Micro AIs: avoid using formula= in SUFs

It’s slow for finding units with moves or attacks left.  The
alternative method of getting all units and then looping over the table
with a condition is much faster.

data/ai/lua/ai_helper.lua

@@ -741,6 +741,34 @@ function ai_helper.get_live_units(filter)
     return wesnoth.get_units(live_filter)
 end
 
+function ai_helper.get_units_with_moves(filter)
+    -- Using formula = '$this_unit.moves > 0' is slow, this method is much faster
+    local all_units = wesnoth.get_units(filter)
+
+    local units = {}
+    for _, unit in ipairs(all_units) do
+        if (unit.moves > 0) then table.insert(units, unit) end
+    end
+
+    return units
+end
+
+function ai_helper.get_units_with_attacks(filter)
+    -- Using formula = '$this_unit.attacks_left > 0' is slow, this method is much faster
+    -- Also need to check that units actually have attacks (as attacks_left > 0 with no attacks is possible)
+    -- The latter has to go through unit.__cfg which is slow, but there is no way around that, as far as I know
+    local all_units = wesnoth.get_units(filter)
+
+    local units = {}
+    for _, unit in ipairs(all_units) do
+        if (unit.attacks_left > 0) and (H.get_schild(unit.__cfg, 'attack')) then
+            table.insert(units, unit)
+        end
+    end
+
+    return units
+end
+
 function ai_helper.get_closest_enemy(loc)
     -- Get the closest enemy to loc, or the leader if loc not specified
     local x, y

data/ai/micro_ais/cas/ca_big_animals.lua

@@ -4,10 +4,9 @@ local LS = wesnoth.require "lua/location_set.lua"
 local MAIUV = wesnoth.require "ai/micro_ais/micro_ai_unit_variables.lua"
 
 local function get_big_animals(cfg)
-    local big_animals = wesnoth.get_units {
+    local big_animals = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        { "and" , cfg.filter },
-        formula = '$this_unit.moves > 0'
+        { "and" , cfg.filter }
     }
     return big_animals
 end

data/ai/micro_ais/cas/ca_bottleneck_attack.lua

@@ -6,8 +6,8 @@ local ca_bottleneck_attack = {}
 function ca_bottleneck_attack:evaluation(ai, cfg, self)
     -- All units with attacks_left and enemies next to them
     -- This will be much easier once the 'attacks' variable is implemented
-    local attackers = wesnoth.get_units {
-        side = wesnoth.current.side, formula = "$this_unit.attacks_left > 0",
+    local attackers = AH.get_units_with_attacks {
+        side = wesnoth.current.side,
         { "filter_adjacent", {
             { "filter_side", { { "enemy_of", {side = wesnoth.current.side} } } }
         } }
@@ -70,7 +70,7 @@ end
 
 function ca_bottleneck_attack:execution(ai, cfg, self)
     if self.data.bottleneck_attacks_done then
-        local units = wesnoth.get_units { side = wesnoth.current.side, formula = '$this_unit.attacks_left > 0' }
+        local units = AH.get_units_with_attacks { side = wesnoth.current.side }
         for i,u in ipairs(units) do
             AH.checked_stopunit_attacks(ai, u)
         end

data/ai/micro_ais/cas/ca_bottleneck_move.lua

@@ -235,13 +235,9 @@ function ca_bottleneck_move:evaluation(ai, cfg, self)
     -- Now find all units, including the leader or not, depending on situation and settings
     local units = {}
     if MAISD.get_mai_self_data(self.data, cfg.ai_id, "side_leader_activated") then
-        units = wesnoth.get_units { side = wesnoth.current.side,
-            formula = '$this_unit.moves > 0'
-        }
+        units = AH.get_units_with_moves { side = wesnoth.current.side }
     else
-        units = wesnoth.get_units { side = wesnoth.current.side, canrecruit = 'no',
-            formula = '$this_unit.moves > 0'
-        }
+        units = AH.get_units_with_moves { side = wesnoth.current.side, canrecruit = 'no' }
     end
 
