The choice to hide APIs was made due to an overabundance of caution.
I think it's valid that a small surface area could be exposed—more over time as internals are solidified.

As a starting point to iterate on, I think something like following could be safely exposed
while keeping the internals hidden.

type PatchFile struct{ ... }

func Parse(filename string, src []byte) (*PatchFile, error)

func (*PatchFile) Apply(src []byte) ([]byte, error)

CC @lverma14 @r-hang

internal ref: GO-2003

Hi! I tried gopatch to reproduce my changes by gopatch.
I did it in half day. I thought it was a very wonderful tool!

I'm using the https://github.com/spf13/afero and I want to apply a patch to something that isn't an actual file.
so, I need some APIs.

I created #181 . PTAL 🙏 If you have a time @abhinav @sywhang