Tabular Output

Fixture

Examples below run against:

DOC:    {"users": [{"id": 1, "name": "Ada", "email": "ada@x.com", "active": true, "age": 30, "role": "admin", "secret": "a", "is_admin": true, "profile": {"name": "Ada", "email": "ada@x.com"}, "score": 85, "first_name": "Ada", "last_name": "Lovelace", "tags": ["math", "code"]}, {"id": 2, "name": "Bob", "email": "bob@y.org", "active": false, "age": 24, "role": "user", "secret": "b", "is_admin": false, "profile": {"name": "Bob", "email": "bob@y.org"}, "score": 40, "first_name": "Bob", "last_name": "Smith"}, {"id": 3, "name": "Cy", "email": "cy@x.com", "active": true, "age": 42, "role": "user", "secret": "c", "is_admin": false, "score": 90, "first_name": "Cy", "last_name": "Young"}], "logs": [{"ts": "10:00", "sev": 1, "msg": "start"}, {"ts": "10:05", "sev": 3, "msg": "fail"}, {"ts": "10:10", "sev": 2, "msg": "warn"}], "tweets": [{"id": 1, "text": "#foo", "entities": {"hashtags": [{"text": "foo"}]}}, {"id": 2, "text": "#bar #foo", "entities": {"hashtags": [{"text": "bar"}, {"text": "foo"}]}}], "records": [{"id": 1, "name": "a", "email": "x@y.com"}, {"id": 2, "name": "b", "email": "u@v.com"}]}

Serialise sequences of objects to row-oriented text formats.

`to_csv(headers?)`

Signature: Array<Object> -> String
Behavior: RFC-4180-ish CSV. Without arguments, the union of object keys is the header set, sorted by first-appearance.

DOC:    [{"name":"Ada","age":36},{"name":"Bob","age":42}]
QUERY:  $.to_csv()
OUT:
"name,age
Ada,36
Bob,42"

With explicit headers:

QUERY:  $.to_csv(["age","name"])
OUT:
"age,name
36,Ada
42,Bob"

Strings containing commas, quotes, or newlines are quoted and escaped per RFC 4180.

`to_tsv(headers?)`

Signature: Array<Object> -> String
Behavior: Same as to_csv but tab-separated. No quoting (tab-in-value is replaced with a space).

QUERY:  $.users.to_tsv(["id","email"])

Composing with the rest of the pipeline

Build a report:

$.users
  .filter(@.active)
  .map(u => u.pick(id, name, email))
  .sort(@.id)
  .to_csv()

Pipe to a file from the CLI:

jetrocli '$.users.filter(@.active).pick(id,name).to_csv()' < users.json > out.csv

Limitations

Nested values are JSON-encoded into the cell. For deeply-nested structures, flatten first with flatten_keys:
```
$.records.map(r => r.flatten_keys()).to_csv()
```
The format is row-major. For wide-narrow long-format reshape, use pivot / zip_shape first.
For Excel-flavored CSV (BOM, CRLF), post-process the result.

Practical examples

# Active-user export
$.users.filter(@.active).map(u => u.pick(id, name, email)).sort(u => u.id).to_csv()

# Daily sales report (use e[0]/e[1] indexing — array-pattern destructure
# inside a lambda doesn't parse in v0.5)
$.sales.group_by(s => s.day).entries().map(e => {
  day:   e[0],
  total: e[1].map(@.amount).sum(),
  count: e[1].count()
}).to_csv()

# Hashtag frequency CSV
$.tweets.flat_map(t => t.entities.hashtags.map(@.text))
  .count_by(@)
  .entries()
  .map(e => {tag: e[0], count: e[1]})
  .to_csv()

# TSV for log shipping
$.logs.map(l => l.pick(ts, level, message)).to_tsv()

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