Happy New Year!
[ginac.git] / ginac / symmetry.cpp
index 1b81819..115df0b 100644 (file)
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's symmetry definitions. */
 
 /*
- *  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 <functional>
-#include <algorithm>
-
 #include "symmetry.h"
 #include "lst.h"
+#include "add.h"
 #include "numeric.h" // for factorial()
-#include "print.h"
+#include "operators.h"
 #include "archive.h"
 #include "utils.h"
-#include "debugmsg.h"
+#include "hash_seed.h"
+
+#include <functional>
+#include <iostream>
+#include <limits>
+#include <stdexcept>
 
 namespace GiNaC {
 
-GINAC_IMPLEMENT_REGISTERED_CLASS(symmetry, basic)
+GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(symmetry, basic,
+  print_func<print_context>(&symmetry::do_print).
+  print_func<print_tree>(&symmetry::do_print_tree))
+
+/*
+   Some notes about the structure of a symmetry tree:
+    - The leaf nodes of the tree are of type "none", have one index, and no
+      children (of course). They are constructed by the symmetry(unsigned)
+      constructor.
+    - Leaf nodes are the only nodes that only have one index.
+    - Container nodes contain two or more children. The "indices" set member
+      is the set union of the index sets of all children, and the "children"
+      vector stores the children themselves.
+    - The index set of each child of a "symm", "anti" or "cycl" node must
+      have the same size. It follows that the children of such a node are
+      either all leaf nodes, or all container nodes with two or more indices.
+*/
 
 //////////
-// default constructor, destructor, copy constructor assignment operator and helpers
+// default constructor
 //////////
 
-symmetry::symmetry() : type(none)
-{
-       debugmsg("symmetry default constructor", LOGLEVEL_CONSTRUCT);
-       tinfo_key = TINFO_symmetry;
-}
-
-void symmetry::copy(const symmetry & other)
+symmetry::symmetry() :  type(none)
 {
-       inherited::copy(other);
-       type = other.type;
-       indices = other.indices;
-       children = other.children;
+       setflag(status_flags::evaluated | status_flags::expanded);
 }
 
-DEFAULT_DESTROY(symmetry)
-
 //////////
 // other constructors
 //////////
 
-symmetry::symmetry(unsigned i) : type(none)
+symmetry::symmetry(unsigned i) :  type(none)
 {
-       debugmsg("symmetry constructor from unsigned", LOGLEVEL_CONSTRUCT);
        indices.insert(i);
-       tinfo_key = TINFO_symmetry;
+       setflag(status_flags::evaluated | status_flags::expanded);
 }
 
-symmetry::symmetry(symmetry_type t, const symmetry &c1, const symmetry &c2) : type(t)
+symmetry::symmetry(symmetry_type t, const symmetry &c1, const symmetry &c2) :  type(t)
 {
-       debugmsg("symmetry constructor from symmetry_type,symmetry &,symmetry &", LOGLEVEL_CONSTRUCT);
        add(c1); add(c2);
-       tinfo_key = TINFO_symmetry;
+       setflag(status_flags::evaluated | status_flags::expanded);
 }
 
 //////////
@@ -79,10 +84,9 @@ symmetry::symmetry(symmetry_type t, const symmetry &c1, const symmetry &c2) : ty
 //////////
 
 /** Construct object from archive_node. */
-symmetry::symmetry(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
+void symmetry::read_archive(const archive_node &n, lst &sym_lst)
 {
-       debugmsg("symmetry ctor from archive_node", LOGLEVEL_CONSTRUCT);
-
+       inherited::read_archive(n, sym_lst);
        unsigned t;
        if (!(n.find_unsigned("type", t)))
                throw (std::runtime_error("unknown symmetry type in archive"));
@@ -109,6 +113,7 @@ symmetry::symmetry(const archive_node &n, const lst &sym_lst) : inherited(n, sym
                }
        }
 }
+GINAC_BIND_UNARCHIVER(symmetry);
 
