nu-complete: descriptions for values

[rsteube]

Related problem

Descriptions are possible for subcommands and flags, but not for the values returned by a custom completion.

Describe the solution you'd like

A way to return values with descriptions.

Describe alternatives you've considered

No response

Additional context and details

    def "nu-complete example" [line: string, pos: int] {
       // return values with descriptions
    }
    
    export extern "example" [
        ...args: string@"nu-complete example"
    ]

[herlon214]

Looks like it's not hard to do, we just need to change the map_completions function:

    fn map_completions<'a>(
        &self,
        list: impl Iterator<Item = &'a Value>,
        span: Span,
        offset: usize,
    ) -> Vec<Suggestion> {
        list.filter_map(move |x| {
            let s = x.as_string();

            match s {
                Ok(s) => Some(Suggestion {
                    value: s,
                    description: None,
                    extra: None,
                    span: reedline::Span {
                        start: span.start - offset,
                        end: span.end - offset,
                    },
                }),
                Err(_) => None,
            }
        })
        .collect()
    }

And accept a Record as well, not only strings.
From the Record we extract the value and description cols/values.