]> www.ginac.de Git - ginac.git/blobdiff - ginac/expairseq.cpp
some more comments and cleanups to mul::expand() and ncmul::expand()
[ginac.git] / ginac / expairseq.cpp
index 997fabd4d9937b9a5e6f671da60b8386743f64ed..f49fefcf208495ddf3a9d9d78f8a744bebf36092 100644 (file)
@@ -26,6 +26,7 @@
 
 #include "expairseq.h"
 #include "lst.h"
+#include "relational.h"
 #include "print.h"
 #include "archive.h"
 #include "debugmsg.h"
@@ -199,10 +200,11 @@ void expairseq::print(const print_context & c, unsigned level) const
                    << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
                    << ", nops=" << nops()
                    << std::endl;
-               for (unsigned i=0; i<seq.size(); ++i) {
+               unsigned num = seq.size();
+               for (unsigned i=0; i<num; ++i) {
                        seq[i].rest.print(c, level + delta_indent);
                        seq[i].coeff.print(c, level + delta_indent);
-                       if (i != seq.size()-1)
+                       if (i != num - 1)
                                c.s << std::string(level + delta_indent, ' ') << "-----" << std::endl;
                }
                if (!overall_coeff.is_equal(default_overall_coeff())) {
@@ -232,7 +234,7 @@ void expairseq::print(const print_context & c, unsigned level) const
                                        c.s << *it-seq.begin() << " ";
                                        ++this_bin_fill;
                                }
-                               os << std::endl;
+                               c.s << std::endl;
                                cum_fill += this_bin_fill;
                                cum_fill_sq += this_bin_fill*this_bin_fill;
                        }
@@ -267,7 +269,7 @@ void expairseq::print(const print_context & c, unsigned level) const
 
        } else {
                c.s << "[[";
-               printseq(c, ',', precedence, level);
+               printseq(c, ',', precedence(), level);
                c.s << "]]";
        }
 }
@@ -298,6 +300,23 @@ ex &expairseq::let_op(int i)
        throw(std::logic_error("let_op not defined for expairseq and derived classes (add,mul,...)"));
 }
 
+ex expairseq::map(map_function & f) const
+{
+       epvector *v = new epvector;
+       v->reserve(seq.size());
+
+       epvector::const_iterator cit = seq.begin(), last = seq.end();
+       while (cit != last) {
+               v->push_back(split_ex_to_pair(f(recombine_pair_to_ex(*cit))));
+               ++cit;
+       }
+
+       if (overall_coeff.is_equal(default_overall_coeff()))
+               return thisexpairseq(v, default_overall_coeff());
+       else
+               return thisexpairseq(v, f(overall_coeff));
+}
+
 ex expairseq::eval(int level) const
 {
        if ((level==1) && (flags &status_flags::evaluated))
@@ -310,40 +329,95 @@ ex expairseq::eval(int level) const
        return (new expairseq(vp,overall_coeff))->setflag(status_flags::dynallocated | status_flags::evaluated);
 }
 
-ex expairseq::evalf(int level) const
+bool expairseq::match(const ex & pattern, lst & repl_lst) const
 {
-       return thisexpairseq(evalfchildren(level),overall_coeff.evalf(level-1));
-}
+       // This differs from basic::match() because we want "a+b+c+d" to
+       // match "d+*+b" with "*" being "a+c", and we want to honor commutativity
 
-ex expairseq::normal(lst &sym_lst, lst &repl_lst, int level) const
-{
-       ex n = thisexpairseq(normalchildren(level),overall_coeff);
-       return n.bp->basic::normal(sym_lst,repl_lst,level);
+       if (tinfo() == pattern.bp->tinfo()) {
+
+               // Check whether global wildcard (one that matches the "rest of the
+               // expression", like "*" above) is present
+               bool has_global_wildcard = false;
+               ex global_wildcard;
+               for (unsigned int i=0; i<pattern.nops(); i++) {
+                       if (is_ex_exactly_of_type(pattern.op(i), wildcard)) {
+                               has_global_wildcard = true;
+                               global_wildcard = pattern.op(i);
+                               break;
+                       }
+               }
+
+               // Unfortunately, this is an O(N^2) operation because we can't
+               // sort the pattern in a useful way...
+
+               // Chop into terms
+               exvector ops;
+               ops.reserve(nops());
+               for (unsigned i=0; i<nops(); i++)
+                       ops.push_back(op(i));
+
+               // Now, for every term of the pattern, look for a matching term in
+               // the expression and remove the match
+               for (unsigned i=0; i<pattern.nops(); i++) {
+                       ex p = pattern.op(i);
+                       if (has_global_wildcard && p.is_equal(global_wildcard))
+                               continue;
+                       exvector::iterator it = ops.begin(), itend = ops.end();
+                       while (it != itend) {
+                               if (it->match(p, repl_lst)) {
+                                       ops.erase(it);
+                                       goto found;
+                               }
+                               ++it;
+                       }
+                       return false; // no match found
+found:         ;
+               }
+
+               if (has_global_wildcard) {
+
+                       // Assign all the remaining terms to the global wildcard (unless
+                       // it has already been matched before, in which case the matches
+                       // must be equal)
+                       unsigned num = ops.size();
+                       epvector *vp = new epvector();
+                       vp->reserve(num);
+                       for (unsigned i=0; i<num; i++)
+                               vp->push_back(split_ex_to_pair(ops[i]));
+                       ex rest = thisexpairseq(vp, default_overall_coeff());
+                       for (unsigned i=0; i<repl_lst.nops(); i++) {
+                               if (repl_lst.op(i).op(0).is_equal(global_wildcard))
+                                       return rest.is_equal(*repl_lst.op(i).op(1).bp);
+                       }
+                       repl_lst.append(global_wildcard == rest);
+                       return true;
+
+               } else {
+
+                       // No global wildcard, then the match fails if there are any
+                       // unmatched terms left
+                       return ops.empty();
+               }
+       }
+       return inherited::match(pattern, repl_lst);
 }
 
