content tests are three-valued: unknown when unreadable or read in part

1 files changed, 5 insertions, 0 deletions

diff --git a/internal/extract/extract.go b/internal/extract/extract.go
index 7e3adec..0843c42 100644
--- a/internal/extract/extract.go
+++ b/internal/extract/extract.go
@@ -23,6 +23,11 @@ var (
 	// ErrUnsupported is returned when the format carries no text krino
 	// knows how to extract.
 	ErrUnsupported = errors.New("no text in this format")
+	// ErrPartial wraps the error of a document read only in part (an
+	// archive entry that would not open or parse). Text returns the text it
+	// did read along with it: a keyword found there is found, but one not
+	// found may be in the part that could not be read (plan 11).
+	ErrPartial = errors.New("part of it could not be read")
 	// ErrTooLarge is returned when the file is larger than the configured
 	// max-read; nothing is read in that case.
 	ErrTooLarge = errors.New("larger than max-read")