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
40 GINAC_IMPLEMENT_REGISTERED_CLASS_NO_CTORS(basic, void)
43 // default ctor, dtor, copy ctor assignment operator and helpers
48 basic::basic(const basic & other) : tinfo_key(TINFO_basic), flags(0), refcount(0)
50 debugmsg("basic copy ctor", LOGLEVEL_CONSTRUCT);
54 const basic & basic::operator=(const basic & other)
56 debugmsg("basic operator=", LOGLEVEL_ASSIGNMENT);
66 // none (all conditionally inlined)
72 // none (all conditionally inlined)
78 /** Construct object from archive_node. */
79 basic::basic(const archive_node &n, const lst &sym_lst) : flags(0), refcount(0)
81 debugmsg("basic ctor from archive_node", LOGLEVEL_CONSTRUCT);
83 // Reconstruct tinfo_key from class name
84 std::string class_name;
85 if (n.find_string("class", class_name))
86 tinfo_key = find_tinfo_key(class_name);
88 throw (std::runtime_error("archive node contains no class name"));
91 /** Unarchive the object. */
92 DEFAULT_UNARCHIVE(basic)
94 /** Archive the object. */
95 void basic::archive(archive_node &n) const
97 n.add_string("class", class_name());
101 // functions overriding virtual functions from bases classes
107 // new virtual functions which can be overridden by derived classes
112 /** Output to ostream formatted as parsable (as in ginsh) input.
113 * Generally, superfluous parenthesis should be avoided as far as possible. */
114 void basic::print(std::ostream & os, unsigned upper_precedence) const
116 debugmsg("basic print",LOGLEVEL_PRINT);
117 os << "[" << class_name() << " object]";
120 /** Output to ostream in ugly raw format, so brave developers can have a look
121 * at the underlying structure. */
122 void basic::printraw(std::ostream & os) const
124 debugmsg("basic printraw",LOGLEVEL_PRINT);
125 os << "[" << class_name() << " object]";
128 /** Output to ostream formatted in tree- (indented-) form, so developers can
129 * have a look at the underlying structure. */
130 void basic::printtree(std::ostream & os, unsigned indent) const
132 debugmsg("basic printtree",LOGLEVEL_PRINT);
133 os << std::string(indent,' ') << "type=" << class_name()
134 << ", hash=" << hashvalue
135 << " (0x" << std::hex << hashvalue << std::dec << ")"
136 << ", flags=" << flags
137 << ", nops=" << nops() << std::endl;
138 for (unsigned i=0; i<nops(); ++i) {
139 op(i).printtree(os,indent+delta_indent);
143 /** Output to ostream formatted as C-source.
145 * @param os a stream for output
146 * @param type variable type (one of the csrc_types)
147 * @param upper_precedence operator precedence of caller
148 * @see ex::printcsrc */
149 void basic::printcsrc(std::ostream & os, unsigned type, unsigned upper_precedence) const
151 debugmsg("basic print csrc", LOGLEVEL_PRINT);
154 /** Little wrapper arount print to be called within a debugger.
155 * This is needed because you cannot call foo.print(cout) from within the
156 * debugger because it might not know what cout is. This method can be
157 * invoked with no argument and it will simply print to stdout.
159 * @see basic::print*/
160 void basic::dbgprint(void) const
162 this->print(std::cerr);
163 std::cerr << std::endl;
166 /** Little wrapper arount printtree to be called within a debugger.
168 * @see basic::dbgprint
169 * @see basic::printtree */
170 void basic::dbgprinttree(void) const
172 this->printtree(std::cerr,0);
175 /** Create a new copy of this on the heap. One can think of this as simulating
176 * a virtual copy constructor which is needed for instance by the refcounted
177 * construction of an ex from a basic. */
178 basic * basic::duplicate() const
180 debugmsg("basic duplicate",LOGLEVEL_DUPLICATE);
181 return new basic(*this);
184 /** Information about the object.
186 * @see class info_flags */
187 bool basic::info(unsigned inf) const
189 // all possible properties are false for basic objects
193 /** Number of operands/members. */
194 unsigned basic::nops() const
196 // iterating from 0 to nops() on atomic objects should be an empty loop,
197 // and accessing their elements is a range error. Container objects should
202 /** Return operand/member at position i. */
203 ex basic::op(int i) const
205 return (const_cast<basic *>(this))->let_op(i);
208 /** Return modifyable operand/member at position i. */
209 ex & basic::let_op(int i)
211 throw(std::out_of_range("op() out of range"));
214 ex basic::operator[](const ex & index) const
216 if (is_exactly_of_type(*index.bp,numeric))
217 return op(static_cast<const numeric &>(*index.bp).to_int());
219 throw(std::invalid_argument("non-numeric indices not supported by this type"));
222 ex basic::operator[](int i) const
227 /** Search ocurrences. An object 'has' an expression if it is the expression
228 * itself or one of the children 'has' it. As a consequence (according to
229 * the definition of children) given e=x+y+z, e.has(x) is true but e.has(x+y)
231 bool basic::has(const ex & other) const
233 GINAC_ASSERT(other.bp!=0);
234 if (is_equal(*other.bp)) return true;
236 for (unsigned i=0; i<nops(); i++)
237 if (op(i).has(other))
244 /** Return degree of highest power in symbol s. */
245 int basic::degree(const ex & s) const
250 /** Return degree of lowest power in symbol s. */
251 int basic::ldegree(const ex & s) const
256 /** Return coefficient of degree n in symbol s. */
257 ex basic::coeff(const ex & s, int n) const
259 return n==0 ? *this : _ex0();
262 /** Sort expression in terms of powers of some symbol.
