this makes sure, that the static part is initialized * properly before the program starts. */ sdata(); i2sMapper stringRep; string name; E defaultValue; }; static sdata staticData; /** * The actual value hold by this instance */ E value; public: /** * default constructor. * Initialize with default value. */ Enum() : value(staticData.defaultValue) {} /** * initialize with Enumeration given. */ Enum(E init) : value(init){ // if this hits you and you're sure, that the // value is right .. is this Enum proper // initialized in the Enum::sdata::sdata() ? assert(inRange(init)); } /** * initialize with the string representation * XXX: throw Exception if not found ? */ Enum(const string& s) : value(getValueFor(s)) { assert(inRange(value)); } /** * assign an Enumeration of this type. In debug * version, assert, that it is really in the Range of * this Enumeration. */ inline Enum& operator = (E setval) { value = setval; assert(inRange(setval)); return *this; } /** * returns the enumeration value hold with this * enum. */ inline operator E () const { return value; } /** * returns the String representation for the value * represented by this instance. */ string toString() const { return getStringFor(value); } /** * returns the C string representation for the value * represented by this instance. */ operator const char *() const { return toString().c_str(); } /** * This static member returns true, if the integer value * given fits int the range of this Enumeration. Use this * to verify input/output. * Fitting in the range of Enumeration here means, that * there actually exists a String representation for it, * so this Enumeration is needed to be initialized properly * in its Enum::sdata::sdata() constructor, you've to * provide. For convenience, use the ENUM_DEFINITION() macro * for this. */ static bool inRange(long i) { return (staticData.stringRep.inRange(i)); } /** * returns the Name for this enumeration. Useful for * error reporting. */ static string getEnumName() { return staticData.name; } /** * gives the String represenatation of a specific * value of this Enumeration. */ static string getStringFor(E e) { return staticData.stringRep.lookup((long) e); } /** * returns the Value for a specific String. * XXX: throw OutOfRangeException ? */ static E getValueFor(const string &s) { return (E) staticData.stringRep.lookup(s.getCStr()); } }; /** * Helper macro to construct an enumeration wrapper Enum for * a specific enum type. * * It defines the static variable holding the static * information and provides the head of its Constructor. * You only have to provide the string-mapping additions in the * constructor body. This macro behaves much like a function declaration, * i.e. you have to start the constructor with { .. * * usage example: *

 * // declaration of enumeration; somewhere
 * class rfsv {
 * [...]
 * 	enum PSI_ERROR_CODES { E_PSI_GEN_NONE, E_PSI_GEN_FAIL, E_PSI_GEN_ARG };
 * [...]
 * };
 *
 * // definition of the Enum with the appropriate string representations
 * ENUM_DEFINITION(rfsv::PSI_ERROR_CODES,
 *	 	   rfsv::E_PSI_GEN_NONE) {
 *	stringRep.add(rfsv::E_PSI_GEN_NONE,	"no error");
 *	stringRep.add(rfsv::E_PSI_GEN_FAIL,	"general");
 *	stringRep.add(rfsv::E_PSI_GEN_ARG,	"bad argument");
 * }
 *

* * @param EnumName The fully qualified Name of the enum type to be wrapped * @param init The fully qualified Name of the initialization * value. * * @author Henner Zeller */ #define ENUM_DEFINITION(EnumName, initWith) \ /** \ * The definition of the static variable holding the static \ * data for this Enumeration wrapper. \ */ \ Enum::sdata Enum::staticData; \ /** \ * actual definition of the constructor for the static data. \ * This is called implicitly by the definition above. \ */ \ Enum::sdata::sdata() : \ name(#EnumName),defaultValue(initWith) /** * Writes enumeration's string representation. */ template inline ostream& operator << (ostream& out, const Enum &e) { return out << gettext(e.toString().c_str()); } #endif /* _ENUM_H_ */ /* * Local variables: * c-basic-offset: 4 * End: */ ref='#n172'>172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436