Warning: This is the manual of the legacy Guile 2.2 series. You may want to read the manual of the current stable series instead.

5.5 Defining New Foreign Object Types

The foreign object type facility is Guile’s mechanism for importing object and types from C or other languages into Guile’s system. If you have a C struct foo type, for example, you can define a corresponding Guile foreign object type that allows Scheme code to handle struct foo * objects.

To define a new foreign object type, the programmer provides Guile with some essential information about the type — what its name is, how many fields it has, and its finalizer (if any) — and Guile allocates a fresh type for it. Foreign objects can be accessed from Scheme or from C.