263 * @param s symbol to sort in. */
264 ex basic::collect(const ex & s) const
267 for (int n=this->ldegree(s); n<=this->degree(s); n++)
268 x += this->coeff(s,n)*power(s,n);
273 /** Perform automatic non-interruptive symbolic evaluation on expression. */
274 ex basic::eval(int level) const
276 // There is nothing to do for basic objects:
280 /** Evaluate object numerically. */
281 ex basic::evalf(int level) const
283 // There is nothing to do for basic objects:
287 /** Perform automatic symbolic evaluations on indexed expression that
288 * contains this object as the base expression. */
289 ex basic::eval_indexed(const basic & i) const
290 // this function can't take a "const ex & i" because that would result
291 // in an infinite eval() loop
293 // There is nothing to do for basic objects
297 /** Add two indexed expressions. They are guaranteed to be of class indexed
298 * (or a subclass) and their indices are compatible. This function is used
299 * internally by simplify_indexed().
301 * @param self First indexed expression; it's base object is *this
302 * @param other Second indexed expression
303 * @return sum of self and other
304 * @see ex::simplify_indexed() */
305 ex basic::add_indexed(const ex & self, const ex & other) const
310 /** Multiply an indexed expression with a scalar. This function is used
311 * internally by simplify_indexed().
313 * @param self Indexed expression; it's base object is *this
314 * @param other Numeric value
315 * @return product of self and other
316 * @see ex::simplify_indexed() */
317 ex basic::scalar_mul_indexed(const ex & self, const numeric & other) const
322 /** Try to contract two indexed expressions that appear in the same product.
323 * If a contraction exists, the function overwrites one or both of the
324 * expressions and returns true. Otherwise it returns false. It is
325 * guaranteed that both expressions are of class indexed (or a subclass)
326 * and that at least one dummy index has been found. This functions is
327 * used internally by simplify_indexed().
329 * @param self Pointer to first indexed expression; it's base object is *this
330 * @param other Pointer to second indexed expression
331 * @param v The complete vector of factors
332 * @return true if the contraction was successful, false otherwise
333 * @see ex::simplify_indexed() */
334 bool basic::contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const
340 /** Substitute a set of objects by arbitrary expressions. The ex returned
341 * will already be evaluated. */
342 ex basic::subs(const lst & ls, const lst & lr) const
344 GINAC_ASSERT(ls.nops() == lr.nops());
346 for (unsigned i=0; i<ls.nops(); i++) {
347 if (is_equal(*ls.op(i).bp))
354 /** Default interface of nth derivative ex::diff(s, n). It should be called
355 * instead of ::derivative(s) for first derivatives and for nth derivatives it
356 * just recurses down.
358 * @param s symbol to differentiate in
359 * @param nth order of differentiation
361 ex basic::diff(const symbol & s, unsigned nth) const
363 // trivial: zeroth derivative
367 // evaluate unevaluated *this before differentiating
368 if (!(flags & status_flags::evaluated))
369 return ex(*this).diff(s, nth);
371 ex ndiff = this->derivative(s);
372 while (!ndiff.is_zero() && // stop differentiating zeros
374 ndiff = ndiff.diff(s);
380 /** Return a vector containing the free indices of an expression. */
381 exvector basic::get_free_indices(void) const
383 return exvector(); // return an empty exvector
386 ex basic::simplify_ncmul(const exvector & v) const
388 return simplified_ncmul(v);
393 /** Default implementation of ex::diff(). It simply throws an error message.
