GiNaC  1.8.0
relational.cpp
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1 
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22 
23 #include "relational.h"
24 #include "operators.h"
25 #include "numeric.h"
26 #include "archive.h"
27 #include "utils.h"
28 #include "hash_seed.h"
29 
30 #include <iostream>
31 #include <stdexcept>
32 
33 namespace GiNaC {
34 
37  print_func<print_tree>(&relational::do_print_tree).
38  print_func<print_python_repr>(&relational::do_print_python_repr))
39 
40 // default constructor
43 
45 
47 // other constructors
49 
50 // public
51 
52 relational::relational(const ex & lhs, const ex & rhs, operators oper) :
53  lh(lhs), rh(rhs), o(oper) { }
54 
56 // archiving
58 
60 {
61  inherited::read_archive(n, sym_lst);
62  unsigned int opi;
63  if (!(n.find_unsigned("op", opi)))
64  throw (std::runtime_error("unknown relational operator in archive"));
65  o = (operators)opi;
66  n.find_ex("lh", lh, sym_lst);
67  n.find_ex("rh", rh, sym_lst);
68 }
70 
72 {
73  inherited::archive(n);
74  n.add_ex("lh", lh);
75  n.add_ex("rh", rh);
76  n.add_unsigned("op", o);
77 }
78 
80 // functions overriding virtual functions from base classes
82 
83 // public
84 
86 {
87  switch (o) {
88  case relational::equal:
89  c.s << "==";
90  break;
92  c.s << "!=";
93  break;
94  case relational::less:
95  c.s << "<";
96  break;
98  c.s << "<=";
99  break;
100  case relational::greater:
101  c.s << ">";
102  break;
104  c.s << ">=";
105  break;
106  default:
107  c.s << "(INVALID RELATIONAL OPERATOR)";
108  break;
109  }
110 }
111 
112 void relational::do_print(const print_context & c, unsigned level) const
113 {
114  if (precedence() <= level)
115  c.s << "(";
116  lh.print(c, precedence());
117  print_operator(c, o);
118  rh.print(c, precedence());
119  if (precedence() <= level)
120  c.s << ")";
121 }
122 
123 void relational::do_print_python_repr(const print_python_repr & c, unsigned level) const
124 {
125  c.s << class_name() << '(';
126  lh.print(c);
127  c.s << ',';
128  rh.print(c);
129  c.s << ",'";
130  print_operator(c, o);
131  c.s << "')";
132 }
133 
134 bool relational::info(unsigned inf) const
135 {
136  switch (inf) {
138  return 1;
140  return o==equal;
142  return o==not_equal;
144  return o==less;
146  return o==less_or_equal;
148  return o==greater;
150  return o==greater_or_equal;
151  }
152  return 0;
153 }
154 
155 size_t relational::nops() const
156 {
157  return 2;
158 }
159 
160 ex relational::op(size_t i) const
161 {
162  GINAC_ASSERT(i<2);
163 
164  return i==0 ? lh : rh;
165 }
166 
168 {
169  const ex &mapped_lh = f(lh);
170  const ex &mapped_rh = f(rh);
171 
172  if (!are_ex_trivially_equal(lh, mapped_lh)
173  || !are_ex_trivially_equal(rh, mapped_rh))
174  return dynallocate<relational>(mapped_lh, mapped_rh, o);
175  else
176  return *this;
177 }
178 
179 ex relational::subs(const exmap & m, unsigned options) const
180 {
181  const ex & subsed_lh = lh.subs(m, options);
182  const ex & subsed_rh = rh.subs(m, options);
183 
184  if (!are_ex_trivially_equal(lh, subsed_lh) || !are_ex_trivially_equal(rh, subsed_rh))
185  return relational(subsed_lh, subsed_rh, o).subs_one_level(m, options);
186  else
187  return subs_one_level(m, options);
188 }
189 
191 {
192  return lh.eval_ncmul(v);
193 }
194 
195 // protected
196 
197 int relational::compare_same_type(const basic & other) const
198 {
199  GINAC_ASSERT(is_exactly_a<relational>(other));
200  const relational &oth = static_cast<const relational &>(other);
201  if (o==oth.o && lh.is_equal(oth.lh) && rh.is_equal(oth.rh))
202  return 0;
203  switch (o) {
204  case equal:
205  case not_equal:
206  if (oth.o!=o)
207  return (o < oth.o) ? -1 : 1;
208  break;
209  case less:
210  if (oth.o!=greater)
211  return (o < oth.o) ? -1 : 1;
212  break;
213  case less_or_equal:
214  if (oth.o!=greater_or_equal)
