As of this weekend (and Benthos v3.13) you can now use a
bloblang processor and complementary condition. These components are in a beta phase, which means that based on feedback the mapping language might change in minor ways in upcoming minor releases.
For the last few weekends I've been dipping my toes in a mapping language design that I'm calling Bloblang. Bloblang is specifically designed for data queries and (eventually) structural data mappings. In Benthos version 3.12, which I'm planning to release today, you can play around with a limited feature set of Bloblang by using it in function interpolations.