static int unpack()

in src/jansson/src/pack_unpack.c [535:685]
122 lines of code
46 McCabe index (conditional complexity)

static int unpack(scanner_t *s, json_t *root, va_list *ap)
{
    switch(token(s))
    {
        case '{':
            return unpack_object(s, root, ap);

        case '[':
            return unpack_array(s, root, ap);

        case 's':
            if(root && !json_is_string(root)) {
                set_error(s, "<validation>", "Expected string, got %s",
                          type_name(root));
                return -1;
            }

            if(!(s->flags & JSON_VALIDATE_ONLY)) {
                const char **str_target;
                size_t *len_target = NULL;

                str_target = va_arg(*ap, const char **);
                if(!str_target) {
                    set_error(s, "<args>", "NULL string argument");
                    return -1;
                }

                next_token(s);

                if(token(s) == '%') {
                    len_target = va_arg(*ap, size_t *);
                    if(!len_target) {
                        set_error(s, "<args>", "NULL string length argument");
                        return -1;
                    }
                }
                else
                    prev_token(s);

                if(root) {
                    *str_target = json_string_value(root);
                    if(len_target)
                        *len_target = json_string_length(root);
                }
            }
            return 0;

        case 'i':
            if(root && !json_is_integer(root)) {
                set_error(s, "<validation>", "Expected integer, got %s",
                          type_name(root));
                return -1;
            }

            if(!(s->flags & JSON_VALIDATE_ONLY)) {
                int *target = va_arg(*ap, int*);
                if(root)
                    *target = (int)json_integer_value(root);
            }

            return 0;

        case 'I':
            if(root && !json_is_integer(root)) {
                set_error(s, "<validation>", "Expected integer, got %s",
                          type_name(root));
                return -1;
            }

            if(!(s->flags & JSON_VALIDATE_ONLY)) {
                json_int_t *target = va_arg(*ap, json_int_t*);
                if(root)
                    *target = json_integer_value(root);
            }

            return 0;

        case 'b':
            if(root && !json_is_boolean(root)) {
                set_error(s, "<validation>", "Expected true or false, got %s",
                          type_name(root));
                return -1;
            }

            if(!(s->flags & JSON_VALIDATE_ONLY)) {
                int *target = va_arg(*ap, int*);
                if(root)
                    *target = json_is_true(root);
            }

            return 0;

        case 'f':
            if(root && !json_is_real(root)) {
                set_error(s, "<validation>", "Expected real, got %s",
                          type_name(root));
                return -1;
            }

            if(!(s->flags & JSON_VALIDATE_ONLY)) {
                double *target = va_arg(*ap, double*);
                if(root)
                    *target = json_real_value(root);
            }

            return 0;

        case 'F':
            if(root && !json_is_number(root)) {
                set_error(s, "<validation>", "Expected real or integer, got %s",
                          type_name(root));
                return -1;
            }

            if(!(s->flags & JSON_VALIDATE_ONLY)) {
                double *target = va_arg(*ap, double*);
                if(root)
                    *target = json_number_value(root);
            }

            return 0;

        case 'O':
            if(root && !(s->flags & JSON_VALIDATE_ONLY))
                json_incref(root);
            /* Fall through */

        case 'o':
            if(!(s->flags & JSON_VALIDATE_ONLY)) {
                json_t **target = va_arg(*ap, json_t**);
                if(root)
                    *target = root;
            }

            return 0;

        case 'n':
            /* Never assign, just validate */
            if(root && !json_is_null(root)) {
                set_error(s, "<validation>", "Expected null, got %s",
                          type_name(root));
                return -1;
            }
            return 0;

        default:
            set_error(s, "<format>", "Unexpected format character '%c'",
                      token(s));
            return -1;
    }
}