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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
|
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|---|---|---|
| .. | ||
| src | ||
| tests | ||
| Cargo.toml | ||
| LICENSE | ||