Editing Raku (programming language) (section)

====Blocks and closures====
Parameters can also be passed to arbitrary blocks, which act as [[Closure (computer science)|closures]]. This is how, for example, <code>for</code> and <code>while</code> loop iterators are named. In the following example, a list is traversed, 3 elements at a time, and passed to the loop's block as the variables, <code>$a, $b, $c</code>.<ref name="syn04">{{cite web | url=https://design.raku.org/S04.html | title=Synopsis 4: Blocks and Statements | author=Wall, Larry | date=2009-05-20 }}</ref>
<syntaxhighlight lang="raku">
for @list -> $a, $b, $c {
    ...
}
</syntaxhighlight>
This is generally referred to as a "pointy sub" or "pointy block", and the arrow behaves almost exactly like the <code>sub</code> keyword, introducing an anonymous closure (or anonymous subroutine in Perl terminology).<ref name="syn6"/>