 /** Archive the object. */
 void symmetry::archive(archive_node &n) const
@@ -118,39 +123,88 @@ void symmetry::archive(archive_node &n) const
        n.add_unsigned("type", type);
 
        if (children.empty()) {
-               std::set<unsigned>::const_iterator i = indices.begin(), iend = indices.end();
-               while (i != iend) {
-                       n.add_unsigned("index", *i);
-                       i++;
+               for (auto & i : indices) {
+                       n.add_unsigned("index", i);
                }
        } else {
-               exvector::const_iterator i = children.begin(), iend = children.end();
-               while (i != iend) {
-                       n.add_ex("child", *i);
-                       i++;
+               for (auto & i : children) {
+                       n.add_ex("child", i);
                }
        }
 }
 
-DEFAULT_UNARCHIVE(symmetry)
-
 //////////
 // functions overriding virtual functions from base classes
 //////////
 
 int symmetry::compare_same_type(const basic & other) const
 {
-       GINAC_ASSERT(is_of_type(other, symmetry));
+       GINAC_ASSERT(is_a<symmetry>(other));
+
+       // For archiving purposes we need to have an ordering of symmetries.
+       const symmetry &othersymm = ex_to<symmetry>(other);
+
+       // Compare type.
+       if (type > othersymm.type)
+               return 1;
+       if (type < othersymm.type)
+               return -1;
+
+       // Compare the index set.
+       size_t this_size = indices.size();
+       size_t that_size = othersymm.indices.size();
+       if (this_size > that_size)
+               return 1;
+       if (this_size < that_size)
+               return -1;
+       auto end = indices.end();
+       for (auto i=indices.begin(),j=othersymm.indices.begin(); i!=end; ++i,++j) {
+               if(*i < *j)
+                       return 1;
+               if(*i > *j)
+                       return -1;
+       }
+
+       // Compare the children.
+       if (children.size() > othersymm.children.size())
+               return 1;
+       if (children.size() < othersymm.children.size())
+               return -1;
+       for (size_t i=0; i<children.size(); ++i) {
+               int cmpval = ex_to<symmetry>(children[i])
+                       .compare_same_type(ex_to<symmetry>(othersymm.children[i]));
+               if (cmpval)
+                       return cmpval;
+       }
 
-       // All symmetry trees are equal. They are not supposed to appear in
-       // ordinary expressions anyway...
        return 0;
 }
 
-void symmetry::print(const print_context & c, unsigned level = 0) const
+unsigned symmetry::calchash() const
 {
-       debugmsg("symmetry print", LOGLEVEL_PRINT);
+       unsigned v = make_hash_seed(typeid(*this));
+
+       if (type == none) {
+               v = rotate_left(v);
+               if (!indices.empty())
+                       v ^= *(indices.begin());
+       } else {
+               for (auto & i : children) {
+                       v = rotate_left(v);
+                       v ^= i.gethash();
+               }
+       }
+
+       if (flags & status_flags::evaluated) {
+               setflag(status_flags::hash_calculated);
+               hashvalue = v;
+       }
 
+       return v;
+}
+
+void symmetry::do_print(const print_context & c, unsigned level) const
+{
        if (children.empty()) {
                if (indices.size() > 0)
                        c.s << *(indices.begin());
@@ -165,8 +219,8 @@ void symmetry::print(const print_context & c, unsigned level = 0) const
                        default: c.s << '?'; break;
                }
                c.s << '(';
-               unsigned num = children.size();
-               for (unsigned i=0; i<num; i++) {
+               size_t num = children.size();
+               for (size_t i=0; i<num; i++) {
                        children[i].print(c);
                        if (i != num - 1)
                                c.s << ",";
@@ -175,15 +229,68 @@ void symmetry::print(const print_context & c, unsigned level = 0) const
        }
 }
 
