Added lume.count() function and tests

lume.lua

@@ -209,6 +209,19 @@ function lume.match(t, fn)
 end
 
 
+function lume.count(t, fn)
+  local count = 0
+  if fn then
+    for k, v in pairs(t) do
+      if fn(v) then count = count + 1 end
+    end
+  else
+    for k in pairs(t) do count = count + 1 end
+  end
+  return count
+end
+
+
 function lume.slice(t, i, j)
   i = i and absindex(#t, i) or 1
   j = j and absindex(#t, j) or #t

test/test_lume.lua

@@ -222,6 +222,15 @@ tests["lume.match"] = function()
   testeq( k, nil  )
 end
 
+-- lume.count
+tests["lume.count"] = function()
+  local t = { a = 1, b = 2, c = 5, [13] = 22, z = 8 }
+  testeq( lume.count(t), 5 )
+  testeq( lume.count(t, function(x) return x % 2 == 0 end ), 3 )
+  local a = { 5, 6, 7, 8, 9 }
+  testeq( lume.count(a), #a )
+end
+
 -- lume.slice
 tests["lume.slice"] = function()
   testeq( lume.slice({"a", "b", "c", "d", "e"}, 2, 4),    {"b", "c", "d"} )