From bcb552cdc42eb2ed9fe821625a46eccea5c08d47 Mon Sep 17 00:00:00 2001 From: Matthew Wild Date: Mon, 10 Aug 2009 15:07:32 +0100 Subject: util.iterators: Add head() iterator, to return the first n items --- util/iterators.lua | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'util/iterators.lua') diff --git a/util/iterators.lua b/util/iterators.lua index 08bb729c..6a437dd7 100644 --- a/util/iterators.lua +++ b/util/iterators.lua @@ -78,6 +78,18 @@ function count(f, s, var) return x; end +-- Return the first n items an iterator returns +function head(n, f, s, var) + local c = 0; + return function (s, var) + if c >= n then + return nil; + end + c = c + 1; + return f(s, var); + end, s; +end + -- Convert the values returned by an iterator to an array function it2array(f, s, var) local t, var = {}; -- cgit v1.2.3