3 * Implementation of GiNaC's ABC. */
6 * GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
44 GINAC_IMPLEMENT_REGISTERED_CLASS_NO_CTORS(basic, void)
47 // default ctor, dtor, copy ctor assignment operator and helpers
52 basic::basic(const basic & other) : tinfo_key(TINFO_basic), flags(0), refcount(0)
54 debugmsg("basic copy ctor", LOGLEVEL_CONSTRUCT);
58 const basic & basic::operator=(const basic & other)
60 debugmsg("basic operator=", LOGLEVEL_ASSIGNMENT);
70 // none (all conditionally inlined)
76 // none (all conditionally inlined)
82 /** Construct object from archive_node. */
83 basic::basic(const archive_node &n, const lst &sym_lst) : flags(0), refcount(0)
85 debugmsg("basic ctor from archive_node", LOGLEVEL_CONSTRUCT);
87 // Reconstruct tinfo_key from class name
88 std::string class_name;
89 if (n.find_string("class", class_name))
90 tinfo_key = find_tinfo_key(class_name);
92 throw (std::runtime_error("archive node contains no class name"));
95 /** Unarchive the object. */
96 DEFAULT_UNARCHIVE(basic)
98 /** Archive the object. */
99 void basic::archive(archive_node &n) const
101 n.add_string("class", class_name());
105 // functions overriding virtual functions from bases classes
111 // new virtual functions which can be overridden by derived classes
116 /** Output to ostream formatted as parsable (as in ginsh) input.
117 * Generally, superfluous parenthesis should be avoided as far as possible. */
118 void basic::print(std::ostream & os, unsigned upper_precedence) const
120 debugmsg("basic print",LOGLEVEL_PRINT);
121 os << "[" << class_name() << " object]";
124 /** Output to ostream in ugly raw format, so brave developers can have a look
125 * at the underlying structure. */
126 void basic::printraw(std::ostream & os) const
128 debugmsg("basic printraw",LOGLEVEL_PRINT);
129 os << "[" << class_name() << " object]";
132 /** Output to ostream formatted in tree- (indented-) form, so developers can
133 * have a look at the underlying structure. */
134 void basic::printtree(std::ostream & os, unsigned indent) const
136 debugmsg("basic printtree",LOGLEVEL_PRINT);
137 os << std::string(indent,' ') << "type=" << class_name()
138 << ", hash=" << hashvalue
139 << " (0x" << std::hex << hashvalue << std::dec << ")"
140 << ", flags=" << flags
141 << ", nops=" << nops() << std::endl;
142 for (unsigned i=0; i<nops(); ++i) {
143 op(i).printtree(os,indent+delta_indent);
147 /** Output to ostream formatted as C-source.
149 * @param os a stream for output
150 * @param type variable type (one of the csrc_types)
151 * @param upper_precedence operator precedence of caller
152 * @see ex::printcsrc */
153 void basic::printcsrc(std::ostream & os, unsigned type, unsigned upper_precedence) const
155 debugmsg("basic print csrc", LOGLEVEL_PRINT);
158 /** Little wrapper arount print to be called within a debugger.
159 * This is needed because you cannot call foo.print(cout) from within the
160 * debugger because it might not know what cout is. This method can be
161 * invoked with no argument and it will simply print to stdout.
163 * @see basic::print*/
164 void basic::dbgprint(void) const
166 this->print(std::cerr);
167 std::cerr << std::endl;
170 /** Little wrapper arount printtree to be called within a debugger.
172 * @see basic::dbgprint
173 * @see basic::printtree */
174 void basic::dbgprinttree(void) const
176 this->printtree(std::cerr,0);
179 /** Create a new copy of this on the heap. One can think of this as simulating
180 * a virtual copy constructor which is needed for instance by the refcounted
181 * construction of an ex from a basic. */
182 basic * basic::duplicate() const
184 debugmsg("basic duplicate",LOGLEVEL_DUPLICATE);
185 return new basic(*this);
188 /** Information about the object.
190 * @see class info_flags */
191 bool basic::info(unsigned inf) const
193 // all possible properties are false for basic objects
197 /** Number of operands/members. */
198 unsigned basic::nops() const
200 // iterating from 0 to nops() on atomic objects should be an empty loop,
201 // and accessing their elements is a range error. Container objects should
206 /** Return operand/member at position i. */
207 ex basic::op(int i) const
209 return (const_cast<basic *>(this))->let_op(i);
212 /** Return modifyable operand/member at position i. */
213 ex & basic::let_op(int i)
215 throw(std::out_of_range("op() out of range"));
218 ex basic::operator[](const ex & index) const
220 if (is_exactly_of_type(*index.bp,numeric))
221 return op(static_cast<const numeric &>(*index.bp).to_int());
223 throw(std::invalid_argument("non-numeric indices not supported by this type"));
226 ex basic::operator[](int i) const
231 /** Search ocurrences. An object 'has' an expression if it is the expression
232 * itself or one of the children 'has' it. As a consequence (according to
233 * the definition of children) given e=x+y+z, e.has(x) is true but e.has(x+y)
235 bool basic::has(const ex & other) const
237 GINAC_ASSERT(other.bp!=0);
238 if (is_equal(*other.bp)) return true;
240 for (unsigned i=0; i<nops(); i++)
241 if (op(i).has(other))
248 /** Return degree of highest power in symbol s. */
249 int basic::degree(const ex & s) const
254 /** Return degree of lowest power in symbol s. */
255 int basic::ldegree(const ex & s) const
260 /** Return coefficient of degree n in symbol s. */
261 ex basic::coeff(const ex & s, int n) const
263 return n==0 ? *this : _ex0();
266 /** Sort expression in terms of powers of some symbol.
