Embodiments described herein are directed to allowing a user to extend the functionality of a software code interpretation system. In one embodiment, a computer system receives user-defined conversion rules from a user for converting dynamic language code to continuation-based abstract memory representations. The computer system identifies portions of software code that are to be converted from dynamic language abstract memory representations into continuation-based abstract memory representations, where the identified code portions include undefined, extensible input primitives. The computer system also generates a dynamic, extensible set of output primitives interpretable by a continuation-based code interpretation system using the received conversion rules and converts the identified code portions including the undefined, extensible input primitives from dynamic language abstract memory representations into continuation-based abstract memory representations using the generated set of output primitives.