> For the complete documentation index, see [llms.txt](https://docs.urbit.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.urbit.org/urbit-os/kernel/clay/marks/examples.md).
# Mark Examples
Clay mark examples - CSV mark implementation with parsing, validation, and conversion code samples.
These are the files used in the [Writing Marks](/urbit-os/kernel/clay/marks/writing-marks.md) guide.
## `/lib/csv-utils/hoon`
/lib/csv-utils.hoon
```hoon
|%
++ validate :: All rows same length?
|= csv=(list (list @t))
^- ?
=/ result
%+ roll csv
|= [row=(list @t) =flag ref=(unit @ud)]
?. flag
[flag ref]
?~ ref
[flag `(lent row)]
?. =(u.ref (lent row))
[%.n ref]
[flag ref]
flag.result
++ en-csv :: csv -> atom (to mime)
|= csv=(list (list @t))
|^ ^- @t
(cat 3 (crip (join '\0a' (turn csv en-row))) '\0a')
++ en-row :: encode row
|= row=(list @t)
^- @t
(crip (join ',' (turn row en-field)))
++ en-field :: encode field
|= field=@t
^- @t
%+ rash
field
%+ cook
|= =tape
^- @t
?~ tape ''
?: =('"' i.tape)
(cat 3 (crip tape) '"')
(crip tape)
;~ pose
(full (star ;~(less ;~(pose doq (mask ",\0a\0d")) next)))
;~ plug
(easy '"')
(star ;~(pose (cold '""' doq) next))
==
==
--
++ de-csv :: atom -> csv (from mime)
|= dat=@t
|^ ^- (list (list @t))
=/ parsed (parse dat)
?. (validate parsed)
~|(%mixed-col-count !!)
parsed
++ parse :: parse cord
|= dat=@t
|^ ^- (list (list @t))
%+ rash
dat
%+ most
;~(pose (jest '\0d\0a') (mask "\0a\0d"))
(most com parse-field)
++ parse-field :: parse field from cord
|^
%+ cook
|=(a=tape (crip a))
;~(pose unenclosed enclosed)
++ unenclosed :: unquoted field
;~ sfix
(star ;~(less ;~(pose doq (mask ",\0a\0d")) next))
;~ pose
;~ plug
;~(pose (jest '\0d\0a') (mask "\0a\0d"))
;~(less next (easy ~))
==
;~(less doq (easy ~))
==
==
++ enclosed :: quoted field
|^
;~ sfix
(ifix [prefix suffix] content)
;~ pose
;~(simu (mask ",\0a\0d") (easy ~))
;~ plug
;~(pose (jest '\0d\0a') (mask "\0a\0d"))
;~(less next (easy ~))
==
;~(less next (easy ~))
==
==
++ content :: quoted field contents
%- star
;~ pose
(cold '"' (jest '""'))
%+ cold '\0a'
;~(pose (jest '\0d\0a') (just '\0d'))
;~(less doq next)
==
++ prefix ;~(pose ;~(plug (star ace) doq) doq) :: quoted field prefix
++ suffix ;~(pose ;~(plug doq (star ace)) doq) :: quoted field suffix
--
--
--
--
++ csv-join
|= [ali=(urge:clay (list @t)) bob=(urge:clay (list @t))]
^- (unit (urge:clay (list @t)))
|^
=. ali (clean ali)
=. bob (clean bob)
|- ^- (unit (urge:clay (list @t)))
?~ ali `bob
?~ bob `ali
?- -.i.ali
%&
?- -.i.bob
%&
?: =(p.i.ali p.i.bob)
%+ bind $(ali t.ali, bob t.bob)
|=(cud=(urge:clay (list @t)) [i.ali cud])
?: (gth p.i.ali p.i.bob)
%+ bind $(p.i.ali (sub p.i.ali p.i.bob), bob t.bob)
|=(cud=(urge:clay (list @t)) [i.bob cud])
%+ bind $(ali t.ali, p.i.bob (sub p.i.bob p.i.ali))
|=(cud=(urge:clay (list @t)) [i.ali cud])
::
%|
?: =(p.i.ali (lent p.i.bob))
%+ bind $(ali t.ali, bob t.bob)
|=(cud=(urge:clay (list @t)) [i.bob cud])
?: (gth p.i.ali (lent p.i.bob))
%+ bind $(p.i.ali (sub p.i.ali (lent p.i.bob)), bob t.bob)
|=(cud=(urge:clay (list @t)) [i.bob cud])
~
==
::
%|
?- -.i.bob
%|
?. =(i.ali i.bob)
~
%+ bind $(ali t.ali, bob t.bob)
|=(cud=(urge:clay (list @t)) [i.ali cud])
::
%&
?: =(p.i.bob (lent p.i.ali))
%+ bind $(ali t.ali, bob t.bob)
|=(cud=(urge:clay (list @t)) [i.ali cud])
?: (gth p.i.bob (lent p.i.ali))
%+ bind $(ali t.ali, p.i.bob (sub p.i.bob (lent p.i.ali)))
|=(cud=(urge:clay (list @t)) [i.ali cud])
~
==
==
++ clean :: clean
|= wig=(urge:clay (list @t))
^- (urge:clay (list @t))
?~ wig ~
?~ t.wig wig
?: ?=(%& -.i.wig)
?: ?=(%& -.i.t.wig)
$(wig [[%& (add p.i.wig p.i.t.wig)] t.t.wig])
[i.wig $(wig t.wig)]
?: ?=(%| -.i.t.wig)
$(wig [[%| (welp p.i.wig p.i.t.wig) (welp q.i.wig q.i.t.wig)] t.t.wig])
[i.wig $(wig t.wig)]
--
--
```
## `/mar/csv/hoon`
/mar/csv.hoon
```hoon
/+ *csv-utils
|_ csv=(list (list @t))
++ grab
|%
++ mime |=((pair mite octs) (de-csv q.q))
++ noun
|= n=*
^- (list (list @t))
=/ result ((list (list @t)) n)
?> (validate result)
result
--
++ grow
|%
++ mime
?> (validate csv)
[/text/csv (as-octs:mimes:html (en-csv csv))]
++ noun
?> (validate csv)
csv
--
++ grad
|%
++ form %csv-diff
++ diff
|= bob=(list (list @t))
^- (urge:clay (list @t))
?> (validate csv)
?> (validate bob)
(lusk:differ csv bob (loss:differ csv bob))
++ pact
|= dif=(urge:clay (list @t))
^- (list (list @t))
=/ result (lurk:differ csv dif)
?> (validate result)
result
++ join
|= $: ali=(urge:clay (list @t))
bob=(urge:clay (list @t))
==
^- (unit (urge:clay (list @t)))
(csv-join ali bob)
++ mash
|= $: [ship desk (urge:clay (list @t))]
[ship desk (urge:clay (list @t))]
==
^- (urge:clay (list @t))
~|(%csv-mash !!)
--
--
```
## `/mar/csv-diff/hoon`
```hoon
|_ dif=(urge:clay (list @t))
++ grab
|%
++ noun (urge:clay (list @t))
--
++ grow
|%
++ noun dif
--
++ grad %noun
--
```
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.
Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:
```
GET https://docs.urbit.org/urbit-os/kernel/clay/marks/examples.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.