-ex expairseq::subs(const lst &ls, const lst &lr) const
+ex expairseq::subs(const lst &ls, const lst &lr, bool no_pattern) const
 {
-       epvector *vp = subschildren(ls,lr);
-       if (vp==0)
-               return inherited::subs(ls, lr);
-       
-       return thisexpairseq(vp,overall_coeff);
+       epvector *vp = subschildren(ls, lr, no_pattern);
+       if (vp)
+               return thisexpairseq(vp, overall_coeff).bp->basic::subs(ls, lr, no_pattern);
+       else
+               return basic::subs(ls, lr, no_pattern);
 }
 
 // protected
 
-/** Implementation of ex::diff() for an expairseq.
- *  It differentiates all elements of the sequence.
- *  @see ex::diff */
-ex expairseq::derivative(const symbol &s) const
-{
-       return thisexpairseq(diffchildren(s),overall_coeff);
-}
-
 int expairseq::compare_same_type(const basic &other) const
 {
        GINAC_ASSERT(is_of_type(other, expairseq));
-       const expairseq &o = static_cast<const expairseq &>(const_cast<basic &>(other));
+       const expairseq &o = static_cast<const expairseq &>(other);
        
        int cmpval;
        
@@ -408,7 +482,7 @@ int expairseq::compare_same_type(const basic &other) const
 
 bool expairseq::is_equal_same_type(const basic &other) const
 {
-       const expairseq &o = dynamic_cast<const expairseq &>(const_cast<basic &>(other));
+       const expairseq &o = static_cast<const expairseq &>(other);
        
        // compare number of elements
        if (seq.size()!=o.seq.size())
@@ -478,15 +552,17 @@ unsigned expairseq::return_type(void) const
 unsigned expairseq::calchash(void) const
 {
        unsigned v = golden_ratio_hash(tinfo());
-       for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
+       epvector::const_iterator i = seq.begin(), end = seq.end();
+       while (i != end) {
 #if !EXPAIRSEQ_USE_HASHTAB
                v = rotate_left_31(v); // rotation would spoil commutativity
 #endif // EXPAIRSEQ_USE_HASHTAB
-               v ^= cit->rest.gethash();
+               v ^= i->rest.gethash();
 #if !EXPAIRSEQ_USE_HASHTAB
                v = rotate_left_31(v);
-               v ^= cit->coeff.gethash();
+               v ^= i->coeff.gethash();
 #endif // EXPAIRSEQ_USE_HASHTAB
+               ++i;
        }
        
        v ^= overall_coeff.gethash();
@@ -504,13 +580,11 @@ unsigned expairseq::calchash(void) const
 ex expairseq::expand(unsigned options) const
 {
        epvector *vp = expandchildren(options);
-       if (vp==0) {
-               // the terms have not changed, so it is safe to declare this expanded
-               setflag(status_flags::expanded);
-               return *this;
-       }
-       
-       return thisexpairseq(vp,overall_coeff);
+       if (vp == NULL) {
+               // The terms have not changed, so it is safe to declare this expanded
+               return (options == 0) ? setflag(status_flags::expanded) : *this;
+       } else
+               return thisexpairseq(vp, overall_coeff);
 }
 
 //////////
@@ -540,9 +614,9 @@ ex expairseq::thisexpairseq(epvector *vp, const ex &oc) const
 void expairseq::printpair(const print_context & c, const expair & p, unsigned upper_precedence) const
 {
        c.s << "[[";
-       p.rest.bp->print(c, precedence);
+       p.rest.bp->print(c, precedence());
        c.s << ",";
-       p.coeff.bp->print(c, precedence);
+       p.coeff.bp->print(c, precedence());
        c.s << "]]";
 }
 
@@ -591,7 +665,7 @@ expair expairseq::combine_pair_with_coeff_to_pair(const expair &p,
        GINAC_ASSERT(is_ex_exactly_of_type(p.coeff,numeric));
        GINAC_ASSERT(is_ex_exactly_of_type(c,numeric));
        
-       return expair(p.rest,ex_to_numeric(p.coeff).mul_dyn(ex_to_numeric(c)));
+       return expair(p.rest,ex_to<numeric>(p.coeff).mul_dyn(ex_to<numeric>(c)));
 }
 
