add "to nuon" enumeration of possible styles

[amtoine]

Description

in order to change the style of the serialized NUON data, nuon::to_nuon takes three mutually exclusive arguments, raw: bool, tabs: Option<usize> and indent: Option<usize> 🤔
this begs to use an enumeration with all possible alternatives, right?

this PR changes the signature of nuon::to_nuon to use nuon::ToStyle which has three variants

• Raw: no newlines
• Tabs(n: usize): newlines and n tabulations as indent
• Spaces(n: usize): newlines and n spaces as indent

User-Facing Changes

the signature of nuon::to_nuon changes from

to_nuon(
    input: &Value,
    raw: bool,
    tabs: Option<usize>,
    indent: Option<usize>,
    span: Option<Span>,
) -> Result<String, ShellError>

to

to_nuon(
    input: &Value,
    style: ToStyle,
    span: Option<Span>
) -> Result<String, ShellError>

Tests + Formatting

After Submitting

[amtoine]

let's land that, this opens the door for new styles in the future, without polluting the signature of nuon::to_nuon :)

[amtoine]

(has been viewed in private btw, not landing this out of thin air 😉)

[sholderbach]

I am not sure when the default and --raw became the same?

[amtoine]

i was like this before i created the nuon crate 😉

55edef5 is the commit of the crate creation and fac2f43 is the commit before

nushell/crates/nu-command/src/formats/to/nuon.rs

Lines 58 to 66 in fac2f43

	let nuon_result = if raw {
	value_to_string(&value, span, 0, None)
	} else if let Some(tab_count) = tabs {
	value_to_string(&value, span, 0, Some(&"\t".repeat(tab_count)))
	} else if let Some(indent) = indent {
	value_to_string(&value, span, 0, Some(&" ".repeat(indent)))
	} else {
	value_to_string(&value, span, 0, None)
	};

[sholderbach]

The origin of --raw being equal to the default is in #8366 and there in turn in an attempt to mirror to json.

[amtoine]

ahah yeah that was me lol