It's occurred to me - after a mere four years - that I've spent much more time writing code for extracting propensity tables and loop modelling than I have actually running it. Since the output of the programs is what I'm really interested in, it's obvious that I should be trying to minimise the development time.
Using Perl or Python would certainly reduce development times but at a cost in terms of performance. However, if it saves a lot of development time, this might actually offset the increased running time to the extent of reducing the overall time to get results. And there's always the option of using SWIG to drop down into C for the heavy-lifting bits.
This of course still means having to write the heavy-lifting bits in C or C++.
I really like functional languages: they let you write high-level code and write it quickly, and then compile it to get optimal performance. The problem with functional languages is that the paradigm is very different to imperative programming so there might be problems persuading coworkers that they're a good idea. There's also the perennial problem of people not wanting to use lesser-used languages that add little or no value to a CV.
I suspect I'm going to end up with a compromise solution such as gcj-compiled Java, a language whose only selling point for me is that it eliminates a lot of the complexity of C++ (while also eliminating some of the good features of C++).