> the fact that there exists a correct answer for every piece of text that will be obvious to readers of that text which is the definition of a grapheme cluster.
No, I insist there is not a single "correct answer," even if a reader has perfect knowledge of the language(s) involved. Now remember, this is already moving the goalposts, since it was claimed that a human needed "no knowledge" to get to this allegedly "correct answer."
You already admit that people who don't speak Arabic will have trouble finding the "grapheme clusters," but even two people who speak Arabic may do your clustering or not, depending on some implicit feeling of "the right way to do it" vs taking the question literally and pasting the smallest highlight-able selection of the string in reverse at a time.
Anyway, take a string like this: "here is some Arabic text: <RLM> <Arabic codepoints> <LRM> And back to English"
Whether you discard the ordering mark[0], keep them, or inverse them is an implementation decision that already produces three completely different strings. Unless we want to write a rulebook for the right way to reverse a string, it remains an impossibility to declare anything the correct answer, and because there is no reason to reverse such a string outside of contrived interview questions and ivory tower debates, it is also meaningless.
You added the requirement that it be a single correct answer. I just asserted that there existed a correct answer. You're being woefully pedantic -- a human who can read the text presented to them but no knowledge of unicode was my intended meaning. Grapheme clusters are language dependent and chosen for readers of languages that use the characters involved. There's no implicit feeling, this is what the standards body has decided is the "right way to do it." If you want to use different grapheme clusters because you think the Unicode people are wrong then fine, use those. You can still reverse the string.
Like what are you even arguing? You declared that something was impossible and then ended with that it's not only possible but it's so possible that there are many reasonable correct answers. Pick one and call it a day.
It is impossible to "correctly reverse a string" because "reverse a string" is not well defined. We explored many different potential definitions of it, to show that there is no meaningful singular answer.
> You added the requirement that it be a single correct answer.
Your original post says "they could produce the correct string reversal"?
No, I insist there is not a single "correct answer," even if a reader has perfect knowledge of the language(s) involved. Now remember, this is already moving the goalposts, since it was claimed that a human needed "no knowledge" to get to this allegedly "correct answer."
You already admit that people who don't speak Arabic will have trouble finding the "grapheme clusters," but even two people who speak Arabic may do your clustering or not, depending on some implicit feeling of "the right way to do it" vs taking the question literally and pasting the smallest highlight-able selection of the string in reverse at a time.
Anyway, take a string like this: "here is some Arabic text: <RLM> <Arabic codepoints> <LRM> And back to English"
Whether you discard the ordering mark[0], keep them, or inverse them is an implementation decision that already produces three completely different strings. Unless we want to write a rulebook for the right way to reverse a string, it remains an impossibility to declare anything the correct answer, and because there is no reason to reverse such a string outside of contrived interview questions and ivory tower debates, it is also meaningless.
[0]: https://en.m.wikipedia.org/wiki/Right-to-left_mark https://en.m.wikipedia.org/wiki/Left-to-right_mark