coroutines: auto recreate dead coroutine and restart

coroutine help

init.lua

@@ -25,7 +25,7 @@ basic_robot.bad_inventory_blocks = { -- disallow taking from these nodes invento
 
 basic_robot.http_api = minetest.request_http_api(); 
 
-basic_robot.version = "2019/02/16a";
+basic_robot.version = "2019/06/03a";
 
 basic_robot.gui = {}; local robogui = basic_robot.gui -- gui management
 basic_robot.data = {}; -- stores all robot related data
@@ -724,7 +724,7 @@ end
 local function setCode( name, script ) -- to run script: 1. initSandbox 2. setCode 3. runSandbox
 	local err;
 	local cor = false;
-	if string.sub(script,1,11) == "--coroutine" then cor = true end
+	if string.find(string.sub(script,1,32), "coroutine") then cor = true end
 	
 	local authlevel = basic_robot.data[name].authlevel;
 	
@@ -980,9 +980,19 @@ minetest.register_entity("basic_robot:robot",{
 			if err and type(err) == "string" then 
 				local i = string.find(err,":");
 				if i then err = string.sub(err,i+1) end
-				if string.sub(err,-5)~="abort" then
+				-- recreate dead coroutine, does this have some side effects like memory leak?
+				if err == "cannot resume dead coroutine" then 
+					local data = basic_robot.data[self.name]
+					data.cor = coroutine.create(data.bytecode)
+					err=runSandbox(self.name)
+					if not err then return end
+				end
+				
+				if string.sub(err,-5)~="abort" and not cor then
 					minetest.chat_send_player(self.owner,"#ROBOT ERROR : " .. err) 
 				end
+				
+				
 				self.running = 0; -- stop execution
 				
 				if string.find(err,"stack overflow") then

robogui.lua

@@ -145,6 +145,7 @@ local help_pages = {
 		"  7. [TECHNIC FUNCTIONALITY]",
 		"  8. [CRYPTOGRAPHY]",
 		"  9. [PUZZLE]",
+		"  10.[COROUTINES] - easier alternative to finite state machines",
 	},
 	
 	["MOVEMENT DIGGING PLACING NODE SENSING"] = {
@@ -300,7 +301,21 @@ local help_pages = {
 		"  count_objects(pos,radius)",
 		"  pdata contains puzzle data like .triggers and .gamedata",
 		"  add_particle(def)"
-	}
+	},
+	
+		["COROUTINES"] = {
+		"back to [Commands reference]",
+		"COROUTINES","",
+		"robot can run code using lua coroutines. To enable this mode just put the word",
+		"coroutine in the first 32 characters of your program. Example: ", "",
+		" --testing program for coroutine",
+		"   for i = 1,5 do ",
+		"       say(i); dig.forward(); move.forward()",
+		"       pause()",
+		"   end",
+	},
+
+	
 	
 }
 for k,v in pairs(help_pages) do