# Nushell core team meeting 2022-06-08

## Attendees

- Darren
- Michael
- Jakub
- JT
- Reilly
- Stefan
- Andrés

## Open topics

## Discussed topics

- Compiler design lessons from jakt selfhost
- Having a compiler stage struct that contains a list of errors to add.
- Error convenience
- Errors in a traceback
- Experience currently depends heavily on the quality of the individual error emitting locations

- Despanning
- Lets try to move from `value.span()` to `expr.span()` instead of doing the hard refactor first
- not carrying spans on `Value` should reduce the memory footprint and thus improve performance.

- Flag passthrough
- Should externs pass undocumented/able flags
- Problem: positionals vs values for flags
- Ordering has to be preserved! (Tools might only accept flags and positionals in a particular order)
- ?: Workaround with annotations for the parameters or flags with `^`

- Optimization for REPL vs IDE
- Nushell is very static + deltas as an optimization for the repl but this is hard if we want to do IDE support for larger scripts.
- Maybe take inspiration from jakts IDE approach
- Treesitterability of nushell

- Performance monitoring
- Jakub introduced `$nu.scope.engine_state` to get statistics about what the engine is holding
- We probably need a GC sooner rather than later.
- Can we serialize stuff as parquet to keep the hot memory smaller.
- Great place for serialized data might be `last_result`

- Data(frame) optimized engine tradeoffs
- Datafusion style engine
- Sequential optimized shell engine
- Dataframe highly efficient on a special subset of problems
- How can we get nushell commands to dispatch on all different data representations.

- SQlite history part 2 (land it in nushoell)
- landed in reedline, nushell not yet adapted to the new API (independent of whether a text file or sqlite is used)
- Goal: have the option in the config to toggle on the new history to test it. (Currently no tangible benefit yet)
- Some TODOs in phiresky's code, porting of the `history` command.
- Benefit of making it a compiler flag instead of config flag is minimal as the API adaptations have to be done anyways