added Gamerules to the GameWorld

src/net/torvald/terrarum/console/GetGR.kt

@@ -0,0 +1,58 @@
+package net.torvald.terrarum.console
+
+import net.torvald.terrarum.*
+import net.torvald.terrarum.modulebasegame.console.GetAV.isNum
+
+/**
+ * Created by minjaesong on 2022-06-03.
+ */
+internal object GetGR : ConsoleCommand {
+    override fun execute(args: Array<String>) {
+        val gameRules = INGAME.world.gameRules
+
+        // check if args[1] is number or not
+        if (args.size > 1 && !args[1].isNum()) { // args[1] is Gamerule name
+            gameRules[args[1]].let {
+                if (it != null) {
+                    Echo("${ccW}Gamerule $ccM${args[1]} $ccW= " +
+                         ccG +
+                         it +
+                         " $ccO" +
+                         it.javaClass.simpleName
+                    )
+                    println("[GetGR] Gamerule ${args[1]} = " +
+                            it +
+                            " " +
+                            it.javaClass.simpleName
+                    )
+                }
+                else {
+                    EchoError("No such Gamerule defined: ${args[1]}")
+                    println("[GetGR] No such Gamerule defined: ${args[1]}")
+                }
+            }
+
+        }
+        else {
+            // args[1] is actor ID
+            val keyset = gameRules.keySet
+
+            Echo("$ccW== List of$ccY Gamerules $ccW==")
+            println("[GetGR] == List of Gamerules ==")
+            if (keyset.isEmpty()) {
+                Echo("$ccK(nothing)")
+                println("[GetGR] (nothing)")
+            }
+            else {
+                keyset.forEach { elem ->
+                    Echo("$ccM$elem $ccW= $ccG${gameRules[elem as String]}")
+                    println("[GetGR] $elem = ${gameRules[elem]}")
+                }
+            }
+        }
+    }
+
+    override fun printUsage() {
+        Echo("Usage: getgr <gamerule>")
+    }
+}