Guile Reference Manual
18.3 Defining New Types (Smobs)
Smobs are Guile's mechanism for adding new non-immediate types to
the system.(5) To define a new smob type, the programmer provides Guile with
some essential information about the type -- how to print it, how to
garbage collect it, and so on -- and Guile returns a fresh type tag for
use in the first word of new cells. The programmer can then use
scm_c_define_gsubr to make a set of C functions that create and
operate on these objects visible to Scheme code.
(You can find a complete version of the example code used in this
section in the Guile distribution, in `doc/example-smob'. That
directory includes a makefile and a suitable main function, so
you can build a complete interactive Guile shell, extended with the
datatypes described here.)
