chaining#

chaining provides the --> operator, which allows the nesting of expressions by chaining them in a sequence.

sugar (-->  ... )

Expands a processing chain into nested expressions so that each expression is passed as a tailing argument to the following expression.

__ can be used as a placeholder token to position the previous expression.

Example:

--> x
    f
    g
    h 2 __
    k

Expands to:

k
    h 2
        g
            f x