Implement `MAP(key, value)` syntax to match documentation

[friendlymatthew]

Describe the bug

The documentation shows the map function supports a simple key-value syntax like map(key, value), but this syntax currently errors!

DataFusion CLI v51.0.0
> SELECT MAP('type', 'test');
Execution error: Expected list, large_list or fixed_size_list, got Utf8

[Itzdhruvpatel]

I appreciate you reporting this. The reason for the error is that DataFusion's current implementation of the MAP() function expects both arguments to be list types (list, large_list, or fixed_size_list) rather than scalar strings (Utf8). Thus, a type mismatch causes the syntax MAP('type', 'test') to fail.

Workaround:
Use arrays to construct the map:
sql
SELECT MAP(ARRAY['type'], ARRAY['test']);

[friendlymatthew]

The reason for the error is that DataFusion's current implementation of the MAP() function expects both arguments to be list types (list, large_list, or fixed_size_list) rather than scalar strings (Utf8). Thus, a type mismatch causes the syntax MAP('type', 'test') to fail.

Hi, you're right about the current behavior - map() currently requires list types rather than accepting scalar values directly. However, this is the issue I'm working to fix

While the workaround you mentioned works with the current impl, the goal here is to make that workaround unnecessary by fixing the underlying limitation

[Itzdhruvpatel]

Thanks for clarifying! That makes sense — right now MAP() requires list types, so the array workaround is the only option:
SELECT MAP(ARRAY['type'], ARRAY['test']); - Workaround

SELECT MAP(
ARRAY['type', 'category'], { for multiple entries }
ARRAY['test', 'demo']
);

[tshauck]

take

[tshauck]

nvm, see the PR attached :)