synced to 1.0 (tens4delta and mink4metric replaced by the new index dimension

[ginac.git] / ginac / idx.cpp

diff --git a/ginac/idx.cpp b/ginac/idx.cpp
index bf103f0ff9593e62d795654e84b7b1d5742a5dd5..59c3ebc3eccd67938d8b6d8714201c06fed3a40a 100644 (file)
--- a/ginac/idx.cpp
+++ b/ginac/idx.cpp
@@ -26,6 +26,8 @@
 #include "idx.h"
 #include "symbol.h"
 #include "lst.h"
+#include "relational.h"
+#include "operators.h"
 #include "print.h"
 #include "archive.h"
 #include "utils.h"
@@ -301,6 +303,7 @@ int varidx::compare_same_type(const basic & other) const
        // Check variance last so dummy indices will end up next to each other
        if (covariant != o.covariant)
                return covariant ? -1 : 1;
+
        return 0;
 }
 
@@ -311,6 +314,7 @@ bool varidx::match_same_type(const basic & other) const
 
        if (covariant != o.covariant)
                return false;
+
        return inherited::match_same_type(other);
 }
 
@@ -402,8 +406,12 @@ bool idx::is_dummy_pair_same_type(const basic & other) const
        if (!value.is_equal(o.value))
                return false;
 
-       // Also the dimension
-       return dim.is_equal(o.dim);
+       // Dimensions need not be equal but must be comparable (so we can
+       // determine the minimum dimension of contractions)
+       if (dim.is_equal(o.dim))
+               return true;
+
+       return (dim < o.dim || dim > o.dim || (is_a<numeric>(dim) && is_a<symbol>(o.dim)) || (is_a<symbol>(dim) && is_a<numeric>(o.dim)));
 }
 
 bool varidx::is_dummy_pair_same_type(const basic & other) const
@@ -433,6 +441,24 @@ bool spinidx::is_dummy_pair_same_type(const basic & other) const
 // non-virtual functions
 //////////
 
+ex idx::replace_dim(const ex & new_dim) const
+{
+       idx *i_copy = static_cast<idx *>(duplicate());
+       i_copy->dim = new_dim;
+       i_copy->clearflag(status_flags::hash_calculated);
+       return i_copy->setflag(status_flags::dynallocated);
+}
+
+ex idx::minimal_dim(const idx & other) const
+{
+       if (dim.is_equal(other.dim) || dim < other.dim || (is_a<numeric>(dim) && is_a<symbol>(other.dim)))
+               return dim;
+       else if (dim > other.dim || (is_a<symbol>(dim) && is_a<numeric>(other.dim)))
+               return other.dim;
+       else
+               throw (std::runtime_error("idx::minimal_dim: index dimensions cannot be ordered"));
+}
+
 ex varidx::toggle_variance(void) const
 {
        varidx *i_copy = static_cast<varidx *>(duplicate());