// @return result.Result<string, error>
func readVersion(repo *git.Repository) result.Result {
path := filepath.Join(gg.CommentRefBase, versionRef)
ref := result.NewResult(repo.References.Lookup(path))
return ref.FlatMap(func(ref interface{}) result.Result {
oid := ref.(*git.Reference).Target()
return result.NewResult(repo.LookupBlob(oid))
}).FlatMap(func(blob interface{}) result.Result {
contents := blob.(*git.Blob).Contents()
return result.NewSuccess(string(contents))
})
}
