Array construction

[rvalek]

Hi! I am trying to construct arrays and maps, to get something like this:

SELECT MAP(ARRAY['a','b'], ARRAY[col1, col2]) FROM ... -- Trino
SELECT MAP_FROM_ARRAYS(['a','b'], [col1, col2]) FROM ... -- Spark

A nice way to do this would be to define the map constructor for each corresponding dialect:

let make_map = keys vals -> s"MAP({keys}, {vals})" # for Trino dialect
let make_map = keys vals -> s"MAP_FROM_ARRAYS({keys}, {vals})" # for Spark dialect

and then call the function like this:

select { mymap = make_map ['a', 'b'] [col1, col2] }

But it doesn't seem like the compiler knows how to construct SQL arrays (for any dialect).
There is also no way to define variadic functions, so I can't define an array constructor with simple s-strings.
Is this correct?

I could try contributing this if it aligns with your vision.

[rvalek]

Took a shot at it: #5312

[rvalek]

PR merged, array support added. Nice!