From bbd9fde49be6b42625d42009d92d435fdf05c0f8 Mon Sep 17 00:00:00 2001 From: Jack Firth Date: Fri, 10 Jul 2015 18:41:56 -0700 Subject: [PATCH] Document zero-arg behavior of lens-compose --- lens/base/compose.scrbl | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/lens/base/compose.scrbl b/lens/base/compose.scrbl index 55b805e..bb64952 100644 --- a/lens/base/compose.scrbl +++ b/lens/base/compose.scrbl @@ -10,7 +10,8 @@ The compound lens operates similarly to composed functions do in that the last @racket[lens] is the first @racket[lens] the compound lens's target is viewed through. Each successive lens "zooms in" - to a more detailed view. + to a more detailed view. When called with no arguments, @racket[lens-compose] + produces the identity lens. @lenses-examples[ (define first-of-second-lens (lens-compose first-lens second-lens)) (lens-view first-of-second-lens '((1 a) (2 b) (3 c)))