267 * @param s symbol to sort in. */
268 ex basic::collect(const ex & s) const
271 for (int n=this->ldegree(s); n<=this->degree(s); n++)
272 x += this->coeff(s,n)*power(s,n);
277 /** Perform automatic non-interruptive symbolic evaluation on expression. */
278 ex basic::eval(int level) const
280 // There is nothing to do for basic objects:
284 /** Evaluate object numerically. */
285 ex basic::evalf(int level) const
287 // There is nothing to do for basic objects:
291 /** Perform automatic symbolic evaluations on indexed expression that
292 * contains this object as the base expression. */
293 ex basic::eval_indexed(const basic & i) const
294 // this function can't take a "const ex & i" because that would result
295 // in an infinite eval() loop
297 // There is nothing to do for basic objects
301 /** Add two indexed expressions. They are guaranteed to be of class indexed
302 * (or a subclass) and their indices are compatible. This function is used
303 * internally by simplify_indexed().
305 * @param self First indexed expression; it's base object is *this
306 * @param other Second indexed expression
307 * @return sum of self and other
308 * @see ex::simplify_indexed() */
309 ex basic::add_indexed(const ex & self, const ex & other) const
314 /** Multiply an indexed expression with a scalar. This function is used
315 * internally by simplify_indexed().
317 * @param self Indexed expression; it's base object is *this
318 * @param other Numeric value
319 * @return product of self and other
320 * @see ex::simplify_indexed() */
321 ex basic::scalar_mul_indexed(const ex & self, const numeric & other) const
326 /** Try to contract two indexed expressions that appear in the same product.
327 * If a contraction exists, the function overwrites one or both of the
328 * expressions and returns true. Otherwise it returns false. It is
329 * guaranteed that both expressions are of class indexed (or a subclass)
330 * and that at least one dummy index has been found. This functions is
331 * used internally by simplify_indexed().
333 * @param self Pointer to first indexed expression; it's base object is *this
334 * @param other Pointer to second indexed expression
335 * @param v The complete vector of factors
336 * @return true if the contraction was successful, false otherwise
337 * @see ex::simplify_indexed() */
338 bool basic::contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const
344 /** Substitute a set of symbols by arbitrary expressions. The ex returned
345 * will already be evaluated. */
346 ex basic::subs(const lst & ls, const lst & lr) const
351 /** Default interface of nth derivative ex::diff(s, n). It should be called
352 * instead of ::derivative(s) for first derivatives and for nth derivatives it
353 * just recurses down.
355 * @param s symbol to differentiate in
356 * @param nth order of differentiation
358 ex basic::diff(const symbol & s, unsigned nth) const
360 // trivial: zeroth derivative
364 // evaluate unevaluated *this before differentiating
365 if (!(flags & status_flags::evaluated))
366 return ex(*this).diff(s, nth);
368 ex ndiff = this->derivative(s);
369 while (!ndiff.is_zero() && // stop differentiating zeros
371 ndiff = ndiff.diff(s);
377 /** Return a vector containing the free indices of an expression. */
378 exvector basic::get_free_indices(void) const
380 return exvector(); // return an empty exvector
383 ex basic::simplify_ncmul(const exvector & v) const
385 return simplified_ncmul(v);
390 /** Default implementation of ex::diff(). It simply throws an error message.
