In JavaScript, I can go
const materials = [
'Hydrogen',
'Helium',
'Lithium',
'Beryllium'
];
console.log(materials.map(material => material.length));
// expected output: Array [8, 6, 7, 9]
I guess that raku has some chops in functional - and I wonder if someone can clarify the equivalent code (see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions )
The most direct equivalent would be
my @materials = <Hydrogen Helium Lithium Beryllium>;
say @materials.map(-> $material { $material.chars });
but an arrow sub is more explicit than you need in this case, because
say @materials.map: *.chars;
would also be sufficient (method call on a "whatever star" returns a code block that calls that method on its argument), and
say @materials».chars;
would also work (hyper-application applied to the dot operator).