+void symmetry::do_print_tree(const print_tree & c, unsigned level) const
+{
+       c.s << std::string(level, ' ') << class_name() << " @" << this
+           << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
+           << ", type=";
+
+       switch (type) {
+               case none: c.s << "none"; break;
+               case symmetric: c.s << "symm"; break;
+               case antisymmetric: c.s << "anti"; break;
+               case cyclic: c.s << "cycl"; break;
+               default: c.s << "<unknown>"; break;
+       }
+
+       c.s << ", indices=(";
+       if (!indices.empty()) {
+               auto i = indices.begin(), end = indices.end();
+               --end;
+               while (i != end)
+                       c.s << *i++ << ",";
+               c.s << *i;
+       }
+       c.s << ")\n";
+
+       for (auto & i : children) {
+               i.print(c, level + c.delta_indent);
+       }
+}
+
 //////////
 // non-virtual functions in this class
 //////////
 
+bool symmetry::has_nonsymmetric() const
+{
+       if (type == antisymmetric || type == cyclic)
+               return true;
+
+       for (auto & i : children)
+               if (ex_to<symmetry>(i).has_nonsymmetric())
+                       return true;
+
+       return false;
+}
+
+bool symmetry::has_cyclic() const
+{
+       if (type == cyclic)
+               return true;
+
+       for (auto & i : children)
+               if (ex_to<symmetry>(i).has_cyclic())
+                       return true;
+
+       return false;
+}
+
 symmetry &symmetry::add(const symmetry &c)
 {
        // All children must have the same number of indices
        if (type != none && !children.empty()) {
-               GINAC_ASSERT(is_ex_exactly_of_type(children[0], symmetry));
+               GINAC_ASSERT(is_exactly_a<symmetry>(children[0]));
                if (ex_to<symmetry>(children[0]).indices.size() != c.indices.size())
                        throw (std::logic_error("symmetry:add(): children must have same number of indices"));
        }
@@ -216,7 +323,73 @@ void symmetry::validate(unsigned n)
 // global functions
 //////////
 
-class sy_is_less : public std::binary_function<ex, ex, bool> {
+static const symmetry & index0()
+{
+       static ex s = dynallocate<symmetry>(0);
+       return ex_to<symmetry>(s);
+}
+
+static const symmetry & index1()
+{
+       static ex s = dynallocate<symmetry>(1);
+       return ex_to<symmetry>(s);
+}
+
+static const symmetry & index2()
+{
+       static ex s = dynallocate<symmetry>(2);
+       return ex_to<symmetry>(s);
+}
+
+static const symmetry & index3()
+{
+       static ex s = dynallocate<symmetry>(3);
+       return ex_to<symmetry>(s);
+}
+
+const symmetry & not_symmetric()
+{
+       static ex s = dynallocate<symmetry>();
+       return ex_to<symmetry>(s);
+}
+
+const symmetry & symmetric2()
+{
+       static ex s = dynallocate<symmetry>(symmetry::symmetric, index0(), index1());
+       return ex_to<symmetry>(s);
+}
+
+const symmetry & symmetric3()
+{
+       static ex s = dynallocate<symmetry>(symmetry::symmetric, index0(), index1()).add(index2());
+       return ex_to<symmetry>(s);
+}
+
+const symmetry & symmetric4()
+{
+       static ex s = dynallocate<symmetry>(symmetry::symmetric, index0(), index1()).add(index2()).add(index3());
+       return ex_to<symmetry>(s);
+}
+
+const symmetry & antisymmetric2()
+{
+       static ex s = dynallocate<symmetry>(symmetry::antisymmetric, index0(), index1());
+       return ex_to<symmetry>(s);
+}
+
+const symmetry & antisymmetric3()
+{
+       static ex s = dynallocate<symmetry>(symmetry::antisymmetric, index0(), index1()).add(index2());
+       return ex_to<symmetry>(s);
+}
+
+const symmetry & antisymmetric4()
+{
+       static ex s = dynallocate<symmetry>(symmetry::antisymmetric, index0(), index1()).add(index2()).add(index3());
+       return ex_to<symmetry>(s);
+}
+
+class sy_is_less {
        exvector::iterator v;
 
 public:
@@ -224,10 +397,10 @@ public:
 
