My concern is actually neither performance nor brevity - my concern is, can you read the code and actually understand what it does, can you write code without running into surprising side-effects, and so on.
DbC might have merit in terms of performance, but perhaps not so much in a scripting language - if performance was critical to a given project, I would not be using a scripting language. The addition of DbC and marginally better performance for certain specific use-cases wouldn't change that for me. On Mon, Apr 10, 2017 at 4:04 AM, Yasuo Ohgaki <yohg...@ohgaki.net> wrote: > Hi Rasmus, > > Although DbC is not what you need, but DbC could solve your issue > more efficiently. i.e. Faster execution, not shorter code. > > https://wiki.php.net/rfc/dbc2 > > With DbC, caller has responsibility to pass correct parameters. > > On Sun, Apr 9, 2017 at 6:30 PM, Rasmus Schultz <ras...@mindplay.dk> wrote: > >> >> $one = "1"; >> $one_int = (int) $one; >> add_one($one_int); >> > > > add_one(&$value) > require (is_int($value)) > { > $value += 1; > } > > // Caller has responsibility to pass correct parameters. > $one = filter_validate($_GET['var'], FILTER_VALIDATE_INT); > add_one($one); > > > > >> class Foo { public function __toString() { return "foo"; } } >> function append_to(string &$str) { $str .= "_bar"; } >> $foo = new Foo(); >> append_to($foo); >> var_dump($foo); // string(7) "foo_bar" > > > > class Foo { public function __toString() { return "foo"; } } > > function append_to(&$str) > require (is_string($str)) > { > $str .= "_bar"; > } > > $foo = new Foo(); > > // Caller has responsibility to pass correct parameters, but it's not > append_to($foo); // Error at DbC precondition check in append_foo() > var_dump($foo); // Cannot reach here in dev mode > > > > I really like parameter type check. > Problem is type check makes execution slower. > Another problem is type check is not enough for many codes. > > With DbC support, we can specify any expressions. Therefore, we can > check much more complex requirements for functions/methods at > development time. > > > > e.g. > function save_age($user_age) > require (is_int($user_age)) > require ($user_age >= 0) > require ($user_age < 150) > { > save_to_somewehre($user_age); > } > //Note: All input parameters must be validated to be correct value for the > app. e.g. use filter_validate()/etc > > > What you really need might be DbC. > > Regards, > > -- > Yasuo Ohgaki > yohg...@ohgaki.net > >
