Finalize 1.8.1 release.

[ginac.git] / ginac / relational.cpp

diff --git a/ginac/relational.cpp b/ginac/relational.cpp
index 4ee87be182f49c883b75f80fcb025d40514de6fa..599a26352de202f949eddd9e8aac1fdee0cc6289 100644 (file)
--- a/ginac/relational.cpp
+++ b/ginac/relational.cpp
@@ -3,7 +3,7 @@
  *  Implementation of relations between expressions */
 
 /*
- *  GiNaC Copyright (C) 1999-2011 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
@@ -171,22 +171,11 @@ ex relational::map(map_function & f) const
 
        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);
@@ -251,7 +240,7 @@ unsigned relational::return_type() const
        GINAC_ASSERT(lh.return_type()==rh.return_type());
        return lh.return_type();
 }
-   
+
 return_type_t relational::return_type_tinfo() const
 {
        GINAC_ASSERT(lh.return_type_tinfo()==rh.return_type_tinfo());
@@ -281,7 +270,7 @@ unsigned relational::calchash() const
                        break;
                case greater:
                case greater_or_equal:
-                       v ^= lhash;
+                       v ^= lhash;
                        lhash = rhash;
                        break;
        }
@@ -301,17 +290,7 @@ unsigned relational::calchash() const
 // 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
@@ -319,37 +298,61 @@ ex relational::rhs() const
 
 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