pmcproxy.pmc

/*
Copyright (C) 2001-2008, Parrot Foundation.

=head1 NAME

src/pmc/pmcproxy.pmc - proxy class object for a PMC enabling introspection

=head1 DESCRIPTION

This class is used to describe a PMC. It can sit in an inheritance hierarchy
of a PDD15 class as well as allowing introspection of the PMC.

PMCProxy is not derived from any other PMC.

=head2 Structure

This class stores its state in the Parrot_Class structure, using the
following fields.

=over 4

=item C<id>

The type number of the PMC that is being described.

=item C<name>

The name of the PMC -- a STRING.

=item C<namespace>

The namespace the PMC is associated with, if any.

=item C<parents>

An array of immediate parent classes.
An empty ResizablePMCArray PMC is allocated during initialization.

=item C<all_parents>

A cached array of ourself and all parent classes, in MRO order.
A ResizablePMCArray PMC is allocated during initialization,
and is populated with the current class.

=back

NOTE: No doubt we will need other things later; this is a start.

=cut

*/

#include "parrot/oo_private.h"

/*

=head2 Functions

=over 4

=cut

*/

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


pmclass PMCProxy extends Class auto_attrs {

/*

=item C<void init()>

Initializes a PMCProxy PMC.

=cut

*/

    VTABLE void init() {
        Parrot_PMCProxy_attributes * const _pmc = PARROT_PMCPROXY(SELF);
        STRING                     * const name = CONST_STRING(INTERP, "proxy");
        PMC                        * const new_attribute
             = Parrot_pmc_new(INTERP, enum_class_Hash);

        SUPER();

        /* Set up the attribute storage for the proxy instance */
        VTABLE_set_string_keyed_str(INTERP, new_attribute, CONST_STRING(INTERP, "name"), name);
        VTABLE_set_pmc_keyed_str(INTERP, _pmc->attrib_metadata, name, new_attribute);

        CLASS_is_anon_CLEAR(SELF);
    }

    VTABLE void init_int(INTVAL type_num) {
        Parrot_Class_attributes *proxy_info;
        INTVAL mro_length, i;

        /* Ensure that it's a valid type number. */
        if (type_num > INTERP->n_vtable_max || type_num <= 0)
            Parrot_ex_throw_from_c_args(INTERP, NULL,
                    EXCEPTION_INVALID_OPERATION,
                    "Attempt to create PMC Proxy for invalid type number!");

        /* Set up the object. */
        SELF.init();

        /* Set up number, name and namespace. */
        proxy_info             = PARROT_CLASS(SELF);
        proxy_info->id         = type_num;
        proxy_info->name       = INTERP->vtables[type_num]->whoami;
        proxy_info->_namespace = INTERP->vtables[type_num]->_namespace;

        /* Build MRO (skip ourself). */
        mro_length = VTABLE_elements(INTERP, INTERP->vtables[type_num]->mro);
        for (i = 1; i < mro_length; ++i) {
            PMC    *pclass = VTABLE_get_pmc_keyed_int(INTERP, INTERP->vtables[type_num]->mro, i);
            PMC    *cns    = pclass->vtable->_namespace;
            STRING *cname  = pclass->vtable->whoami;
            if (!STRING_equal(INTERP, cname, CONST_STRING(INTERP, "scalar"))) {
                PMC *pproxy = Parrot_oo_get_class(INTERP, cns);
                VTABLE_push_pmc(INTERP, proxy_info->all_parents, pproxy);
            }
        }

        /* PMCs just do single inheritance, so we'll assume that if we have a
         * second entry in our MRO, it goes in the parents list. */
        if (VTABLE_elements(INTERP, proxy_info->all_parents) >= 2)
            VTABLE_push_pmc(INTERP, proxy_info->parents,
                    VTABLE_get_pmc_keyed_int(INTERP, proxy_info->all_parents, 1));

        if (!PMC_IS_NULL(proxy_info->_namespace) &&
            PMC_IS_NULL(VTABLE_get_class(INTERP, proxy_info->_namespace))) {

            /* Link the proxy and the namespace, caching the proxy object for
             * later retrieval on class lookup. */
             Parrot_pcc_invoke_method_from_c_args(INTERP, proxy_info->_namespace, CONST_STRING(INTERP, "set_class"), "P->", SELF);

