product more robust against empty input

2014-01-30 23:55:43 -06:00 · 2014-01-30 23:55:43 -06:00 · e01fb17d02
commit e01fb17d02
parent f070edb8b9
2 changed files with 6 additions and 0 deletions
--- a/lib/pure/algorithm.nim
+++ b/lib/pure/algorithm.nim
@ -148,6 +148,7 @@ proc product*[T](x: openarray[seq[T]]): seq[seq[T]] =
  var next: seq[T] = @[]
  next.setLen(x.len)
  for i in 0..(x.len-1):
+    if len(x[i]) == 0: return
    initial[i] = len(x[i])-1
  indexes = initial
  while true: