Could this be described as a requirement of the class ?
class Mine
require(invariant-expr)
extends Something
implements Someface {
public function method($param) : return
require(input-expr),
return(output-expr) {
}
}
To avoid invariant keyword maybe.
Cheers
Joe
On Mon, Feb 9, 2015 at 11:05 AM, Dmitry Stogov <dmi...@zend.com> wrote:
> invariant is for classes only. It should be called before and/or after
> each method to check object consistency.
>
> syntax with expressions may work if we put constraints before the function
> body .
>
> function foo($a int): int
> require(expr1)
> require(expr2, msg)
> return(expr3)
> {
> }
>
> Yasuo, I would suggest to describe both syntax options.
>
> Thanks. Dmitry.
>
> On Mon, Feb 9, 2015 at 1:46 PM, Joe Watkins <pthre...@pthreads.org> wrote:
>
>> Morning Yasuo,
>>
>> Can you explain what invariant is for ?
>>
>> I prefer a list of contracts with a single expression, over blocks of
>> expressions in one contract.
>> An IDE can just as easy generate a block of code or set of contracts,
>> so it's really just a matter of how complex it makes the implementation if
>> you allow any block of code in the contract. I think it does make it
>> unnecessarily complicated to implement, I can be wrong.
>>
>> If there is going to be two rfc's, I will vote no on the annotations
>> based one, I'd rather no time was wasted on even writing it; Before you
>> convince anyone that DBC is a good idea you have to convince them
>> annotations is a good idea, many have tried and failed.
>>
>> Cheers
>> Joe
>>
>> On Mon, Feb 9, 2015 at 10:34 AM, Yasuo Ohgaki <yohg...@ohgaki.net> wrote:
>>
>>> Hi Dmitry and Joe,
>>>
>>> On Mon, Feb 9, 2015 at 6:01 PM, Dmitry Stogov <dmi...@zend.com> wrote:
>>>
>>>> Usage of "return" is a good idea.
>>>> The more heads the better result :)
>>>>
>>>
>>> Less additional reserved word :)
>>> So I'll use "require" and "return" for D like RFC.
>>> We haven't talk much about invariants. I'll write my idea.
>>>
>>> Current RFC is large enough already, I'll prepare new one.
>>> We may decide what to do with 2 RFCs.
>>>
>>> We have choices for with block or without block. I prefer with block
>>> version, since
>>> assert expression could be messy. With block, IDE may do it's jobs. i.e.
>>> Hide blocks.
>>>
>>> ==============================================
>>> Function/Method
>>>
>>> [With block]
>>> function foo()
>>> require {
>>> assert(assert-expr, 'msg');
>>> assert(assert-expr, 'msg');
>>> assert(assert-expr, 'msg');
>>> }
>>> return {
>>> assert(assert-expr, 'msg');
>>> assert(assert-expr, 'msg');
>>> assert(assert-expr, 'msg');
>>> }
>>> invariant {
>>> assert(assert-expr, 'msg');
>>> assert(assert-expr, 'msg');
>>> assert(assert-expr, 'msg');
>>> }
>>> {
>>> // body
>>> }
>>>
>>> _OR_
>>>
>>> [Without block]
>>> function foo() {
>>> require(assert-expr, 'msg');
>>> require(assert-expr, 'msg');
>>> require(assert-expr, 'msg');
>>> invariant(assert-expr, 'msg');
>>> invariant(assert-expr, 'msg');
>>> invariant(assert-expr, 'msg');
>>> return(assert-expr, 'msg');
>>> return(assert-expr, 'msg');
>>> return(assert-expr, 'msg');
>>>
>>> // function body
>>> }
>>>
>>>
>>> Currently, following code wouldn't work (PHP 7.0.0-dev)
>>> ----------
>>> assert(function() {return FALSE;}, 'AAAAA');
>>> ----------
>>>
>>> For block version, which do you prefer, allow any PHP syntax or assert
>>> only?
>>> People may use anonymous function to do fancy jobs anyway if it's
>>> supported.
>>>
>>> No block version only accepts EXPR obviously, but anonymous function may
>>> be used with this as well.
>>>
>>>
>>> ==============================================
>>> Class invariants
>>>
>>> [With block]
>>> class Foo {
>>> __invariants() {
>>> assert(assert-expr, 'msg');
>>> assert(assert-expr, 'msg');
>>> assert(assert-expr, 'msg');
>>> }
>>> }
>>>
>>> _OR_
>>>
>>> [Without block]
>>> class Foo {
>>> __construct() {
>>> invariant(assert-expr, 'msg'); // Only allow in __construct()?
>>> Allowing invariant.
>>> invariant(assert-expr, 'msg');
>>> invariant(assert-expr, 'msg');
>>> }
>>> }
>>>
>>>
>>> ==============================================
>>> Global invariant
>>>
>>> I'm not sure if we should have
>>>
>>> function __invariants() {
>>> assert(assert-expr, 'msg');
>>> assert(assert-expr, 'msg');
>>> assert(assert-expr, 'msg');
>>> }
>>>
>>> _OR_
>>>
>>> invariant {
>>> assert(assert-expr, 'msg');
>>> assert(assert-expr, 'msg');
>>> assert(assert-expr, 'msg');
>>> }
>>>
>>> to assert global vars, whole app state, etc. It may be useful for unit
>>> tests as well as app development.
>>>
>>>
>>> I'll start working after I get comment from you.
>>>
>>> Regards,
>>>
>>> --
>>> Yasuo Ohgaki
>>> yohg...@ohgaki.net
>>>
>>
>>
>