        bool operator() (const ex &lh, const ex &rh) const
        {
-               GINAC_ASSERT(is_ex_exactly_of_type(lh, symmetry));
-               GINAC_ASSERT(is_ex_exactly_of_type(rh, symmetry));
+               GINAC_ASSERT(is_exactly_a<symmetry>(lh));
+               GINAC_ASSERT(is_exactly_a<symmetry>(rh));
                GINAC_ASSERT(ex_to<symmetry>(lh).indices.size() == ex_to<symmetry>(rh).indices.size());
-               std::set<unsigned>::const_iterator ait = ex_to<symmetry>(lh).indices.begin(), aitend = ex_to<symmetry>(lh).indices.end(), bit = ex_to<symmetry>(rh).indices.begin();
+               auto ait = ex_to<symmetry>(lh).indices.begin(), aitend = ex_to<symmetry>(lh).indices.end(), bit = ex_to<symmetry>(rh).indices.begin();
                while (ait != aitend) {
                        int cmpval = v[*ait].compare(v[*bit]);
                        if (cmpval < 0)
@@ -240,7 +413,7 @@ public:
        }
 };
 
-class sy_swap : public std::binary_function<ex, ex, void> {
+class sy_swap {
        exvector::iterator v;
 
 public:
@@ -250,10 +423,10 @@ public:
 
        void operator() (const ex &lh, const ex &rh)
        {
-               GINAC_ASSERT(is_ex_exactly_of_type(lh, symmetry));
-               GINAC_ASSERT(is_ex_exactly_of_type(rh, symmetry));
+               GINAC_ASSERT(is_exactly_a<symmetry>(lh));
+               GINAC_ASSERT(is_exactly_a<symmetry>(rh));
                GINAC_ASSERT(ex_to<symmetry>(lh).indices.size() == ex_to<symmetry>(rh).indices.size());
-               std::set<unsigned>::const_iterator ait = ex_to<symmetry>(lh).indices.begin(), aitend = ex_to<symmetry>(lh).indices.end(), bit = ex_to<symmetry>(rh).indices.begin();
+               auto ait = ex_to<symmetry>(lh).indices.begin(), aitend = ex_to<symmetry>(lh).indices.end(), bit = ex_to<symmetry>(rh).indices.begin();
                while (ait != aitend) {
                        v[*ait].swap(v[*bit]);
                        ++ait; ++bit;
@@ -264,20 +437,20 @@ public:
 
 int canonicalize(exvector::iterator v, const symmetry &symm)
 {
-       // No children? Then do nothing
-       if (symm.children.empty())
-               return INT_MAX;
+       // Less than two elements? Then do nothing
+       if (symm.indices.size() < 2)
+               return std::numeric_limits<int>::max();
 
        // Canonicalize children first
        bool something_changed = false;
        int sign = 1;
-       exvector::const_iterator first = symm.children.begin(), last = symm.children.end();
+       auto first = symm.children.begin(), last = symm.children.end();
        while (first != last) {
-               GINAC_ASSERT(is_ex_exactly_of_type(*first, symmetry));
+               GINAC_ASSERT(is_exactly_a<symmetry>(*first));
                int child_sign = canonicalize(v, ex_to<symmetry>(*first));
                if (child_sign == 0)
                        return 0;
-               if (child_sign != INT_MAX) {
+               if (child_sign != std::numeric_limits<int>::max()) {
                        something_changed = true;
                        sign *= child_sign;
                }
@@ -294,6 +467,8 @@ int canonicalize(exvector::iterator v, const symmetry &symm)
                case symmetry::antisymmetric:
                        // Sort the children in ascending order, keeping track of the signum
                        sign *= permutation_sign(first, last, sy_is_less(v), sy_swap(v, something_changed));
+                       if (sign == 0)
+                               return 0;
                        break;
                case symmetry::cyclic:
                        // Permute the smallest child to the front
@@ -302,7 +477,7 @@ int canonicalize(exvector::iterator v, const symmetry &symm)
                default:
                        break;
        }
-       return something_changed ? sign : INT_MAX;
+       return something_changed ? sign : std::numeric_limits<int>::max();
 }
 
 
@@ -314,31 +489,31 @@ static ex symm(const ex & e, exvector::const_iterator first, exvector::const_ite
        if (num < 2)
                return e;
 
-       // Transform object vector to a list
-       exlist iv_lst;
-       iv_lst.insert(iv_lst.begin(), first, last);
-       lst orig_lst(iv_lst, true);
+       // Transform object vector to a lst (for subs())
+       lst orig_lst(first, last);
 
        // Create index vectors for permutation
        unsigned *iv = new unsigned[num], *iv2;
        for (unsigned i=0; i<num; i++)
                iv[i] = i;
-       iv2 = (asymmetric ? new unsigned[num] : NULL);
+       iv2 = (asymmetric ? new unsigned[num] : nullptr);
 
        // Loop over all permutations (the first permutation, which is the
        // identity, is unrolled)
-       ex sum = e;
+       exvector sum_v;
+       sum_v.push_back(e);
        while (std::next_permutation(iv, iv + num)) {
                lst new_lst;
                for (unsigned i=0; i<num; i++)
                        new_lst.append(orig_lst.op(iv[i]));
-               ex term = e.subs(orig_lst, new_lst);
+               ex term = e.subs(orig_lst, new_lst, subs_options::no_pattern|subs_options::no_index_renaming);
                if (asymmetric) {
                        memcpy(iv2, iv, num * sizeof(unsigned));
                        term *= permutation_sign(iv2, iv2 + num);
                }
-               sum += term;
+               sum_v.push_back(term);
        }
+       ex sum = dynallocate<add>(sum_v);
 
        delete[] iv;
        delete[] iv2;
@@ -363,10 +538,8 @@ ex symmetrize_cyclic(const ex & e, exvector::const_iterator first, exvector::con
        if (num < 2)
                return e;
 
-       // Transform object vector to a list
-       exlist iv_lst;
-       iv_lst.insert(iv_lst.begin(), first, last);
-       lst orig_lst(iv_lst, true);
+       // Transform object vector to a lst (for subs())
+       lst orig_lst(first, last);
        lst new_lst = orig_lst;
 
        // Loop over all cyclic permutations (the first permutation, which is
@@ -375,7 +548,7 @@ ex symmetrize_cyclic(const ex & e, exvector::const_iterator first, exvector::con
        for (unsigned i=0; i<num-1; i++) {
                ex perm = new_lst.op(0);
                new_lst.remove_first().append(perm);
-               sum += e.subs(orig_lst, new_lst);
+               sum += e.subs(orig_lst, new_lst, subs_options::no_pattern|subs_options::no_index_renaming);
        }
        return sum / num;
 }
@@ -383,20 +556,14 @@ ex symmetrize_cyclic(const ex & e, exvector::const_iterator first, exvector::con
 /** Symmetrize expression over a list of objects (symbols, indices). */
 ex ex::symmetrize(const lst & l) const
 {
-       exvector v;
-       v.reserve(l.nops());
-       for (unsigned i=0; i<l.nops(); i++)
-               v.push_back(l.op(i));
+       exvector v(l.begin(), l.end());
        return symm(*this, v.begin(), v.end(), false);
 }
 
 /** Antisymmetrize expression over a list of objects (symbols, indices). */
 ex ex::antisymmetrize(const lst & l) const
 {
-       exvector v;
-       v.reserve(l.nops());
-       for (unsigned i=0; i<l.nops(); i++)
-               v.push_back(l.op(i));
+       exvector v(l.begin(), l.end());
        return symm(*this, v.begin(), v.end(), true);
 }
 
@@ -404,10 +571,7 @@ ex ex::antisymmetrize(const lst & l) const
  *  (symbols, indices). */
 ex ex::symmetrize_cyclic(const lst & l) const
 {
-       exvector v;
-       v.reserve(l.nops());
-       for (unsigned i=0; i<l.nops(); i++)
-               v.push_back(l.op(i));
+       exvector v(l.begin(), l.end());
        return GiNaC::symmetrize_cyclic(*this, v.begin(), v.end());
 }