]> www.ginac.de Git - ginac.git/blobdiff - ginac/utils.h
* Supplement some (now deprecated) macros by inlined template functions:
[ginac.git] / ginac / utils.h
index 6e1d3ae8a55caa31987db800a2da7180fe712bba..3e8e17cae884c498773c5fb2860a8d3d1ee76795 100644 (file)
 #ifndef __GINAC_UTILS_H__
 #define __GINAC_UTILS_H__
 
-#include <strstream>
+#include "config.h"
+
 #include <string>
 #include <stdexcept>
-#include "config.h"
+#if defined(HAVE_SSTREAM)
+#include <sstream>
+#elif defined(HAVE_STRSTREAM)
+#include <strstream>
+#else
+#error Need either sstream or strstream
+#endif
 #include "assertion.h"
 
 namespace GiNaC {
@@ -36,9 +43,15 @@ namespace GiNaC {
 template<class T>
 std::string ToString(const T & t)
 {
+#if defined(HAVE_SSTREAM)
+       std::ostringstream buf;
+       buf << t << std::ends;
+       return buf.str();
+#else
        char buf[256];
        std::ostrstream(buf,sizeof(buf)) << t << std::ends;
        return buf;
+#endif
 }
 
 /** Exception class thrown by classes which provide their own series expansion
@@ -113,27 +126,195 @@ inline unsigned golden_ratio_hash(unsigned n)
 #endif
 }
 
-// Compute the sign of a permutation of a vector of things.
-template <typename T>
-int permutation_sign(std::vector<T> s)
+/* Compute the sign of a permutation of a container, with and without an
+   explicitly supplied comparison function. If the sign returned is 1 or -1,
+   the container is sorted after the operation. */
+template <class It>
+int permutation_sign(It first, It last)
 {
-       if (s.size() < 2)
+       if (first == last)
+               return 0;
+       --last;
+       if (first == last)
+               return 0;
+       It flag = first;
+       int sign = 1;
+
+       do {
+               It i = last, other = last;
+               --other;
+               bool swapped = false;
+               while (i != first) {
+                       if (*i < *other) {
+                               std::iter_swap(other, i);
+                               flag = other;
+                               swapped = true;
+                               sign = -sign;
+                       } else if (!(*other < *i))
+                               return 0;
+                       --i; --other;
+               }
+               if (!swapped)
+                       return sign;
+               ++flag;
+               if (flag == last)
+                       return sign;
+               first = flag;
+               i = first; other = first;
+               ++other;
+               swapped = false;
+               while (i != last) {
+                       if (*other < *i) {
+                               std::iter_swap(i, other);
+                               flag = other;
+                               swapped = true;
+                               sign = -sign;
+                       } else if (!(*i < *other))
+                               return 0;
+                       ++i; ++other;
+               }
+               if (!swapped)
+                       return sign;
+               last = flag;
+               --last;
+       } while (first != last);
+
+       return sign;
+}
+
+template <class It, class Cmp, class Swap>
+int permutation_sign(It first, It last, Cmp comp, Swap swapit)
+{
+       if (first == last)
+               return 0;
+       --last;
+       if (first == last)
                return 0;
-       int sigma = 1;
-       for (typename std::vector<T>::iterator i=s.begin(); i!=s.end()-1; ++i) {
-               for (typename std::vector<T>::iterator j=i+1; j!=s.end(); ++j) {
-                       if (*i == *j)
+       It flag = first;
+       int sign = 1;
+
+       do {
+               It i = last, other = last;
+               --other;
+               bool swapped = false;
+               while (i != first) {
+                       if (comp(*i, *other)) {
+                               swapit(*other, *i);
+                               flag = other;
+                               swapped = true;
+                               sign = -sign;
+                       } else if (!comp(*other, *i))
+                               return 0;
+                       --i; --other;
+               }
+               if (!swapped)
+                       return sign;
+               ++flag;
+               if (flag == last)
+                       return sign;
+               first = flag;
+               i = first; other = first;
+               ++other;
+               swapped = false;
+               while (i != last) {
+                       if (comp(*other, *i)) {
+                               swapit(*i, *other);
+                               flag = other;
+                               swapped = true;
+                               sign = -sign;
+                       } else if (!comp(*i, *other))
                                return 0;
-                       if (*i > *j) {
-                               iter_swap(i,j);
-                               sigma = -sigma;
+                       ++i; ++other;
+               }
+               if (!swapped)
+                       return sign;
+               last = flag;
+               --last;
+       } while (first != last);
+
+       return sign;
+}
+
+/* Implementation of shaker sort, only compares adjacent elements. */
+template <class It, class Cmp, class Swap>
+void shaker_sort(It first, It last, Cmp comp, Swap swapit)
+{
+       if (first == last)
+               return;
+       --last;
+       if (first == last)
+               return;
+       It flag = first;
+
+       do {
+               It i = last, other = last;
+               --other;
+               bool swapped = false;
+               while (i != first) {
+                       if (comp(*i, *other)) {
+                               swapit(*other, *i);
+                               flag = other;
+                               swapped = true;
+                       }
+                       --i; --other;
+               }
+               if (!swapped)
+                       return;
+               ++flag;
+               if (flag == last)
+                       return;
+               first = flag;
+               i = first; other = first;
+               ++other;
+               swapped = false;
+               while (i != last) {
+                       if (comp(*other, *i)) {
+                               swapit(*i, *other);
+                               flag = other;
+                               swapped = true;
                        }
+                       ++i; ++other;
                }
+               if (!swapped)
+                       return;
+               last = flag;
+               --last;
+       } while (first != last);
+}
+
+/* In-place cyclic permutation of a container (no copying, only swapping). */
+template <class It, class Swap>
+void cyclic_permutation(It first, It last, It new_first, Swap swapit)
+{
+       unsigned num = last - first;
+again:
+       if (first == new_first || num < 2)
+               return;
+
+       unsigned num1 = new_first - first, num2 = last - new_first;
+       if (num1 >= num2) {
+               It a = first, b = new_first;
+               while (b != last) {
+                       swapit(*a, *b);
+                       ++a; ++b;
+               }
+               if (num1 > num2) {
+                       first += num2;
+                       num = num1;
+                       goto again;
+               }
+       } else {
+               It a = new_first, b = last;
+               do {
+                       --a; --b;
+                       swapit(*a, *b);
+               } while (a != first);
+               last -= num1;
+               num = num2;
+               goto again;
        }
-       return sigma;
 }
 
-void append_exvector_to_exvector(exvector & dest, const exvector & source);
 
 // Collection of `construct on first use' wrappers for safely avoiding
 // internal object replication without running into the `static
@@ -292,10 +473,25 @@ int classname::compare_same_type(const basic & other) const \
 }
 
 #define DEFAULT_PRINT(classname, text) \
-void classname::print(std::ostream & os, unsigned upper_precedence) const \
+void classname::print(const print_context & c, unsigned level) const \
+{ \
+       debugmsg(#classname " print", LOGLEVEL_PRINT); \
+       if (is_a<print_tree>(c)) \
+               inherited::print(c, level); \
+       else \
+               c.s << text; \
+}
+
+#define DEFAULT_PRINT_LATEX(classname, text, latex) \
+void classname::print(const print_context & c, unsigned level) const \
 { \
        debugmsg(#classname " print", LOGLEVEL_PRINT); \
-       os << text; \
+       if (is_a<print_tree>(c)) \
+               inherited::print(c, level); \
+       else if (is_a<print_latex>(c)) \
+               c.s << latex; \
+       else \
+               c.s << text; \
 }
 
 } // namespace GiNaC