Dyalog doesn't have an explicit implementation for maps, but you get the same effect with column-major table stores and the implicit hashmap backing of the search-like primitives [0]. E.g.

    keys←'foo' 'bar' 'baz'
    values←1729 42 0.5721

    indexOf←keys∘⍳  ⍝ The dyadic ⍳ here is what builds a hashmap

Then you can use it like

    data←(values⍪¯1)[indexOf 'bar' 'bar' 'baz' 'foo' 'invalid' 'foo']

where ¯1 is just the value you want missing keys to map to. If you're okay erroring in that case, it can be left off. For map "literals", a syntax like the following gets you there for now:

    k v ←'foo' 1729
    k v⍪←'bar' 42
    k v⍪←'baz' 0.5721

In version 20, proper array literal notation [1] is landing, where you'll be able to do:

    keys  values←↓⍉[
    'foo' 1729
    'bar' 42
    'baz' 0.5721]

In practice, I suspect that this ends up being more ergonomic than actual maps would be in the language. That said K is all about maps and the entire language is designed around them instead of arrays like APL. IIRC, there was also some discussion on the J forums a while back about whether or not to have explicit hashmap support [2].

[0]:https://help.dyalog.com/19.0/#Language/Defined%20Functions%2...

[1]:https://aplwiki.com/wiki/Array_notation

[2]:https://groups.google.com/a/jsoftware.com/g/forum/c/VYmmHyRo...

It's likely a combination of both. It's certainly possible to write Kap in a much more condensed form. But things like if-statements and hash maps does allow for a more imperative style.