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# Description
Add `metadata access`, which allows accessing/inspecting the metadata of
a stream in a closure.
```nu
ls | metadata access {|meta|
...
}
```
- The metadata is provided as an argument to the closure, identical to
the record obtained with `metadata` command.
- `metadata access` passes its input stream into the closure as it is.
- Within the closure, both the metadata and the stream are available.
The closure may modify, collect or pass the stream as it is.
# Motivation
- Without this command, nu code can't act on metadata without losing the
stream, use cases requiring both the stream and metadata must be
implemented either as a built-in or a plugin.
- This command allows users to enhance presentation of data, similar to
`table` coloring the output of `ls`.
Nushell core libraries and plugins
These sub-crates form both the foundation for Nu and a set of plugins which extend Nu with additional functionality.
Foundational libraries are split into two kinds of crates:
- Core crates - those crates that work together to build the Nushell language engine
- Support crates - a set of crates that support the engine with additional features like JSON support, ANSI support, and more.
Plugins are likewise also split into two types:
- Core plugins - plugins that provide part of the default experience of Nu, including access to the system properties, processes, and web-connectivity features.
- Extra plugins - these plugins run a wide range of different capabilities like working with different file types, charting, viewing binary data, and more.