A Higher-order Module Discipline with Separate Compilation, Dynamic Linking, and Pickling

We present a higher-order module discipline with separate compilation and concurrent dynamic linking. Based on first-order modules one can program security policies for systems that link modules from untrusted locations (e.g., Java). We introduce a pickling operation that writes persistent clones of volatile, possibly higher-order data structures on the file system. Our pickling operation respects lexical binding. Our module discipline is based on functors, which are annotated functions that are applied to modules and return modules. Pickled computed functors can be used interchangeably with compiled functors. In contrast to compiled functors, pickled computed functors can carry computed data structures with them, which has significant practical applications.