Elegant way to write when inside a for loop? - raku

Question

I can write something like this (elem here is an XML::Element but it doesn't really matter):
for $elem.nodes {
when XML::Element { ... }
when XML::Text { ... }
...
default { note qq{Ignoring unknown XML node "$_".} }
}
which looks nice, but doesn't give me a readable name for $_ inside the code using it, which is why I'd prefer to write this:
for $elem.nodes -> $child {
when XML::Element { ... }
when XML::Text { ... }
...
default { note qq{Ignoring unknown XML node "$child".} }
}
but this doesn't work because now $_ isn't set, and so I actually need to write
for $elem.nodes -> $child {
given $child {
when XML::Element { ... }
when XML::Text { ... }
...
default { note qq{Ignoring unknown XML node "$child".} }
}
}
which is a bit redundant and adds an extra level of indentation.
It's definitely not the end of the world, but am I missing some simple way to have both a readable variable name and avoid given?

Answer 1

You can bind the variable above the when statements, it's a little uglier but it does the job.
for $elem.nodes {
my $child = $_;
when XML::Element { say 'I am XML!' }
when XML::Text { say 'I am text!' }
default { say "I am default: $child" }
}
Edit: In Raku I think it is perfectly reasonable to stick to using $_ seeing as the idea of $_ has been around for quite some time.

Answer 2

for #a -> $x { {
when 2 { say "$x ... a" }
when 4 { say "$x ... b" }
} given $x }
naughty double curlies and a post-given?