added a section about error handling

[ginac.git] / ginac / mul.cpp

diff --git a/ginac/mul.cpp b/ginac/mul.cpp
index 3cfb7ff6c437d4aeb7c82fb87cfc39f436e6588f..da23307e186a0526608f38dadedb814f25bc78a6 100644 (file)
--- a/ginac/mul.cpp
+++ b/ginac/mul.cpp
@@ -141,7 +141,7 @@ void mul::print(const print_context & c, unsigned level) const
                        c.s << "(";
 
                if (!overall_coeff.is_equal(_ex1())) {
-                       overall_coeff.bp->print(c, precedence());
+                       overall_coeff.print(c, precedence());
                        c.s << "*";
                }
 
@@ -330,13 +330,17 @@ ex mul::coeff(const ex & s, int n) const
        return _ex0();
 }
 
+/** Perform automatic term rewriting rules in this class.  In the following
+ *  x, x1, x2,... stand for a symbolic variables of type ex and c, c1, c2...
+ *  stand for such expressions that contain a plain number.
+ *  - *(...,x;0) -> 0
+ *  - *(+(x1,x2,...);c) -> *(+(*(x1,c),*(x2,c),...))
+ *  - *(x;1) -> x
+ *  - *(;c) -> c
+ *
+ *  @param level cut-off in recursive evaluation */
 ex mul::eval(int level) const
 {
-       // simplifications  *(...,x;0) -> 0
-       //                  *(+(x,y,...);c) -> *(+(*(x,c),*(y,c),...)) (c numeric())
-       //                  *(x;1) -> x
-       //                  *(;c) -> c
-       
        debugmsg("mul eval",LOGLEVEL_MEMBER_FUNCTION);
        
        epvector *evaled_seqp = evalchildren(level);
@@ -349,12 +353,12 @@ ex mul::eval(int level) const
 #ifdef DO_GINAC_ASSERT
        epvector::const_iterator i = seq.begin(), end = seq.end();
        while (i != end) {
-               GINAC_ASSERT((!is_ex_exactly_of_type(i->rest, mul)) ||
+               GINAC_ASSERT((!is_exactly_a<mul>(i->rest)) ||
                             (!(ex_to<numeric>(i->coeff).is_integer())));
                GINAC_ASSERT(!(i->is_canonical_numeric()));
                if (is_ex_exactly_of_type(recombine_pair_to_ex(*i), numeric))
                    print(print_tree(std::cerr));
-               GINAC_ASSERT(!is_ex_exactly_of_type(recombine_pair_to_ex(*i), numeric));
+               GINAC_ASSERT(!is_exactly_a<numeric>(recombine_pair_to_ex(*i)));
                /* for paranoia */
                expair p = split_ex_to_pair(recombine_pair_to_ex(*i));
                GINAC_ASSERT(p.rest.is_equal(i->rest));
@@ -644,22 +648,22 @@ ex mul::default_overall_coeff(void) const
 
 void mul::combine_overall_coeff(const ex & c)
 {
-       GINAC_ASSERT(is_ex_exactly_of_type(overall_coeff,numeric));
-       GINAC_ASSERT(is_ex_exactly_of_type(c,numeric));
+       GINAC_ASSERT(is_exactly_a<numeric>(overall_coeff));
+       GINAC_ASSERT(is_exactly_a<numeric>(c));
        overall_coeff = ex_to<numeric>(overall_coeff).mul_dyn(ex_to<numeric>(c));
 }
 
 void mul::combine_overall_coeff(const ex & c1, const ex & c2)
 {
-       GINAC_ASSERT(is_ex_exactly_of_type(overall_coeff,numeric));
-       GINAC_ASSERT(is_ex_exactly_of_type(c1,numeric));
-       GINAC_ASSERT(is_ex_exactly_of_type(c2,numeric));
+       GINAC_ASSERT(is_exactly_a<numeric>(overall_coeff));
+       GINAC_ASSERT(is_exactly_a<numeric>(c1));
+       GINAC_ASSERT(is_exactly_a<numeric>(c2));
        overall_coeff = ex_to<numeric>(overall_coeff).mul_dyn(ex_to<numeric>(c1).power(ex_to<numeric>(c2)));
 }
 
 bool mul::can_make_flat(const expair & p) const
 {
-       GINAC_ASSERT(is_ex_exactly_of_type(p.coeff,numeric));
+       GINAC_ASSERT(is_exactly_a<numeric>(p.coeff));
        // this assertion will probably fail somewhere
        // it would require a more careful make_flat, obeying the power laws
        // probably should return true only if p.coeff is integer