— Scheme Procedure: struct-vtable? obj
— C Function: scm_struct_vtable_p (obj)

Return #t if obj is a vtable structure.

Note that because vtables are simply structures with a particular layout, struct-vtable? can potentially return true on an application structure which merely happens to look like a vtable.

— Scheme Variable: vtable-index-layout
— C Macro: scm_vtable_index_layout

The field number of the layout specification in a vtable. The layout specification is a symbol like pwpw formed from the fields string passed to make-vtable, or created by make-struct-layout (see Vtable Vtables).

          (define v (make-vtable "pwpw" 0))
          (struct-ref v vtable-index-layout) ⇒ pwpw

This field is read-only, since the layout of structures using a vtable cannot be changed.

— Scheme Variable: vtable-index-vtable
— C Macro: scm_vtable_index_vtable

A self-reference to the vtable, ie. a type s field. This is used by C code within Guile and has no use at the Scheme level.

— Scheme Variable: vtable-index-printer
— C Macro: scm_vtable_index_printer

The field number of the printer function. This field contains #f if the default print function should be used.

          (define (my-print-func struct port)
            ...)
          (define v (make-vtable "pwpw" my-print-func))
          (struct-ref v vtable-index-printer) ⇒ my-print-func

This field is writable, allowing the print function to be changed dynamically.

— Scheme Procedure: struct-vtable-name vtable
— Scheme Procedure: set-struct-vtable-name! vtable name
— C Function: scm_struct_vtable_name (vtable)
— C Function: scm_set_struct_vtable_name_x (vtable, name)

Get or set the name of vtable. name is a symbol and is used in the default print function when printing structures created from vtable.

          (define v (make-vtable "pw"))
          (set-struct-vtable-name! v 'my-name)
          
          (define s (make-struct v 0))
          (display s) -| #<my-name b7ab3ae0:b7ab3730>

— Scheme Procedure: struct-vtable-tag vtable
— C Function: scm_struct_vtable_tag (vtable)

Return the tag of the given vtable.