Final Shift for Call/cc: Direct Implementation of Shift and Reset

摘要

We present a direct implementation of the shift and reset control operators in the Scheme 48 system. The new implementation improves upon the traditional technique of simulating shift and reset via call/cc. Typical applications of these operators exhibit space savings and a significant overall performance gain. Our technique is based upon the popular incremental stack/heap strategy for representing continuations. We present implementation details as well as some benchmark measurements for typical applications.