Commit Graph

9 Commits

Author SHA1 Message Date
Reilly Wood
21b84a6d65
Optional members in cell paths: Attempt 2 (#8379)
This is a follow up from https://github.com/nushell/nushell/pull/7540.
Please provide feedback if you have the time!

## Summary

This PR lets you use `?` to indicate that a member in a cell path is
optional and Nushell should return `null` if that member cannot be
accessed.

Unlike the previous PR, `?` is now a _postfix_ modifier for cell path
members. A cell path of `.foo?.bar` means that `foo` is optional and
`bar` is not.

`?` does _not_ suppress all errors; it is intended to help in situations
where data has "holes", i.e. the data types are correct but something is
missing. Type mismatches (like trying to do a string path access on a
date) will still fail.

### Record Examples

```bash

{ foo: 123 }.foo # returns 123

{ foo: 123 }.bar # errors
{ foo: 123 }.bar? # returns null

{ foo: 123 } | get bar # errors
{ foo: 123 } | get bar? # returns null

{ foo: 123 }.bar.baz # errors
{ foo: 123 }.bar?.baz # errors because `baz` is not present on the result from `bar?`
{ foo: 123 }.bar.baz? # errors
{ foo: 123 }.bar?.baz? # returns null
```

### List Examples
```
〉[{foo: 1} {foo: 2} {}].foo
Error: nu:🐚:column_not_found

  × Cannot find column
   ╭─[entry #30:1:1]
 1 │ [{foo: 1} {foo: 2} {}].foo
   ·                    ─┬  ─┬─
   ·                     │   ╰── cannot find column 'foo'
   ·                     ╰── value originates here
   ╰────
〉[{foo: 1} {foo: 2} {}].foo?
╭───┬───╮
│ 0 │ 1 │
│ 1 │ 2 │
│ 2 │   │
╰───┴───╯
〉[{foo: 1} {foo: 2} {}].foo?.2 | describe
nothing

〉[a b c].4? | describe
nothing

〉[{foo: 1} {foo: 2} {}] | where foo? == 1
╭───┬─────╮
│ # │ foo │
├───┼─────┤
│ 0 │   1 │
╰───┴─────╯
```

# Breaking changes

1. Column names with `?` in them now need to be quoted.
2. The `-i`/`--ignore-errors` flag has been removed from `get` and
`select`
1. After this PR, most `get` error handling can be done with `?` and/or
`try`/`catch`.
4. Cell path accesses like this no longer work without a `?`:
```bash
〉[{a:1 b:2} {a:3}].b.0
2
```
We had some clever code that was able to recognize that since we only
want row `0`, it's OK if other rows are missing column `b`. I removed
that because it's tricky to maintain, and now that query needs to be
written like:


```bash
〉[{a:1 b:2} {a:3}].b?.0
2
```

I think the regression is acceptable for now. I plan to do more work in
the future to enable streaming of cell path accesses, and when that
happens I'll be able to make `.b.0` work again.
2023-03-15 20:50:58 -07:00
Stefan Holderbach
ab480856a5
Use variable names directly in the format strings (#7906)
# Description

Lint: `clippy::uninlined_format_args`

More readable in most situations.
(May be slightly confusing for modifier format strings
https://doc.rust-lang.org/std/fmt/index.html#formatting-parameters)

Alternative to #7865

# User-Facing Changes

None intended

# Tests + Formatting

(Ran `cargo +stable clippy --fix --workspace -- -A clippy::all -D
clippy::uninlined_format_args` to achieve this. Depends on Rust `1.67`)
2023-01-29 19:37:54 -06:00
Stefan Holderbach
e5d38dcff6
Address lints from clippy for beta/nightly (#5709)
* Fix clippy lints in tests

* Replace `format!` in `.push_str()` with `write!`

Stylistically that might be a bit rough but elides an allocation.

Fallibility of allocation is more explicit, but ignored with `let _ =`
like in the clippy example:

https://rust-lang.github.io/rust-clippy/master/index.html#format_push_string

* Remove unused lifetime

* Fix macro crate relative import

* Derive `Eq` for `PartialEq` with `Eq` members

https://rust-lang.github.io/rust-clippy/master/index.html#derive_partial_eq_without_eq

* Remove unnnecessary `.to_string()` for Cow<str>

* Remove `.to_string()` for `tendril::Tendril`

Implements `Deref<Target = str>`
2022-06-04 18:47:36 +12:00
JT
1837bf775c
Default values (#4770) 2022-03-07 15:08:56 -05:00
JT
d620f76a21
Make comparisons/sort-by more 'global' (#4500)
* Make comparisons/sort-by more 'global'

* Let custom values do their own comparisons
2022-02-16 13:30:37 -06:00
Arthur Targaryen
f82e2fbac6
Port find command (#658)
* Add `Find` command

* Complete rustdoc for test `Value` constructors

* Use `Option::unwrap_or` instead of match

* Add `Value::test_filesize` constructor

* Handle searching for terms in `find`

* Fix `find` command signature

* Return multiple elements when `find`ing by predicate

* Do not accept rest parameter with predicate

* Handle `CellPath` in `r#in` and `not_in` for `Find`

* Use `PipelineData::filter`
2022-01-23 16:32:02 -06:00
JT
6b76dd7cd7 Add select 2021-10-02 17:55:05 +13:00
JT
5843acec02 Add wrap and get and cell_path parsing 2021-10-02 15:59:11 +13:00
JT
3b7d7861e3 Add cell paths 2021-09-07 10:02:24 +12:00