Perl Hashes look sequential to me, they look exactly like a specialised array with the the condition that it contains an even number of entries.

#my %var = ('k1' => 'v1', 'k2' => 'v2');
my %var = ('k1', 'v1', 'k2','v2');
print $var{k2}. "\n";
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I now what interpolation means in other contexts, I'm not sure in relation to hashes.

As tempting as it is to use the some of the convenient shortcuts of Perl (and I am aware of the one you're suggesting), I prefer to use explicit notation in all languages as a rule of thumb, its safer, clearer, and avoids potentially unintended behavious.

Defining what the primitives are for a particular language is irrelevant to my original question, so I won't pursue it.