ch06 exercises

exercises/ch06/ex6_4.lua

@@ -0,0 +1,34 @@
+local function shuffle(l)
+    for i = 1, #l do
+        local new_i = math.random(1, #l)
+        local tmp = l[new_i]
+        l[new_i] = l[i]
+        l[i] = tmp
+    end
+end
+
+local function table_str(t)
+    local str = "{"
+    for _, v in pairs(t) do
+        if type(v) == "string" then
+            v = '"' .. v .. '"'
+        end
+        str = ("%s %s,"):format(str, v)
+    end
+
+    str = str .. " }"
+
+    return str
+end
+
+local function test(l)
+    local str = ("%s -> "):format(table_str(l))
+    shuffle(l)
+    str = str .. table_str(l)
+    print(str)
+end
+
+math.randomseed(os.time())
+
+test({ 1, 2, 3, 4 })
+test({ "a", "b", "c", "d" })