215  return (o < oth.o) ? -1 : 1;
216  break;
217  case greater:
218  if (oth.o!=less)
219  return (o < oth.o) ? -1 : 1;
220  break;
221  case greater_or_equal:
222  if (oth.o!=less_or_equal)
223  return (o < oth.o) ? -1 : 1;
224  break;
225  }
226  const int lcmpval = lh.compare(oth.rh);
227  return (lcmpval!=0) ? lcmpval : rh.compare(oth.lh);
228 }
229 
230 bool relational::match_same_type(const basic & other) const
231 {
232  GINAC_ASSERT(is_exactly_a<relational>(other));
233  const relational &oth = static_cast<const relational &>(other);
234 
235  return o == oth.o;
236 }
237 
238 unsigned relational::return_type() const
239 {
241  return lh.return_type();
242 }
243 
245 {
247  return lh.return_type_tinfo();
248 }
249 
250 unsigned relational::calchash() const
251 {
252  unsigned v = make_hash_seed(typeid(*this));
253  unsigned lhash = lh.gethash();
254  unsigned rhash = rh.gethash();
255 
256  v = rotate_left(v);
257  switch(o) {
258  case equal:
259  case not_equal:
260  if (lhash>rhash) {
261  v ^= lhash;
262  lhash = rhash;
263  } else {
264  v ^= rhash;
265  }
266  break;
267  case less:
268  case less_or_equal:
269  v ^= rhash;
270  break;
271  case greater:
272  case greater_or_equal:
273  v ^= lhash;
274  lhash = rhash;
275  break;
276  }
277  v = rotate_left(v);
278  v ^= lhash;
279 
280  // store calculated hash value only if object is already evaluated
283  hashvalue = v;
284  }
285 
286  return v;
287 }
288 
290 // new virtual functions which can be overridden by derived classes
292 
293 // none
294 
296 // non-virtual functions in this class
298 
300 {
301  return cond? &safe_bool_helper::nonnull : nullptr;
302 }
303 
309 relational::operator relational::safe_bool() const
310 {
311  const ex df = lh-rh;
312  if (!is_exactly_a<numeric>(df))
313  // cannot decide on non-numerical results
314  return o==not_equal ? make_safe_bool(true) : make_safe_bool(false);
315 
316  switch (o) {
317  case equal:
318  return make_safe_bool(ex_to<numeric>(df).is_zero());
319  case not_equal:
320  return make_safe_bool(!ex_to<numeric>(df).is_zero());
321  case less:
322  return make_safe_bool(ex_to<numeric>(df)<(*_num0_p));
323  case less_or_equal:
324  return make_safe_bool(ex_to<numeric>(df)<=(*_num0_p));
325  case greater:
326  return make_safe_bool(ex_to<numeric>(df)>(*_num0_p));
327  case greater_or_equal:
328  return make_safe_bool(ex_to<numeric>(df)>=(*_num0_p));
329  default:
330  throw(std::logic_error("invalid relational operator"));
331  }
332 }
333 
334 } // namespace GiNaC
size_t nops() const override
Number of operands/members.
Definition: relational.cpp:155
unsigned return_type() const override
Definition: relational.cpp:238
unsigned hashvalue
hash value
Definition: basic.h:303
int compare(const ex &other) const
Definition: ex.h:322
ex subs(const exmap &m, unsigned options=0) const
Definition: ex.h:826
unsigned calchash() const override
Compute the hash value of an object and if it makes sense to store it in the objects status_flags...
Definition: relational.cpp:250
bool is_equal(const ex &other) const
Definition: ex.h:345
const basic & setflag(unsigned f) const
Set some status_flags.
Definition: basic.h:288
void read_archive(const archive_node &n, lst &syms) override
Read (a.k.a.
Definition: relational.cpp:59
ex rhs(const ex &thisex)
Definition: ex.h:817
Definition: add.cpp:38
ex eval_ncmul(const exvector &v) const
Definition: ex.h:123
This class holds a relation consisting of two expressions and a logical relation between them...
Definition: relational.h:34
Archiving of GiNaC expressions.
This class is the ABC (abstract base class) of GiNaC&#39;s class hierarchy.
Definition: basic.h:104
Context for python-parsable output.
Definition: print.h:138
bool are_ex_trivially_equal(const ex &e1, const ex &e2)
Compare two objects of class quickly without doing a deep tree traversal.
