Refactored out most of internal work for summarizing data opening
the door for generating charts from it. A model is introduced
to hold information needed for a summary, Histogram command is
an example of a partial usage. This is the beginning.
Removed implicit arithmetic traits on Value and Primitive to avoid
mixed types panics. The std operations traits can't fail and we
can't guarantee that. We can handle gracefully now since compute_values
was introduced after the parser changes four months ago. The handling
logic should be taken care of either explicitly or in compute_values.
The zero identity trait was also removed (and implementing this forced
us to also implement Add, Mult, etc)
Also: the `math` operations now remove in the output if a given column is not computable:
```
> ls | math sum
──────┬──────────
size │ 150.9 KB
──────┴──────────
```
* from-eml initial ver
* Adding tests for `from-eml`
* Add eml to prepares_and_decorates_filesystem_source_files
* Sort the file order
Co-authored-by: Jonathan Turner <jonathandturner@users.noreply.github.com>
* Better message error
* Use custom canonicalize in FileStructure build
* Better glob error in ls
* Use custom canonicalize, remove some duplicate code in cd.
* Enable recursive copying with patterns.
* Change test to fit new error message
* Test recursive with glob pattern
* Show that not matches were found in cp
* Fix typo in message error
* Change old canonicalize usage, follow newest changes
* headers plugin
* Remove plugin
* Add non-functioning headers command
* Add ability to extract headers from first row
* Refactor header extraction
* Rebuild indexmap with proper headers
* Rebuild result properly
* Compiling, probably wrapped too much?
* Refactoring
* Deal with case of empty header cell
* Deal with case of empty header cell
* Fix formatting
* Fix linting, attempt 2.
* Move whole_stream_command(Headers) to more appropriate section
* ... more linting
* Return Err(ShellError...) instead of panic, yield each row instead of entire table
* Insert Column[index] if no header info is found.
* Update error description
* Add initial test
* Add tests for headers command
* Lint test cases in headers
* Change ShellError for headers, Add sample_headers file to utils.rs
* Add empty sheet to test file
* Revert "Add empty sheet to test file"
This reverts commit a4bf38a31d.
* Show error message when given empty table
This improves incremental build time when working on what was previously
the root package. For example, previously all plugins would be rebuilt
with a change to `src/commands/classified/external.rs`, but now only
`nu-cli` will have to be rebuilt (and anything that depends on it).
