key.pmc

/*
Copyright (C) 2001-2009, Parrot Foundation.
$Id$

=head1 NAME

src/pmc/key.pmc - Key PMC

=head1 DESCRIPTION

These are the vtable functions for the Key PMC class.

=head2 Methods

=over 4

=cut

*/

/* HEADERIZER HFILE: none */
/* HEADERIZER BEGIN: static */
/* HEADERIZER END: static */

pmclass Key auto_attrs {
    ATTR PMC      *next_key; /* Sometimes it's the next key, sometimes it's
                                not.  The Key code is like that. */
    ATTR INTVAL    int_key;  /* int value of this key, or something magical if
                                it's a hash iterator key */
    ATTR FLOATVAL  num_key;  /* num value of this key, if any */
    ATTR STRING   *str_key;  /* STRING value of this key, if any */
                             /* Theoretically there'd also be a pmc_key here,
                              * but that code looks broken and unneeded. */


/*

=item C<void init()>

Initializes the key.

=cut

*/

    VTABLE void init() {
        PObj_custom_mark_SET(SELF);
    }

/*

=item C<PMC *clone()>

Creates and returns a clone of the key.

=cut

*/

    VTABLE PMC *clone() {
        PMC * const dest = Parrot_pmc_new(INTERP, SELF->vtable->base_type);
        PMC *dkey        = dest;
        PMC *key         = SELF;

        for (; key ;) {
            switch (PObj_get_FLAGS(key) & KEY_type_FLAGS) {
              case KEY_integer_FLAG:
              case KEY_integer_FLAG | KEY_register_FLAG:
                key_set_integer(INTERP, dkey, key_integer(INTERP, key));
                break;
              case KEY_number_FLAG:
              case KEY_number_FLAG | KEY_register_FLAG:
                key_set_number(INTERP, dkey, key_number(INTERP, key));
                break;
              case KEY_string_FLAG:
              case KEY_string_FLAG | KEY_register_FLAG:
                key_set_string(INTERP, dkey, VTABLE_get_string(INTERP, key));
                break;
              case KEY_pmc_FLAG:
              case KEY_pmc_FLAG | KEY_register_FLAG:
                Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_UNIMPLEMENTED,
                        "this is broken - see TT #1683");
              default:
                break;
            }

            key = key_next(INTERP, key);

            if (key) {
                PMC * const p = key_new(INTERP);
                key_append(INTERP, dkey, p);
                dkey = p;
            }
        }

        return dest;
    }

/*

=item C<void mark()>

Marks the key as live.

=cut

*/

    VTABLE void mark() {
        key_mark(INTERP, SELF);
    }

/*

=item C<INTVAL get_integer()>

Returns the integer value of the key.

=cut

*/

    VTABLE INTVAL get_integer() {
        return key_integer(INTERP, SELF);
    }

/*

=item C<FLOATVAL get_number()>

Returns the floating-point number value of the key.

=cut

*/

    VTABLE FLOATVAL get_number() {
        return key_number(INTERP, SELF);
    }

/*

=item C<STRING *get_string()>

Returns the Parrot string value of the key.

=cut

*/

    VTABLE STRING *get_string() {
        /* key_string() is only useful if this PMC has a key type */
        if (PObj_get_FLAGS(SELF) & KEY_type_FLAGS)
            return key_string(INTERP, SELF);

        return CONST_STRING(INTERP, "");
    }

/*

=item C<PMC *get_pmc()>

Returns the PMC value of the key.

=cut

*/

    VTABLE PMC *get_pmc() {
        return key_pmc(INTERP, SELF);
    }

/*

=item C<void set_integer_native(INTVAL value)>

=cut

*/

    VTABLE void set_integer_native(INTVAL value) {
        key_set_integer(INTERP, SELF, value);
    }

/*

=item C<void set_number_native(FLOATVAL value)>

Sets the value of the key to C<value>.

=cut

*/

    VTABLE void set_number_native(FLOATVAL value) {
        key_set_number(INTERP, SELF, value);
    }

/*

=item C<void set_string_native(STRING *value)>


=cut

*/

    VTABLE void set_string_native(STRING *value) {
        key_set_string(INTERP, SELF, value);
    }

/*

=item C<void set_pmc(PMC *value)>

Sets the value of the key to C<*value>.

=cut

*/

    VTABLE void set_pmc(PMC *value) {
        Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_UNIMPLEMENTED,
                "this is broken - see TT #1683");
    }

/*

=item C<void push_pmc(PMC *value)>

Appends C<*value> to the key.

