2.29.2 Issues

There is no single best way to make hash tables. The tables presented in this SRFI aim at being both conceptually simple and usable for a wide variety of applications. Even though a portable implementation is provided, Scheme implementations can speed things up considerably by e.g. providing an internal hash function for symbols. Moreover, almost every Scheme implementation already has some kind of low–level hash table functionality, because that’s the natural way to implement the global environment, and specifically, to provide support for string->symbol. There might be some benefit in integration between implementation–specific environment data types and the hash table API presented here; however, these issues are left open.

This SRFI does not conform to the interface of maps presented in SRFI-44. Following SRFI-44 would seriously cripple the interface of hash tables. The naming of the operations for maps in SRFI-44 goes against common use and is unnatural. However, this SRFI has been written so that it does not prevent a SRFI-44 API to hash tables. An implementation supporting both SRFI-44 and this SRFI is encouraged to provide a SRFI-44 interface to hash tables in addition to the one presented here.