Introducing StringSlice for Segment.Text

[xoofx]

Hello Spectre.Console friends!

I'm starting to evaluate how I can use Spectre.Console for editing/rendering syntax highlighted languages and I have a suggestion to improve its support.

Is your feature request related to a problem? Please describe.

While a Segment has a Text property defined as a string, it forces to split the original text string by its styled strings and to maintain externally a map of the split strings with the original string. e.g:

var x = 5; would generate var, x, =, 5, ; and we would have to keep the character position of each splits from the original string.

Describe the solution you'd like

Instead of using a string for Segment.Text we could use a string slice (e.g a string + offset + length) which could allow to use the same original string but offer a view on it to the segment.

Most of the code using it would not change much, as the contact of this type would mostly replicate the contract of a string.

There is the type StringSegment but it would bring a new dependencies. Also I discovered that it doesn't provide a char iterator (and some other methods, e.g like Trim)

So the question is: can we use StringSegment (we can provide extension methods/enumerator on it likely) or should we introduce a new type?

Describe alternatives you've considered

Maintaining the map to the original string outside of Spectre.Console.

Additional context

I can make a draft PR if you are interested in this feature? 🙂

[patriksvensson]

@xoofx Sounds like an excellent idea. We're aware of the problem but deliberately haven't been optimizing stuff (yet) in favor of getting things to work.

If you want to send a draft PR for this, it would be greatly appreciated.

[xoofx]

Great. What should I do about the type? Use StringSegment with a dependency to Microsoft.Extensions.Primitives or add a type e.g StringSlice and copy paste the code from it?

[patriksvensson]

I have no problem adding a dependency on Microsoft.Extensions.Primitives if supported by all the tfm:s that we support. I'll leave that decision to you, whatever you find the cleanest.

Again, really appreciate you raising this issue (and, of course, doing a PR).

[xoofx]

Hey,
So I have been digging into the changes. Got them partially working but it got quite viral and many little things in the lib are by design not prepared for such a change (lots of allocations here and there, many assumptions about string concatenations e.g Segment.Merge...etc.) so even after my changes, that would not solve the issue I brought up originally... so, unfortunately, I'm not sure I would like to bring such changes to Spectre.Console myself, as they are too disruptive.

Also, after digging more into the details, I'm a bit too frustrated by the Console API itself so I have started to play with more xplat virtual terminal sequences (with mouse events...etc.) (quite related to dotnet/runtime#52374 actually) and I don't know where I'm heading 🙂

So I'm gonna close this issue, my apologize for the false hope!