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(const print_context & c, unsigned level) const
137 debugmsg("symbol print", LOGLEVEL_PRINT);
139 if (is_of_type(c, print_tree)) {
141 c.s << std::string(level, ' ') << name << " (" << class_name() << ")"
142 << ", serial=" << serial
143 << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
146 } else if (is_of_type(c, print_latex)) {
147 if (name=="alpha" || name=="beta" || name=="gamma"
148 || name=="delta" || name=="epsilon" || name=="varepsilon"
149 || name=="zeta" || name=="eta" || name=="theta"
150 || name=="vartheta" || name=="iota" || name=="kappa"
151 || name=="lambda" || name=="mu" || name=="nu"
152 || name=="xi" || name=="omicron" || name=="pi"
153 || name=="varpi" || name=="rho" || name=="varrho"
154 || name=="sigma" || name=="varsigma" || name=="tau"
155 || name=="upsilon" || name=="phi" || name=="varphix"
156 || name=="chi" || name=="psi" || name=="omega"
157 || name=="Gamma" || name=="Delta" || name=="Theta"
158 || name=="Lambda" || name=="Xi" || name=="Pi"
159 || name=="Sigma" || name=="Upsilon" || name=="Phi"
160 || name=="Psi" || name=="Omega")
168 bool symbol::info(unsigned inf) const
170 if (inf==info_flags::symbol) return true;
171 if (inf==info_flags::polynomial ||
172 inf==info_flags::integer_polynomial ||
173 inf==info_flags::cinteger_polynomial ||
174 inf==info_flags::rational_polynomial ||
175 inf==info_flags::crational_polynomial ||
176 inf==info_flags::rational_function)
179 return inherited::info(inf);
182 ex symbol::expand(unsigned options) const
187 bool symbol::has(const ex & other) const
189 if (this->is_equal(*other.bp))
195 int symbol::degree(const ex & s) const
197 return is_equal(*s.bp) ? 1 : 0;
200 int symbol::ldegree(const ex & s) const
202 return is_equal(*s.bp) ? 1 : 0;
205 ex symbol::coeff(const ex & s, int n) const
208 return n==1 ? _ex1() : _ex0();
210 return n==0 ? *this : _ex0();
213 ex symbol::eval(int level) const
215 if (level == -max_recursion_level)
216 throw(std::runtime_error("max recursion level reached"));
218 if (asexinfop->is_assigned) {
219 setflag(status_flags::evaluated);
221 return (asexinfop->assigned_expression);
223 return (asexinfop->assigned_expression).eval(level);
231 /** Implementation of ex::diff() for single differentiation of a symbol.
235 ex symbol::derivative(const symbol & s) const
237 if (compare_same_type(s))
243 int symbol::compare_same_type(const basic & other) const
245 GINAC_ASSERT(is_of_type(other,symbol));
246 const symbol *o = static_cast<const symbol *>(&other);
247 if (serial==o->serial) return 0;
248 return serial < o->serial ? -1 : 1;
251 bool symbol::is_equal_same_type(const basic & other) const
253 GINAC_ASSERT(is_of_type(other,symbol));
254 const symbol *o = static_cast<const symbol *>(&other);
255 return serial==o->serial;
258 unsigned symbol::return_type(void) const
260 return return_types::commutative;
263 unsigned symbol::return_type_tinfo(void) const
268 unsigned symbol::calchash(void) const
270 // this is where the schoolbook method
271 // (golden_ratio_hash(tinfo()) ^ serial)
272 // is not good enough yet...
273 hashvalue = golden_ratio_hash(golden_ratio_hash(tinfo()) ^ serial);
274 setflag(status_flags::hash_calculated);
279 // virtual functions which can be overridden by derived classes
285 // non-virtual functions in this class
290 void symbol::assign(const ex & value)
292 asexinfop->is_assigned = 1;
293 asexinfop->assigned_expression = value;
294 clearflag(status_flags::evaluated | status_flags::expanded);
297 void symbol::unassign(void)
299 if (asexinfop->is_assigned) {
300 asexinfop->is_assigned = 0;
301 asexinfop->assigned_expression = _ex0();
303 setflag(status_flags::evaluated | status_flags::expanded);
308 /** Symbols not constructed with a string get one assigned using this
309 * prefix and a number. */
310 std::string & symbol::autoname_prefix(void)
312 static std::string *s = new std::string("symbol");
317 // static member variables
322 unsigned symbol::next_serial = 0;
325 // subclass assigned_ex_info
328 /** Default ctor. Defaults to unassigned. */
329 symbol::assigned_ex_info::assigned_ex_info(void) : is_assigned(0), refcount(1)