From d7f5ff243ecc816cad86b5e49ec4ad7c2ceaf83d Mon Sep 17 00:00:00 2001 From: Matthew Wild Date: Fri, 17 May 2013 08:31:03 +0100 Subject: util.iterators: Add filter() to run results through a filter function --- util/iterators.lua | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/util/iterators.lua b/util/iterators.lua index 8f521fc4..bcda48b4 100644 --- a/util/iterators.lua +++ b/util/iterators.lua @@ -123,7 +123,21 @@ function it.tail(n, f, s, var) local ret = results[((count-1+pos)%n)+1]; return unpack(ret, 1, ret.n); end - --return reverse(head(n, reverse(f, s, var))); + --return reverse(head(n, reverse(f, s, var))); -- ! +end + +function it.filter(filter, f, s, var) + if type(filter) ~= "function" then + local filter_value = filter; + function filter(x) return x ~= filter_value; end + end + return function (s, var) + local ret; + repeat ret = pack(f(s, var)); + var = ret[1]; + until var == nil or filter(unpack(ret, 1, ret.n)); + return unpack(ret, 1, ret.n); + end, s, var; end local function _ripairs_iter(t, key) if key > 1 then return key-1, t[key-1]; end end -- cgit v1.2.3