Define and call

Define a reusable calculation

A function takes inputs called parameters and returns the value of its body. Uppercase names can name callables. Add(3, 4) passes two arguments and returns 7.

Runnable RiXRun cell

Add(x, y) -> x + y; Add(3, 4);

The same function also works with exact fractions.

Runnable RiXRun cell

Add(x, y) -> x + y; Add(1 / 3, 1 / 6);

The result is 1/2. Each level-two topic starts fresh, so this cell includes its own definition. Change either argument and rerun.

Use a short anonymous function

(x) -> x * 2 describes the same rule without naming it. A map pipe applies the rule once to each array item.

Runnable RiXRun cell

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

The result is [2, 4, 6]. See Pipes for that traversal. Scope and imports explains how nested functions see surrounding names; Multifunctions and Partial application are later options.