 
@@ -619,7 +693,7 @@ void expairseq::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));
-       overall_coeff = ex_to_numeric(overall_coeff).add_dyn(ex_to_numeric(c));
+       overall_coeff = ex_to<numeric>(overall_coeff).add_dyn(ex_to<numeric>(c));
 }
 
 void expairseq::combine_overall_coeff(const ex &c1, const ex &c2)
@@ -627,8 +701,8 @@ void expairseq::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));
-       overall_coeff = ex_to_numeric(overall_coeff).
-                       add_dyn(ex_to_numeric(c1).mul(ex_to_numeric(c2)));
+       overall_coeff = ex_to<numeric>(overall_coeff).
+                       add_dyn(ex_to<numeric>(c1).mul(ex_to<numeric>(c2)));
 }
 
 bool expairseq::can_make_flat(const expair &p) const
@@ -659,26 +733,26 @@ void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
        if (lh.bp->tinfo()==tinfo()) {
                if (rh.bp->tinfo()==tinfo()) {
 #if EXPAIRSEQ_USE_HASHTAB
-                       unsigned totalsize = ex_to_expairseq(lh).seq.size() +
-                                            ex_to_expairseq(rh).seq.size();
+                       unsigned totalsize = ex_to<expairseq>(lh).seq.size() +
+                                            ex_to<expairseq>(rh).seq.size();
                        if (calc_hashtabsize(totalsize)!=0) {
                                construct_from_2_ex_via_exvector(lh,rh);
                        } else {
 #endif // EXPAIRSEQ_USE_HASHTAB
-                               construct_from_2_expairseq(ex_to_expairseq(lh),
-                                                          ex_to_expairseq(rh));
+                               construct_from_2_expairseq(ex_to<expairseq>(lh),
+                                                          ex_to<expairseq>(rh));
 #if EXPAIRSEQ_USE_HASHTAB
                        }
 #endif // EXPAIRSEQ_USE_HASHTAB
                        return;
                } else {
 #if EXPAIRSEQ_USE_HASHTAB
-                       unsigned totalsize = ex_to_expairseq(lh).seq.size()+1;
+                       unsigned totalsize = ex_to<expairseq>(lh).seq.size()+1;
                        if (calc_hashtabsize(totalsize)!=0) {
                                construct_from_2_ex_via_exvector(lh, rh);
                        } else {
 #endif // EXPAIRSEQ_USE_HASHTAB
-                               construct_from_expairseq_ex(ex_to_expairseq(lh), rh);
+                               construct_from_expairseq_ex(ex_to<expairseq>(lh), rh);
 #if EXPAIRSEQ_USE_HASHTAB
                        }
 #endif // EXPAIRSEQ_USE_HASHTAB
@@ -686,12 +760,12 @@ void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
                }
        } else if (rh.bp->tinfo()==tinfo()) {
 #if EXPAIRSEQ_USE_HASHTAB
-               unsigned totalsize=ex_to_expairseq(rh).seq.size()+1;
+               unsigned totalsize=ex_to<expairseq>(rh).seq.size()+1;
                if (calc_hashtabsize(totalsize)!=0) {
                        construct_from_2_ex_via_exvector(lh,rh);
                } else {
 #endif // EXPAIRSEQ_USE_HASHTAB
-                       construct_from_expairseq_ex(ex_to_expairseq(rh),lh);
+                       construct_from_expairseq_ex(ex_to<expairseq>(rh),lh);
 #if EXPAIRSEQ_USE_HASHTAB
                }
 #endif // EXPAIRSEQ_USE_HASHTAB
@@ -724,8 +798,8 @@ void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
                        
                        int cmpval = p1.rest.compare(p2.rest);
                        if (cmpval==0) {
-                               p1.coeff=ex_to_numeric(p1.coeff).add_dyn(ex_to_numeric(p2.coeff));
-                               if (!ex_to_numeric(p1.coeff).is_zero()) {
+                               p1.coeff=ex_to<numeric>(p1.coeff).add_dyn(ex_to<numeric>(p2.coeff));
+                               if (!ex_to<numeric>(p1.coeff).is_zero()) {
                                        // no further processing is necessary, since this
                                        // one element will usually be recombined in eval()
                                        seq.push_back(p1);
@@ -763,8 +837,8 @@ void expairseq::construct_from_2_expairseq(const expairseq &s1,
                int cmpval = (*first1).rest.compare((*first2).rest);
                if (cmpval==0) {
                        // combine terms
-                       const numeric &newcoeff = ex_to_numeric((*first1).coeff).
-                                                  add(ex_to_numeric((*first2).coeff));
+                       const numeric &newcoeff = ex_to<numeric>((*first1).coeff).
+                                                  add(ex_to<numeric>((*first2).coeff));
                        if (!newcoeff.is_zero()) {
                                seq.push_back(expair((*first1).rest,newcoeff));
                                if (expair_needs_further_processing(seq.end()-1)) {
@@ -819,16 +893,15 @@ void expairseq::construct_from_expairseq_ex(const expairseq &s,
        
