50 Ways to Love Your CX Data
Fifty examples that walk through CX data — bare attributes through anchors and merge, with stops at quoted strings, multi-line text, comments, collection literals, typed columns, and a final whole-shop document. Each step adds one shape; no shape requires anything the earlier ones do not already give you. The companion §15 covers directives.
1. The atom
Just name=value. In CX this is a valid document on its own — logfmt mode, intended for log lines and structured events.
size=large
2. Several atoms — a one-line event
A whole log line — no brackets, no root, just attributes.
time=2026-05-09T12:00:00Z level=INFO svc=oven pizza=Margherita
3. Empty element
Brackets give a name. Empty, but a thing.
[pizza]
4. Element with one property
The atom from example 1, now attached to a pizza.
[pizza size=large]
5. Several properties
Keep adding. No commas required between attrs.
[pizza size=large crust=thin price=12]
6. Bare flag (no equals-value)
Presence means yes, absence means no — same idea as --verbose or HTML's required. Here, this pizza is controversial.
[pizza name=Hawaiian controversial]
7. Explicit boolean values
When you want both polarities, write the word.
[pizza vegan=true gluten-free=false]
8. Booleans are ordinary attributes
Booleans are ordinary attributes — name=true / name=false; the bare tokens auto-type as bool.
[pizza vegan=true nuts=false gluten=false]
9. Numbers — int, decimal, negative, hex, underscores
All bare, all auto-typed. Underscores in numbers are readability sugar.
[pizza price=12.50 discount=-2 ovens=4 mask=0xFF00FF batch=1_000_000]
10. Quoted — single quotes
Reads: attribute name, value is the string "BBQ Chicken".
[pizza name='BBQ Chicken']
11. Quoted — double quotes
Pick the quote that does not appear in the value.
[pizza name="Quattro Formaggi"]
12. Mix when the value has an apostrophe
Double-quote around an apostrophe; no escaping needed.
[pizza name="Tony's Special"]
13. The empty string
Distinct from missing: the attribute is there, just empty.
[pizza name=Mystery description=""]
14. Escape sequences inside quotes
Same family as C and JSON: \\n, \\r, \\t, \\uXXXX, \\", \\\\.
[pizza alert='Hot!\\nHandle with care.\\tCafé']
15. Entity references (XML-style)
&, <, > are recognized in body text — they round-trip faithfully, and an --xml emit renders them as proper XML entities. In attribute values they are not decoded: the characters stay literal (and --xml escapes the ampersand a second time). For a literal & or < in an attribute, just write the character inside quotes.
[note Cheese & Pepper]
16. Null
A real null value, distinct from empty string or the word "null" as a string.
[pizza discount=null reviewed=null]
17. Date and datetime literals
ISO 8601 shapes are auto-typed as date or datetime.
[promo starts=2026-05-01 ends=2026-05-31 cutoff=2026-05-31T23:59:00Z]
18. Plain text body
After the name, the rest of the bracket is text.
[motto Hand-tossed since 1987]
19. Attributes plus text body
Reads: element pizza, attribute name=Margherita, then text body "Classic since day one.".
[pizza name=Margherita Classic since day one.]
20. Multi-line text — preserved as written
Whitespace and newlines inside a text body are kept literally.
[description
Stone-baked, hand-stretched,
and ready in 90 seconds.]
21. Triple-quoted string
Three quotes open and close. Single and double quotes inside need no escaping. Common leading whitespace is stripped.
[bio '''
Born in Naples, 1955.
Started New Haven in 1987.
Still on the line every Friday.
''']
22. Block content [| … |]
Like a text body, but indentation and newlines are kept verbatim; the block closes with |]. Unlike triple-quoted, inner elements such as [em best] are still real markup.
[poem [|
Roses are red,
violets are blue,
the [em best] pizza
is waiting for you.
|]]
23. Raw text [# … #]
The CDATA of CX. Brackets, quotes, <, > — all literal characters. The terminator is #].
[snippet [# if (x < 10) { return "[pizza]"; } #]]
24. Embedded code in another language
Raw text is how you embed SQL, JS, or regex without escaping every quote.
[query language=sql [#
SELECT name, price FROM pizza
WHERE price < 15 AND vegan = true;
#]]
25. Line comment
# comments out the rest of the line. Lives outside elements, like a script header.
# weekend special — pulled Monday
[pizza name=TruffleSpecial price=24]
26. Inline block comment
Element-shaped — fits inside brackets where # cannot reach.
[pizza name=Diavola [; TODO confirm price ] price=14]
27. Multi-line block comment
Canonical for multi-line notes.
[;
Pricing review:
- Diavola: bump to 16?
- Hawaiian: hold at 14
]
28. When to use which
# for line-scoped headers; [; … ] when the comment must nest inside an element or span lines. Not HTML's <!-- … --> — CX has its own.
# top-of-file header
[shop [; inline aside on this branch ] port=8080]
29. Nesting
Brackets inside brackets.
[pizza name=Margherita [base tomato]]
30. Siblings
Same shape, side by side. No separators required.
[pizza [topping cheese] [topping basil] [topping oil]]
31. Inline prose with markup
Prose and tags interleave freely. The same shapes you would write in HTML.
[note Try the [b Margherita] — our [em best seller], hand-tossed [strong daily].]
32. A whole article — prose and data
Headings, paragraphs, links, emphasis — CX handles document text as cleanly as XML.
[article
[h1 New Haven Story]
[p Founded in [em 1987]. See the [a href=/menu menu].]
[p Still [strong hand-tossing] every pie.]]