392 * @exception logic_error (differentiation not supported by this type)
394 ex basic::derivative(const symbol & s) const
396 throw(std::logic_error("differentiation not supported by this type"));
399 /** Returns order relation between two objects of same type. This needs to be
400 * implemented by each class. It may never return anything else than 0,
401 * signalling equality, or +1 and -1 signalling inequality and determining
402 * the canonical ordering. (Perl hackers will wonder why C++ doesn't feature
403 * the spaceship operator <=> for denoting just this.) */
404 int basic::compare_same_type(const basic & other) const
406 return compare_pointers(this, &other);
409 /** Returns true if two objects of same type are equal. Normally needs
410 * not be reimplemented as long as it wasn't overwritten by some parent
411 * class, since it just calls compare_same_type(). The reason why this
412 * function exists is that sometimes it is easier to determine equality
413 * than an order relation and then it can be overridden. */
414 bool basic::is_equal_same_type(const basic & other) const
416 return this->compare_same_type(other)==0;
419 unsigned basic::return_type(void) const
421 return return_types::commutative;
424 unsigned basic::return_type_tinfo(void) const
429 /** Compute the hash value of an object and if it makes sense to store it in
430 * the objects status_flags, do so. The method inherited from class basic
431 * computes a hash value based on the type and hash values of possible
432 * members. For this reason it is well suited for container classes but
433 * atomic classes should override this implementation because otherwise they
434 * would all end up with the same hashvalue. */
435 unsigned basic::calchash(void) const
437 unsigned v = golden_ratio_hash(tinfo());
438 for (unsigned i=0; i<nops(); i++) {
439 v = rotate_left_31(v);
440 v ^= (const_cast<basic *>(this))->op(i).gethash();
443 // mask out numeric hashes:
446 // store calculated hash value only if object is already evaluated
447 if (flags & status_flags::evaluated) {
448 setflag(status_flags::hash_calculated);
455 /** Expand expression, i.e. multiply it out and return the result as a new
457 ex basic::expand(unsigned options) const
459 return this->setflag(status_flags::expanded);
464 // non-virtual functions in this class
469 /** Substitute objects (symbols, indices, tensors, functions, indexed) in
470 * expression and return the result as a new expression. There are two
471 * valid types of replacement arguments: 1) a relational like object==ex
472 * and 2) a list of relationals lst(object1==ex1,object2==ex2,...), which
473 * is converted to subs(lst(object1,object2,...),lst(ex1,ex2,...)). */
474 ex basic::subs(const ex & e) const
476 if (e.info(info_flags::relation_equal)) {
479 if (!e.info(info_flags::list)) {
480 throw(std::invalid_argument("basic::subs(ex): argument must be a list"));
484 for (unsigned i=0; i<e.nops(); i++) {
485 if (!e.op(i).info(info_flags::relation_equal)) {
486 throw(std::invalid_argument("basic::subs(ex): argument must be a list or equations"));
488 ex s = e.op(i).op(0);
489 ex r = e.op(i).op(1);
490 if (!is_ex_of_type(s, symbol) && !is_ex_of_type(s, idx) &&
491 !is_ex_of_type(s, tensor) && !is_ex_of_type(s, function) &&
492 !is_ex_of_type(s, indexed)) {
493 throw(std::invalid_argument("basic::subs(ex): lhs must be a symbol, idx, tensor, function or indexed"));
501 /** Compare objects to establish canonical ordering.
502 * All compare functions return: -1 for *this less than other, 0 equal,
504 int basic::compare(const basic & other) const
506 unsigned hash_this = gethash();
507 unsigned hash_other = other.gethash();
509 if (hash_this<hash_other) return -1;
510 if (hash_this>hash_other) return 1;
512 unsigned typeid_this = tinfo();
513 unsigned typeid_other = other.tinfo();
515 if (typeid_this<typeid_other) {
516 // std::cout << "hash collision, different types: "
517 // << *this << " and " << other << std::endl;
518 // this->printraw(std::cout);
519 // std::cout << " and ";
520 // other.printraw(std::cout);
521 // std::cout << std::endl;
524 if (typeid_this>typeid_other) {
525 // std::cout << "hash collision, different types: "
526 // << *this << " and " << other << std::endl;
527 // this->printraw(std::cout);
528 // std::cout << " and ";
529 // other.printraw(std::cout);
530 // std::cout << std::endl;
534 GINAC_ASSERT(typeid(*this)==typeid(other));
536 // int cmpval = compare_same_type(other);
537 // if ((cmpval!=0) && (hash_this<0x80000000U)) {
538 // std::cout << "hash collision, same type: "
539 // << *this << " and " << other << std::endl;
540 // this->printraw(std::cout);
541 // std::cout << " and ";
542 // other.printraw(std::cout);
543 // std::cout << std::endl;
547 return compare_same_type(other);
550 /** Test for equality.
551 * This is only a quick test, meaning objects should be in the same domain.
552 * You might have to .expand(), .normal() objects first, depending on the
553 * domain of your computation, to get a more reliable answer.
555 * @see is_equal_same_type */
556 bool basic::is_equal(const basic & other) const
558 if (this->gethash()!=other.gethash())
560 if (this->tinfo()!=other.tinfo())
563 GINAC_ASSERT(typeid(*this)==typeid(other));
565 return this->is_equal_same_type(other);
570 /** Stop further evaluation.
572 * @see basic::eval */
573 const basic & basic::hold(void) const
575 return this->setflag(status_flags::evaluated);
578 /** Ensure the object may be modified without hurting others, throws if this
579 * is not the case. */
580 void basic::ensure_if_modifiable(void) const
582 if (this->refcount>1)
583 throw(std::runtime_error("cannot modify multiply referenced object"));
587 // static member variables
592 unsigned basic::precedence = 70;
593 unsigned basic::delta_indent = 4;
599 int max_recursion_level = 1024;