3 * Implementation of GiNaC's light-weight expression handles. */
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
32 #include "relational.h"
34 #include "input_lexer.h"
47 // functions overriding virtual functions from bases classes
53 // new virtual functions which can be overridden by derived classes
59 // non-virtual functions in this class
64 /** Efficiently swap the contents of two expressions. */
65 void ex::swap(ex & other)
67 debugmsg("ex swap",LOGLEVEL_MEMBER_FUNCTION);
70 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
71 GINAC_ASSERT(other.bp!=0);
72 GINAC_ASSERT(other.bp->flags & status_flags::dynallocated);
79 /** Print expression to stream. The formatting of the output is determined
80 * by the kind of print_context object that is passed. Possible formattings
81 * include ginsh-parsable output (the default), tree-like output for
82 * debugging, and C++ source.
83 * @see print_context */
84 void ex::print(const print_context & c, unsigned level) const
86 debugmsg("ex print", LOGLEVEL_PRINT);
91 /** Print expression to stream in a tree-like format suitable for debugging. */
92 void ex::printtree(std::ostream & os) const
94 debugmsg("ex printtree", LOGLEVEL_PRINT);
96 bp->print(print_tree(os));
99 /** Little wrapper arount print to be called within a debugger. */
100 void ex::dbgprint(void) const
102 debugmsg("ex dbgprint", LOGLEVEL_PRINT);
107 /** Little wrapper arount printtree to be called within a debugger. */
108 void ex::dbgprinttree(void) const
110 debugmsg("ex dbgprinttree", LOGLEVEL_PRINT);
115 ex ex::expand(unsigned options) const
118 if (bp->flags & status_flags::expanded)
121 return bp->expand(options);
124 /** Compute partial derivative of an expression.
126 * @param s symbol by which the expression is derived
127 * @param nth order of derivative (default 1)
128 * @return partial derivative as a new expression */
129 ex ex::diff(const symbol & s, unsigned nth) const
136 return bp->diff(s, nth);
139 /** Simplify/canonicalize expression containing indexed objects. This
140 * performs contraction of dummy indices where possible and checks whether
141 * the free indices in sums are consistent.
143 * @return simplified expression */
144 ex ex::simplify_indexed(void) const
146 return GiNaC::simplify_indexed(*this);
149 /** Simplify/canonicalize expression containing indexed objects. This
150 * performs contraction of dummy indices where possible, checks whether
151 * the free indices in sums are consistent, and automatically replaces
152 * scalar products by known values if desired.
154 * @param sp Scalar products to be replaced automatically
155 * @return simplified expression */
156 ex ex::simplify_indexed(const scalar_products & sp) const
158 return GiNaC::simplify_indexed(*this, sp);
161 ex ex::operator[](const ex & index) const
163 debugmsg("ex operator[ex]",LOGLEVEL_OPERATOR);
168 ex ex::operator[](int i) const
170 debugmsg("ex operator[int]",LOGLEVEL_OPERATOR);
175 /** Return modifyable operand/member at position i. */
176 ex & ex::let_op(int i)
178 debugmsg("ex let_op()",LOGLEVEL_MEMBER_FUNCTION);
181 return bp->let_op(i);
184 /** Left hand side of relational expression. */
185 ex ex::lhs(void) const
187 debugmsg("ex lhs()",LOGLEVEL_MEMBER_FUNCTION);
188 if (!is_ex_of_type(*this,relational))
189 throw std::runtime_error("ex::lhs(): not a relation");
190 return (*static_cast<relational *>(bp)).lhs();
193 /** Right hand side of relational expression. */
194 ex ex::rhs(void) const
196 debugmsg("ex rhs()",LOGLEVEL_MEMBER_FUNCTION);
197 if (!is_ex_of_type(*this,relational))
198 throw std::runtime_error("ex::rhs(): not a relation");
199 return (*static_cast<relational *>(bp)).rhs();
202 /** Used internally by operator+() to add two ex objects together. */
203 ex ex::exadd(const ex & rh) const
205 return (new add(*this,rh))->setflag(status_flags::dynallocated);
208 /** Used internally by operator*() to multiply two ex objects together. */
209 ex ex::exmul(const ex & rh) const
211 // Check if we are constructing a mul object or a ncmul object. Due to
212 // ncmul::eval()'s rule to pull out commutative elements we need to check
213 // only one of the elements.
214 if (rh.bp->return_type()==return_types::commutative ||
215 bp->return_type()==return_types::commutative)
216 return (new mul(*this,rh))->setflag(status_flags::dynallocated);
218 return (new ncmul(*this,rh))->setflag(status_flags::dynallocated);
223 /** Make this ex writable (if more than one ex handle the same basic) by
224 * unlinking the object and creating an unshared copy of it. */
225 void ex::makewriteable()
227 debugmsg("ex makewriteable",LOGLEVEL_MEMBER_FUNCTION);
229 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
230 if (bp->refcount > 1) {
231 basic * bp2 = bp->duplicate();
233 bp2->setflag(status_flags::dynallocated);
237 GINAC_ASSERT(bp->refcount==1);
240 /** Ctor from basic implementation.
241 * @see ex::ex(const basic &) */
242 void ex::construct_from_basic(const basic & other)
244 if ((other.flags & status_flags::evaluated)==0) {
246 const ex & tmpex = other.eval(1); // evaluate only one (top) level
249 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
251 if ((other.flags & status_flags::dynallocated)&&(other.refcount==0))
252 delete &const_cast<basic &>(other);
254 if (other.flags & status_flags::dynallocated) {
255 // ok, it is already on the heap, so just copy bp:
256 bp = &const_cast<basic &>(other);
258 // create a duplicate on the heap:
259 bp = other.duplicate();
260 bp->setflag(status_flags::dynallocated);
266 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
269 void ex::construct_from_int(int i)
271 switch (i) { // some tiny efficiency-hack
294 bp->setflag(status_flags::dynallocated);
296 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
297 GINAC_ASSERT(bp->refcount==1);
301 void ex::construct_from_uint(unsigned int i)
303 switch (i) { // some tiny efficiency-hack
318 bp->setflag(status_flags::dynallocated);
320 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
321 GINAC_ASSERT(bp->refcount==1);
325 void ex::construct_from_long(long i)
327 switch (i) { // some tiny efficiency-hack
350 bp->setflag(status_flags::dynallocated);
352 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
353 GINAC_ASSERT(bp->refcount==1);
357 void ex::construct_from_ulong(unsigned long i)
359 switch (i) { // some tiny efficiency-hack
374 bp->setflag(status_flags::dynallocated);
376 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
377 GINAC_ASSERT(bp->refcount==1);
381 void ex::construct_from_double(double d)
384 bp->setflag(status_flags::dynallocated);
386 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
387 GINAC_ASSERT(bp->refcount==1);
390 void ex::construct_from_string_and_lst(const std::string &s, const ex &l)
393 set_lexer_symbols(l);
394 ginac_yyrestart(NULL);
396 throw (std::runtime_error(get_parser_error()));
400 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
406 // static member variables
412 // functions which are not member functions