Does the JVM prevent tail call optimizations?
I saw this quote on the question: What is a good functional language on which to build a web service?
Scala in particular doesn't support tail-call elimination except in self-recursive functions, which limits the kinds of composition you can do (this is a fundamental limitation of the JVM).
Is this true? If so, what is it about the JVM that creates this fundamental limitation?
Answer
This post: Recursion or Iteration? might help.
In short, tail call optimization is hard to do in the JVM because of the security model and the need to always have a stack trace available. These requirements could in theory be supported, but it would probably require a new bytecode (see John Rose's informal proposal).
There is also more discussion in Sun bug #4726340, where the evaluation (from 2002) ends:
I believe this could be done nonetheless, but it is not a small task.
Currently, there is some work going on in the Da Vinci Machine project. The tail call subproject's status is listed as "proto 80%"; it is unlikely to make it into Java 7, but I think it has a very good chance at Java 8.