add basic target selector

mods/CORE/mcl_commands/init.lua

@@ -99,6 +99,15 @@ mcl_commands.types = {
 				return S("Player doesn't exist.")
 			end
 		end},
+	target     = {"([A-Za-z0-9-_]+)",
+		function(res, pointer)
+			--if minetest.player_exists(res[pointer]) then
+			if res[pointer] then
+				return nil, res[pointer], pointer+1
+			else
+				return S("Player doesn't exist.")
+			end
+		end},
 	json         = {"(.+)",  --FIXME
 		function(res, pointer)
 			local parsed = parse_json(res[pointer])
@@ -360,4 +369,41 @@ function mcl_commands.rename_chatcommand(newname, cmd, bypass)
 	else
 		minetest.log("action", "[mcl_commands] ["..cmd.."] command not renamed to ["..newname.."]")
 	end
+end
+
+function mcl_commands.get_target_selector(target, pos, name)
+	if minetest.player_exists(target) then
+		return minetest.get_player_by_name(target)
+	elseif target == "@a" then
+		return nil, minetest.get_connected_players()
+	elseif target == "@r" then
+		local connected = minetest.get_connected_players()
+		return nil, connected[math.random(1, #connected)]
+	elseif target == "@s" then
+		if name then
+			local player = minetest.get_player_by_name(name)
+		end
+		if player then
+			return nil, player
+		else
+			return S("Not a valid player")
+		end
+	elseif target == "@p" then
+		local smallest = math.huge
+		local nearest
+		for _,player in pairs(minetest.get_connected_players()) do
+			local distance = vector.distance(pos, player:get_pos())
+			if distance < min_distance then
+				min_distance = distance
+				nearest = player
+			end
+		end
+		if nearest then
+			return nil, nearest
+		else
+			return S("No player online")
+		end
+	elseif target == "@e" then
+		return minetest.luaentities --TODO: add filtering of not valid entities.
+	end
 end