What about cases where you want to illustrate that the something being done is not "standard" -- to provide an extra hint.
Either way, there is at least one case where the custom block iterator doesn't cover the usage of "for" - where you need the variables outside the scope of the loop.
It's a good question, but I'd have to say: only if you equate "nonstandard" with "considered harmful."
Needless to say, I don't.
For one, there is a large difference between the spaghetti code that can result from liberal and
injudicious goto usage vs. whatever you might encounter by using "for" instead of ".each"
In the goto case - we use it all the time under different names with special circumstances: method calls, loops, breaks, nexts, etc.
In the case of for vs. each - it depends. In some cases you may indeed be iterating over the contents of some object in particular. But what if you are iterating over the contents of two disparate objects? Should we use ".each" on one and keep a separate counter for the other?
And then, there are those times when you actually want the variables in the loop to be available outside the scope of the loop, as I mentioned in the previous comment. It might not be standard, but it does happen. One instance is where you are letting doing evals on variables introduced by the objects in the loop. That just can't happen with the .each call, and you need the "for" loop to do it.
And I would add, even if it were possible to keep track of that in a block we pass to #each, I would rather not do so because of the psychological implications of doing so. If I want to iterate over two disparate objects, I need a way of expressing that, and the "for" loop is it.
Comments
What about cases where you want to illustrate that the something being done is not "standard" -- to provide an extra hint.
Either way, there is at least one case where the custom block iterator doesn't cover the usage of "for" - where you need the variables outside the scope of the loop.
Doesn't the same logic suggest marking "nonstandard" C code with "gotos"?
It's a good question, but I'd have to say: only if you equate "nonstandard" with "considered harmful."
Needless to say, I don't.
For one, there is a large difference between the spaghetti code that can result from liberal and injudicious goto usage vs. whatever you might encounter by using "for" instead of ".each"
In the goto case - we use it all the time under different names with special circumstances: method calls, loops, breaks, nexts, etc.
In the case of for vs. each - it depends. In some cases you may indeed be iterating over the contents of some object in particular. But what if you are iterating over the contents of two disparate objects? Should we use ".each" on one and keep a separate counter for the other?
And then, there are those times when you actually want the variables in the loop to be available outside the scope of the loop, as I mentioned in the previous comment. It might not be standard, but it does happen. One instance is where you are letting doing evals on variables introduced by the objects in the loop. That just can't happen with the .each call, and you need the "for" loop to do it.
And I would add, even if it were possible to keep track of that in a block we pass to #each, I would rather not do so because of the psychological implications of doing so. If I want to iterate over two disparate objects, I need a way of expressing that, and the "for" loop is it.