Use Shift-Up & Shift-Down to navigate in lists

[charbeljc]

Say your prompt is something like this, with ^ indicating your cursor position.

.[0].hosts[0]
        ^

if you type Ctl-Down, it will become

.[0].hosts[1]
        ^

[ynqa]

@charbeljc Thank you so much for proposing the introduction of a new mechanism.

I have two points to mention:

• ctrl+{up, down} is often reserved for operations on the laptop side. For example, in the default settings of MacOS, pressing ctrl+up opens mission control. Since this cannot be interrupted, I recommend using a different key binding.
• In the current implementation, pressing ctrl+{up, down} continues to move forward even if it is ineffective. I would like to use a mechanism like a ring-buffer to make it cycle (for example, if there are 3 Arrays, pressing ctrl+down would move 0 -> 1 -> 2 -> 0).

[charbeljc]

Hi, I changed to shift-{up, down} and implemented cycling. Let me know what you think.

[ynqa]

@charbeljc Does this mean that the jq filter is evaluated twice in a single iteration?

If so, I would like to stop that because even now, given large data, the evaluation of a single jq filter can hang, and there's no benefit that justifies making it slower by evaluating the filter more than once.

• Painfully slow on 16MB (minified) JSON #2

The strategy I have in mind is to improve suggestions. Currently, they are managed as a Vec<String>.

From https://github.com/ynqa/jnv/blob/v0.2.0/src/jnv.rs#L50

let suggestions = all_kinds
    .iter()
    .filter_map(|kind| kind.path())
    .map(|segments| {
        if segments.is_empty() {
            ".".to_string()
        } else {
            segments
                .iter()
                .map(|segment| match segment {
                    JsonPathSegment::Key(key) => {
                        if key.contains('.') || key.contains('-') || key.contains('@') {
                            format!(".\"{}\"", key)
                        } else {
                            format!(".{}", key)
                        }
                    }
                    JsonPathSegment::Index(index) => format!("[{}]", index),
                })
                .collect::<String>()
        }
    });

If the result of the filter currently points to an Array, I plan to make changes so that you can search through this suggestions by using Shift+up, down. This eliminates the need to evaluate the jq filter again.

[charbeljc]

This is not the exact same filter that's got evaluated. For instance, if your prompt is

.[0].hosts[0]
        ^

We evaluate

.[0].hosts | length

Off course this don't change things performance wise... If you can achieve the same effect with enhanced suggestions, it would be great !