Fix off-by-one error in rolling-map

[factor.git] / basis / sequences / windowed / windowed.factor

diff --git a/basis/sequences/windowed/windowed.factor b/basis/sequences/windowed/windowed.factor
index df2b05b58ce9e5499dafb092b87badae1f8dcf58..2e60214083d883cc246201b61ea24d214af52259 100644 (file)
--- a/basis/sequences/windowed/windowed.factor
+++ b/basis/sequences/windowed/windowed.factor
@@ -26,7 +26,7 @@ M: windowed-sequence length
 
 :: rolling-map ( ... seq n quot: ( ... slice -- ... elt ) -- ... newseq )
     seq length [
-        [ n [-] ] [ seq <slice-unsafe> ] bi quot call
+        1 + [ n [-] ] [ seq <slice-unsafe> ] bi quot call
     ] { } map-integers ; inline
 
 : rolling-sum ( seq n -- newseq )