     -- If there's no units with moves left, nothing to be done here
@@ -487,13 +483,9 @@ function ca_bottleneck_move:execution(ai, cfg, self)
     if self.data.bottleneck_moves_done then
         local units = {}
         if MAISD.get_mai_self_data(self.data, cfg.ai_id, "side_leader_activated") then
-            units = wesnoth.get_units { side = wesnoth.current.side,
-                formula = '$this_unit.moves > 0'
-            }
+            units = AH.get_units_with_moves { side = wesnoth.current.side }
         else
-            units = wesnoth.get_units { side = wesnoth.current.side, canrecruit = 'no',
-                formula = '$this_unit.moves > 0'
-            }
+            units = AH.get_units_with_moves { side = wesnoth.current.side, canrecruit = 'no' }
         end
         for i,u in ipairs(units) do
             AH.checked_stopunit_moves(ai, u)

data/ai/micro_ais/cas/ca_coward.lua

@@ -3,11 +3,10 @@ local AH = wesnoth.require "ai/lua/ai_helper.lua"
 
 local function get_coward(cfg)
     local filter = cfg.filter or { id = cfg.id }
-    local coward = wesnoth.get_units({
+    local coward = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        { "and", filter },
-        formula = '$this_unit.moves > 0' }
-    )[1]
+        { "and", filter }
+    }[1]
     return coward
 end
 

data/ai/micro_ais/cas/ca_forest_animals_move.lua

@@ -7,10 +7,9 @@ local function get_forest_animals(cfg)
     -- We want the deer/rabbits to move first, tuskers later
     local deer_type = cfg.deer_type or "no_unit_of_this_type"
     local rabbit_type = cfg.rabbit_type or "no_unit_of_this_type"
-    local forest_animals = wesnoth.get_units {
+    local forest_animals = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        type = deer_type .. ',' .. rabbit_type,
-        formula = '$this_unit.moves > 0'
+        type = deer_type .. ',' .. rabbit_type
     }
 
     local tusker_type = cfg.tusker_type or "no_unit_of_this_type"

data/ai/micro_ais/cas/ca_forest_animals_tusker_attack.lua

@@ -2,10 +2,9 @@ local H = wesnoth.require "lua/helper.lua"
 local AH = wesnoth.require "ai/lua/ai_helper.lua"
 
 local function get_tuskers(cfg)
-    local tuskers = wesnoth.get_units {
+    local tuskers = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        type = cfg.tusker_type,
-        formula = '$this_unit.moves > 0'
+        type = cfg.tusker_type
     }
     return tuskers
 end

data/ai/micro_ais/cas/ca_forest_animals_tusklet_move.lua

@@ -2,10 +2,9 @@ local H = wesnoth.require "lua/helper.lua"
 local AH = wesnoth.require "ai/lua/ai_helper.lua"
 
 local function get_tusklets(cfg)
-    local tusklets = wesnoth.get_units {
+    local tusklets = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        type = cfg.tusklet_type,
-        formula = '$this_unit.moves > 0'
+        type = cfg.tusklet_type
     }
     return tusklets
 end

data/ai/micro_ais/cas/ca_goto.lua

@@ -57,8 +57,9 @@ function ca_goto:evaluation(ai, cfg, self)
     if (not locs[1]) then return 0 end
 
     -- Find the goto units
-    local all_units = wesnoth.get_units { side = wesnoth.current.side,
-        { "and", cfg.filter }, formula = '$this_unit.moves > 0'
+    local all_units = AH.get_units_with_moves {
+        side = wesnoth.current.side,
+        { "and", cfg.filter }
     }
 
     -- Exclude released units

data/ai/micro_ais/cas/ca_hang_out.lua

@@ -5,10 +5,9 @@ local MAIUV = wesnoth.require "ai/micro_ais/micro_ai_unit_variables.lua"
 local MAISD = wesnoth.require "ai/micro_ais/micro_ai_self_data.lua"
 
 local function get_hang_out_units(cfg)
-    local units = wesnoth.get_units {
+    local units = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        { "and", cfg.filter },
-        formula = '$this_unit.moves > 0'
+        { "and", cfg.filter }
     }
     return units
 end

