Added lume.ripairs() function, updated README and tests

README.md

@@ -361,6 +361,17 @@ lume.hotswap("lume") -- Reloads the lume module
 assert(lume.hotswap("inexistant_module")) -- Raises an error
 ```
 
+### lume.ripairs(t)
+Performs the same function as `ipairs()` but iterates in reverse; this allows
+the removal of items from the table during iteration without any items being
+skipped.
+```lua
+-- Prints "3->c", "2->b" and "1->a" on separate lines
+for i, v in lume.ripairs({ "a", "b", "c" }) do
+  print(i .. "->" .. v)
+end
+```
+
 ### lume.rgba(color)
 Takes the 32bit integer `color` argument and returns 4 numbers, one for each
 channel, with a range of 0 - 255. The returned values can be used as the

lume.lua

@@ -578,6 +578,20 @@ function lume.hotswap(modname)
 end
 
 
+local ripairs_iter = function(t, i)
+  i = i - 1
+  local v = t[i]
+  if v then return i, v end
+end
+
+function lume.ripairs(t)
+  if t == nil then
+    return noop
+  end
+  return ripairs_iter, t, (#t + 1)
+end
+
+
 function lume.rgba(color)
   local a = math_floor((color / 16777216) % 256)
   local r = math_floor((color /    65536) % 256)

test/test_lume.lua

@@ -486,6 +486,18 @@ tests["lume.hotswap"] = function()
   testeq( type(err),  "string"  )
 end
 
+-- lume.ripairs
+tests["lume.ripairs"] = function()
+  local t = { "a", "b", "c" }
+  local r = {}
+  for i, v in lume.ripairs(t) do
+    table.insert(r, { i, v })
+  end
+  testeq( r, { { 3, "c" }, { 2, "b" }, { 1, "a" } })
+  for i, v in lume.ripairs(nil) do
+  end
+end
+
 -- lume.rgba
 tests["lume.rgba"] = function()
   local r, g, b, a = lume.rgba(0x12345678)