395 * @exception logic_error (differentiation not supported by this type)
397 ex basic::derivative(const symbol & s) const
399 throw(std::logic_error("differentiation not supported by this type"));
402 /** Returns order relation between two objects of same type. This needs to be
403 * implemented by each class. It may never return anything else than 0,
404 * signalling equality, or +1 and -1 signalling inequality and determining
405 * the canonical ordering. (Perl hackers will wonder why C++ doesn't feature
406 * the spaceship operator <=> for denoting just this.) */
407 int basic::compare_same_type(const basic & other) const
409 return compare_pointers(this, &other);
412 /** Returns true if two objects of same type are equal. Normally needs
413 * not be reimplemented as long as it wasn't overwritten by some parent
414 * class, since it just calls compare_same_type(). The reason why this
415 * function exists is that sometimes it is easier to determine equality
416 * than an order relation and then it can be overridden. */
417 bool basic::is_equal_same_type(const basic & other) const
419 return this->compare_same_type(other)==0;
422 unsigned basic::return_type(void) const
424 return return_types::commutative;
427 unsigned basic::return_type_tinfo(void) const
432 /** Compute the hash value of an object and if it makes sense to store it in
433 * the objects status_flags, do so. The method inherited from class basic
434 * computes a hash value based on the type and hash values of possible
435 * members. For this reason it is well suited for container classes but
436 * atomic classes should override this implementation because otherwise they
437 * would all end up with the same hashvalue. */
438 unsigned basic::calchash(void) const
440 unsigned v = golden_ratio_hash(tinfo());
441 for (unsigned i=0; i<nops(); i++) {
442 v = rotate_left_31(v);
443 v ^= (const_cast<basic *>(this))->op(i).gethash();
446 // mask out numeric hashes:
449 // store calculated hash value only if object is already evaluated
450 if (flags & status_flags::evaluated) {
451 setflag(status_flags::hash_calculated);
458 /** Expand expression, i.e. multiply it out and return the result as a new
460 ex basic::expand(unsigned options) const
462 return this->setflag(status_flags::expanded);
467 // non-virtual functions in this class
472 /** Substitute objects in an expression (syntactic substitution) and return
473 * the result as a new expression. There are two valid types of
474 * replacement arguments: 1) a relational like object==ex and 2) a list of
475 * relationals lst(object1==ex1,object2==ex2,...), which is converted to
476 * subs(lst(object1,object2,...),lst(ex1,ex2,...)). */
477 ex basic::subs(const ex & e) const
479 if (e.info(info_flags::relation_equal)) {
482 if (!e.info(info_flags::list)) {
483 throw(std::invalid_argument("basic::subs(ex): argument must be a list"));
487 for (unsigned i=0; i<e.nops(); i++) {
489 if (!r.info(info_flags::relation_equal)) {
490 throw(std::invalid_argument("basic::subs(ex): argument must be a list or equations"));
498 /** Compare objects to establish canonical ordering.
499 * All compare functions return: -1 for *this less than other, 0 equal,
501 int basic::compare(const basic & other) const
503 unsigned hash_this = gethash();
504 unsigned hash_other = other.gethash();
506 if (hash_this<hash_other) return -1;
507 if (hash_this>hash_other) return 1;
509 unsigned typeid_this = tinfo();
510 unsigned typeid_other = other.tinfo();
512 if (typeid_this<typeid_other) {
513 // std::cout << "hash collision, different types: "
514 // << *this << " and " << other << std::endl;
515 // this->printraw(std::cout);
516 // std::cout << " and ";
517 // other.printraw(std::cout);
518 // std::cout << std::endl;
521 if (typeid_this>typeid_other) {
522 // std::cout << "hash collision, different types: "
523 // << *this << " and " << other << std::endl;
524 // this->printraw(std::cout);
525 // std::cout << " and ";
526 // other.printraw(std::cout);
527 // std::cout << std::endl;
531 GINAC_ASSERT(typeid(*this)==typeid(other));
533 // int cmpval = compare_same_type(other);
534 // if ((cmpval!=0) && (hash_this<0x80000000U)) {
535 // std::cout << "hash collision, same type: "
536 // << *this << " and " << other << std::endl;
537 // this->printraw(std::cout);
538 // std::cout << " and ";
539 // other.printraw(std::cout);
540 // std::cout << std::endl;
544 return compare_same_type(other);
547 /** Test for equality.
548 * This is only a quick test, meaning objects should be in the same domain.
549 * You might have to .expand(), .normal() objects first, depending on the
550 * domain of your computation, to get a more reliable answer.
552 * @see is_equal_same_type */
553 bool basic::is_equal(const basic & other) const
555 if (this->gethash()!=other.gethash())
557 if (this->tinfo()!=other.tinfo())
560 GINAC_ASSERT(typeid(*this)==typeid(other));
562 return this->is_equal_same_type(other);
567 /** Stop further evaluation.
569 * @see basic::eval */
570 const basic & basic::hold(void) const
572 return this->setflag(status_flags::evaluated);
575 /** Ensure the object may be modified without hurting others, throws if this
576 * is not the case. */
577 void basic::ensure_if_modifiable(void) const
579 if (this->refcount>1)
580 throw(std::runtime_error("cannot modify multiply referenced object"));
584 // static member variables
589 unsigned basic::precedence = 70;
590 unsigned basic::delta_indent = 4;
596 int max_recursion_level = 1024;