Re^2: Joining an array

How this code works? $" is the separator used when arrays are extrapolated in certain contexts (like in say "@array"), tie-ing it to 'main' means that it will be implemented in the scope of the main program. I'm not sure about bless\my$i and what ${$_[0]} is referring to when invoked in FETCH.

Give a man a fish and you feed him for a day. Give him a fishnet and you feed him for a lifetime. Ooops! Wait a minute! What if the fishnet brakes down? He will ask for an other fishnet or worse starve to death. Better yet to teach him how to make a fishnet. But what if he forgets how to make a fishnet? It is better to teach him where to look for knowledge on how to make a fishnet. But this can also go wrong. So ultimately it is best just telling him: 'Help yourself, stupid!'

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Re^3: Joining an array by JavaFan (Canon) on Feb 12, 2012 at 10:47 UTC
When you tie a variable, the TIE* method, in this case TIESCALAR, has to return an object. An object is nothing more than a blessed reference. `\my $i` is a reference to the variable `$i`. `bless` blesses its argument. If bless is given just one argument, it blesses the reference to the current package. The first argument to the `FETCH` method is the object returned from bless. `$_[0]` is the first argument of a method, and `${EXPRESSION THAT RETURNS A SCALAR REFERENCE}` is a way to dereference a scalar reference. So, you get back the `$i`.	[reply] [d/l] [select]
Re^4: Joining an array by chessgui (Scribe) on Feb 12, 2012 at 11:17 UTC
I was confused because I've thought that explicitly blessing with a class name was a must. However it is just a good practice becoming significant with inheritance (which is not the case here). Give a man a fish and you feed him for a day. Give him a fishnet and you feed him for a lifetime. Ooops! Wait a minute! What if the fishnet brakes down? He will ask for an other fishnet or worse starve to death. Better yet to teach him how to make a fishnet. But what if he forgets how to make a fishnet? It is better to teach him where to look for knowledge on how to make a fishnet. But this can also go wrong. So ultimately it is best just telling him: 'Help yourself, stupid!'	[reply] [d/l]
Re^3: Joining an array by afoken (Chancellor) on Feb 12, 2012 at 09:47 UTC
tie, perltie Update: What happens is that the `main` package is (ab)used as a class implementing a tied scalar for `$"`. Whenever perl wants to use the value of the tied scalar `$"`, it calls the object method `FETCH` instead, in this case, `main::FETCH`. And that method returns either "`=`" or "`&`", depending on how often it was called before. The modulo operator `%` switches between the two values with every call. To construct the object on which `FETCH` will be invoked, `tie` calls the `TIESCALAR` class method that returns a blessed reference to a scalar value, that value is used to count the calls inside `FETCH`. Alexander -- Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)	[reply] [d/l] [select]