C APIs in extension and extensible languages
Scripting languages are used in conjuction with C code in two ways: as extension languages, where the interpreter is embedded as a library into an application; or as extensible languages, where the interpreter loads C code as add-on modules. These two scenarios share many similarities, as in both of them two-way communication of code and data needs to take place. However, the differences between them impose design tradeoffs that affect the C API that bridges the two languages, often making a scripting language more suitable for extending than embedding, or vice-versa. This paper discusses how these tradeoffs are handled in the APIs of popular scripting languages, and the impact on their use as embedded or extensible languages.
programming languages application programming interfaces