data/ai/micro_ais/cas/ca_healer_move.lua

@@ -17,17 +17,26 @@ function ca_healer_move:evaluation(ai, cfg, self)
 
     cfg = cfg or {}
 
-    local healers = wesnoth.get_units { side = wesnoth.current.side, ability = "healing",
-        formula = '$this_unit.moves > 0', { "and", cfg.filter }
+    local all_healers = wesnoth.get_units {
+        side = wesnoth.current.side,
+        ability = "healing",
+        { "and", cfg.filter }
     }
+
+    local healers, healers_noMP = {}, {}
+    for _, healer in ipairs(all_healers) do
+        if (healer.moves > 0) then
+            table.insert(healers, healer)
+        else
+            table.insert(healers_noMP, healer)
+        end
+    end
+
     if (not healers[1]) then return 0 end
 
-    local healers_noMP = wesnoth.get_units { side = wesnoth.current.side, ability = "healing",
-        formula = '$this_unit.moves = 0', { "and", cfg.filter }
-    }
-
-    local all_units = wesnoth.get_units{ side = wesnoth.current.side,
-        {"and", cfg.filter_second}
+    local all_units = wesnoth.get_units {
+        side = wesnoth.current.side,
+        { "and", cfg.filter_second }
     }
 
     local healees, units_MP = {}, {}

data/ai/micro_ais/cas/ca_herding_attack_close_enemy.lua

@@ -10,10 +10,9 @@ local function get_sheep(cfg)
 end
 
 local function get_dogs(cfg)
-    local dogs = wesnoth.get_units {
+    local dogs = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        { "and", cfg.filter },
-        formula = '$this_unit.moves > 0'
+        { "and", cfg.filter }
     }
     return dogs
 end

data/ai/micro_ais/cas/ca_herding_dog_move.lua

@@ -3,11 +3,10 @@ local AH = wesnoth.require "ai/lua/ai_helper.lua"
 local LS = wesnoth.require "lua/location_set.lua"
 
 local function get_dog(cfg)
-    local dogs = wesnoth.get_units {
+    local dogs = AH.get_units_with_moves {
         side = wesnoth.current.side,
         { "and", cfg.filter },
-        formula = '$this_unit.moves > 0',
-        { "not", { { "filter_adjacent", { side = wesnoth.current.side, {"and", cfg.filter_second} } } } }
+        { "not", { { "filter_adjacent", { side = wesnoth.current.side, { "and", cfg.filter_second } } } } }
     }
     return dogs[1]
 end

data/ai/micro_ais/cas/ca_herding_herd_sheep.lua

@@ -4,10 +4,9 @@ local AH = wesnoth.require "ai/lua/ai_helper.lua"
 local herding_area = wesnoth.require "ai/micro_ais/cas/ca_herding_f_herding_area.lua"
 
 local function get_dogs(cfg)
-    local dogs = wesnoth.get_units {
+    local dogs = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        { "and", cfg.filter },
-        formula = '$this_unit.moves > 0'
+        { "and", cfg.filter }
     }
     return dogs
 end

data/ai/micro_ais/cas/ca_herding_sheep_move.lua

@@ -5,10 +5,9 @@ local LS = wesnoth.require "lua/location_set.lua"
 local herding_area = wesnoth.require "ai/micro_ais/cas/ca_herding_f_herding_area.lua"
 
 local function get_next_sheep(cfg)
-    local sheep = wesnoth.get_units {
+    local sheep = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        { "and", cfg.filter_second },
-        formula = '$this_unit.moves > 0'
+        { "and", cfg.filter_second }
     }
     return sheep[1]
 end
@@ -47,7 +46,10 @@ function ca_herding_sheep_move:execution(ai, cfg)
     -- If this move remains within herding area or dogs have no moves left, or sheep doesn't move
     -- make it a full move, otherwise partial move
     local herding_area = herding_area(cfg)
-    local dogs = wesnoth.get_units { side = wesnoth.current.side, {"and", cfg.filter}, formula = '$this_unit.moves > 0' }
+    local dogs = AH.get_units_with_moves {
+        side = wesnoth.current.side,
+        { "and", cfg.filter }
+    }
     if herding_area:get(x, y) or (not dogs[1]) or ((x == sheep.x) and (y == sheep.y)) then
         AH.movefull_stopunit(ai, sheep, x, y)
     else

