Fwd: [PHP-DEV] [RFC] Immutable variables and objects

Hi, This accidentally went off-list, forwarding for everyone else’s sake. > Begin forwarded message: > > Date: 30 January 2015 16:01:43 GMT > Subject: Re: [PHP-DEV] [RFC] Immutable variables and objects > From: Alexander Lisachenko <lisachenko.it@gmail.com> > To: Andrea Faulds <ajf@ajf.me> > > > 2015-01-30 18:41 GMT+03:00 Andrea Faulds <ajf@ajf.me > <mailto:ajf@ajf.me>>: > So what you’re suggesting is a special type of variable modifier which makes that variable > have completely different copying semantics to usual? > > That would be quite strange, I don’t see that getting much support. > > > > Yes, this should affect a variable state and passing an object to the function to make it > immutable. But this technique (weakly immutable) is quite useful in several languages. For example, > in Java: > > final int j = 42; > j = 43; // does not compile. j is final so can't be reassigned > or alternative in C++ > const int j = 42; > j = 43; // does not compile. j is const so can't be reassigned > > One more example is passing an argument to function as immutable in C++ with "const" > and then make a mutable copy of object with const_cast. > Thanks. -- Andrea Faulds http://ajf.me/