        // merge p into s.seq
        while (first!=last) {
-               int cmpval=(*first).rest.compare(p.rest);
+               int cmpval = (*first).rest.compare(p.rest);
                if (cmpval==0) {
                        // combine terms
-                       const numeric &newcoeff = ex_to_numeric((*first).coeff).
-                                                  add(ex_to_numeric(p.coeff));
+                       const numeric &newcoeff = ex_to<numeric>(first->coeff).
+                                                  add(ex_to<numeric>(p.coeff));
                        if (!newcoeff.is_zero()) {
-                               seq.push_back(expair((*first).rest,newcoeff));
-                               if (expair_needs_further_processing(seq.end()-1)) {
+                               seq.push_back(expair(first->rest,newcoeff));
+                               if (expair_needs_further_processing(seq.end()-1))
                                        needs_further_processing = true;
-                               }
                        }
                        ++first;
                        p_pushed = true;
@@ -875,7 +948,6 @@ void expairseq::construct_from_exvector(const exvector &v)
        canonicalize();
        combine_same_terms_sorted_seq();
 #endif // EXPAIRSEQ_USE_HASHTAB
-       return;
 }
 
 void expairseq::construct_from_epvector(const epvector &v)
@@ -892,7 +964,6 @@ void expairseq::construct_from_epvector(const epvector &v)
        canonicalize();
        combine_same_terms_sorted_seq();
 #endif // EXPAIRSEQ_USE_HASHTAB
-       return;
 }
 
 /** Combine this expairseq with argument exvector.
@@ -910,7 +981,7 @@ void expairseq::make_flat(const exvector &v)
        while (cit!=v.end()) {
                if (cit->bp->tinfo()==this->tinfo()) {
                        ++nexpairseqs;
-                       noperands += ex_to_expairseq(*cit).seq.size();
+                       noperands += ex_to<expairseq>(*cit).seq.size();
                }
                ++cit;
        }
@@ -922,7 +993,7 @@ void expairseq::make_flat(const exvector &v)
        cit = v.begin();
        while (cit!=v.end()) {
                if (cit->bp->tinfo()==this->tinfo()) {
-                       const expairseq &subseqref = ex_to_expairseq(*cit);
+                       const expairseq &subseqref = ex_to<expairseq>(*cit);
                        combine_overall_coeff(subseqref.overall_coeff);
                        epvector::const_iterator cit_s = subseqref.seq.begin();
                        while (cit_s!=subseqref.seq.end()) {
@@ -937,8 +1008,6 @@ void expairseq::make_flat(const exvector &v)
                }
                ++cit;
        }
-       
-       return;
 }
 
 /** Combine this expairseq with argument epvector.
@@ -956,7 +1025,7 @@ void expairseq::make_flat(const epvector &v)
        while (cit!=v.end()) {
                if (cit->rest.bp->tinfo()==this->tinfo()) {
                        ++nexpairseqs;
-                       noperands += ex_to_expairseq((*cit).rest).seq.size();
+                       noperands += ex_to<expairseq>(cit->rest).seq.size();
                }
                ++cit;
        }
@@ -969,13 +1038,13 @@ void expairseq::make_flat(const epvector &v)
        while (cit!=v.end()) {
                if (cit->rest.bp->tinfo()==this->tinfo() &&
                    this->can_make_flat(*cit)) {
-                       const expairseq &subseqref = ex_to_expairseq((*cit).rest);
-                       combine_overall_coeff(ex_to_numeric(subseqref.overall_coeff),
-                                                           ex_to_numeric((*cit).coeff));
+                       const expairseq &subseqref = ex_to<expairseq>(cit->rest);
+                       combine_overall_coeff(ex_to<numeric>(subseqref.overall_coeff),
+                                                           ex_to<numeric>(cit->coeff));
                        epvector::const_iterator cit_s = subseqref.seq.begin();
                        while (cit_s!=subseqref.seq.end()) {
-                               seq.push_back(expair((*cit_s).rest,
-                                                    ex_to_numeric((*cit_s).coeff).mul_dyn(ex_to_numeric((*cit).coeff))));
+                               seq.push_back(expair(cit_s->rest,
+                                                    ex_to<numeric>(cit_s->coeff).mul_dyn(ex_to<numeric>(cit->coeff))));
                                //seq.push_back(combine_pair_with_coeff_to_pair(*cit_s,
                                //                                              (*cit).coeff));
                                ++cit_s;
@@ -988,16 +1057,12 @@ void expairseq::make_flat(const epvector &v)
                }
                ++cit;
        }
-       return;
 }
 
-
 /** Brings this expairseq into a sorted (canonical) form. */
 void expairseq::canonicalize(void)
 {
-       // canonicalize
-       sort(seq.begin(),seq.end(),expair_is_less());
-       return;
+       sort(seq.begin(), seq.end(), expair_is_less());
 }
 
 
@@ -1017,14 +1082,14 @@ void expairseq::combine_same_terms_sorted_seq(void)
                // possible from then on the sequence has changed and must be compacted
                bool must_copy = false;
                while (itin2!=last) {
-                       if ((*itin1).rest.compare((*itin2).rest)==0) {
-                               (*itin1).coeff = ex_to_numeric((*itin1).coeff).
-                                                add_dyn(ex_to_numeric((*itin2).coeff));
+                       if ((*itin1).rest.compare(itin2->rest)==0) {
+                               (*itin1).coeff = ex_to<numeric>(itin1->coeff).
+                                                add_dyn(ex_to<numeric>(itin2->coeff));
                                if (expair_needs_further_processing(itin1))
                                        needs_further_processing = true;
                                must_copy = true;
                        } else {
-                               if (!ex_to_numeric((*itin1).coeff).is_zero()) {
+                               if (!ex_to<numeric>(itin1->coeff).is_zero()) {
                                        if (must_copy)
                                                *itout = *itin1;
                                        ++itout;
@@ -1033,7 +1098,7 @@ void expairseq::combine_same_terms_sorted_seq(void)
                        }
                        ++itin2;
                }
-               if (!ex_to_numeric((*itin1).coeff).is_zero()) {
+               if (!ex_to<numeric>(itin1->coeff).is_zero()) {
                        if (must_copy)
                                *itout = *itin1;
                        ++itout;
@@ -1047,7 +1112,6 @@ void expairseq::combine_same_terms_sorted_seq(void)
                seq.clear();
                construct_from_epvector(v);
        }
-       return;
 }
 
