lens conjunction doesn't work

[LLFourn]

I would expect the following to output only the second element:

printf '[{"cond1": "false", "cond2": "true"}, {"cond1": "true", "cond2": "true"}]' | jql '.[]|={"cond1":"true"}|={"cond2":"true"}'

but it outputs

[
  {
    "cond1": "false",
    "cond2": "true"
  },
  {
    "cond1": "true",
    "cond2": "true"
  }
]

How do you do a conjunction on the lens conditions?

[yamafaktory]

This is not a bug, lenses - by design - were not made for that purpose. It's more about filtering the data so e.g. given the following test.json file:

[
  {
    "cond1": "false",
    "cond2": "true",
    "foo": 123
  },
  {
    "cond1": "true",
    "cond2": "true",
    "bar": 456
  },
  {
    "cond1": "true",
    "cond2": "false",
    "yup": 789
  }
]

You can pick two elements that are holding some key/value pairs:

 jql '.|={"cond1":"false","yup":"789"}' test.json

[
  {
    "cond1": "false",
    "cond2": "true",
    "foo": 123
  },
  {
    "cond1": "true",
    "cond2": "false",
    "yup": 789
  }
]

Moving this to a discussion since changing this would break the actual grammar and the goal was to keep the tool as simple as possible.

[LLFourn]

Right. I understood that the syntax you used was a disjunction bwetween each condition but I expected |={COND1}|={COND2} to apply COND2 on the set of elements that passed the COND1 lens. I mean the pipe symbol seems to be hinting at POSIX shell pipe semantics but in this case it's not. For example you could do what I want with two invocations of jql piped together.

printf '[{"cond1": "false", "cond2": "true"}, {"cond1": "true", "cond2": "true"}]' | jql '.[]|={"cond1":"true"}' | jql '.[]|={"cond2":"true"}'

It is quite unintuitive that:

jql '.[]|={"cond1":"true"}' | jql '.[]|={"cond2":"true"}

is not the same as a single

jql '.[]|={"cond1":"true"}|={"cond2":"true"}' 

[yamafaktory]

Gotcha, thanks for clarifying. Indeed something needs to be fixed, I will have a look at it.

[yamafaktory]

@LLFourn I've just release a new major version that fixes the bug:

• lenses and default filters are now merged into one enum (hence the major version since some other projects are consuming jql as a library)
• the pest grammar has be simplified
• piping lenses together - or with default filters - will just work as expected

Thanks a ton for submitting the initial issue and for pushing forward 🚀, you've helped me to fix a major flow in the tool!

[LLFourn]

Fantastic work. Cheers mate.