Various Lua AI code: use simpler and faster new syntax

No change in behavior.

data/ai/lua/ai_helper.lua

@@ -736,12 +736,11 @@ 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_child(unit.__cfg, 'attack')) then
+        if (unit.attacks_left > 0) and (#unit.attacks > 0) then
             table.insert(units, unit)
         end
     end

data/ai/lua/ca_high_xp_attack.lua

@@ -40,7 +40,7 @@ function ca_attack_highxp:evaluation(cfg, data)
         if (unit.side == wesnoth.current.side) and (unit.attacks_left > 0) and (#unit.attacks > 0) then
             table.insert(units, unit)
 
-            local level = wesnoth.unit_types[unit.type].level
+            local level = unit.level
             if (level > max_unit_level) then
                 max_unit_level = level
             end
@@ -60,7 +60,7 @@ function ca_attack_highxp:evaluation(cfg, data)
                 local ind_attackers, ind_other_units = {}, {}
                 for i_u,unit in ipairs(units) do
                     if (H.distance_between(enemy.x, enemy.y, unit.x, unit.y) <= unit.moves + 1) then
-                        if (wesnoth.unit_types[unit.type].level >= XP_to_levelup) then
+                        if (unit.level >= XP_to_levelup) then
                             potential_target = true
                             table.insert(ind_attackers, i_u)
                         else

data/ai/lua/retreat.lua

@@ -13,7 +13,7 @@ function retreat_functions.min_hp(unit)
     -- The minimum hp to retreat is a function of level and terrain defense
     -- We want to stay longer on good terrain and leave early on very bad terrain
     local hp_per_level = wesnoth.unit_defense(unit, wesnoth.get_terrain(unit.x, unit.y))/15
-    local level = wesnoth.unit_types[unit.type].level
+    local level = unit.level
 
     -- Leaders are considered to be higher level because of their value
     if unit.canrecruit then level = level+2 end

data/ai/micro_ais/cas/ca_assassin_move.lua

@@ -111,7 +111,7 @@ function ca_assassin_move:execution(cfg, data)
         local zoc_active = (not is_skirmisher)
 
         if zoc_active then
-            local level = wesnoth.unit_types[enemy.type].level
+            local level = enemy.level
             if (level == 0) then zoc_active = false end
         end
 

data/ai/micro_ais/cas/ca_bottleneck_move.lua

@@ -319,7 +319,7 @@ function ca_bottleneck_move:evaluation(cfg, data)
                 local unit_in_way = wesnoth.get_unit(xa, ya)
                 local data = { x = xa, y = ya,
                     defender = enemy,
-                    defender_level = wesnoth.unit_types[enemy.type].level,
+                    defender_level = enemy.level,
                     unit_in_way = unit_in_way
                 }
                 table.insert(attacks, data)

data/ai/micro_ais/cas/ca_fast_combat.lua

@@ -77,7 +77,7 @@ function ca_fast_combat:evaluation(cfg, data)
         local unit_info = FAU.get_unit_info(unit, data.gamedata)
         local unit_copy = FAU.get_unit_copy(unit.id, data.gamedata)
 
-        if (unit.attacks_left > 0) and (H.get_child(unit.__cfg, 'attack')) then
+        if (unit.attacks_left > 0) and (#unit.attacks > 0) then
             local attacks = AH.get_attacks({ unit }, { include_occupied = cfg.include_occupied_attack_hexes })
 
             if (#attacks > 0) then

data/ai/micro_ais/cas/ca_fast_combat_leader.lua

@@ -37,7 +37,7 @@ function ca_fast_combat_leader:evaluation(cfg, data)
         end
     end
 
-    if (leader.attacks_left == 0) or (not H.get_child(leader.__cfg, 'attack')) then return 0 end
+    if (leader.attacks_left == 0) or (#leader.attacks == 0) then return 0 end
 
     local excluded_enemies_map = LS.create()
 

data/ai/micro_ais/cas/ca_messenger_move.lua

@@ -88,7 +88,7 @@ function ca_messenger_move:execution(cfg)
 
     -- Test whether an attack without retaliation or with little damage is possible
     if (messenger.attacks_left <= 0) then return end
-    if (not H.get_child(messenger.__cfg, 'attack')) then return end
+    if (#messenger.attacks == 0) then return end
 
     local targets = wesnoth.get_units {
         { "filter_side", { { "enemy_of", { side = wesnoth.current.side } } } },