33. Deeper nesting — children with their own data
Each child carries its own attributes.
[pizza name=Quattro
[topping cheese price=2]
[topping ham price=3]
[topping olives price=2]]
34. Multiple top-level elements (no required root)
A document can be a flat list.
[pizza name=Margherita]
[pizza name=Hawaiian]
[pizza name=Diavola]
35. Multi-document file
One file, several independent documents. Same separator as YAML — three dashes on a line by themselves between documents.
36. Sequence (a, b, c) — flat list
Reads: element toppings, body is the sequence of three strings.
Collections live in a child element's body — attributes hold a single
scalar, never a collection.
[pizza [toppings (cheese, basil, oil)]]
37. Array [a, b, c] — nested list
Arrays preserve structure; sequences flatten. Use arrays when nesting matters.
[grid [cells [1, 2, 3]]]
38. Nested arrays
A matrix is just an array of arrays.
[board
[cells [[1, 0, 1],
[0, 1, 0],
[1, 0, 1]]]]
39. Map {k: v} — named key to value
Reads: element prices, body is a map with three entries.
[pizza [prices {small: 9, medium: 12, large: 15}]]
40. Collections in body position
Sequences, arrays, and maps can sit inside an element body too.
[favorites
(Margherita, Hawaiian, Diavola)]
41. Mixed-shape composition
Map of sequences, multi-line. Compose freely.
[stats {
monday: (12, 8, 14),
tuesday: (10, 9, 11),
wednesday: (15, 11, 18)
}]
42. Explicit type annotation
A glued ::T ascription on the name pins the body's type, overriding auto-typing.
[count::int 42]
[ratio::decimal 3.14159]
43. Typed array as body
::int[] for typed; ::[] for inferred (string array here).
[oven-temps::int[] 220 240 260 480]
[tags::[] cheap fast tasty]
44. Plain table — header plus rows
The [table[…]] block declares column names once. Each line below is a row.
[menu [table[name size price]]
Margherita medium 12
Hawaiian large 14
Diavola medium 13]
45. Typed columns
Each column can carry a colon-type. Cells parse accordingly.
[orders [table[item::string qty::int paid::bool when::date]]
Margherita 2 true 2026-05-09
Hawaiian 1 false 2026-05-09]
46. Quoted cells and nulls
Quote cells with spaces. null is a real null in the cell.
[shifts [table[cook hours::int notes]]
Pepe 8 morning
Maria 6 'closing crew'
'Jean-Luc' 4 null]
47. Anchor and alias
&classic names this element; [*classic] is an alias node referencing it. Which reading you get depends on the projection. The lossless projections carry the reference as written: canonical CX emit prints [*classic] back out, and --xml marks it with a cx: attribute, so the document round-trips byte-faithfully. The semantic projections resolve it: under --json/--yaml/--csv (any lossy projection) and inside a program's $doc, each alias expands to a deep copy of its anchor — the JSON of the example below carries two full Margheritas inside menu. cx lint (CX-L004) errors on a reference whose anchor does not exist, and a lossy projection of a dangling alias refuses outright.
[pizza &classic name=Margherita price=12 [base tomato]]
[menu [*classic] [*classic]]
48. Merge declaration
*classic declares a merge from the anchor, with the element's own attrs as overrides. The same split as the alias: the lossless projections keep the declaration as written — canonical emit prints [pizza *classic …], --xml emits a cx:merge="classic" attribute — while the semantic projections apply it: under a lossy projection or $doc, the second pizza inherits name=Margherita price=12 [base tomato] and its own attrs win on collision, so it comes out name=ClassicXL size=large price=16 with the tomato base. CX-L004 checks the target anchor exists.
[pizza &classic name=Margherita price=12 [base tomato]]
[pizza *classic name=ClassicXL size=large price=16]
49. A recipe — prose, data, table, all together
Tabular ingredients, prose steps with inline markup, multi-line notes — all in one document, one syntax.
[recipe name=Margherita serves=2
[ingredients [table[item amount::string]]
flour 300g
water 200ml
yeast 2g
'San Marzano tomato' 150g
mozzarella 120g
basil 'a handful']
[steps
[step Mix the dough and rest [em 24 hours] cold.]
[step Stretch by hand — no rolling pin.]
[step Bake at [strong 480 degrees] for 90 seconds.]]
[notes '''
A wetter dough gives a softer cornicione.
Do not skip the cold rest.
''']]
50. The whole shop
XML decl, anchor, block comments, typed table, a merge declaration (carried on the lossless projections, applied on the semantic ones — see 48), map and sequence children, triple-quoted text. One syntax, everywhere.
[?xml version=1.0 encoding=UTF-8]
[shop &flagship name='New Haven' port=8080 open=true
[; opening hours ]
[hours mon-fri=11-22 sat=12-23 sun=closed]
[; menu reviewed 2026-05-01 ]
[menu [table[name::string size price::decimal vegan::bool]]
Margherita medium 12.00 true
Hawaiian large 14.00 false
Diavola medium 13.00 false]
[staff [cook &lead name=Pepe shift=morning founder=true]
[cook *lead name=Maria shift=closing founder=false]]
[contact address='123 Via Forno'
[coords {lat: 40.8518, lon: 14.2681}]
[phones ('+39 555 0101', '+39 555 0102')]]
[tagline '''
Hand-tossed since 1987.
Still tossing.
''']]
The arc. Bare attribute → element → strings → text bodies → comments → structure → collections → typed arrays → tables → anchors → the whole shop. Every step adds one shape; no shape requires anything the earlier ones do not already give you.