Pipes

Map every item

|>> applies a function to each array value and returns an array of results. The callback's first parameter receives one value at a time.

Runnable RiXRun cell

[1, 2, 3] |>> (x) -> x * 2;

The result is [2, 4, 6]. Try x ^ 2 instead and predict the new array.

Filter by a condition

|>? keeps values whose predicate succeeds. This example keeps 2 and 4. Write % 2 == 0 explicitly: zero alone is truthy in RiX.

Runnable RiXRun cell

[1, 2, 3, 4] |>? (x) -> x % 2 == 0;

Combine a finite array

|>: reduces the array with a function of the accumulated value and the next value. It starts with the first item, so the sum below is 10.

Runnable RiXRun cell

[1, 2, 3, 4] |>: (total, value) -> total + value;

For an empty collection, use an explicit initial value or choose another operation. Callback forms can also receive a one-based index and the original source when needed; Arrays provides a position-aware example. Start with one value parameter until the other context has a purpose.

Keep going

Use Generators to make a finite input array and Transform a report to combine map and filter in a task. Lazy and async pipelines have separate advanced lessons.