*   Copyright (c) 2001, 2002 Michael J. Roberts.  All Rights Reserved.

 *   

 *   Please see the accompanying license file, LICENSE.TXT, for information

 *   on using and copying this software.  

 */

/*

Name

  vmcset.h - T3 CharacterSet metaclass

Function

Notes

Modified

  06/06/01 MJRoberts  - Creation

*/

#ifndef VMCSET_H

#define VMCSET_H

#include <stdlib.h>

#include "vmtype.h"

#include "vmobj.h"

#include "vmglob.h"

/* ------------------------------------------------------------------------ */

/*

 *   A CharacterSet is a simple encapsulation of a pair of CCharmap

 *   character mappings: one mapping from Unicode to a local character set,

 *   and one mapping in the reverse direction.  A CharacterSet is

 *   parameterized on creation by the name of the mapping, using the

 *   standard CCharmap names.

 *   

 *   In an image file, a CharacterSet contains simply the standard CCharmap

 *   name of the mapping:

 *   

 *   UINT2 length-in-bytes

 *.  BYTE name[]

 *   

 *   On creation, we will create the pair of CCharmap objects, if the name

 *   of the mapping is valid.  It is legal to create a CharacterSet with an

 *   unknown mapping, but such a character set object cannot be used to

 *   perform mappings.

 *   

 *   CharacterSet objects are constants at run-time.  

 */

class CVmObjCharSet: public CVmObject

{

    friend class CVmMetaclassCharSet;

public:

    /* metaclass registration object */

    static class CVmMetaclass *metaclass_reg_;

    class CVmMetaclass *get_metaclass_reg() const { return metaclass_reg_; }

    /* am I of the given metaclass? */

    virtual int is_of_metaclass(class CVmMetaclass *meta) const

    {

        /* try my own metaclass and my base class */

        return (meta == metaclass_reg_

                || CVmObject::is_of_metaclass(meta));

    }

    /* create dynamically using stack arguments */

    static vm_obj_id_t create_from_stack(VMG_ const uchar **pc_ptr,

                                         uint argc);

    /* 

     *   call a static property - we don't have any of our own, so simply

     *   "inherit" the base class handling 

     */

    static int call_stat_prop(VMG_ vm_val_t *result,

                              const uchar **pc_ptr, uint *argc,

                              vm_prop_id_t prop)

    {

        /* explicitly inherit our superclass handling */

        return CVmObject::call_stat_prop(vmg_ result, pc_ptr, argc, prop);

    }

    /* reserve constant data */

    virtual void reserve_const_data(VMG_ class CVmConstMapper *,

                                    vm_obj_id_t /*self*/)

    {

        /* we can't be converted to constant data */

    }

    /* convert to constant data */

    virtual void convert_to_const_data(VMG_ class CVmConstMapper *,

                                       vm_obj_id_t /*self*/)

    {

        /* 

         *   we don't reference any data and can't be converted to constant

         *   data ourselves, so there's nothing to do here 

         */

    }

    /* create with no initial contents */

    static vm_obj_id_t create(VMG_ int in_root_set);

    /* create with the given character set name */

    static vm_obj_id_t create(VMG_ int in_root_set, const char *charset_name,

                              size_t charset_name_len);

    /* determine if an object is a CharacterSet */

    static int is_charset(VMG_ vm_obj_id_t obj)

        { return vm_objp(vmg_ obj)->is_of_metaclass(metaclass_reg_); }

    /* notify of deletion */

    void notify_delete(VMG_ int in_root_set);

    /* set a property */

    void set_prop(VMG_ class CVmUndo *undo,

                  vm_obj_id_t self, vm_prop_id_t prop, const vm_val_t *val);

    /* get a property */

    int get_prop(VMG_ vm_prop_id_t prop, vm_val_t *val,

                 vm_obj_id_t self, vm_obj_id_t *source_obj, uint *argc);

    /* undo operations */

    void notify_new_savept() { }

    void apply_undo(VMG_ struct CVmUndoRecord *) { }

    /* we reference nothing */

    void mark_undo_ref(VMG_ struct CVmUndoRecord *) { }

    void remove_stale_undo_weak_ref(VMG_ struct CVmUndoRecord *) { }

    void mark_refs(VMG_ uint /*state*/) { }

    void remove_stale_weak_refs(VMG0_) { }

    /* load from an image file */

    void load_from_image(VMG_ vm_obj_id_t self, const char *ptr, size_t siz);

    /* rebuild for image file */

    virtual ulong rebuild_image(VMG_ char *buf, ulong buflen);

    /* save to a file */

    void save_to_file(VMG_ class CVmFile *fp);

    /* restore from a file */

    void restore_from_file(VMG_ vm_obj_id_t self,

                           class CVmFile *fp, class CVmObjFixup *fixups);

    /* 

     *   Check a value for equality.  We will match another byte array with

     *   the same number of elements and the same value for each element.  

