3 ms·

That's mail. Parsing mail is undecidable, this is known, it's an ancient format (I use that term in the loosest sense) and can only be handled on a best-effort

That's mail. Parsing mail is undecidable, this is known, it's an ancient format (I use that term in the loosest sense) and can only be handled on a best-effort basis. That is not a property of plain text files, of the sort we see above. The rule there is very simple: single newlines are wrapping, double newlines are paragraph breaks. Yes, you want to put a tiny bit more effort into it to do a good job, someone might be sloppy about trimming tailing whitespace on empty lines and so on, it would be silly to let your parser break on three newlines, and so on. > Hard wrapping text loses information. Nonsense. Spoiler alert: I hard-wrapped every paragraph in the reply above. So that's the existence proof: no it doesn't.

mrob 2y ago
Your "existence proof" is no such thing; you simply moved the deleted information to the metadata by telling us which reconstruction algorithm to use.
- samatman 2y ago
  As far as I am able to parse it, this sentence is meaningless. Hacker News, not known for the immense sophistication of its markup, is, somehow, mysteriously, able to tell the difference between one newline (still a paragraph) and more than one (new paragraph). I don't know how they do it with all the deleted metadata reconstruction algorithm undecidable problems you're sure exist. Perhaps they use an LLM, to do a better job. We may never know for sure.
  - mrob 2y ago
    here is a free verse poem with lines of unknown length and deliberate lack of uppercase or punctuation It's plain text. "Plain text" does not impose any restrictions on formatting. Was the poem two lines or three? Hard wrapping plain text loses information because it inserts non-semantic line breaks using the same character as already used for semantic line breaks. There is no way reliable way to distinguish the two, so the transformation is not reversible in the general case. The best you can do is guess from context, which, as the poem demonstrates, is not always possible.

mrob 2y ago

Your "existence proof" is no such thing; you simply moved the deleted information to the metadata by telling us which reconstruction algorithm to use.

samatman 2y ago
As far as I am able to parse it, this sentence is meaningless. Hacker News, not known for the immense sophistication of its markup, is, somehow, mysteriously, able to tell the difference between one newline (still a paragraph) and more than one (new paragraph). I don't know how they do it with all the deleted metadata reconstruction algorithm undecidable problems you're sure exist. Perhaps they use an LLM, to do a better job. We may never know for sure.
- mrob 2y ago
  here is a free verse poem with lines of unknown length and deliberate lack of uppercase or punctuation It's plain text. "Plain text" does not impose any restrictions on formatting. Was the poem two lines or three? Hard wrapping plain text loses information because it inserts non-semantic line breaks using the same character as already used for semantic line breaks. There is no way reliable way to distinguish the two, so the transformation is not reversible in the general case. The best you can do is guess from context, which, as the poem demonstrates, is not always possible.