# interoperability
api needs to facilitate easy interoperability with other languages and tools,
for that certain considerations are taken:

* number of public api calls is kept at the minimum
* procedure signatures can only use basic types, no aggregates, with exception of Vec/Matrix types and alike,
  with no expectation on new additions (see [/include/twn_types.h](/include/twn_types.h))
* optionals can be expressed via pointer passage of value primitives, with NULL expressive default, but they should be immutable
* opaque types are passed around as pointers
* when mutation on input is done, - it shouldn't be achieved from a mutable pointer, but return value
* module prefix is used for namespacing, actual symbols come after the prefix (`module_symbol`)
* symbols should not contain letters at the start nor after the namespace prefix
* [/include/twn_api.json](/include/twn_api.json) file is hand-kept with a schema to aid automatic binding generation and other tooling