* Implementation of relations between expressions */
/*
- * GiNaC Copyright (C) 1999-2008 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2021 Johannes Gutenberg University Mainz, Germany
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#include <iostream>
-#include <stdexcept>
-
#include "relational.h"
#include "operators.h"
#include "numeric.h"
#include "archive.h"
#include "utils.h"
+#include "hash_seed.h"
+
+#include <iostream>
+#include <stdexcept>
namespace GiNaC {
// default constructor
//////////
-relational::relational() : basic(&relational::tinfo_static) {}
+relational::relational() { }
//////////
// other constructors
// public
-relational::relational(const ex & lhs, const ex & rhs, operators oper) : basic(&relational::tinfo_static), lh(lhs), rh(rhs), o(oper) {}
+relational::relational(const ex & lhs, const ex & rhs, operators oper) :
+ lh(lhs), rh(rhs), o(oper) { }
//////////
// archiving
//////////
-relational::relational(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
+void relational::read_archive(const archive_node& n, lst& sym_lst)
{
+ inherited::read_archive(n, sym_lst);
unsigned int opi;
if (!(n.find_unsigned("op", opi)))
throw (std::runtime_error("unknown relational operator in archive"));
n.find_ex("lh", lh, sym_lst);
n.find_ex("rh", rh, sym_lst);
}
+GINAC_BIND_UNARCHIVER(relational);
void relational::archive(archive_node &n) const
{
n.add_unsigned("op", o);
}
-DEFAULT_UNARCHIVE(relational)
-
//////////
// functions overriding virtual functions from base classes
//////////
if (!are_ex_trivially_equal(lh, mapped_lh)
|| !are_ex_trivially_equal(rh, mapped_rh))
- return (new relational(mapped_lh, mapped_rh, o))->setflag(status_flags::dynallocated);
+ return dynallocate<relational>(mapped_lh, mapped_rh, o);
else
return *this;
}
-ex relational::eval(int level) const
-{
- if (level==1)
- return this->hold();
-
- if (level == -max_recursion_level)
- throw(std::runtime_error("max recursion level reached"));
-
- return (new relational(lh.eval(level-1),rh.eval(level-1),o))->setflag(status_flags::dynallocated | status_flags::evaluated);
-}
-
ex relational::subs(const exmap & m, unsigned options) const
{
const ex & subsed_lh = lh.subs(m, options);
GINAC_ASSERT(lh.return_type()==rh.return_type());
return lh.return_type();
}
-
-tinfo_t relational::return_type_tinfo() const
+
+return_type_t relational::return_type_tinfo() const
{
GINAC_ASSERT(lh.return_type_tinfo()==rh.return_type_tinfo());
return lh.return_type_tinfo();
unsigned relational::calchash() const
{
- unsigned v = golden_ratio_hash((p_int)tinfo());
+ unsigned v = make_hash_seed(typeid(*this));
unsigned lhash = lh.gethash();
unsigned rhash = rh.gethash();
break;
case greater:
case greater_or_equal:
- v ^= lhash;
+ v ^= lhash;
lhash = rhash;
break;
}
// new virtual functions which can be overridden by derived classes
//////////
-/** Left hand side of relational. */
-ex relational::lhs() const
-{
- return lh;
-}
-
-/** Right hand side of relational. */
-ex relational::rhs() const
-{
- return rh;
-}
+// none
//////////
// non-virtual functions in this class
relational::safe_bool relational::make_safe_bool(bool cond) const
{
- return cond? &safe_bool_helper::nonnull : 0;
+ return cond? &safe_bool_helper::nonnull : nullptr;
}
-/** Cast the relational into a boolean, mainly for evaluation within an
+/** Cast the relational into a Boolean, mainly for evaluation within an
* if-statement. Note that (a<b) == false does not imply (a>=b) == true in
* the general symbolic case. A false result means the comparison is either
* false or undecidable (except of course for !=, where true means either
* unequal or undecidable). */
relational::operator relational::safe_bool() const
{
- const ex df = lh-rh;
- if (!is_exactly_a<numeric>(df))
- // cannot decide on non-numerical results
- return o==not_equal ? make_safe_bool(true) : make_safe_bool(false);
-
- switch (o) {
- case equal:
- return make_safe_bool(ex_to<numeric>(df).is_zero());
- case not_equal:
- return make_safe_bool(!ex_to<numeric>(df).is_zero());
- case less:
- return make_safe_bool(ex_to<numeric>(df)<(*_num0_p));
- case less_or_equal:
- return make_safe_bool(ex_to<numeric>(df)<=(*_num0_p));
- case greater:
- return make_safe_bool(ex_to<numeric>(df)>(*_num0_p));
- case greater_or_equal:
- return make_safe_bool(ex_to<numeric>(df)>=(*_num0_p));
- default:
- throw(std::logic_error("invalid relational operator"));
+ const ex df = lh-rh; // like ::canonical() method
+ // We treat numeric and symbolic expression differently
+ if (is_exactly_a<numeric>(df)) {
+ switch (o) {
+ case equal:
+ return make_safe_bool(ex_to<numeric>(df).is_zero());
+ case not_equal:
+ return make_safe_bool(!ex_to<numeric>(df).is_zero());
+ case less:
+ return make_safe_bool(ex_to<numeric>(df)<(*_num0_p));
+ case less_or_equal:
+ return make_safe_bool(ex_to<numeric>(df)<=(*_num0_p));
+ case greater:
+ return make_safe_bool(ex_to<numeric>(df)>(*_num0_p));
+ case greater_or_equal:
+ return make_safe_bool(ex_to<numeric>(df)>=(*_num0_p));
+ default:
+ throw(std::logic_error("invalid relational operator"));
+ }
+ } else {
+ // The conversion for symbolic expressions is based on the info flags
+ switch (o) {
+ case equal:
+ return make_safe_bool(df.is_zero());
+ case not_equal:
+ return make_safe_bool(! df.is_zero());
+ case less:
+ return make_safe_bool(df.info(info_flags::negative));
+ case less_or_equal:
+ return make_safe_bool((-df).info(info_flags::nonnegative));
+ case greater:
+ return make_safe_bool(df.info(info_flags::positive));
+ case greater_or_equal:
+ return make_safe_bool(df.info(info_flags::nonnegative));
+ default:
+ throw(std::logic_error("invalid relational operator"));
+ }
}
}
+/** Returns an equivalent relational with zero right-hand side.
+ */
+ex relational::canonical() const
+{
+ return relational(lh-rh, _ex0, o);
+}
+
} // namespace GiNaC
git://www.ginac.de / ginac.git / blobdiff