# Mark Examples
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
--
```
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