Append¶

aggregating category: array no `||` new-mode: required resultSize: 1

Concatenates two or more ARRAY inputs into a single ARRAY, preserving order.

Append is an array-aware aggregating rule: it accepts two or more ARRAY-typed inputs and returns one ARRAY containing every element in input order (input one's elements first, then input two's, …).

The rule has two equivalent shapes:

Parameter form — Append(:arr1, :arr2, ...) resolves the inputs by field name. At least two field references are required.
Pipeline form — :arr1, :arr2 => Append() consumes all positional pipeline inputs in order.

Available in new mode only.

Parameters¶

Parameter form¶

N — arr Mandatory — accepts: field: Two or more field references, each referring to an ARRAY-typed input field.

Pipeline form (no parameters)¶

No parameters accepted.

Input type¶

ARRAY

Output type¶

ARRAY

Requires¶

All inputs must be ARRAY-typed.
At least two inputs are required.

Examples¶

Pipeline form

:base, :extra => Append() => :combined

Parameter form

Append(:base, :extra)

Construct an ARRAY by appending a virtual extension (test094)

:n => AsInt() => :n_int
Fill(9, :n_int)[] => :base
SetValue([0]) => :zero
Append(:base, :zero)[]

Errors¶

`Append': all inputs must be ARRAY-typed

A non-ARRAY value reached the rule at runtime.
`Append' parameter form requires at least two field references

Fewer than two parameters were supplied.
`Append': field:f' not found in input set`

A named field reference does not match any input field.
`Append' is only available in new mode (setnew mode : "true"' in etl.conf)`

New mode is not enabled in etl.conf.