String operations in C#

[admin]

In order to match my derivatives calculators with Maple I began to rebuild string operations in my program. First I tried to compare relative speed of operations with String and StringBuilder objects. StringBuilder is kind of emulating C++ style because memory is allocated similar to alloc command in C and symbols are handled as char array. The beginning was inspiring: concatenation was thousands time faster for StringBuilder. The second test was disappointing: Replace operation was only twice faster for StringBuilder. Then Remove was much faster for StringBuilder. Insertion was twice faster in StringBuilder.
On other hand StringBuilder gives effect only for thousands of operations in loop. I use a lot of recursive procedures that use just a few string concatenations. To unify all procedures into one with loops? But mathematics by nature is recursive. After all the whole point of using C# is to concentrate on mathematics and leave memory management to Microsoft.