object *display_proc(object *arguments) {
object *obj;
char *str = NULL;
obj = car(arguments);
switch (obj->type) {
case CHARACTER:
printf("%c", obj->data.character.value);
break;
case FIXNUM:
printf("%ld", obj->data.fixnum.value);
break;
case FLOATNUM:
printf("%f", obj->data.floatnum.value);
break;
case STRING:
printf("%s", str = obj->data.string.value);
break;
case SYMBOL:
printf("%s", obj->data.symbol.value);
break;
case ERROR:
printf("Error %ld: %s", obj->data.error.error_num, obj->data.error.error_msg);
break;
default:
fprintf(stderr, "cannot display type\n");
} // switch
return ok_symbol();
}
object *close_output_port_proc(object *arguments) {
int result;
result = fclose(car(arguments)->data.output_port.stream);
if (result == EOF) {
fprintf(stderr, "could not close output port\n");
exit(EXIT_FAILURE);
}
return ok_symbol();
}
object *write_char_proc(object *arguments) {
object *character;
FILE *out;
character = car(arguments);
arguments = cdr(arguments);
out = is_empty(arguments) ?
stdout :
car(arguments)->data.output_port.stream;
putc(character->data.character.value, out);
fflush(out);
return ok_symbol();
}
object *write_proc(object *arguments) {
object *exp;
FILE *out;
exp = car(arguments);
arguments = cdr(arguments);
out = is_empty(arguments) ?
stdout :
car(arguments)->data.output_port.stream;
write(out, exp);
fflush(out);
return ok_symbol();
}
object *eval_definition(object *exp, object *env) {
define_variable(definition_variable(exp), eval(definition_value(exp), env), env);
return ok_symbol();
}
object *eval_assignment(object *exp, object *env) {
set_variable_value(assignment_variable(exp), eval(assignment_value(exp), env), env);
return ok_symbol();
}
object *set_cdr_proc(object *arguments) {
set_cdr(car(arguments), cadr(arguments));
return ok_symbol();
}
