Happy New Year!
[ginac.git] / ginac / relational.cpp
index 6d51a56..92b5431 100644 (file)
@@ -3,7 +3,7 @@
  *  Implementation of relations between expressions */
 
 /*
- *  GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2019 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
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-#include <stdexcept>
-
 #include "relational.h"
+#include "operators.h"
 #include "numeric.h"
-#include "print.h"
 #include "archive.h"
 #include "utils.h"
-#include "debugmsg.h"
+#include "hash_seed.h"
+
+#include <iostream>
+#include <stdexcept>
 
 namespace GiNaC {
 
-GINAC_IMPLEMENT_REGISTERED_CLASS(relational, basic)
+GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(relational, basic,
+  print_func<print_context>(&relational::do_print).
+  print_func<print_tree>(&relational::do_print_tree).
+  print_func<print_python_repr>(&relational::do_print_python_repr))
 
 //////////
-// default ctor, dtor, copy ctor assignment operator and helpers
+// default constructor
 //////////
 
-relational::relational() : basic(TINFO_relational)
-{
-       debugmsg("relational default ctor",LOGLEVEL_CONSTRUCT);
-}
-
-void relational::copy(const relational & other)
-{
-       basic::copy(other);
-       lh=other.lh;
-       rh=other.rh;
-       o=other.o;
-}
-
-DEFAULT_DESTROY(relational)
+relational::relational() { }
 
 //////////
-// other ctors
+// other constructors
 //////////
 
 // public
 
-relational::relational(const ex & lhs, const ex & rhs, operators oper) : basic(TINFO_relational)
-{
-       debugmsg("relational ctor ex,ex,operator",LOGLEVEL_CONSTRUCT);
-       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, const lst &sym_lst) : inherited(n, sym_lst)
+void relational::read_archive(const archive_node& n, lst& sym_lst)
 {
-       debugmsg("relational ctor from archive_node", LOGLEVEL_CONSTRUCT);
+       inherited::read_archive(n, sym_lst);
        unsigned int opi;
        if (!(n.find_unsigned("op", opi)))
                throw (std::runtime_error("unknown relational operator in archive"));
@@ -80,6 +66,7 @@ relational::relational(const archive_node &n, const lst &sym_lst) : inherited(n,
        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
 {
@@ -89,103 +76,120 @@ void relational::archive(archive_node &n) const
        n.add_unsigned("op", o);
 }
 
-DEFAULT_UNARCHIVE(relational)
-
 //////////
 // functions overriding virtual functions from base classes
 //////////
 
 // public
 
-void relational::print(const print_context & c, unsigned level) const
+static void print_operator(const print_context & c, relational::operators o)
 {
-       debugmsg("relational print",LOGLEVEL_PRINT);
-
-       if (is_a<print_tree>(c)) {
-
-               inherited::print(c, level);
+       switch (o) {
+       case relational::equal:
+               c.s << "==";
+               break;
+       case relational::not_equal:
+               c.s << "!=";
+               break;
+       case relational::less:
+               c.s << "<";
+               break;
+       case relational::less_or_equal:
+               c.s << "<=";
+               break;
+       case relational::greater:
+               c.s << ">";
+               break;
+       case relational::greater_or_equal:
+               c.s << ">=";
+               break;
+       default:
+               c.s << "(INVALID RELATIONAL OPERATOR)";
+               break;
+       }
+}
 
-       } else {
+void relational::do_print(const print_context & c, unsigned level) const
+{
+       if (precedence() <= level)
+               c.s << "(";
+       lh.print(c, precedence());
+       print_operator(c, o);
+       rh.print(c, precedence());
+       if (precedence() <= level)
+               c.s << ")";
+}
 
-               if (precedence() <= level)
-                       c.s << "(";
-               lh.print(c, precedence());
-               switch (o) {
-               case equal:
-                       c.s << "==";
-                       break;
-               case not_equal:
-                       c.s << "!=";
-                       break;
-               case less:
-                       c.s << "<";
-                       break;
-               case less_or_equal:
-                       c.s << "<=";
-                       break;
-               case greater:
-                       c.s << ">";
-                       break;
-               case greater_or_equal:
-                       c.s << ">=";
-                       break;
-               default:
-                       c.s << "(INVALID RELATIONAL OPERATOR)";
-               }
-               rh.print(c, precedence());
-               if (precedence() <= level)
-                       c.s << ")";
-       }
+void relational::do_print_python_repr(const print_python_repr & c, unsigned level) const
+{
+       c.s << class_name() << '(';
+       lh.print(c);
+       c.s << ',';
+       rh.print(c);
+       c.s << ",'";
+       print_operator(c, o);
+       c.s << "')";
 }
 
 bool relational::info(unsigned inf) const
 {
        switch (inf) {
-       case info_flags::relation:
-               return 1;
-       case info_flags::relation_equal:
-               return o==equal;
-       case info_flags::relation_not_equal:
-               return o==not_equal;
-       case info_flags::relation_less:
-               return o==less;
-       case info_flags::relation_less_or_equal:
-               return o==less_or_equal;
-       case info_flags::relation_greater:
-               return o==greater;
-       case info_flags::relation_greater_or_equal:
-               return o==greater_or_equal;
+               case info_flags::relation:
+                       return 1;
+               case info_flags::relation_equal:
+                       return o==equal;
+               case info_flags::relation_not_equal:
+                       return o==not_equal;
+               case info_flags::relation_less:
+                       return o==less;
+               case info_flags::relation_less_or_equal:
+                       return o==less_or_equal;
+               case info_flags::relation_greater:
+                       return o==greater;
+               case info_flags::relation_greater_or_equal:
+                       return o==greater_or_equal;
        }
        return 0;
 }
 
-unsigned relational::nops() const
+size_t relational::nops() const
 {
        return 2;
 }
 
