Add `textdiff.Replacement` to support range-based edits as in Go's analysis.TextEdit.

[jschaf]

Hi, first off: this is a really nice library. It's a pleasure reading to read through the source code and accompanying blog post.

Context

I'd like to use this library to manage diffs for a meta-linter. Many linters emit fixes as range-based replacements rather than as diffs, like so:

{"start": 10, "end": 20, "replacement": "foo bar"}

To convert the replacements into a diff for display and patching, I've implemented similar logic as textdiff.

Feature requests

• FR1: Add textdiff.Replacement to natively support range-based edits.
• FR2: Add a conversion function from []textdiff.Replacement to []textdiff.Hunk.
• FR3: Generalize to diff. This is a nice-to-have since I don't need it, but it seems helpful to maintain parity with textdiff.

References

• Go analysis package converts from analysis.TextEdit to diff.Edit: cs go/x/tools/internal/analysis/driverutil/fix.go

[znkr]

Thank you for the nice words. I don't quite understand the feature request. Would it be possible to implement this functionality in your meta-linter? Then we could have a discussion if this should be part of this diff package or not. Right now, I am not quite sure what you are asking about and why it makes sense to have that functionality in this library.

[jschaf]

Would it be possible to implement this functionality in your meta-linter?

Sure, here's the (not great) code extracted into a separate repo. See Fix.Hunks:

https://github.com/jschaf/experiment-diff-replacement/blob/main/replace.go#L19