Expressions And Operators: Pipe

The binary pipe operator, |>, evaluates its left-hand operand, and stores the result in the pre-defined pipe variable $$. There is a sequence point after the evaluation of the left-hand operand. Then the right-hand operand is evaluated, and its type and value become the type and value of the whole expression. The right-hand operand must contain at least one occurrence of the pipe variable $$. For example:

$x = vec[2,1,3]
  |> Vec\map($$, $a ==> $a * $a)
  |> Vec\sort($$);

A pipe expression cannot be used as the right-hand operand of an assignment operator.