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Comment by rmind | Hacker News Reader

This is because certain coding standards are designed to be idiot-proof. Unfortunately, that can result in tasteless code and sometimes undesirable workarounds (e.g. using "goto" have one exit path for errors is a perfectly valid use).

When Dijkstra wrote his famous essay "Go To Statement Considered Harmful" (1968), it was a manifesto against unstructured programming i.e. the spaghetti code. However, the use of "goto" per se does not imply unstructured programming. Donald Knuth wrote a wonderful essay "Structured Programming with go to Statements" (1974) to make this point.

Availability of "goto" in C merely gives us more flexibility, but it does not mean that we should start writing unstructured code.

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Dijkstra was concerned about being able to reason about code, and spaghetti code can make it impossible to decompose. A single goto within a function is not a big deal, and that's not really what he was worried about.

Few people have worked on real spaghetti code, thousands of lines with no functions, no modules, just spectacular leaps forward, backwards, leaping forward into the middle of huge loops, leaping backwards into the middle of loops, giant loops nested with and partially overlapping other loops.

I worked on such code, trying to decompose it in order to organize it into subroutines. It resisted my efforts almost completely. Fortran IV I think.

Lua added goto just recently, and it's benign, because it can't escape its calling context.

Users were agitating for `continue` to join `break` for control flow interruption. Lua instead chose to provide all the non-structured control flows you would like as a primitive; scoping it lexically keeps it from breaking composition.

I still hope that we might be able to convince the Lua authors to add continue one day. It would be very convenient.

I think the real reason why it hasn't been added to the language yet is that it has a weird interaction with the way Lua scopes its repeat-until loops. The justification about having a single control-flow structure is more of an excuse.

As a contrasting opinion, I would like the break keyword to be formally defined as a sugar for a special labeled goto.

Since it's a keyword, you can't create your own ::break:: label, so that would be fine.

I'd be OK with that. But let me type `break` and `continue`, with all the sugar that entails :)

I’ve seen a few Fortran goto subroutines. I somehow get the feeling that the two following facts are mathematically related: some graphs cannot be drawn on a two-dimensional sheet of paper, and some subroutines cannot be decomposed into smaller subroutines.

> Few people have worked on real spaghetti code

The closest I've come was my own code: minsweeper on my Ti-82 graphical calculator. I Separated the program in various sections, then used `goto` to jump where I needed. I was tempted at some point to use the "call program" facility instead, but that would have meant exposing those programs to the end users, so I just lumped everything in one file.

Reminds me why I love functions.

Oh god, I feel for you. My first real language was when I had my TI-84, and you NEEDED goto if you didn't want to clutter up the user's machine with a bunch of things they should never-ever press. God, what horrible yet nostalgic memories.

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