In C3 it's complicated. On one hand the lack of goto means defers are more straightforward, but the biggest problem is that once you have a different way to handle cleanup and you have labelled break/continue, and you have the nextcase to jump to arbitrary cases, there's very little left for goto to do.

It is limited to when you want to jump from within an if statement out across some statements and run the remaining code. It saves one level of indentation, but being so rare, it's hard to justify the complexity.

I keep going back and see if I find some usecase that could motivate putting goto back in but it so far nothing. The "nextcase" allows C3 to express arbitrary jumps back and forth, although not as straightforward as goto.

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bluecalm 4 days ago | parent [-]

Looking at my own code one case I wouldn't get with defer and better switch is avoiding a flag pattern.

For example when you iterate over a block and check if positions are 0 (+ do some work) and once you encounter a non zero you jump to a different "non-empty" section but if it's zeros to the end you jump over non-empty to go to end section. Without goto you need to set a flag and add another conditional there.

Other than that what you mentioned: flatting the if structure is nice. When you have a few simple cases and then a complicated one and a finishing session at the end it's just cleaner and easier to read with goto. It could be handled with a switch statement but not everything is "switchable" and the way most people write it it's another 2 indentation levels (1 with a convention of not indenting cases but I see C3 docs avoid it).

I get it's rare but goto (other than error handling) is rare and I don't think people have a tendency to abuse it. If anything people abuse "structured" construct building an arrow pattern with multiple indentation levels for no good reason.

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lerno 3 days ago | parent [-]

That's the kind of thing I was thinking about. You can solve that with a switch in C3, but it's not as nice. However, this accounts for no more than 1% of all my goto uses (from a quick inspection), which is too little to build a feature from (discipline is needed to prevent a language from ballooning, it's hard to say no). I am looking for some use for it that can redeem its inclusion.

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bluecalm 3 days ago | parent [-]

I agree it's very rare. I have this goto. A few that go to common return block that can be handled by other means and the rest is either error handling or things handled by labelled break or switch.

I mean we know you can program without it and defer/labelled switch and labelled break/continue cover 99%+ of use cases of it. I am still not convinced those are in fact easier to read but I get it's a reasonable design choice to make.

	▲	lerno 3 days ago \| parent [-]
		They have different wins. I think labelled break/continue help because they are clearer in locally expressing what the point is. If you see `goto NEXT;` you can kind of guess the intention, but `continue OUTER;` doesn't require you to read the code at the label and check what's happening there. `defer catch` and `defer try` helps avoiding some booleans otherwise needed with just a basic defer. `defer` on its own otherwise sometimes needs booleans to track what should be closed. With goto those naturally go to different cleanup sections. I keep revisiting goto though. I like it a lot for its simplicity.