data/ai/micro_ais/cas/ca_herding_sheep_runs_dog.lua

@@ -2,9 +2,10 @@ local H = wesnoth.require "lua/helper.lua"
 local AH = wesnoth.require "ai/lua/ai_helper.lua"
 
 local function get_next_sheep(cfg)
-    local sheep = wesnoth.get_units { side = wesnoth.current.side, {"and", cfg.filter_second},
-        formula = '$this_unit.moves > 0',
-        { "filter_adjacent", { side = wesnoth.current.side, {"and", cfg.filter} } }
+    local sheep = AH.get_units_with_moves {
+        side = wesnoth.current.side,
+        { "and", cfg.filter_second },
+        { "filter_adjacent", { side = wesnoth.current.side, { "and", cfg.filter } } }
     }
     return sheep[1]
 end

data/ai/micro_ais/cas/ca_herding_sheep_runs_enemy.lua

@@ -2,11 +2,12 @@ local H = wesnoth.require "lua/helper.lua"
 local AH = wesnoth.require "ai/lua/ai_helper.lua"
 
 local function get_next_sheep(cfg)
-    local sheep = wesnoth.get_units { side = wesnoth.current.side, {"and", cfg.filter_second},
-        formula = '$this_unit.moves > 0',
+    local sheep = AH.get_units_with_moves {
+        side = wesnoth.current.side,
+        { "and", cfg.filter_second },
         { "filter_location",
             {
-                { "filter", { { "filter_side", {{"enemy_of", {side = wesnoth.current.side} }} } }
+                { "filter", { { "filter_side", { { "enemy_of", {side = wesnoth.current.side} } } } }
                 },
                 radius = (cfg.attention_distance or 8)
             }

data/ai/micro_ais/cas/ca_hunter.lua

@@ -39,11 +39,10 @@ end
 
 local function get_hunter(cfg)
     local filter = cfg.filter or { id = cfg.id }
-    local hunter = wesnoth.get_units({
+    local hunter = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        { "and", filter },
-        formula = '$this_unit.moves > 0' }
-    )[1]
+        { "and", filter }
+    }[1]
     return hunter
 end
 

data/ai/micro_ais/cas/ca_lurkers.lua

@@ -2,8 +2,9 @@ local LS = wesnoth.require "lua/location_set.lua"
 local AH = wesnoth.require "ai/lua/ai_helper.lua"
 
 local function get_lurker(cfg)
-    local lurker = wesnoth.get_units { side = wesnoth.current.side,
-        { "and", cfg.filter }, formula = '$this_unit.moves > 0'
+    local lurker = AH.get_units_with_moves {
+        side = wesnoth.current.side,
+        { "and", cfg.filter }
     }[1]
     return lurker
 end

data/ai/micro_ais/cas/ca_messenger_attack.lua

@@ -69,20 +69,11 @@ local function messenger_find_clearing_attack(unit, goal_x, goal_y, cfg)
 
     -- Find all units that can attack this enemy
     local filter = cfg.filter or { id = cfg.id }
-    local all_units = wesnoth.get_units {
+    local units = AH.get_units_with_attacks {
         side = wesnoth.current.side,
         { "not", filter },
         { "and", cfg.filter_second }
     }
-
-    -- Only keep units that have attacks and have attacks left
-    local units = {}
-    for _, unit in ipairs(all_units) do
-        if (unit.attacks_left > 0) and (H.get_child(unit.__cfg, 'attack')) then
-            table.insert(units, unit)
-        end
-    end
-
     if (not units[1]) then return end
 
     local attacks = AH.get_attacks(units, { simulate_combat = true })

data/ai/micro_ais/cas/ca_messenger_escort_move.lua

@@ -6,9 +6,8 @@ local MAIUV = wesnoth.require "ai/micro_ais/micro_ai_unit_variables.lua"
 local messenger_next_waypoint = wesnoth.require "ai/micro_ais/cas/ca_messenger_f_next_waypoint.lua"
 
