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 name = TeX_name = autoname_prefix()+ToString(serial);
44 asexinfop = new assigned_ex_info;
45 setflag(status_flags::evaluated | status_flags::expanded);
48 /** For use by copy ctor and assignment operator. */
49 void symbol::copy(const symbol & other)
51 inherited::copy(other);
53 TeX_name = other.TeX_name;
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)
78 symbol::symbol(const std::string & initname) : inherited(TINFO_symbol)
81 TeX_name = default_TeX_name();
82 serial = next_serial++;
83 asexinfop = new assigned_ex_info;
84 setflag(status_flags::evaluated | status_flags::expanded);
87 symbol::symbol(const std::string & initname, const std::string & texname) : inherited(TINFO_symbol)
91 serial = next_serial++;
92 asexinfop = new assigned_ex_info;
93 setflag(status_flags::evaluated | status_flags::expanded);
100 /** Construct object from archive_node. */
101 symbol::symbol(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
103 serial = next_serial++;
104 if (!(n.find_string("name", name)))
105 name = autoname_prefix() + ToString(serial);
106 if (!(n.find_string("TeXname", TeX_name)))
107 TeX_name = default_TeX_name();
108 asexinfop = new assigned_ex_info;
109 setflag(status_flags::evaluated);
112 /** Unarchive the object. */
113 ex symbol::unarchive(const archive_node &n, const lst &sym_lst)
115 ex s = (new symbol(n, sym_lst))->setflag(status_flags::dynallocated);
117 // If symbol is in sym_lst, return the existing symbol
118 for (unsigned i=0; i<sym_lst.nops(); i++) {
119 if (is_ex_of_type(sym_lst.op(i), symbol) && (ex_to<symbol>(sym_lst.op(i)).name == ex_to<symbol>(s).name))
120 return sym_lst.op(i);
125 /** Archive the object. */
126 void symbol::archive(archive_node &n) const
128 inherited::archive(n);
129 n.add_string("name", name);
130 if (TeX_name != default_TeX_name())
131 n.add_string("TeX_name", TeX_name);
135 // functions overriding virtual functions from base classes
140 basic *symbol::duplicate() const
142 return new symbol(*this);
145 void symbol::print(const print_context & c, unsigned level) const
147 if (is_a<print_tree>(c)) {
149 c.s << std::string(level, ' ') << name << " (" << class_name() << ")"
150 << ", serial=" << serial
151 << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
154 } else if (is_a<print_latex>(c)) {
156 } else if (is_a<print_python_repr>(c)) {
157 c.s << class_name() << "('" << name;
158 if (TeX_name != default_TeX_name())
159 c.s << "','" << TeX_name;
165 bool symbol::info(unsigned inf) const
167 if (inf==info_flags::symbol) return true;
168 if (inf==info_flags::polynomial ||
169 inf==info_flags::integer_polynomial ||
170 inf==info_flags::cinteger_polynomial ||
171 inf==info_flags::rational_polynomial ||
172 inf==info_flags::crational_polynomial ||
173 inf==info_flags::rational_function)
176 return inherited::info(inf);
179 int symbol::degree(const ex & s) const
181 return is_equal(ex_to<basic>(s)) ? 1 : 0;
184 int symbol::ldegree(const ex & s) const
186 return is_equal(ex_to<basic>(s)) ? 1 : 0;
189 ex symbol::coeff(const ex & s, int n) const
191 if (is_equal(ex_to<basic>(s)))
192 return n==1 ? _ex1 : _ex0;
194 return n==0 ? *this : _ex0;
197 ex symbol::eval(int level) const
199 if (level == -max_recursion_level)
200 throw(std::runtime_error("max recursion level reached"));
202 if (asexinfop->is_assigned) {
203 setflag(status_flags::evaluated);
205 return (asexinfop->assigned_expression);
207 return (asexinfop->assigned_expression).eval(level);
215 /** Implementation of ex::diff() for single differentiation of a symbol.
219 ex symbol::derivative(const symbol & s) const
221 if (compare_same_type(s))
227 int symbol::compare_same_type(const basic & other) const
229 GINAC_ASSERT(is_a<symbol>(other));
230 const symbol *o = static_cast<const symbol *>(&other);
231 if (serial==o->serial) return 0;
232 return serial < o->serial ? -1 : 1;
235 bool symbol::is_equal_same_type(const basic & other) const
237 GINAC_ASSERT(is_a<symbol>(other));
238 const symbol *o = static_cast<const symbol *>(&other);
239 return serial==o->serial;
242 unsigned symbol::calchash(void) const
244 // this is where the schoolbook method
245 // (golden_ratio_hash(tinfo()) ^ serial)
246 // is not good enough yet...
247 hashvalue = golden_ratio_hash(golden_ratio_hash(tinfo()) ^ serial);
248 setflag(status_flags::hash_calculated);
253 // virtual functions which can be overridden by derived classes
259 // non-virtual functions in this class
264 void symbol::assign(const ex & value)
266 asexinfop->is_assigned = 1;
267 asexinfop->assigned_expression = value;
268 clearflag(status_flags::evaluated | status_flags::expanded);
271 void symbol::unassign(void)
273 if (asexinfop->is_assigned) {
274 asexinfop->is_assigned = 0;
275 asexinfop->assigned_expression = _ex0;
277 setflag(status_flags::evaluated | status_flags::expanded);
282 /** Symbols not constructed with a string get one assigned using this
283 * prefix and a number. */
284 std::string & symbol::autoname_prefix(void)
286 static std::string *s = new std::string("symbol");
290 /** Return default TeX name for symbol. This recognizes some greek letters. */
291 std::string symbol::default_TeX_name(void) const
293 if (name=="alpha" || name=="beta" || name=="gamma"
294 || name=="delta" || name=="epsilon" || name=="varepsilon"
295 || name=="zeta" || name=="eta" || name=="theta"
296 || name=="vartheta" || name=="iota" || name=="kappa"
297 || name=="lambda" || name=="mu" || name=="nu"
298 || name=="xi" || name=="omicron" || name=="pi"
299 || name=="varpi" || name=="rho" || name=="varrho"
300 || name=="sigma" || name=="varsigma" || name=="tau"
301 || name=="upsilon" || name=="phi" || name=="varphi"
302 || name=="chi" || name=="psi" || name=="omega"
303 || name=="Gamma" || name=="Delta" || name=="Theta"
304 || name=="Lambda" || name=="Xi" || name=="Pi"
305 || name=="Sigma" || name=="Upsilon" || name=="Phi"
306 || name=="Psi" || name=="Omega")
313 // static member variables
318 unsigned symbol::next_serial = 0;
321 // subclass assigned_ex_info
324 /** Default ctor. Defaults to unassigned. */
325 symbol::assigned_ex_info::assigned_ex_info(void) : is_assigned(0), refcount(1)