3 * Implementation of GiNaC's symbolic objects. */
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
35 GINAC_IMPLEMENT_REGISTERED_CLASS_NO_CTORS(symbol, basic)
38 // default ctor, dtor, copy ctor assignment operator and helpers
41 symbol::symbol() : inherited(TINFO_symbol), serial(next_serial++)
43 debugmsg("symbol default ctor", LOGLEVEL_CONSTRUCT);
44 name = autoname_prefix()+ToString(serial);
45 asexinfop = new assigned_ex_info;
46 setflag(status_flags::evaluated | status_flags::expanded);
49 /** For use by copy ctor and assignment operator. */
50 void symbol::copy(const symbol & other)
52 inherited::copy(other);
54 serial = other.serial;
55 asexinfop = other.asexinfop;
56 ++asexinfop->refcount;
59 void symbol::destroy(bool call_parent)
61 if (--asexinfop->refcount == 0)
64 inherited::destroy(call_parent);
73 symbol::symbol(const symbol & other)
75 debugmsg("symbol copy ctor", LOGLEVEL_CONSTRUCT);
79 symbol::symbol(const std::string & initname) : inherited(TINFO_symbol)
81 debugmsg("symbol ctor from string", LOGLEVEL_CONSTRUCT);
83 serial = next_serial++;
84 asexinfop = new assigned_ex_info;
85 setflag(status_flags::evaluated | status_flags::expanded);
92 /** Construct object from archive_node. */
93 symbol::symbol(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
95 debugmsg("symbol ctor from archive_node", LOGLEVEL_CONSTRUCT);
96 serial = next_serial++;
97 if (!(n.find_string("name", name)))
98 name = autoname_prefix() + ToString(serial);
99 asexinfop = new assigned_ex_info;
100 setflag(status_flags::evaluated);
103 /** Unarchive the object. */
104 ex symbol::unarchive(const archive_node &n, const lst &sym_lst)
106 ex s = (new symbol(n, sym_lst))->setflag(status_flags::dynallocated);
108 // If symbol is in sym_lst, return the existing symbol
109 for (unsigned i=0; i<sym_lst.nops(); i++) {
110 if (is_ex_of_type(sym_lst.op(i), symbol) && (ex_to_symbol(sym_lst.op(i)).name == ex_to_symbol(s).name))
111 return sym_lst.op(i);
116 /** Archive the object. */
117 void symbol::archive(archive_node &n) const
119 inherited::archive(n);
120 n.add_string("name", name);
124 // functions overriding virtual functions from bases classes
129 basic *symbol::duplicate() const
131 debugmsg("symbol duplicate", LOGLEVEL_DUPLICATE);
132 return new symbol(*this);
135 void symbol::print(std::ostream & os, unsigned upper_precedence) const
137 debugmsg("symbol print",LOGLEVEL_PRINT);
141 void symbol::printraw(std::ostream & os) const
143 debugmsg("symbol printraw",LOGLEVEL_PRINT);
144 os << "symbol(" << "name=" << name << ",serial=" << serial
145 << ",hash=" << hashvalue << ",flags=" << flags << ")";
148 void symbol::printtree(std::ostream & os, unsigned indent) const
150 debugmsg("symbol printtree",LOGLEVEL_PRINT);
151 os << std::string(indent,' ') << name << " (symbol): "
152 << "serial=" << serial
153 << ", hash=" << hashvalue
154 << " (0x" << std::hex << hashvalue << std::dec << ")"
155 << ", flags=" << flags << std::endl;
158 void symbol::printcsrc(std::ostream & os, unsigned type, unsigned upper_precedence) const
160 debugmsg("symbol print csrc", LOGLEVEL_PRINT);
164 bool symbol::info(unsigned inf) const
166 if (inf==info_flags::symbol) return true;
167 if (inf==info_flags::polynomial ||
168 inf==info_flags::integer_polynomial ||
169 inf==info_flags::cinteger_polynomial ||
