Implement key functionality of jq

[cryptaliagy]

from https://github.com/gl-yziquel

@gl-yziquel

Hi.

Been using tomlq to parse various build related stuff on my machine. For instance, in executable Justfiles, or for autotools scaffolding, like that:

https://github.com/gl-yziquel/skeleton-autotools/blob/master/configure.ac#L4

One feature I'd like, in order to have nice output surrounding the output of just --list would be to be able to list the features of a cargo rust project. And present them nicely. I would therefore love if the keys functionalities of jq were implemented with tq.

[gl-yziquel]

@cryptaliagy

I've switched internally to using the tomlq tool of the python yq package. I have all the functionality I need. But the performance hit is very significant compared to tq.

https://github.com/cmeister2/tomlq.git

[cryptaliagy]

@gl-yziquel I've started taking a look at what would be involved. I can't promise I'll have this feature in the very near-term future, but I'll see if I can start implementing a very basic grammar with minimal function support (just keys and the existing functionality at this point) before year end

[gl-yziquel]

@gl-yziquel I've started taking a look at what would be involved. I can't promise I'll have this feature in the very near-term future, but I'll see if I can start implementing a very basic grammar with minimal function support (just keys and the existing functionality at this point) before year end

I'm not expecting anything. I know people are busy. I just raised the issue because I noticed it.

[cryptaliagy]

Very fair, and thank you for the suggested functionality!

I've added #10 which might help your usecase while not resolving this issue in particular. This will add support for you to export values from tomlq as JSON, which you can chain with jq for a (hopefully) more efficient setup.

tq -f Cargo.toml features -o json | jq keys