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Comment by Apreche | Hacker News Reader

The shortcoming of using the control characters is that there is no easy way to type them on a keyboard. You can trivially edit csv in a text editor.

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Technically there is (not sure about easy, most of these require ctrl+shift, but they are on the keyboard):

    CTRL   DEC HEX CHR NAME
    Ctrl-\  28  1C  FS File Separator (Right Arrow)
    Ctrl-]  29  1D  GS Group Separator (Left Arrow)
    Ctrl-^  30  1E  RS Record Separator (Up Arrow)
    Ctrl-_  31  1F  US Unit Separator (Down Arrow)

From https://www3.rocketsoftware.com/bluezone/help/v42/en/bzadmin...

You can type them in the terminal by prefixing with Ctrl-V, so you can enter a record separator by pressing Ctrl-V, Ctrl-Shift-6. Typing Ctrl-\ is tricky because some programs interpret it to mean end of input, e.g. it exits the Python repl, but I don't think that one in particular is super important to type manually. In hindsight if these were assigned to Ctrl-<letter>, they would have been a lot easier to type and use.

ctrl-letters are used for other things

It looks like it would just be be ctrl+^, which seems pretty straightforward.

ctrl+_ to separate cells, ctrl+^ to separate rows - works perfectly in notepad++.

I think the proposal can be improved by using ctrl+^ followed by a newline as a row separator, it looks much more readable plus will allow various line-based CLI tools to be used unless there are newlines in the cells.

Straightforward is completely subjective. But a comma is relatively much simpler in an absolute sense.

Ctrl+shift+6 is a 3-key chord, it’s potentially hard to discover (I can’t say I’ve actually ever seen it), it seems likely to be overridden by applications, and caret isn’t a natural separator and is more commonly used for other things, like exponents.

A comma is 1 key on the keyboard, and it’s already a natural separator; the very meaning of comma is separator. Note how many commas are used in this thread compared to the number of record separators. :P

Having to type both ctrl+shift+6 and ctrl+shift+minus a lot seems like a small physical and mental friction compared to using commas and returns each time a character is typed, that adds up to a lot of physical and mental friction over time. Enough that the eventual implication is that you need better tooling than a text editor provides in order to author delimited files, enough that it sort of undermines the idea of having a text file. It’s a mistake to think that because a key chord exists that it’s a solved problem, and a mistake to underestimate the value of making commonly used items as simple as possible, especially if it’s going to affect a lot of different people.

While I agree with the sentiment of that, it still seems a lot easier than escaping characters. I would probably opt for a mix. Control separation with new lines

Isn’t escaping a separate orthogonal issue? Or am I misunderstanding your point? Several people have pointed out that the special ascii field separator will have to be escaped if used within a field, just like a comma is. It seems like escaping is an issue either way, and aside from that, a comma is easier in practice than a special character at every level of interaction; discovery, typing, displaying, tooling, printing, standards, etc..?

I would concede that having the special characters inside fields will be less common than having commas inside CSV field is. I guess that is worth a lot even if it doesn’t fully solve the problem.

> no easy way to type them on a keyboard

or probably to see them in the screen in any sensible form.

Also, what to do if you want to embed those ctrl characters in a field? you are likely back to the way that CSV does it with quotes, commas and CRLFs.

That’s the whole point of having field and record separators as distinct values in ASCII. There is no other valid use for them, so no escaping is necessary. Have you ever used ASCII value 30 for anything, anywhere, in your life?

No, no one has ever used that character because it can't be typed or displayed which is the entire point of the thread you're replying to

But that’s my point. The person I responded to was objecting that they might want to use control characters like ASCII 30 as values in a field. As you and I agree, that will never happen.

What about the cases where people don’t want to use it but still do?

People C&P values from a source that includes those characters and they‘ll break your export file

Sometimes the content of a cell in e.g. a CSV file will be another CSV file. This inevitably happens with pretty much every format, whether CSV, TSV, JSON, etc, so you'll need some sort of quoting rule no matter what you do.

I have seen no end of CSV data that embeds CSV data in a field. I'm sure this will happen for whatever character format you pick.

Out of curiosity, in which general circumstances do you tend to see this sort of data? A lot of the support I see for ASV/USV/whatever comes from the idea that this is negligibly rare, which has always sounded to me like a dangerous assumption for a general-purpose format.

Some (many?) years ago i wrote a FOSS tool for messing with CSV called CSVfix. People used to mail me CSV files and ask how to parse them. Also, in my general consulting/contracting work I came across all sorts of weird stuff, a lot of it machine-generated.

> I have seen no end of CSV data that embeds CSV data in a field.

So in CSV [1] a record is separated by a CRLF (0x0D 0xA[2]) and a field value is separated by a comma (0x2c). In ADT (ASC?), the record separator is 0x1E and the unit/field separator is 0x1F.

But there are two more separators defined: file (0x1C) and group (0x1D).

I'm not sure if it's defined anywhere, but if if you wish to embed ADT data with-in a ADT file, and have it as part of the CSV-equivalent field (unit), you could say that:

    after the 0x1E record separator, put a group separator (0x1D)
    which will denote the beginning of ADT sequence which will
    be treated as a unit value. The end of the value shall
    ("MUST"?) be denoted by another group separator, after which
    a unit separator will indicate the next field.

The fact that there are four separation characters would allow for some to be used for embedding applications to tell parsers that a new 'level' of parsing is being done.

[1] https://datatracker.ietf.org/doc/html/rfc4180

[2] https://www.man7.org/linux/man-pages/man7/ascii.7.html

> There is no other valid use for them, so no escaping is necessary.

Famous last words...

> Have you ever used ASCII value 30 for anything, anywhere, in your life?

No but if this format took off I would be.

And then because text editors start displaying them so the files make sense, people start using them for other purposes, like separating values on a line or copying spreadsheet cells to the clipboard, because it's more "semantic", and those lines get pasted into a field in a tool that exports its data as CSV.

What then?

And equally as important, you can cat a CSV file and easily understand it.

Or concatenate them, or diff or grep.

This is a bit silly. Any modern text editor (whether vim or VSCode or BBEdit or Notepad++ or whatever) is capable of displaying control characters and of copy/pasting them. Keyboard shortcuts for inserting any characters whatsoever are easy to add. And even with CSV files, if you’re editing them by hand rather than manipulating them with code, you’re probably doing it wrong.

All of this is easy (use the proper editor, configure it for this particular weirdass situation, do something other than the thing you want to do, etc) in a way that’s exactly analogous to ‘you can spin up your own dropbox over the weekend with ftp and rsync’.

Maybe you with a hex editor that shows dual pane: hex and text.

I asser that is still not convenient or scalable. You will need to mentally parse each number (two characters) to ensure it is correct. Compare this with a simple glyph (i.e. a single comma) which is easy to eyeball.

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