Concat

String concatenation

Signature

concat(expr: AttrName|(Tuple->Numeric)) -> Aggregator

Examples

concat(:name)

concat(:name, between: ', ')

concat(between: ', '){|t| t.name }

concat(->(t){ t.name.upcase }, between: ', ')

Description

Concatenates string representations of input values.

Implementation notes

This aggregate function can be applied to any data type, not only String attributes. Ruby's to_s will be used on values prior to concatenation.

The options are:

• before starts the resulting string (defaults to '')
• after ends the resulting string (defaults to '')
• between is used between each value

As of current Alf version, the order in which the values are concatenated is not guaranteed. So far, this function is thus non-deterministic.