For string heavy workload, C is ideal, provided that you don't use C string functions. You can always allocate a very large buffer and do your string operation

For string heavy workload, C is ideal, provided that you don't use C string functions. You can always allocate a very large buffer and do your string operations there, using memncpy and the assorted functions which can be inlined in many architectures and be really fast. Then you can dispose of the buffer really quickly with one call or reuse it for later operations by simply setting a few pointers to initial status...