The Delphi compiler used the constant expression folder to evaluate debugger expressions; it had hooks for converting symbol references into values, and for per

The Delphi compiler used the constant expression folder to evaluate debugger expressions; it had hooks for converting symbol references into values, and for performing method calls, but a good chunk of the evaluation was interpreted that way. I thought it was a nifty reuse. (Obviously, the expression is parsed, typed and bound using the compiler front end using the same symbols as the compiled code, so that bit is easy.)