 local function get_escorts(cfg)
-    local escorts = wesnoth.get_units {
+    local escorts = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        formula = '$this_unit.moves > 0',
         { "and", cfg.filter_second }
     }
     return escorts
@@ -33,7 +32,7 @@ function ca_messenger_escort_move:execution(ai, cfg)
     local _, _, _, messengers = messenger_next_waypoint(cfg)
 
     local enemies = wesnoth.get_units {
-        { "filter_side", {{"enemy_of", {side = wesnoth.current.side} }} }
+        { "filter_side", { { "enemy_of", { side = wesnoth.current.side } } } }
     }
 
     local base_rating_map = LS.create()

data/ai/micro_ais/cas/ca_patrol.lua

@@ -4,11 +4,10 @@ local MAIUV = wesnoth.require "ai/micro_ais/micro_ai_unit_variables.lua"
 
 local function get_patrol(cfg)
     local filter = cfg.filter or { id = cfg.id }
-    local patrol = wesnoth.get_units({
+    local patrol = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        { "and", filter },
-        formula = '$this_unit.moves > 0' }
-    )[1]
+        { "and", filter }
+    }[1]
     return patrol
 end
 

data/ai/micro_ais/cas/ca_protect_unit_attack.lua

@@ -11,7 +11,7 @@ function ca_protect_unit_attack:evaluation(ai, cfg, self)
 
     local units = {}
     for i,id in ipairs(cfg.id) do
-        table.insert(units, wesnoth.get_units{ id = id, formula = '$this_unit.attacks_left > 0' }[1])
+        table.insert(units, AH.get_units_with_attacks { id = id }[1])
     end
     if (not units[1]) then return 0 end
 

data/ai/micro_ais/cas/ca_protect_unit_finish.lua

@@ -5,7 +5,7 @@ local ca_protect_unit_finish = {}
 function ca_protect_unit_finish:evaluation(ai, cfg, self)
     -- If a unit can make it to the goal, this is the first thing that happens
     for i,id in ipairs(cfg.id) do
-        local unit = wesnoth.get_units{ id = id, formula = '$this_unit.moves > 0' }[1]
+        local unit = AH.get_units_with_moves { id = id }[1]
         if unit then
             local path, cost = wesnoth.find_path(unit, cfg.goal_x[i], cfg.goal_y[i])
             if (cost <= unit.moves) and ((unit.x ~= cfg.goal_x[i]) or (unit.y ~= cfg.goal_y[i])) then

data/ai/micro_ais/cas/ca_protect_unit_move.lua

@@ -6,7 +6,7 @@ local BC = wesnoth.require "ai/lua/battle_calcs.lua"
 local function get_protected_units(cfg)
     local units = {}
     for i,id in ipairs(cfg.id) do
-        table.insert(units, wesnoth.get_units { id = id, formula = '$this_unit.moves > 0' }[1])
+        table.insert(units, AH.get_units_with_moves { id = id }[1])
     end
     return units
 end

data/ai/micro_ais/cas/ca_return_guardian.lua

@@ -2,11 +2,10 @@ local AH = wesnoth.require "ai/lua/ai_helper.lua"
 
 local function get_guardian(cfg)
     local filter = cfg.filter or { id = cfg.id }
-    local guardian = wesnoth.get_units({
+    local guardian = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        { "and", filter },
-        formula = '$this_unit.moves > 0' }
-    )[1]
+        { "and", filter }
+    }[1]
     return guardian
 end
 

data/ai/micro_ais/cas/ca_simple_attack.lua

@@ -6,14 +6,10 @@ local LS = wesnoth.require "lua/location_set.lua"
 local ca_simple_attack = {}
 
 function ca_simple_attack:evaluation(ai, cfg, self)
-    local all_units = wesnoth.get_units { side = wesnoth.current.side, { "and", cfg.filter } }
-    -- Only keep units that have attacks and have attacks left
-    local units = {}
-    for _, unit in ipairs(all_units) do
-        if (unit.attacks_left > 0) and (H.get_child(unit.__cfg, 'attack')) then
-            table.insert(units, unit)
-        end
-    end
+    local units = AH.get_units_with_attacks {
+        side = wesnoth.current.side,
+        { "and", cfg.filter }
+    }
     if (not units[1]) then return 0 end
 
