go/internal/diff/myers
Alan Donovan d96b2388c6 internal/diff: simplify API, break span dependency
diff.TextEdit (now called simply Edit) no longer has a Span,
and no longer depends on the span package, which is really
part of gopls. Instead, it records only start/end byte
offsets within an (implied) file.

The diff algorithms have been simplified to avoid the need to
map offsets to line/column numbers (e.g. using a token.File).
All the conditions actually needed by the logic can be derived
by local string operations on the source text.

This change will allow us to move the span package into the
gopls module.

I was expecting that gopls would want to define its own
Span-augmented TextEdit type but, surprisingly, diff.Edit
is quite convenient to use throughout the entire repo:
in all places in gopls that manipulate Edits, the implied
file is obvious. In most cases, less conversion boilerplate
is required than before.

API Notes:
- diff.TextEdit -> Edit (it needn't be text)
- diff.ApplyEdits -> Apply
- source.protocolEditsFromSource is now private

Change-Id: I4d7cef078dfbd189b4aef477f845db320af6c5f6
Reviewed-on: https://go-review.googlesource.com/c/tools/+/436781
Run-TryBot: Alan Donovan <adonovan@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
gopls-CI: kokoro <noreply+kokoro@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Auto-Submit: Alan Donovan <adonovan@google.com>
2022-10-05 20:32:15 +00:00
..
diff.go internal/diff: simplify API, break span dependency 2022-10-05 20:32:15 +00:00
diff_test.go