From a37f067c905d472aba0d70130718660f1470163e Mon Sep 17 00:00:00 2001 From: Matthew Wild Date: Mon, 23 Jan 2012 00:00:10 +0000 Subject: util.iterators: Make a standard library (no longer injects into global namespace) --- util/iterators.lua | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) (limited to 'util/iterators.lua') diff --git a/util/iterators.lua b/util/iterators.lua index aa0b172b..fb89f4a5 100644 --- a/util/iterators.lua +++ b/util/iterators.lua @@ -8,8 +8,10 @@ --[[ Iterators ]]-- +local it = {}; + -- Reverse an iterator -function reverse(f, s, var) +function it.reverse(f, s, var) local results = {}; -- First call the normal iterator @@ -34,12 +36,12 @@ end local function _keys_it(t, key) return (next(t, key)); end -function keys(t) +function it.keys(t) return _keys_it, t; end -- Iterate only over values in a table -function values(t) +function it.values(t) local key, val; return function (t) key, val = next(t, key); @@ -48,7 +50,7 @@ function values(t) end -- Given an iterator, iterate only over unique items -function unique(f, s, var) +function it.unique(f, s, var) local set = {}; return function () @@ -65,7 +67,7 @@ function unique(f, s, var) end --[[ Return the number of items an iterator returns ]]-- -function count(f, s, var) +function it.count(f, s, var) local x = 0; while true do @@ -79,7 +81,7 @@ function count(f, s, var) end -- Return the first n items an iterator returns -function head(n, f, s, var) +function it.head(n, f, s, var) local c = 0; return function (s, var) if c >= n then @@ -91,7 +93,7 @@ function head(n, f, s, var) end -- Skip the first n items an iterator returns -function skip(n, f, s, var) +function it.skip(n, f, s, var) for i=1,n do var = f(s, var); end @@ -99,7 +101,7 @@ function skip(n, f, s, var) end -- Return the last n items an iterator returns -function tail(n, f, s, var) +function it.tail(n, f, s, var) local results, count = {}, 0; while true do local ret = { f(s, var) }; @@ -121,13 +123,13 @@ function tail(n, f, s, var) end local function _range_iter(max, curr) if curr < max then return curr + 1; end end -function range(x, y) +function it.range(x, y) if not y then x, y = 1, x; end -- Default to 1..x if y not given return _range_iter, y, x-1; end -- Convert the values returned by an iterator to an array -function it2array(f, s, var) +function it.to_array(f, s, var) local t, var = {}; while true do var = f(s, var); @@ -139,7 +141,7 @@ end -- Treat the return of an iterator as key,value pairs, -- and build a table -function it2table(f, s, var) +function it.to_table(f, s, var) local t, var2 = {}; while true do var, var2 = f(s, var); @@ -149,3 +151,4 @@ function it2table(f, s, var) return t; end +return it; -- cgit v1.2.3