Feature: Support map lambda functions

[b41sh]

Summary

• map_filter(map, lambda_expr)
• map_transform_keys(map, lambda_expr)
• map_transform_values(map, lambda_expr)

for example:

SELECT map_filter({1:0,2:2,3:-1}, (k, v) -> k > v);
SELECT map_transform_keys({1:1,2:2,3:3}, (k, v) -> k + 1);
SELECT map_transform_values({1:1,2:2,3:3}, (k, v) -> k + v);

reference document:
https://docs.databricks.com/en/sql/language-manual/functions/map_filter.html
https://docs.databricks.com/en/sql/language-manual/functions/transform_keys.html
https://docs.databricks.com/en/sql/language-manual/functions/transform_values.html

[Dragonliu2018]

i want to try it