Added lume.reject(), updated tests and README.md

README.md

@@ -173,6 +173,14 @@ an array and retains its original keys.
 lume.filter({1, 2, 3, 4}, function(x) return x % 2 == 0 end) -- Returns {2, 4}
 ```
 
+### lume.reject(t, fn [, retainkeys])
+The opposite of `lume.filter()`: Calls `fn` on each value of `t` table; returns
+a new table with only the values where `fn` returned false. If `retainkeys` is
+true the table is not treated as an array and retains its original keys.
+```lua
+lume.filter({1, 2, 3, 4}, function(x) return x % 2 == 0 end) -- Returns {1, 3}
+```
+
 ### lume.merge(...)
 Returns a new table with all the given tables merged together. If a key exists
 in multiple tables the right-most table's value is used.

lume.lua

@@ -287,6 +287,23 @@ function lume.filter(t, fn, retainkeys)
 end
 
 
+function lume.reject(t, fn, retainkeys)
+  fn = iteratee(fn)
+  local iter = getiter(t)
+  local rtn = {}
+  if retainkeys then
+    for k, v in iter(t) do
+      if not fn(v) then rtn[k] = v end
+    end
+  else
+    for k, v in iter(t) do
+      if not fn(v) then rtn[#rtn + 1] = v end
+    end
+  end
+  return rtn
+end
+
+
 function lume.merge(...)
   local rtn = {}
   for i = 1, select("#", ...) do

test/test_lume.lua

@@ -253,6 +253,16 @@ tests["lume.filter"] = function()
   testeq( t, {{ x=1, y=1 }, {x=1, y=3}} )
 end
 
+-- lume.reject
+tests["lume.reject"] = function()
+  local t = lume.reject({1, 2, 3, 4, 5}, function(x) return x % 2 == 0 end  ) 
+  testeq( t, {1, 3, 5} )
+  local t = lume.reject({a=1, b=2, c=3}, function(x) return x == 2 end, true) 
+  testeq( t, {a=1, c=3} )
+  local t = lume.reject({{ x=1, y=1 }, { x=2, y=2 }, { x=1, y=3 }}, { x = 1 })
+  testeq( t, {{ x=2, y=2 }} )
+end
+
 -- lume.merge
 tests["lume.merge"] = function()
   testeq( lume.merge(),                       {}              )