On 07/01/2008, Stefan Priebsch <[EMAIL PROTECTED]> wrote:
> Robert Cummings schrieb:
> > The onus should be on consumers of my API to use it properly, not on me
> > to jump through hoops to make sure they gave me the correct data at
> > every step of the way. I stopped holding hands in grade 3 or so.
>
> Still you force any defensive coder to repeat explicit type checks and
> type casts all over whenever one of your API functions is called.
>
> Regards,
>
> Stefan
>
This argument implies that the coder constantly shifts type on their variables.
If I have a counter, I'll use an integer. I'll initialise it to 0. I
__CAN__ use a string of "0", but as soon as I say +1 it is juggled an
integer until some other use juggles it to something else.
The only time I see auto type juggling useful (for internal data not
user input) is in string concatenation and then it fails for boolean
types (""/"1" rather than "0"/"1" or even better "true"/"false"). But
then, it is only the result of the juggle that is used. The original
variable isn't juggled.
Type juggling is a great thing, but next to useless if you are a
"defensive coder".
You know that converting from type a to type b MAY result in data loss
("1 defensive coder" + 1 = 2, not "2 defensive coder", so you rarely
do it. Instead you will use functions to absolutely confirm the
conversion and check values.
That's defensive.
>From what I can tell this is what is being asked for.
1 - Scalar type hints act as type jugglers at the interface of the
function/method rather than having type checking code in the
function/method.
You will still need to have value checks if they are appropriate.
So, function x(string $s, int $i) will get a string and an integer, no
matter what is sent.
Thinking about this, simply because we all know PHP __CAN__ type
juggle, there is no need for any errors/warnings/notices on scalar
types. It will be up to the API developer to make sure appropriate
values are supplied (if necessary), so this reduces the type checking.
Richard.
--
-----
Richard Quadling
Zend Certified Engineer : http://zend.com/zce.php?c=ZEND002498&r=213474731
"Standing on the shoulders of some very clever giants!"
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