eval(). The latest, Actionscript 3.0, does not.
Peter Fisk's Smalltalk and Lisp in Flex is a treasure in its own right. But in light of Adobe taking away
eval(), the desire to have some kind of language interpreter at runtime goes exponential.
But Adobe appears intent to make Actionscript as much a static language as possible, and one that has a fairly strict boundary between development-time and run-time. Sadly.
I don't think this can or should be chalked up to security. There are better solutions to security than to throw out run-time evaluation altogether.
Oh well. As Peter has demonstrated, reflection still works fine, so you just build your own
eval() for whatever language you desire.