 #if EXPAIRSEQ_USE_HASHTAB
@@ -1130,14 +1194,13 @@ void expairseq::remove_hashtab_entry(epvector::const_iterator element)
                ++epplit;
        }
        if (!erased) {
-               printtree(cout,0);
-               cout << "tried to erase " << element-seq.begin() << std::endl;
-               cout << "size " << seq.end()-seq.begin() << std::endl;
+               std::cout << "tried to erase " << element-seq.begin() << std::endl;
+               std::cout << "size " << seq.end()-seq.begin() << std::endl;
 
-               unsigned hashindex = calc_hashindex((*element).rest);
+               unsigned hashindex = calc_hashindex(element->rest);
                epplist &eppl = hashtab[hashindex];
-               epplist::iterator epplit=eppl.begin();
-               bool erased=false;
+               epplist::iterator epplit = eppl.begin();
+               bool erased = false;
                while (epplit!=eppl.end()) {
                        if (*epplit == element) {
                                eppl.erase(epplit);
@@ -1172,10 +1235,10 @@ void expairseq::move_hashtab_entry(epvector::const_iterator oldpos,
        GINAC_ASSERT(epplit!=eppl.end());
 }
 
-void expairseq::sorted_insert(epplist &eppl, epp elem)
+void expairseq::sorted_insert(epplist &eppl, epvector::const_iterator elem)
 {
-       epplist::iterator current = eppl.begin();
-       while ((current!=eppl.end())&&((*(*current)).is_less(*elem))) {
+       epplist::const_iterator current = eppl.begin();
+       while ((current!=eppl.end()) && ((*current)->is_less(*elem))) {
                ++current;
        }
        eppl.insert(current,elem);
@@ -1183,24 +1246,24 @@ void expairseq::sorted_insert(epplist &eppl, epp elem)
 
 void expairseq::build_hashtab_and_combine(epvector::iterator &first_numeric,
                                           epvector::iterator &last_non_zero,
-                                          vector<bool> &touched,
+                                          std::vector<bool> &touched,
                                           unsigned &number_of_zeroes)
 {
-       epp current=seq.begin();
+       epp current = seq.begin();
 
        while (current!=first_numeric) {
-               if (is_ex_exactly_of_type((*current).rest,numeric)) {
+               if (is_ex_exactly_of_type(current->rest,numeric)) {
                        --first_numeric;
                        iter_swap(current,first_numeric);
                } else {
                        // calculate hashindex
-                       unsigned currenthashindex = calc_hashindex((*current).rest);
+                       unsigned currenthashindex = calc_hashindex(current->rest);
 
                        // test if there is already a matching expair in the hashtab-list
                        epplist &eppl=hashtab[currenthashindex];
                        epplist::iterator epplit = eppl.begin();
                        while (epplit!=eppl.end()) {
-                               if ((*current).rest.is_equal((*(*epplit)).rest))
+                               if (current->rest.is_equal((*epplit)->rest))
                                        break;
                                ++epplit;
                        }
@@ -1210,8 +1273,8 @@ void expairseq::build_hashtab_and_combine(epvector::iterator &first_numeric,
                                ++current;
                        } else {
                                // epplit points to a matching expair, combine it with current
-                               (*(*epplit)).coeff = ex_to_numeric((*(*epplit)).coeff).
-                                                    add_dyn(ex_to_numeric((*current).coeff));
+                               (*epplit)->coeff = ex_to<numeric>((*epplit)->coeff).
+                                                  add_dyn(ex_to<numeric>(current->coeff));
                                
                                // move obsolete current expair to end by swapping with last_non_zero element
                                // if this was a numeric, it is swapped with the expair before first_numeric 
@@ -1221,7 +1284,7 @@ void expairseq::build_hashtab_and_combine(epvector::iterator &first_numeric,
                                --last_non_zero;
                                ++number_of_zeroes;
                                // test if combined term has coeff 0 and can be removed is done later
-                               touched[(*epplit)-seq.begin()]=true;
+                               touched[(*epplit)-seq.begin()] = true;
                        }
                }
        }
@@ -1229,7 +1292,7 @@ void expairseq::build_hashtab_and_combine(epvector::iterator &first_numeric,
 
 void expairseq::drop_coeff_0_terms(epvector::iterator &first_numeric,
                                    epvector::iterator &last_non_zero,
-                                   vector<bool> &touched,
+                                   std::vector<bool> &touched,
                                    unsigned &number_of_zeroes)
 {
        // move terms with coeff 0 to end and remove them from hashtab
@@ -1240,7 +1303,7 @@ void expairseq::drop_coeff_0_terms(epvector::iterator &first_numeric,
                if (!touched[i]) {
                        ++current;
                        ++i;
-               } else if (!ex_to_numeric((*current).coeff).is_zero()) {
+               } else if (!ex_to<numeric>((*current).coeff).is_zero()) {
                        ++current;
                        ++i;
                } else {
@@ -1250,8 +1313,9 @@ void expairseq::drop_coeff_0_terms(epvector::iterator &first_numeric,
                        if (current!=last_non_zero) {
                                iter_swap(current,last_non_zero);
                                --first_numeric;
-                               bool numeric_swapped=first_numeric!=last_non_zero;
-                               if (numeric_swapped) iter_swap(first_numeric,current);
+                               bool numeric_swapped = first_numeric!=last_non_zero;
+                               if (numeric_swapped)
+                                       iter_swap(first_numeric,current);
                                epvector::iterator changed_entry;
 
