dfr concat-str for expression

Creates a concat string expression.

Signature

> dfr concat-str

Examples

Creates a concat string expression

> let df = ([[a b c]; [one two 1] [three four 2]] | dfr into-df);
    $df | dfr with-column ((dfr concat-str "-" [(dfr col a) (dfr col b) ((dfr col c) * 2)]) | dfr as concat)
╭───┬───────┬──────┬───┬──────────────╮
│ # │   a   │  b   │ c │    concat    │
├───┼───────┼──────┼───┼──────────────┤
│ 0 │ one   │ two  │ 1 │ one-two-2    │
│ 1 │ three │ four │ 2 │ three-four-4 │
╰───┴───────┴──────┴───┴──────────────╯