     */

    int equals(VMG_ vm_obj_id_t self, const vm_val_t *val, int depth) const;

    /* calculate a hash value for the array */

    uint calc_hash(VMG_ vm_obj_id_t self, int depth) const;

    /* our data are constant - we never change */

    int is_changed_since_load() const { return FALSE; }

    /*

     *   Get the to-local and to-unicode mappers.  If the mapper isn't

     *   available, we'll throw an UnknownCharacterSetException. 

     */

    class CCharmapToLocal *get_to_local(VMG0_) const;

    class CCharmapToUni *get_to_uni(VMG0_) const;

protected:

    /* create with no initial contents */

    CVmObjCharSet() { ext_ = 0; }

    /* create from the given character set name */

    CVmObjCharSet(VMG_ const char *charset_name, size_t charset_name_len);

    /* allocate and initialize */

    void alloc_ext(VMG_ const char *charset_name, size_t charset_name_len);

    /* get a pointer to my extension */

    const struct vmobj_charset_ext_t *get_ext_ptr() const

        { return (vmobj_charset_ext_t *)ext_; }

    /* does the given unicode character have a round-trip mapping? */

    static int is_rt_mappable(wchar_t c, class CCharmapToLocal *to_local,

                              class CCharmapToUni *to_uni);

    /* property evaluator - undefined function */

    int getp_undef(VMG_ vm_obj_id_t, vm_val_t *, uint *) { return FALSE; }

    /* property evaluator - get the character set name */

    int getp_get_name(VMG_ vm_obj_id_t self, vm_val_t *val, uint *argc);

    /* determine if the mapping is known */

    int getp_is_known(VMG_ vm_obj_id_t self, vm_val_t *val, uint *argc);

    /* 

     *   property evaluator - determine if the a character code (given as an

     *   integer) or the characters in a string can be mapped from Unicode

     *   to this local character set 

     */

    int getp_is_mappable(VMG_ vm_obj_id_t self, vm_val_t *val, uint *argc);

    /* 

     *   property evaluator - determine if the character code (given as an

     *   integer) or the characters in a string have a round-trip mapping

     *   from Unicode to local and back 

     */

    int getp_is_rt_mappable(VMG_ vm_obj_id_t self, vm_val_t *val, uint *argc);

    /* property evaluation function table */

    static int (CVmObjCharSet::*func_table_[])(

        VMG_ vm_obj_id_t self, vm_val_t *retval, uint *argc);

};

/*

 *   Our extension structure 

 */

struct vmobj_charset_ext_t

{

    /* unicode-to-local mapping object */

    class CCharmapToLocal *to_local;

    /* local-to-unicode mapping object */

    class CCharmapToUni *to_uni;

    /* length of character set name */

    size_t charset_name_len;

    /* name of the character set */

    char charset_name[1];

};

/* ------------------------------------------------------------------------ */

/*

 *   Registration table object 

 */

class CVmMetaclassCharSet: public CVmMetaclass

{

public:

    /* get the global name */

    const char *get_meta_name() const { return "character-set/030001"; }

    /* create from image file */

    void create_for_image_load(VMG_ vm_obj_id_t id)

    {

        new (vmg_ id) CVmObjCharSet();

        G_obj_table->set_obj_gc_characteristics(id, FALSE, FALSE);

    }

    /* create from restoring from saved state */

    void create_for_restore(VMG_ vm_obj_id_t id)

    {

        new (vmg_ id) CVmObjCharSet();

        G_obj_table->set_obj_gc_characteristics(id, FALSE, FALSE);

    }

    /* create dynamically using stack arguments */

    vm_obj_id_t create_from_stack(VMG_ const uchar **pc_ptr, uint argc)

        { return CVmObjCharSet::create_from_stack(vmg_ pc_ptr, argc); }

    /* call a static property */

    int call_stat_prop(VMG_ vm_val_t *result,

                       const uchar **pc_ptr, uint *argc,

                       vm_prop_id_t prop)

    {

        return CVmObjCharSet::call_stat_prop(vmg_ result, pc_ptr, argc, prop);

    }

};

#endif /* VMCSET_H */

/*

 *   Register the class 

 */