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(g-wrap.info)Adding a new type

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Adding a new type
=================

 - Function: add-type scheme-sym c-name fn-to-scm fn-from-scm fn-isa
     Defines a new Scheme type corresponding to C-type C-NAME, and
     associates it with symbol SCHEME-SYM.   Objects of this type are
     printed with C-function C-PRINT-NAME,  deallocated by C-function
     C-DIE-NAME, and checked for equality with  C-function C-EQ-NAME.

     Scheme-sym should be a symbol, and the other arguments should be
     strings.

 - Function: new-type scheme-sym c-name c-print-fn c-die-fn c-eq-fn
          [options ...]
     As does `add-type', this command defines a new Scheme type
     corresponding to C-type C-NAME, and associates it with symbol
     SCHEME-SYM. SCHEME-SYM can then be used as a type parameter  in
     functions `new-constant' and `new-function'.   In addition, a
     function called C-NAME? is generated to test if  any Scheme object
     is an object of this type.

     `new-type' also documents the type in documentation file.  If
     `(doc DESCRIPTION)' is passed as an option,  DESCRIPTION is used
     to document the type.

     Example:
          (new-type 'MAT  "MAT"  "MAT_print"  "m_free"  "MAT_eq")

        *  A Scheme function `MAT?' is defined to test to see if a
          Scheme  value has this type.

        *  C functions must be provided for performing the tasks of
          performing the  basic jobs which the interpreter needs to
          perform for Scheme objects.   In this example,  `MAT_print'
          writes the representation of the matrix to a port,  `MAT_die'
          deallocates the matrix,  `MAT_eq' checks for equality of
          matrices.   See Note: C code needed for adding new types to
          see how to  write these functions.

        *  This allows `MAT's to be used as function parameters and  as
          return values.

        *  For Guile, this creates a new smob type for holding (`MAT*')
          pointers, and for RScheme it creates a new object-class for
          the type.