subs() and normal() use maps instead of lists, resulting in a huge performance

[ginac.git] / ginac / tensor.cpp

diff --git a/ginac/tensor.cpp b/ginac/tensor.cpp
index d78eff6604078ebf1b913e63d4682bba54c7c20f..f8e5635a64af3caeb67c6557ca8e21cff6b50815 100644 (file)
--- a/ginac/tensor.cpp
+++ b/ginac/tensor.cpp
@@ -171,7 +171,10 @@ ex tensdelta::eval_indexed(const basic & i) const
        // dimension
        if (!i1.get_dim().is_equal(i2.get_dim())) {
                ex min_dim = i1.minimal_dim(i2);
-               return i.subs(lst(i1 == i1.replace_dim(min_dim), i2 == i2.replace_dim(min_dim)));
+               exmap m;
+               m[i1] = i1.replace_dim(min_dim);
+               m[i2] = i2.replace_dim(min_dim);
+               return i.subs(m);
        }
 
        // Trace of delta tensor is the (effective) dimension of the space
@@ -212,7 +215,10 @@ ex tensmetric::eval_indexed(const basic & i) const
        // dimension
        if (!i1.get_dim().is_equal(i2.get_dim())) {
                ex min_dim = i1.minimal_dim(i2);
-               return i.subs(lst(i1 == i1.replace_dim(min_dim), i2 == i2.replace_dim(min_dim)));
+               exmap m;
+               m[i1] = i1.replace_dim(min_dim);
+               m[i2] = i2.replace_dim(min_dim);
+               return i.subs(m);
        }
 
        // A metric tensor with one covariant and one contravariant index gets