# c0sv
This is a binary CSV format. Incredibly simple, and separated by ASCII Control
characters. This uses SOH (Start of Heading), STX (Start of Text), ETX (End of
Text), ESC (Escape), US (Unit Separator), and RS (Record Separator).
The stream is expressed in the following faux-EBNF (where * represents any
single byte):
```ebnf
stream = [header], STX, records, ETX
header = SOH, units
units = unit, { US, unit}
unit = { (* - control) | (ESC, *) }
```
This is mostly a simple experiment to see how feasible it would be to create a
very CSV-like format using these ASCII control characters for delimitation (and
particularly to use the control characters in the way they are intended to be
used). It's probably not extraordinarily useful, because the only real purpose
of CSV is exchange where manual readability and/or writability is important. If
you want good binary flexibility, you're probably better off using a good binary
format, like bincode or messagepack.
Still, this does have some convenient aspects, such as the fact that it is
rather easily streamable, allowing processing records while needing only one in
memory at a time. At the expense of being slower to parse, this format is
capable of being slightly smaller than most other binary formats, as there are
no length prefixes.
# Advantages
Over CSV:
* Headers are explicitly delimited, so there is never any guessing about whether
the first row constitutes a header.
* There is only one method of escaping, so there is not any need for confusion
about how to handle special characters like commas or newlines in fields.
Parsing is also simpler in this case, as CSV parsers often try naively to
process interleaved newlines.
* The end of the document is also explicitly delimited, so multiple documents
with headers can be concatenated in the same stream and parsed without any
loss.
# Disadvantages
* Control characters aren't really printable, so this format can not be easily
edited with a text editor.
* Because fields and records are delimited with a separator, There is a minimum
of a single field and a single record. A document represented by `[STX][ETX]`
is a document with a single record consisting of a single empty field. This
means it is impossible to represent a record without any fields (it will be a
single empty field, rather than having no fields), or a document without any
records (it will be a document with a single record of a single empty field).
That last one could feasibly be solvable by using the record separator and unit
separator as prefixes instead of separators, but that's less fun, and doesn't
fit the semantics of the control characters. It also increases the document
size by one extra byte per record.