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)
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 file is hand-kept with a schema to aid automatic binding generation and other tooling