Add $nu.scope.engine_state

[kubouch]

Description

Adds a new $nu.scope.engine_state entry that includes the number of all inserted items in the engine state. It can be useful for tracking how the engine state grows over time.

Example output:

> $nu.scope.engine_state
  source_bytes   52951
  num_vars       421
  num_commands   339
  num_aliases    20
  num_blocks     371
  num_modules    9
  num_env_vars   220

Tests

Make sure you've run and fixed any issues with these commands:

• cargo fmt --all -- --check to check standard code formatting (cargo fmt --all applies these changes)
• cargo clippy --workspace --features=extra -- -D warnings -D clippy::unwrap_used -A clippy::needless_collect to check that you're using the standard code style
• cargo test --workspace --features=extra to check that all the tests pass

[stormasm]

This is a very nice cool addition ! 😃
Should definitely be useful for figuring out the size of things once we start adding very large data frames...

Actually maybe not...

If we have several large data frames in memory...
Are they inside the engine from a memory point of view ?

From a garbage collection point of view.
I guess we can not drop that data frame and clean up the memory...

[fdncred]

nice - i just reran the failed test and it passed this time.

[fdncred]

This looks fun. let's land and play. :)

[fdncred]

we should have a contest to see who can make the biggest numbers without crashing nushell. here's my entry, which is just my standard load with nothing extra.