170 inf==info_flags::rational_polynomial ||
171 inf==info_flags::crational_polynomial ||
172 inf==info_flags::rational_function)
175 return inherited::info(inf);
178 ex symbol::expand(unsigned options) const
183 bool symbol::has(const ex & other) const
185 if (this->is_equal(*other.bp))
191 int symbol::degree(const symbol & s) const
193 return compare_same_type(s)==0 ? 1 : 0;
196 int symbol::ldegree(const symbol & s) const
198 return compare_same_type(s)==0 ? 1 : 0;
201 ex symbol::coeff(const symbol & s, int n) const
203 if (compare_same_type(s)==0)
204 return n==1 ? _ex1() : _ex0();
206 return n==0 ? *this : _ex0();
209 ex symbol::eval(int level) const
211 if (level == -max_recursion_level)
212 throw(std::runtime_error("max recursion level reached"));
214 if (asexinfop->is_assigned) {
215 setflag(status_flags::evaluated);
217 return (asexinfop->assigned_expression);
219 return (asexinfop->assigned_expression).eval(level);
225 ex symbol::subs(const lst & ls, const lst & lr) const
227 GINAC_ASSERT(ls.nops()==lr.nops());
228 #ifdef DO_GINAC_ASSERT
229 for (unsigned i=0; i<ls.nops(); i++)
230 GINAC_ASSERT(is_ex_exactly_of_type(ls.op(i),symbol)||
231 is_ex_of_type(ls.op(i),idx));
232 #endif // def DO_GINAC_ASSERT
234 for (unsigned i=0; i<ls.nops(); i++) {
235 if (is_ex_exactly_of_type(ls.op(i),symbol)) {
236 if (compare_same_type(ex_to_symbol(ls.op(i)))==0)
245 /** Implementation of ex::diff() for single differentiation of a symbol.
249 ex symbol::derivative(const symbol & s) const
251 if (compare_same_type(s))
257 int symbol::compare_same_type(const basic & other) const
259 GINAC_ASSERT(is_of_type(other,symbol));
260 const symbol *o = static_cast<const symbol *>(&other);
261 if (serial==o->serial) return 0;
262 return serial < o->serial ? -1 : 1;
265 bool symbol::is_equal_same_type(const basic & other) const
267 GINAC_ASSERT(is_of_type(other,symbol));
268 const symbol *o = static_cast<const symbol *>(&other);
269 return serial==o->serial;
272 unsigned symbol::return_type(void) const
274 return return_types::commutative;
277 unsigned symbol::return_type_tinfo(void) const
282 unsigned symbol::calchash(void) const
284 // this is where the schoolbook method
285 // (golden_ratio_hash(tinfo()) ^ serial)
286 // is not good enough yet...
287 hashvalue = golden_ratio_hash(golden_ratio_hash(tinfo()) ^ serial);
288 setflag(status_flags::hash_calculated);
293 // virtual functions which can be overridden by derived classes
299 // non-virtual functions in this class
304 void symbol::assign(const ex & value)
306 asexinfop->is_assigned = 1;
307 asexinfop->assigned_expression = value;
308 clearflag(status_flags::evaluated | status_flags::expanded);
311 void symbol::unassign(void)
313 if (asexinfop->is_assigned) {
314 asexinfop->is_assigned = 0;
315 asexinfop->assigned_expression = _ex0();
317 setflag(status_flags::evaluated | status_flags::expanded);
322 /** Symbols not constructed with a string get one assigned using this
323 * prefix and a number. */
324 std::string & symbol::autoname_prefix(void)
326 static std::string *s = new std::string("symbol");
331 // static member variables
336 unsigned symbol::next_serial = 0;
339 // subclass assigned_ex_info
342 /** Default ctor. Defaults to unassigned. */
343 symbol::assigned_ex_info::assigned_ex_info(void) : is_assigned(0), refcount(1)