-ex & relational::let_op(int i)
+ex relational::op(size_t i) const
 {
-       GINAC_ASSERT(i>=0);
        GINAC_ASSERT(i<2);
 
        return i==0 ? lh : rh;
 }
 
-ex relational::eval(int level) const
+ex relational::map(map_function & f) 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);
+       const ex &mapped_lh = f(lh);
+       const ex &mapped_rh = f(rh);
+
+       if (!are_ex_trivially_equal(lh, mapped_lh)
+        || !are_ex_trivially_equal(rh, mapped_rh))
+               return dynallocate<relational>(mapped_lh, mapped_rh, o);
+       else
+               return *this;
 }
 
-ex relational::simplify_ncmul(const exvector & v) const
+ex relational::subs(const exmap & m, unsigned options) const
 {
-       return lh.simplify_ncmul(v);
+       const ex & subsed_lh = lh.subs(m, options);
+       const ex & subsed_rh = rh.subs(m, options);
+
+       if (!are_ex_trivially_equal(lh, subsed_lh) || !are_ex_trivially_equal(rh, subsed_rh))
+               return relational(subsed_lh, subsed_rh, o).subs_one_level(m, options);
+       else
+               return subs_one_level(m, options);
+}
+
+ex relational::eval_ncmul(const exvector & v) const
+{
+       return lh.eval_ncmul(v);
 }
 
 // protected
@@ -194,15 +198,33 @@ int relational::compare_same_type(const basic & other) const
 {
        GINAC_ASSERT(is_exactly_a<relational>(other));
        const relational &oth = static_cast<const relational &>(other);
-       
-       if (o == oth.o) {
-               int cmpval = lh.compare(oth.lh);
-               if (cmpval)
-                       return cmpval;
-               else
-                       return rh.compare(oth.rh);
+       if (o==oth.o && lh.is_equal(oth.lh) && rh.is_equal(oth.rh))
+               return 0;
+       switch (o) {
+               case equal:
+               case not_equal:
+                       if (oth.o!=o)
+                               return (o < oth.o) ? -1 : 1;
+                       break;
+               case less:
+                       if (oth.o!=greater)
+                               return (o < oth.o) ? -1 : 1;
+                       break;
+               case less_or_equal:
+                       if (oth.o!=greater_or_equal)
+                               return (o < oth.o) ? -1 : 1;
+                       break;
+               case greater:
+                       if (oth.o!=less)
+                               return (o < oth.o) ? -1 : 1;
+                       break;
+               case greater_or_equal:
+                       if (oth.o!=less_or_equal)
+                               return (o < oth.o) ? -1 : 1;
+                       break;
        }
-       return (o < oth.o) ? -1 : 1;
+       const int lcmpval = lh.compare(oth.rh);
+       return (lcmpval!=0) ? lcmpval : rh.compare(oth.lh);
 }
 
 bool relational::match_same_type(const basic & other) const
@@ -213,65 +235,99 @@ bool relational::match_same_type(const basic & other) const
        return o == oth.o;
 }
 
-unsigned relational::return_type(void) const
+unsigned relational::return_type() const
 {
        GINAC_ASSERT(lh.return_type()==rh.return_type());
        return lh.return_type();
 }
-   
-unsigned relational::return_type_tinfo(void) 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 = make_hash_seed(typeid(*this));
+       unsigned lhash = lh.gethash();
+       unsigned rhash = rh.gethash();
+
+       v = rotate_left(v);
+       switch(o) {
+               case equal:
+               case not_equal:
+                       if (lhash>rhash) {
+                               v ^= lhash;
+                               lhash = rhash;
+                       } else {
+                               v ^= rhash;
+                       }
+                       break;
+               case less:
+               case less_or_equal:
+                       v ^= rhash;
+                       break;
+               case greater:
+               case greater_or_equal:
+                       v ^= lhash;
+                       lhash = rhash;
+                       break;
+       }
+       v = rotate_left(v);
+       v ^= lhash;
+
+       // store calculated hash value only if object is already evaluated
+       if (flags & status_flags::evaluated) {
+               setflag(status_flags::hash_calculated);
+               hashvalue = v;
+       }
+
+       return v;
+}
+
 //////////
 // new virtual functions which can be overridden by derived classes
 //////////
 
-/** Left hand side of relational. */
-ex relational::lhs(void) const
-{
-       return lh;
-}
-
-/** Right hand side of relational. */
-ex relational::rhs(void) const
-{
-       return rh;    
-}
+// none
 
 //////////
 // non-virtual functions in this class
 //////////
 
-/** Cast the relational into a boolean, mainly for evaluation within an 
+relational::safe_bool relational::make_safe_bool(bool cond) const
+{
+       return cond? &safe_bool_helper::nonnull : nullptr;
+}
+
+/** 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 bool() const
+relational::operator relational::safe_bool() const
 {
        const ex df = lh-rh;
-       if (!is_ex_exactly_of_type(df,numeric))
+       if (!is_exactly_a<numeric>(df))
                // cannot decide on non-numerical results
-               return o==not_equal ? true : false;
-       
+               return o==not_equal ? make_safe_bool(true) : make_safe_bool(false);
+
        switch (o) {
-       case equal:
-               return ex_to<numeric>(df).is_zero();
-       case not_equal:
-               return !ex_to<numeric>(df).is_zero();
-       case less:
-               return ex_to<numeric>(df)<_num0();
-       case less_or_equal:
-               return ex_to<numeric>(df)<=_num0();
-       case greater:
-               return ex_to<numeric>(df)>_num0();
-       case greater_or_equal:
-               return ex_to<numeric>(df)>=_num0();
-       default:
-               throw(std::logic_error("invalid relational operator"));
+               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"));
        }
 }