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> It's impossible to write any program in a language where all behavior is undefined. Such a language, by definition, has no semantics, and so no notion of a pr

> It's impossible to write any program in a language where all behavior is undefined. Such a language, by definition, has no semantics, and so no notion of a program. In fact, a language with no semantics of any kind is not a language at all. So, it's necessary to remove a sufficient amount of undefined behavior before something is even usable in a coherent way? Which is another way of saying, you have to have defined enough behavior to be able to even get to the point of knowing whether or not the programmer is the one responsible for the "bug". Undefined behavior seems to be necessarily worse than programmer error, since to be able to determine the latter you have to have removed some part of the former. :shrug:, going to get back to work.

pron 7y ago
Undefined behavior means that certain expressions, like 1/0 in arithemtic, have no meaning; i.e. they are grammatically correct but nonsensical. For something to be a language, it is necessary for it to be able to state things that do have a meaning. But if some of its sentences have no meaning, it does not necessarily impact those that do. You don't need to "remove" anything. By default, sentences people say have meanings but not all of them do. To understand the sentence "I like pizza" you don't need to "remove" any undefinedness, just as you don't need to "remove" undefinedness to determine 2 + 3 = 5 even though some arithmetical sentences are meaningless, like 1/0 < 5. It's like asking which is "worse", saying "England is a country in Africa" (false) or "Love ate a circle" (meaningless)? Both are "bad" in their own way. But undefined behavior can certainly be inconvenient, because it is insufficient to determine whether a sentence is "well-formed", i.e. grammatically correct, in order for it to be meaningful, as some grammatically correct sentences are nonsensical. But it's certainly not catastrophic, because mathematics has a lot of undefined sentences, and we still use it successfully.
- Loveateacircle 7y ago
  Having read this entire exchange I can say with absolute certainty that I did not understand it at all. I did however enjoy it very much.

pron 7y ago

Undefined behavior means that certain expressions, like 1/0 in arithemtic, have no meaning; i.e. they are grammatically correct but nonsensical. For something to be a language, it is necessary for it to be able to state things that do have a meaning. But if some of its sentences have no meaning, it does not necessarily impact those that do. You don't need to "remove" anything. By default, sentences people say have meanings but not all of them do. To understand the sentence "I like pizza" you don't need to "remove" any undefinedness, just as you don't need to "remove" undefinedness to determine 2 + 3 = 5 even though some arithmetical sentences are meaningless, like 1/0 < 5. It's like asking which is "worse", saying "England is a country in Africa" (false) or "Love ate a circle" (meaningless)? Both are "bad" in their own way. But undefined behavior can certainly be inconvenient, because it is insufficient to determine whether a sentence is "well-formed", i.e. grammatically correct, in order for it to be meaningful, as some grammatically correct sentences are nonsensical. But it's certainly not catastrophic, because mathematics has a lot of undefined sentences, and we still use it successfully.

Loveateacircle 7y ago
Having read this entire exchange I can say with absolute certainty that I did not understand it at all. I did however enjoy it very much.