circuitpython/py/objnamedtuple.c

/*
 * This file is part of the Micro Python project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2013, 2014 Damien P. George
 * Copyright (c) 2014 Paul Sokolovsky
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include <string.h>

#include "mpconfig.h"
#include "misc.h"
#include "nlr.h"
#include "qstr.h"
#include "obj.h"
#include "objtuple.h"

#if MICROPY_PY_COLLECTIONS

typedef struct _mp_obj_namedtuple_type_t {
    mp_obj_type_t base;
    mp_uint_t n_fields;
    mp_obj_t fields[];
} mp_obj_namedtuple_type_t;

typedef struct _mp_obj_namedtuple_t {
    mp_obj_tuple_t tuple;
} mp_obj_namedtuple_t;

STATIC mp_uint_t namedtuple_find_field(mp_obj_namedtuple_type_t *type, qstr name) {
    for (mp_uint_t i = 0; i < type->n_fields; i++) {
        if (MP_OBJ_QSTR_VALUE(type->fields[i]) == name) {
            return i;
        }
    }
    return -1;
}

STATIC void namedtuple_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind) {
    mp_obj_namedtuple_t *o = o_in;
    print(env, "%s(", qstr_str(o->tuple.base.type->name));
    const mp_obj_t *fields = ((mp_obj_namedtuple_type_t*)o->tuple.base.type)->fields;
    for (mp_uint_t i = 0; i < o->tuple.len; i++) {
        if (i > 0) {
            print(env, ", ");
        }
        print(env, "%s=", qstr_str(MP_OBJ_QSTR_VALUE(fields[i])));
        mp_obj_print_helper(print, env, o->tuple.items[i], PRINT_REPR);
    }
    print(env, ")");
}

STATIC void namedtuple_load_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
    mp_obj_namedtuple_t *self = self_in;
    int id = namedtuple_find_field((mp_obj_namedtuple_type_t*)self->tuple.base.type, attr);
    if (id == -1) {
        return;
    }
    dest[0] = self->tuple.items[id];
}

STATIC bool namedtuple_store_attr(mp_obj_t self_in, qstr attr, mp_obj_t value) {
    nlr_raise(mp_obj_new_exception_msg(&mp_type_AttributeError, "can't set attribute"));
}

STATIC mp_obj_t namedtuple_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
    mp_obj_namedtuple_type_t *type = type_in;
    mp_uint_t num_fields = type->n_fields;
    if (n_args + n_kw != num_fields) {
        // Counts include implicit "self"
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
                                               "__new__() takes %d positional arguments but %d were given",
                                               num_fields + 1, n_args + n_kw + 1));
    }

    mp_obj_t *arg_objects;
    if (n_args == num_fields) {
        arg_objects = (mp_obj_t*)args;
    } else {
        size_t alloc_size = sizeof(mp_obj_t) * num_fields;
        arg_objects = alloca(alloc_size);
        memset(arg_objects, 0, alloc_size);

        for (mp_uint_t i = 0; i < n_args; i++) {
            arg_objects[i] = args[i];
        }

        for (mp_uint_t i = n_args; i < n_args + 2 * n_kw; i += 2) {
            qstr kw = MP_OBJ_QSTR_VALUE(args[i]);
            int id = namedtuple_find_field(type, kw);
            if (id == -1) {
                nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
                            "__new__() got an unexpected keyword argument '%s'",
                            qstr_str(kw)));
            }
            if (arg_objects[id] != NULL) {
                nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
                            "__new__() got multiple values for argument '%s'",
                            qstr_str(kw)));
            }
            arg_objects[id] = args[i + 1];
        }
    }

    mp_obj_tuple_t *tuple = mp_obj_new_tuple(num_fields, arg_objects);
    tuple->base.type = type_in;
    return tuple;
}

STATIC const mp_obj_tuple_t namedtuple_base_tuple = {{&mp_type_tuple}, 1, {(mp_obj_t)&mp_type_tuple}};

STATIC mp_obj_t mp_obj_new_namedtuple_type(qstr name, mp_uint_t n_fields, mp_obj_t *fields) {
    mp_obj_namedtuple_type_t *o = m_new_obj_var(mp_obj_namedtuple_type_t, mp_obj_t, n_fields);
    o->base.base.type = &mp_type_type;
    o->base.name = name;
    o->base.print = namedtuple_print;
    o->base.make_new = namedtuple_make_new;
    o->base.unary_op = mp_obj_tuple_unary_op;
    o->base.binary_op = mp_obj_tuple_binary_op;
    o->base.load_attr = namedtuple_load_attr;
    o->base.store_attr = namedtuple_store_attr;
    o->base.subscr = mp_obj_tuple_subscr;
    o->base.getiter = mp_obj_tuple_getiter;
    o->base.bases_tuple = (mp_obj_t)&namedtuple_base_tuple;
    o->n_fields = n_fields;
    memcpy(o->fields, fields, sizeof(mp_obj_t) * n_fields);
    return o;
}

STATIC mp_obj_t new_namedtuple_type(mp_obj_t name_in, mp_obj_t fields_in) {
    qstr name = MP_OBJ_QSTR_VALUE(name_in);
    mp_uint_t n_fields;
    mp_obj_t *fields;
    mp_obj_list_get(fields_in, &n_fields, &fields);
    return mp_obj_new_namedtuple_type(name, n_fields, fields);
}
MP_DEFINE_CONST_FUN_OBJ_2(mp_namedtuple_obj, new_namedtuple_type);

#endif // MICROPY_PY_COLLECTIONS