            /* Extract any methods from the namespace */
            Parrot_oo_extract_methods_from_namespace(INTERP, SELF,
                    proxy_info->_namespace);
        }

        { /* Create inherited attributes */
            /* Each attribute is prefixed with his type
             * and terminated by an space,
             * the list is '\0' terminated
             */
            const char * attr = INTERP->vtables[type_num]->attribute_defs;
            while (* attr) {
                const char * const current = attr + 1;
                size_t l;
                char attrtype = * attr;
                while (* attr != ' ') ++attr;
                l= attr - current;
                if (attrtype != ':') {
                    STRING *sattr = Parrot_str_new(INTERP, current, l);
                    SELF.add_attribute(sattr, NULL);
                }
                ++attr;
            }
        }
    }

    VTABLE void init_pmc(PMC *init_data) {
        const INTVAL type_num = VTABLE_get_integer(INTERP, init_data);
        SELF.init_int(type_num);
    }

/*

=item C<PMC *instantiate(PMC *init)>

Creates an instance of the PMC.

=cut

*/
    VTABLE PMC *instantiate(PMC *init) {
        Parrot_Class_attributes * const _pmc = PARROT_CLASS(SELF);

        if (!PMC_IS_NULL(init))
            return Parrot_pmc_new_init(INTERP, _pmc->id, init);

        return Parrot_pmc_new(INTERP, _pmc->id);
    }

/*

=item C<INTVAL isa_pmc(PMC *classname)>

Returns whether the class is or inherits from C<*classname>.

=cut

*/

    VTABLE INTVAL isa_pmc(PMC *lookup) {
        Parrot_Class_attributes * const _proxy = PARROT_CLASS(SELF);
        INTVAL        i, num_classes;
        STRING       *classname;
        PMC          *classobj;

        if (PMC_IS_NULL(lookup))
            return 0;

        if (SUPER(lookup))
            return 1;

        classobj = Parrot_oo_get_class(INTERP, lookup);

        if (PMC_IS_NULL(classobj))
            return 0;

        classname = VTABLE_get_string(INTERP, classobj);

        /* Check if the passed name is the same as the stored short name. */
        if (STRING_equal(INTERP, classname, _proxy->name))
            return 1;

        /* Check if the class object is the same as self's class object */
        if (VTABLE_is_same(INTERP, SELF, classobj))
            return 1;

        /* Check if the passed name is the same as the fully qualified name. */
        if (STRING_equal(INTERP, classname, VTABLE_get_string(INTERP, SELF)))
            return 1;

        /* Look in the isa hash. */
        if (INTERP->vtables[_proxy->id]) {
            Hash *isa_hash = INTERP->vtables[_proxy->id]->isa_hash;
            PARROT_ASSERT(isa_hash);
            if (parrot_hash_exists(INTERP, isa_hash, classname))
                return 1;
        }

        /* Iterate over all the parents and check if they respond true
         * for 'isa' on the original comparison. */
        num_classes = VTABLE_elements(INTERP, _proxy->parents);

        for (i = 0; i < num_classes; ++i) {
            PMC * const cur_class = VTABLE_get_pmc_keyed_int(INTERP,
                _proxy->parents, i);

            if (VTABLE_isa_pmc(INTERP, cur_class, lookup))
                return 1;
        }

        return 0;
    }

/*

=item C<INTVAL isa(STRING *classname)>

Returns whether the class is or inherits from C<*classname>.

=cut

*/

    VTABLE INTVAL isa(STRING *classname) {
        Parrot_Class_attributes * const _proxy = PARROT_CLASS(SELF);
        const STRING * const pmc_proxy = CONST_STRING(INTERP, "PMCProxy");

        if (STRING_equal(INTERP, classname, pmc_proxy))
            return 1;

        if (SUPER(classname))
            return 1;

        /* Look in the isa hash. */
        if (INTERP->vtables[_proxy->id]) {
            Hash *isa_hash = INTERP->vtables[_proxy->id]->isa_hash;

            if (!isa_hash && STRING_equal(INTERP,
                     INTERP->vtables[_proxy->id]->whoami, classname)) {
                return 1;
            }

            if (isa_hash && parrot_hash_exists(INTERP, isa_hash, classname))
                return 1;
        }

        return 0;
    }

/*

=item C<INTVAL does(STRING *role_name)>

Returns whether the class does the role with the given C<*rolename>.

