Added lume.concat(), updated README and tests

README.md

@@ -159,6 +159,12 @@ and `t2` have a conflicting key, the value from `t2` is used.
 lume.merge({2, 3}, {4, 5}) -- Returns {2, 3, 4, 5}
 ```
 
+### lume.concat(...)
+Returns a new array consisting of all the given arrays concatenated into one.
+```lua
+lume.concat({1, 2}, {3, 4}, {5, 6}) -- Returns {1, 2, 3, 4, 5, 6}
+```
+
 ### lume.find(t, value)
 Returns the index/key of `value` in `t`. Returns `nil` if that value does not
 exist in the table.

lume.lua

@@ -260,6 +260,19 @@ function lume.merge(t, t2, retainkeys)
 end
 
 
+function lume.concat(...)
+  local rtn = {}
+  for i = 1, select("#", ...) do
+    local t = select(i, ...)
+    local iter = getiter(t)
+    for k, v in iter(t) do
+      rtn[#rtn + 1] = v
+    end
+  end
+  return rtn
+end
+
+
 function lume.find(t, value)
   local iter = getiter(t)
   for k, v in iter(t) do

test/test_lume.lua

@@ -220,6 +220,14 @@ tests["lume.merge"] = function()
   testeq( lume.merge({a=1, b=2}, {b=3, c=4}, true), {a=1, b=3, c=4}     )
 end
 
+-- lume.concat
+tests["lume.concat"] = function()
+  testeq( lume.concat(nil),                            {}                    )
+  testeq( lume.concat({1, 2, 3}),                      {1, 2, 3}             )
+  testeq( lume.concat({1, 2, 3}, {4, 5, 6}),           {1, 2, 3, 4, 5, 6}    )
+  testeq( lume.concat({1, 2, 3}, {4, 5, 6}, nil, {7}), {1, 2, 3, 4, 5, 6, 7} )
+end
+
 -- lume.find
 tests["lume.find"] = function()
   testeq( lume.find({"a", "b", "c"}, "b"),  2   )