=cut

*/

    void push_pmc(PMC *value) {
        if (value->vtable->base_type != enum_class_Key)
            Parrot_ex_throw_from_c_args(INTERP, NULL, EXCEPTION_INVALID_OPERATION,
                "Can only push another Key onto a Key PMC.");

        key_append(INTERP, SELF, value);
    }

/*

=item C<PMC *shift_pmc()>

Returns the next key.

Actually doesn't remove the entry but might be useful to traverse a key
chain.

=cut

*/

    VTABLE PMC *shift_pmc() {
        PMC *next_key;

        GET_ATTR_next_key(INTERP, SELF, next_key);
        return next_key;
    }

/*

=back

=head2 Iterator Interface

=over 4

=item C<PMC *get_pmc_keyed(PMC *key)>

Returns the key itself.

=cut

*/

    VTABLE PMC *get_pmc_keyed(PMC *key) {
        return key;
    }

/*

=item C<void visit(PMC *info)>

This is used by freeze/thaw to visit the contents of the Key.

=item C<void freeze(PMC *info)>

Archives the Key.

=item C<void thaw(PMC *info)>

Unarchives the Key.

=item C<void thawfinish(PMC *info)>

Called after the Key has been thawed: convert last PMC_NULL key to NULL.

=cut

*/

    VTABLE void visit(PMC *info) {
        /* Sometimes visit gets an uninitialized Key.  Initialize it. */
        if (!PMC_data(SELF))
            SELF.init();

        VISIT_PMC_ATTR(INTERP, info, SELF, Key, next_key);
    }

    void freeze(PMC *info) {
        /* write flags */
        const INTVAL flags  = (PObj_get_FLAGS(SELF) & KEY_type_FLAGS);

        /* write the contents of a register - else thaw can't restore
         * the register state */
        VTABLE_push_integer(INTERP, info, flags & ~KEY_register_FLAG);

        /* and contents of this key component */
        switch (flags) {
          case KEY_integer_FLAG:
          case KEY_integer_FLAG | KEY_register_FLAG:
            VTABLE_push_integer(INTERP, info, key_integer(INTERP, SELF));
            break;
          case KEY_number_FLAG:
          case KEY_number_FLAG | KEY_register_FLAG:
            VTABLE_push_float(INTERP, info, key_number(INTERP, SELF));
            break;
          case KEY_string_FLAG:
          case KEY_string_FLAG | KEY_register_FLAG:
            VTABLE_push_string(INTERP, info, key_string(INTERP, SELF));
            break;
          default:
            Parrot_ex_throw_from_c_args(INTERP, NULL, EXCEPTION_KEY_NOT_FOUND,
                    "Unsupported key type in Key.freeze");
            break;
        }
    }

    void thaw(PMC *info) {
        const INTVAL flags  = VTABLE_shift_integer(INTERP, info) & KEY_type_FLAGS;

        PObj_get_FLAGS(SELF) |= flags;
        PObj_custom_mark_SET(SELF);

        if (!PMC_data(SELF))
            SELF.init();

        /* get contents */
        switch (flags) {
          case KEY_integer_FLAG:
            SET_ATTR_int_key(INTERP, SELF, VTABLE_shift_integer(INTERP, info));
            break;
          case KEY_number_FLAG:
            VTABLE_set_number_native(INTERP, SELF, VTABLE_shift_float(INTERP, info));
            break;
          case KEY_string_FLAG:
            VTABLE_set_string_native(INTERP, SELF, VTABLE_shift_string(INTERP, info));
            break;
          default:
            Parrot_ex_throw_from_c_args(INTERP, NULL, EXCEPTION_KEY_NOT_FOUND,
                    "Unsupported key type in Key.thaw");
            break;
        }
    }

    VTABLE void thawfinish(PMC *info) {
        PMC *key = SELF;
        UNUSED(info)

        while (1) {
            PMC *next;
            GET_ATTR_next_key(INTERP, key, next);

            if (PMC_IS_NULL(next)) {
                SET_ATTR_next_key(INTERP, key, NULL);
                break;
            }

            key = next;
        }
    }

    VTABLE STRING* get_repr() {
        return key_set_to_string(INTERP, SELF);
    }

/*
=item C<set_register(reg_no, type)>

Set key to hold particular register.

=cut
*/
    METHOD set_register(INTVAL reg_no, INTVAL reg_type) {
        key_set_register(INTERP, SELF, reg_no, reg_type);
    }

}

/*

=back

=cut

*/

/*
 * Local variables:
 *   c-file-style: "parrot"
 * End:
 * vim: expandtab shiftwidth=4:
 */