=cut

*/

    VTABLE INTVAL does(STRING *role_name) {
        Parrot_Class_attributes * const attrs = PARROT_CLASS(SELF);
        const INTVAL id = attrs->id;
        const INTVAL type_does = Parrot_pmc_type_does(INTERP, role_name, id);
        if (type_does)
            return 1;
        return VTABLE_isa(INTERP, SELF, role_name);
    }

/*

=item C<INTVAL type()>

Returns the integer type of the class.

=cut

*/


    VTABLE INTVAL type() {
        const Parrot_Class_attributes * const _class = PARROT_CLASS(SELF);
        return _class->id;
    }

/*

=item C<PMC *inspect()>

Returns a Hash describing the PMC, with key/value pairs as described in
inspect_str.

=cut

*/
    VTABLE PMC *inspect()
    {
        /* Create a hash, then use inspect_str to get all of the data to
         * fill it up with. */
        STRING * const name_str    = CONST_STRING(INTERP, "name");
        STRING * const ns_str      = CONST_STRING(INTERP, "namespace");
        STRING * const meth_str    = CONST_STRING(INTERP, "methods");
        STRING * const parents_str = CONST_STRING(INTERP, "parents");

        PMC * const metadata = Parrot_pmc_new(INTERP, enum_class_Hash);

        VTABLE_set_pmc_keyed_str(INTERP, metadata, name_str,
            VTABLE_inspect_str(INTERP, SELF, name_str));
        VTABLE_set_pmc_keyed_str(INTERP, metadata, ns_str,
            VTABLE_inspect_str(INTERP, SELF, ns_str));
        VTABLE_set_pmc_keyed_str(INTERP, metadata, meth_str,
            VTABLE_inspect_str(INTERP, SELF, meth_str));
        VTABLE_set_pmc_keyed_str(INTERP, metadata, parents_str,
            VTABLE_inspect_str(INTERP, SELF, parents_str));

        return metadata;
    }

/*

=item C<STRING *name()>

Gets the name of the PMC.

=cut

*/

    METHOD name() {
        Parrot_Class_attributes * const _pmc     = PARROT_CLASS(SELF);
        STRING       * const ret_name = _pmc->name;
        RETURN(STRING *ret_name);
    }

/*

=item C<void get_namespace()>

Gets the namespace that this class is attached to.

=cut

*/

    METHOD get_namespace() {
        Parrot_Class_attributes * const _pmc          = PARROT_CLASS(SELF);
        PMC          * const ret_namespace = _pmc->_namespace;
        RETURN(PMC *ret_namespace);
    }

/*

=item C<void new(PMC *args)>

Creates an instance of the PMC.

=cut

*/

    METHOD new(PMC *args :optional, int got_args :opt_flag) {
        PMC * const obj = VTABLE_instantiate(INTERP, SELF, args);
        UNUSED(got_args);
        RETURN(PMC *obj);
    }

/*

=item C<void methods()>

Return a hash where the keys are method names and the values are methods.

=cut

*/

    METHOD methods() {
        PMC * const ret_methods = VTABLE_inspect_str(INTERP, SELF, CONST_STRING(INTERP, "methods"));
        RETURN(PMC *ret_methods);
    }

/*

=item C<void parents()>

Return the parents array PMC.

=cut

*/

    METHOD parents() {
        PMC * const ret_parents = VTABLE_inspect_str(INTERP, SELF, CONST_STRING(INTERP, "parents"));
        RETURN(PMC *ret_parents);
    }

/*

=item C<void inspect(STRING *what :optional)>

Gets all introspection data for the PMC or, if the optional string
parameter is supplied, a particular item of introspection data.

=cut

*/

    METHOD inspect(STRING *what :optional, int got_what :opt_flag) {
        /* Just delegate to the appropriate vtable. */
        PMC * const found =
            got_what
                ? VTABLE_inspect_str(INTERP, SELF, what)
                : VTABLE_inspect(INTERP, SELF);

        RETURN(PMC *found);
    }

/*

=item C<STRING *get_string()>

Return the name of the low-level class (without the HLL namespace).

=cut

*/

    VTABLE STRING *get_string() {
        Parrot_Class_attributes * const proxy_info = PARROT_CLASS(SELF);
        return proxy_info->name;
    }


} /* END pmclass */

/*

=back

=head1 SEE ALSO

F<docs/pdds/pdd17_pmc.pod>.

=cut

*/

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