                                if (numeric_swapped)
@@ -1283,9 +1347,11 @@ void expairseq::drop_coeff_0_terms(epvector::iterator &first_numeric,
  *  debugging purposes. */
 bool expairseq::has_coeff_0(void) const
 {
-       for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
-               if ((*cit).coeff.is_zero())
+       epvector::const_iterator i = seq.begin(), end = seq.end();
+       while (i != end) {
+               if (i->coeff.is_zero())
                        return true;
+               ++i;
        }
        return false;
 }
@@ -1293,12 +1359,11 @@ bool expairseq::has_coeff_0(void) const
 void expairseq::add_numerics_to_hashtab(epvector::iterator first_numeric,
                                                                                epvector::const_iterator last_non_zero)
 {
-       if (first_numeric==seq.end()) return; // no numerics    
+       if (first_numeric == seq.end()) return; // no numerics
        
-       epvector::iterator current = first_numeric;
-       epvector::const_iterator last = last_non_zero+1;
-       while (current!=last) {
-               sorted_insert(hashtab[hashmask],current);
+       epvector::const_iterator current = first_numeric, last = last_non_zero + 1;
+       while (current != last) {
+               sorted_insert(hashtab[hashmask], current);
                ++current;
        }
 }
@@ -1329,41 +1394,18 @@ void expairseq::combine_same_terms(void)
        epvector::iterator first_numeric = seq.end();
        epvector::iterator last_non_zero = seq.end()-1;
        
-       vector<bool> touched;
-       touched.reserve(seq.size());
-       for (unsigned i=0; i<seq.size(); ++i) touched[i]=false;
+       unsigned num = seq.size();
+       std::vector<bool> touched(num);
        
        unsigned number_of_zeroes = 0;
        
        GINAC_ASSERT(!has_coeff_0());
        build_hashtab_and_combine(first_numeric,last_non_zero,touched,number_of_zeroes);
-       /*
-       cout << "in combine:" << std::endl;
-       printtree(cout,0);
-       cout << "size=" << seq.end() - seq.begin() << std::endl;
-       cout << "first_numeric=" << first_numeric - seq.begin() << std::endl;
-       cout << "last_non_zero=" << last_non_zero - seq.begin() << std::endl;
-       for (unsigned i=0; i<seq.size(); ++i) {
-               if (touched[i]) cout << i << " is touched" << std::endl;
-       }
-       cout << "end in combine" << std::endl;
-       */
        
        // there should not be any terms with coeff 0 from the beginning,
        // so it should be safe to skip this step
        if (number_of_zeroes!=0) {
                drop_coeff_0_terms(first_numeric,last_non_zero,touched,number_of_zeroes);
-               /*
-               cout << "in combine after drop:" << std::endl;
-               printtree(cout,0);
-               cout << "size=" << seq.end() - seq.begin() << std::endl;
-               cout << "first_numeric=" << first_numeric - seq.begin() << std::endl;
-               cout << "last_non_zero=" << last_non_zero - seq.begin() << std::endl;
-               for (unsigned i=0; i<seq.size(); ++i) {
-                       if (touched[i]) cout << i << " is touched" << std::endl;
-               }
-               cout << "end in combine after drop" << std::endl;
-               */
        }
        
        add_numerics_to_hashtab(first_numeric,last_non_zero);
@@ -1394,25 +1436,25 @@ bool expairseq::is_canonical() const
        if (hashtabsize > 0) return 1; // not canoncalized
 #endif // EXPAIRSEQ_USE_HASHTAB
        
