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# Description
The `cell-path` is a type that can be created statically with
`$.nested.structure.5`, but can't be created from user input. This makes
it difficult to take advantage of commands that accept a cell-path to
operate on data structures.
This PR adds `into cell-path` for dynamic cell-path creation.
`into cell-path` accepts the following input shapes:
* Bare integer (equivalent to `$.1`)
* List of strings and integers
* List of records with entries `value` and `optional`
* String (parsed into a cell-path)
## Example usage
An example of where `into cell-path` can be used is in working with `git
config --list`. The git configuration has a tree structure that maps
well to nushell records. With dynamic cell paths it is easy to convert
`git config list` to a record:
```nushell
git config --list
| lines
| parse -r '^(?<key>[^=]+)=(?<value>.*)'
| reduce --fold {} {|entry, result|
let path = $entry.key | into cell-path
$result
| upsert $path {||
$entry.value
}
}
| select remote
```
Output:
```
╭────────┬──────────────────────────────────────────────────────────────────╮
│ │ ╭──────────┬───────────────────────────────────────────────────╮ │
│ remote │ │ │ ╭───────┬───────────────────────────────────────╮ │ │
│ │ │ upstream │ │ url │ git@github.com:nushell/nushell.git │ │ │
│ │ │ │ │ fetch │ +refs/heads/*:refs/remotes/upstream/* │ │ │
│ │ │ │ ╰───────┴───────────────────────────────────────╯ │ │
│ │ │ │ ╭───────┬─────────────────────────────────────╮ │ │
│ │ │ origin │ │ url │ git@github.com:drbrain/nushell │ │ │
│ │ │ │ │ fetch │ +refs/heads/*:refs/remotes/origin/* │ │ │
│ │ │ │ ╰───────┴─────────────────────────────────────╯ │ │
│ │ ╰──────────┴───────────────────────────────────────────────────╯ │
╰────────┴──────────────────────────────────────────────────────────────────╯
```
## Errors
`lex()` + `parse_cell_path()` are forgiving about what is allowed in a
cell-path so it will allow what appears to be nonsense to become a
cell-path:
```nushell
let table = [["!@$%^&*" value]; [key value]]
$table | get ("!@$%^&*.0" | into cell-path)
# => key
```
But it will reject bad cell-paths:
```
❯ "a b" | into cell-path
Error: nu:🐚:cant_convert
× Can't convert to cell-path.
╭─[entry #14:1:1]
1 │ "a b" | into cell-path
· ───────┬──────
· ╰── can't convert string to cell-path
╰────
help: "a b" is not a valid cell-path (Parse mismatch during operation.)
```
# User-Facing Changes
New conversion command `into cell-path`
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
# After Submitting
Automatic documentation updates
|
||
|---|---|---|
| .. | ||
| src | ||
| tests | ||
| Cargo.toml | ||
| LICENSE | ||
| README.md | ||
nu-protocol
The nu-protocol crate holds the definitions of structs/traits that are used throughout Nushell. This gives us one way to expose them to many other crates, as well as make these definitions available to each other, without causing mutually recursive dependencies.