Hi Patrick, On Tue, Feb 10, 2015 at 4:06 PM, Patrick Schaaf <p...@bof.de> wrote:
> Am 10.02.2015 07:25 schrieb "Yasuo Ohgaki" <yohg...@ohgaki.net>: > > > > https://wiki.php.net/rfc/dbc2 > > First of all, thanks for your effort so far. > > Some questions, after reading the RFC, with no particular order: > > 1) Regarding invariants: those will be called for method calls on objects. > What about static class methods? Could we have static class invariants > (static require(.....))? Would these be called for both static and > nonstatic method calls (nonstatic method calls can change static class > state, too) > Static calls should not use $this->var, so invariant condition is ignored. It should be in the RFC. > 2) the pre- and postconditions could be useful for ordinary, non-OO > functions, too, to check parameters, return, and global state invariants > I proposed __invariant() function, but some would not like to have it. Since you've requested, we may consider again. Rre/postconditions (require/return) can be used for non-OO functions. It should be in the RFC. I'll add it in the RFC later. > 3) I think that method preconditions are not sufficient. Pretty often, > public methods first sanitize and validate their input parameters, and > rightly so. In these cases, it would be useful to have the checking, in the > same general framework, at an arbitrary point in the function body. In > other words, assert (with an expression as the first argument, instead of a > string....). > I might misunderstand you. Anyway, assert( $var > 0 ) is allowed. So you can write usual PHP code. Even we can assert( foo() ) // The same applies to require()/return() is allowed. However, PHP does not allow in place closure call currently. We cannot do assert(function() { return $a > 0;} ) It's just ignored. This is the same as current assert(). > 4) regarding the error message second argument to the condition > definitions, it would be useful to have these not only as plain > (extrapolated) strings, but as full expressions-that-evaluate-to-string. > That would permit hooking to arbitrary private logging and log formatting > methods. > assert( $var > 0, '$var must be positive') is allowed. This should be in the RFC. require()/return() works just like assert(). > 5) and a bit off-topic, it would be useful to be able to declare (sic) > whole methods to be nonproduction only: Methods that will only be used in > pre/post/invariant condition expresions (or error formatters a la my point > 4) > Do you mean enable DbC partially? Like declare(dbc=1); At the top of script? I think it would not happen, but others may think it should. Anyone? Regards, -- Yasuo Ohgaki yohg...@ohgaki.net