     -- Get all possible attacks

data/ai/micro_ais/cas/ca_stationed_guardian.lua

@@ -3,11 +3,10 @@ local AH = wesnoth.require "ai/lua/ai_helper.lua"
 
 local function get_guardian(cfg)
     local filter = cfg.filter or { id = cfg.id }
-    local guardian = wesnoth.get_units({
+    local guardian = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        { "and", filter },
-        formula = '$this_unit.moves > 0' }
-    )[1]
+        { "and", filter }
+    }[1]
     return guardian
 end
 

data/ai/micro_ais/cas/ca_swarm_scatter.lua

@@ -13,12 +13,7 @@ local function get_enemies(cfg)
 end
 
 local function get_swarm_units(cfg)
-    local units = {}
-    local all_units = wesnoth.get_units { side = wesnoth.current.side }
-    for i,u in ipairs(all_units) do
-        if (u.moves > 0) then table.insert(units, u) end
-    end
-    return units
+    return AH.get_units_with_moves { side = wesnoth.current.side }
 end
 
 local swarm_scatter = {}

data/ai/micro_ais/cas/ca_wolves_move.lua

@@ -4,10 +4,9 @@ local BC = wesnoth.require "ai/lua/battle_calcs.lua"
 local LS = wesnoth.require "lua/location_set.lua"
 
 local function get_wolves(cfg)
-    local wolves = wesnoth.get_units {
+    local wolves = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        { "and", cfg.filter },
-        formula = '$this_unit.moves > 0'
+        { "and", cfg.filter }
     }
     return wolves
 end

data/ai/micro_ais/cas/ca_wolves_multipacks_attack.lua

@@ -12,7 +12,10 @@ function ca_wolves_multipacks_attack:evaluation(ai, cfg)
     -- If wolves have attacks left, call this CA
     -- It will generally be disabled by being black-listed, so as to avoid
     -- having to do the full attack evaluation for every single move
-    local wolves = wesnoth.get_units { side = wesnoth.current.side, type = unit_type, formula = '$this_unit.attacks_left > 0' }
+    local wolves = AH.get_units_with_attacks {
+        side = wesnoth.current.side,
+        type = unit_type
+    }
 
     if wolves[1] then return cfg.ca_score end
     return 0

data/ai/micro_ais/cas/ca_wolves_multipacks_wander.lua

@@ -11,7 +11,10 @@ function ca_wolves_multipacks_wander:evaluation(ai, cfg)
     local unit_type = cfg.type or "Wolf"
 
     -- When there's nothing to attack, the wolves wander and regroup into their packs
-    local wolves = wesnoth.get_units { side = wesnoth.current.side, type = unit_type, formula = '$this_unit.moves > 0' }
+    local wolves = AH.get_units_with_moves {
+        side = wesnoth.current.side,
+        type = unit_type
+    }
 
     if wolves[1] then return cfg.ca_score end
     return 0

data/ai/micro_ais/cas/ca_wolves_wander.lua

@@ -4,8 +4,9 @@ local BC = wesnoth.require "ai/lua/battle_calcs.lua"
 local LS = wesnoth.require "lua/location_set.lua"
 
 local function get_wolves(cfg)
-    local wolves = wesnoth.get_units { side = wesnoth.current.side,
-        formula = '$this_unit.moves > 0', { "and", cfg.filter }
+    local wolves = AH.get_units_with_moves {
+        side = wesnoth.current.side,
+        { "and", cfg.filter }
     }
     return wolves
 end

data/ai/micro_ais/cas/ca_zone_guardian.lua

@@ -4,11 +4,10 @@ local LS = wesnoth.require "lua/location_set.lua"
 
 local function get_guardian(cfg)
     local filter = cfg.filter or { id = cfg.id }
-    local guardian = wesnoth.get_units({
+    local guardian = AH.get_units_with_moves {
         side = wesnoth.current.side,
-        { "and", filter },
-        formula = '$this_unit.moves > 0' }
-    )[1]
+        { "and", filter }
+    }[1]
     return guardian
 end