-       epvector::const_iterator it = seq.begin();
+       epvector::const_iterator it = seq.begin(), itend = seq.end();
        epvector::const_iterator it_last = it;
-       for (++it; it!=seq.end(); it_last=it, ++it) {
-               if (!((*it_last).is_less(*it) || (*it_last).is_equal(*it))) {
-                       if (!is_ex_exactly_of_type((*it_last).rest,numeric) ||
-                               !is_ex_exactly_of_type((*it).rest,numeric)) {
+       for (++it; it!=itend; it_last=it, ++it) {
+               if (!(it_last->is_less(*it) || it_last->is_equal(*it))) {
+                       if (!is_ex_exactly_of_type(it_last->rest,numeric) ||
+                               !is_ex_exactly_of_type(it->rest,numeric)) {
                                // double test makes it easier to set a breakpoint...
-                               if (!is_ex_exactly_of_type((*it_last).rest,numeric) ||
-                                       !is_ex_exactly_of_type((*it).rest,numeric)) {
+                               if (!is_ex_exactly_of_type(it_last->rest,numeric) ||
+                                       !is_ex_exactly_of_type(it->rest,numeric)) {
                                        printpair(std::clog, *it_last, 0);
                                        std::clog << ">";
                                        printpair(std::clog, *it, 0);
                                        std::clog << "\n";
                                        std::clog << "pair1:" << std::endl;
-                                       (*it_last).rest.print(print_tree(std::clog));
-                                       (*it_last).coeff.print(print_tree(std::clog));
+                                       it_last->rest.print(print_tree(std::clog));
+                                       it_last->coeff.print(print_tree(std::clog));
                                        std::clog << "pair2:" << std::endl;
-                                       (*it).rest.print(print_tree(std::clog));
-                                       (*it).coeff.print(print_tree(std::clog));
+                                       it->rest.print(print_tree(std::clog));
+                                       it->coeff.print(print_tree(std::clog));
                                        return 0;
                                }
                        }
@@ -1432,8 +1474,8 @@ epvector * expairseq::expandchildren(unsigned options) const
        epvector::const_iterator last = seq.end();
        epvector::const_iterator cit = seq.begin();
        while (cit!=last) {
-               const ex &expanded_ex = (*cit).rest.expand(options);
-               if (!are_ex_trivially_equal((*cit).rest,expanded_ex)) {
+               const ex &expanded_ex = cit->rest.expand(options);
+               if (!are_ex_trivially_equal(cit->rest,expanded_ex)) {
                        
                        // something changed, copy seq, eval and return it
                        epvector *s = new epvector;
@@ -1447,12 +1489,12 @@ epvector * expairseq::expandchildren(unsigned options) const
                        }
                        // copy first changed element
                        s->push_back(combine_ex_with_coeff_to_pair(expanded_ex,
-                                                                  (*cit2).coeff));
+                                                                  cit2->coeff));
                        ++cit2;
                        // copy rest
                        while (cit2!=last) {
-                               s->push_back(combine_ex_with_coeff_to_pair((*cit2).rest.expand(options),
-                                                                          (*cit2).coeff));
+                               s->push_back(combine_ex_with_coeff_to_pair(cit2->rest.expand(options),
+                                                                          cit2->coeff));
                                ++cit2;
                        }
                        return s;
@@ -1482,11 +1524,11 @@ epvector * expairseq::evalchildren(int level) const
                throw(std::runtime_error("max recursion level reached"));
        
        --level;
-       epvector::const_iterator last=seq.end();
-       epvector::const_iterator cit=seq.begin();
+       epvector::const_iterator last = seq.end();
+       epvector::const_iterator cit = seq.begin();
        while (cit!=last) {
-               const ex &evaled_ex = (*cit).rest.eval(level);
-               if (!are_ex_trivially_equal((*cit).rest,evaled_ex)) {
+               const ex &evaled_ex = cit->rest.eval(level);
+               if (!are_ex_trivially_equal(cit->rest,evaled_ex)) {
                        
                        // something changed, copy seq, eval and return it
                        epvector *s = new epvector;
@@ -1500,12 +1542,12 @@ epvector * expairseq::evalchildren(int level) const
                        }
                        // copy first changed element
                        s->push_back(combine_ex_with_coeff_to_pair(evaled_ex,
-                                                                  (*cit2).coeff));
+                                                                  cit2->coeff));
                        ++cit2;
                        // copy rest
                        while (cit2!=last) {
-                               s->push_back(combine_ex_with_coeff_to_pair((*cit2).rest.eval(level),
-                                                                          (*cit2).coeff));
+                               s->push_back(combine_ex_with_coeff_to_pair(cit2->rest.eval(level),
+                                                                          cit2->coeff));
                                ++cit2;
                        }
                        return s;
@@ -1517,125 +1559,98 @@ epvector * expairseq::evalchildren(int level) const
 }
 
 
-/** Member-wise evaluate numerically all expairs in this sequence.
+/** Member-wise substitute in this sequence.
  *
- *  @see expairseq::evalf()
- *  @return epvector with all entries evaluated numerically. */
-epvector expairseq::evalfchildren(int level) const
+ *  @see expairseq::subs()
+ *  @return pointer to epvector containing pairs after application of subs,
+ *    or NULL pointer if no members were changed. */
+epvector * expairseq::subschildren(const lst &ls, const lst &lr, bool no_pattern) const
 {
-       if (level==1)
-               return seq;
-       
-       if (level==-max_recursion_level)
-               throw(std::runtime_error("max recursion level reached"));
-       
-       epvector s;
-       s.reserve(seq.size());
-       
-       --level;
-       for (epvector::const_iterator it=seq.begin(); it!=seq.end(); ++it) {
-               s.push_back(combine_ex_with_coeff_to_pair((*it).rest.evalf(level),
-                                                         (*it).coeff.evalf(level)));
-       }
-       return s;
-}
+       GINAC_ASSERT(ls.nops()==lr.nops());
 
+       // The substitution is "complex" when any of the objects to be substituted
+       // is a product or power. In this case we have to recombine the pairs
+       // because the numeric coefficients may be part of the search pattern.
+       bool complex_subs = false;
+       for (unsigned i=0; i<ls.nops(); ++i)
+               if (is_ex_exactly_of_type(ls.op(i), mul) || is_ex_exactly_of_type(ls.op(i), power)) {
+                       complex_subs = true;
+                       break;
+               }
 
