5.5.2 Guile Initialization

The following configuration statement causes loading and initialization of the guile module:

load-module mod-name {
   command "guile init-script=script"
           " init-fun=function";
}

Upon module initialization stage, the module attempts to load the file named script. The file is loaded using primitive-load call (see Loading in The Guile Reference Manual), i.e. the load paths are not searched, so script must be an absolute path name. The init-fun parameter supplies the name of the initialization function. This Scheme function constructs virtual function tables for the module itself and for each database that uses this module. It must be declared as follows:

(define (function arg)
  ...)

This function is called several times. First of all, it is called after the script is loaded. This time it is given #f as its argument, and its return value is saved as a global function table. Then, it is called for each database statement that has mod-name (used in load-module above) in its handler keyword, e.g.:

database {
   name db-name;
   handler "mod-name …";
}

This time, it is given db-name as its argument and the value it returns is stored as the virtual function table for this particular database.

The following example function returns a complete virtual function table:

(define-public (my-dico-init arg)
  (list (cons "open" open-module)
        (cons "close" close-module)
        (cons "descr" descr)
        (cons "info" info)
        (cons "lang" lang)
        (cons "define" define-word)
        (cons "match" match-word)
        (cons "output" output)
        (cons "result-count" result-count)))