Refactor how preprocess functions work a bit

1 files changed, 4 insertions, 5 deletions

diff --git a/src/post/preprocess.go b/src/post/preprocess.go
index 7aceee2..2f3e091 100644
--- a/src/post/preprocess.go
+++ b/src/post/preprocess.go
@@ -1,14 +1,13 @@
 package post
 
 // PreprocessFunctions are functions which can be used by posts themselves to
-// interleave dynamic content into their bodies. Usually this is used for
-// properly constructing URLs, but also for things like displaying images.
-type PreprocessFunctions struct {
+// interleave dynamic content into their bodies.
+type PreprocessFunctions interface {
 	// Image returns a string which should be inlined into the post body in
-	// order to display an.
+	// order to render an image.
 	//
 	// The first argument to Image _must_ be the ID of an image asset. The
 	// second argument _may_ be a description of the image which will be used as
 	// alt text, or possibly displayed to the user with the image.
-	Image func(args ...string) (string, error)
+	Image(args ...string) (string, error)
 }