-/** Member-wise normalize all expairs in this sequence.
- *
- *  @see expairseq::normal()
- *  @return epvector with all entries normalized. */
-epvector expairseq::normalchildren(int level) const
-{
-       if (level==1)
-               return seq;
-       
-       if (level==-max_recursion_level)
-               throw(std::runtime_error("max recursion level reached"));
-       
-       epvector s;
-       s.reserve(seq.size());
-       
-       --level;
-       for (epvector::const_iterator it=seq.begin(); it!=seq.end(); ++it) {
-               s.push_back(combine_ex_with_coeff_to_pair((*it).rest.normal(level),
-                                                         (*it).coeff));
-       }
-       return s;
-}
+       if (complex_subs) {
 
+               // Substitute in the recombined pairs
+               epvector::const_iterator cit = seq.begin(), last = seq.end();
+               while (cit != last) {
 
-/** Member-wise differentiate all expairs in this sequence.
- *
- *  @see expairseq::diff()
- *  @return epvector with all entries differentiated. */
-epvector expairseq::diffchildren(const symbol &y) const
-{
-       epvector s;
-       s.reserve(seq.size());
-       
-       for (epvector::const_iterator it=seq.begin(); it!=seq.end(); ++it) {
-               s.push_back(combine_ex_with_coeff_to_pair((*it).rest.diff(y),
-                                                         (*it).coeff));
-       }
-       return s;
-}
+                       const ex &orig_ex = recombine_pair_to_ex(*cit);
+                       const ex &subsed_ex = orig_ex.subs(ls, lr, no_pattern);
+                       if (!are_ex_trivially_equal(orig_ex, subsed_ex)) {
 
+                               // Something changed, copy seq, subs and return it
+                               epvector *s = new epvector;
+                               s->reserve(seq.size());
 
-/** Member-wise substitute in this sequence.
- *
- *  @see expairseq::subs()
- *  @return pointer to epvector containing pairs after application of subs or zero
- *  pointer, if no members were changed. */
-epvector * expairseq::subschildren(const lst &ls, const lst &lr) const
-{
-       // returns a NULL pointer if nothing had to be substituted
-       // returns a pointer to a newly created epvector otherwise
-       // (which has to be deleted somewhere else)
-       GINAC_ASSERT(ls.nops()==lr.nops());
-       
-       epvector::const_iterator last = seq.end();
-       epvector::const_iterator cit = seq.begin();
-       while (cit!=last) {
-               const ex &subsed_ex=(*cit).rest.subs(ls,lr);
-               if (!are_ex_trivially_equal((*cit).rest,subsed_ex)) {
+                               // Copy parts of seq which are known not to have changed
+                               s->insert(s->begin(), seq.begin(), cit);
+
+                               // Copy first changed element
+                               s->push_back(split_ex_to_pair(subsed_ex));
+                               ++cit;
+
+                               // Copy rest
+                               while (cit != last) {
+                                       s->push_back(split_ex_to_pair(recombine_pair_to_ex(*cit).subs(ls, lr, no_pattern)));
+                                       ++cit;
+                               }
+                               return s;
+                       }
+
+                       ++cit;
+               }
+
+       } else {
+
+               // Substitute only in the "rest" part of the pairs
+               epvector::const_iterator cit = seq.begin(), last = seq.end();
+               while (cit != last) {
+
+                       const ex &subsed_ex = cit->rest.subs(ls, lr, no_pattern);
+                       if (!are_ex_trivially_equal(cit->rest, subsed_ex)) {
                        
-                       // something changed, copy seq, subs and return it
-                       epvector *s = new epvector;
-                       s->reserve(seq.size());
+                               // Something changed, copy seq, subs and return it
+                               epvector *s = new epvector;
+                               s->reserve(seq.size());
+
+                               // Copy parts of seq which are known not to have changed
+                               s->insert(s->begin(), seq.begin(), cit);
                        
-                       // copy parts of seq which are known not to have changed
-                       epvector::const_iterator cit2 = seq.begin();
-                       while (cit2!=cit) {
-                               s->push_back(*cit2);
-                               ++cit2;
-                       }
-                       // copy first changed element
-                       s->push_back(combine_ex_with_coeff_to_pair(subsed_ex,
-                                                                  (*cit2).coeff));
-                       ++cit2;
-                       // copy rest
-                       while (cit2!=last) {
-                               s->push_back(combine_ex_with_coeff_to_pair((*cit2).rest.subs(ls,lr),
-                                                                          (*cit2).coeff));
-                               ++cit2;
+                               // Copy first changed element
+                               s->push_back(combine_ex_with_coeff_to_pair(subsed_ex, cit->coeff));
+                               ++cit;
+
+                               // Copy rest
+                               while (cit != last) {
+                                       s->push_back(combine_ex_with_coeff_to_pair(cit->rest.subs(ls, lr, no_pattern),
+                                                                                  cit->coeff));
+                                       ++cit;
+                               }
+                               return s;
                        }
-                       return s;
+
+                       ++cit;
                }
-               ++cit;
        }
        
-       return 0; // signalling nothing has changed
+       // Nothing has changed
+       return NULL;
 }
 
 //////////
 // static member variables
 //////////
 
-// protected
-
-unsigned expairseq::precedence = 10;
-
 #if EXPAIRSEQ_USE_HASHTAB
 unsigned expairseq::maxhashtabsize = 0x4000000U;
 unsigned expairseq::minhashtabsize = 0x1000U;