Definition: ex.h:684
ex eval_ncmul(const exvector &v) const override
Definition: relational.cpp:190
unsigned gethash() const
Definition: ex.h:233
ex subs(const exmap &m, unsigned options=0) const override
Substitute a set of objects by arbitrary expressions.
Definition: relational.cpp:179
Interface to several small and furry utilities needed within GiNaC but not of any interest to the use...
bool is_zero(const ex &thisex)
Definition: ex.h:820
safe_bool make_safe_bool(bool) const
Definition: relational.cpp:299
void(safe_bool_helper::* safe_bool)()
Definition: relational.h:92
relational(const ex &lhs, const ex &rhs, operators oper=equal)
Definition: relational.cpp:52
print_func< print_context >(&varidx::do_print). print_func< print_latex >(&varidx
Definition: idx.cpp:45
unsigned options
Definition: factor.cpp:2480
ex lhs(const ex &thisex)
Definition: ex.h:814
mvec m
Definition: factor.cpp:771
#define GINAC_ASSERT(X)
Assertion macro for checking invariances.
Definition: assertion.h:33
ex subs_one_level(const exmap &m, unsigned options) const
Helper function for subs().
Definition: basic.cpp:585
static unsigned make_hash_seed(const std::type_info &tinfo)
We need a hash function which gives different values for objects of different types.
Definition: hash_seed.h:36
static void print_operator(const print_context &c, relational::operators o)
Definition: relational.cpp:85
GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(add, expairseq, print_func< print_context >(&add::do_print). print_func< print_latex >(&add::do_print_latex). print_func< print_csrc >(&add::do_print_csrc). print_func< print_tree >(&add::do_print_tree). print_func< print_python_repr >(&add::do_print_python_repr)) add
Definition: add.cpp:40
To distinguish between different kinds of non-commutative objects.
Definition: registrar.h:43
unsigned precedence() const override
Return relative operator precedence (for parenthezing output).
Definition: relational.h:55
std::vector< ex > exvector
Definition: basic.h:46
std::map< ex, ex, ex_is_less > exmap
Definition: basic.h:50
Interface to GiNaC&#39;s overloaded operators.
Function object for map().
Definition: basic.h:85
return_type_t return_type_tinfo() const
Definition: ex.h:231
size_t n
Definition: factor.cpp:1463
Base class for print_contexts.
Definition: print.h:102
void archive(archive_node &n) const override
Save (a.k.a.
Definition: relational.cpp:71
bool match_same_type(const basic &other) const override
Returns true if the attributes of two objects are similar enough for a match.
Definition: relational.cpp:230
void do_print_tree(const print_tree &c, unsigned level) const
Tree output to stream.
Definition: basic.cpp:175
void do_print_python_repr(const print_python_repr &c, unsigned level) const
Definition: relational.cpp:123
void print(const print_context &c, unsigned level=0) const
Print expression to stream.
Definition: ex.cpp:56
This class stores all properties needed to record/retrieve the state of one object of class basic (or...
Definition: archive.h:48
Lightweight wrapper for GiNaC&#39;s symbolic objects.
Definition: ex.h:72
unsigned rotate_left(unsigned n)
Rotate bits of unsigned value by one bit to the left.
Definition: utils.h:48
.calchash() has already done its job
Definition: flags.h:205
ex op(size_t i) const override
Return operand/member at position i.
Definition: relational.cpp:160
virtual int compare_same_type(const basic &other) const
Returns order relation between two objects of same type.
Definition: basic.cpp:719
unsigned return_type() const
Definition: ex.h:230
void do_print(const print_context &c, unsigned level) const
Definition: relational.cpp:112
Wrapper template for making GiNaC classes out of STL containers.
Definition: container.h:73
Interface to relations between expressions.
Makes the interface to the underlying bignum package available.
size_t c
Definition: factor.cpp:770
ex map(map_function &f) const override
Construct new expression by applying the specified function to all sub-expressions (one level only...
Definition: relational.cpp:167
.eval() has already done its job
Definition: flags.h:203
bool info(unsigned inf) const override
Information about the object.
Definition: relational.cpp:134
unsigned flags
of type status_flags
Definition: basic.h:302
GINAC_BIND_UNARCHIVER(add)
const numeric * _num0_p
Definition: utils.cpp:175
return_type_t return_type_tinfo() const override
Definition: relational.cpp:244
Type-specific hash seed.

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