Lua AIs: use math.huge to initialize extrema variables

(cherry-picked from commit cb423b2)

data/ai/lua/ai_helper.lua

@@ -1052,7 +1052,7 @@ function ai_helper.get_closest_enemy(loc, side, cfg)
         x, y = loc[1], loc[2]
     end
 
-    local closest_distance, location = 9e99
+    local closest_distance, location = math.huge
     for _,enemy in ipairs(enemies) do
         enemy_distance = M.distance_between(x, y, enemy.x, enemy.y)
         if (enemy_distance < closest_distance) then
@@ -1088,7 +1088,7 @@ function ai_helper.has_weapon_special(unit, special)
 end
 
 function ai_helper.get_cheapest_recruit_cost()
-    local cheapest_unit_cost = 9e99
+    local cheapest_unit_cost = math.huge
     for _,recruit_id in ipairs(wesnoth.sides[wesnoth.current.side].recruit) do
         if wesnoth.unit_types[recruit_id].cost < cheapest_unit_cost then
             cheapest_unit_cost = wesnoth.unit_types[recruit_id].cost
@@ -1408,7 +1408,7 @@ function ai_helper.find_best_move(units, rating_function, cfg)
     -- If this is an individual unit, turn it into an array
     if units.hitpoints then units = { units } end
 
-    local max_rating, best_hex, best_unit = -9e99, {}, {}
+    local max_rating, best_hex, best_unit = - math.huge, {}, {}
     for _,unit in ipairs(units) do
         -- Hexes each unit can reach
         local reach_map = ai_helper.get_reachable_unocc(unit, cfg)
@@ -1452,7 +1452,7 @@ function ai_helper.move_unit_out_of_way(ai, unit, cfg)
     local reach = wesnoth.find_reach(unit, cfg)
     local reach_map = LS.create()
 
-    local max_rating, best_hex = -9e99
+    local max_rating, best_hex = - math.huge
     for _,loc in ipairs(reach) do
         local unit_in_way = wesnoth.get_unit(loc[1], loc[2])
         if (not unit_in_way)       -- also excludes current hex

data/ai/lua/battle_calcs.lua

@@ -199,10 +199,10 @@ function battle_calcs.best_weapons(attacker, defender, dst, cache)
     local defender_info = battle_calcs.unit_attack_info(defender, cache)
 
     -- Best attacker weapon
-    local max_rating, best_att_weapon, best_def_weapon = -9e99, 0, 0
+    local max_rating, best_att_weapon, best_def_weapon = - math.huge, 0, 0
     for att_weapon_number,att_weapon in ipairs(attacker_info.attacks) do
         local att_damage = battle_calcs.strike_damage(attacker, defender, att_weapon_number, 0, { dst[1], dst[2] }, cache)
-        local max_def_rating, tmp_best_def_weapon = -9e99, 0
+        local max_def_rating, tmp_best_def_weapon = - math.huge, 0
         for def_weapon_number,def_weapon in ipairs(defender_info.attacks) do
             if (def_weapon.range == att_weapon.range) then
                 local def_damage = battle_calcs.strike_damage(defender, attacker, def_weapon_number, 0, { defender.x, defender.y }, cache)
@@ -214,7 +214,7 @@ function battle_calcs.best_weapons(attacker, defender, dst, cache)
         end
 
         local rating = att_damage * att_weapon.number
-        if (max_def_rating > -9e99) then rating = rating - max_def_rating / 2. end
+        if (max_def_rating > - math.huge) then rating = rating - max_def_rating / 2. end
 
         if (rating > max_rating) then
             max_rating, best_att_weapon, best_def_weapon = rating, att_weapon_number, tmp_best_def_weapon
@@ -1245,7 +1245,7 @@ function battle_calcs.relative_damage_map(units, enemies, cache)
     -- against any of the enemy units
     local unit_ratings = {}
     for i,unit in ipairs(units) do
-        local max_rating, best_enemy = -9e99, {}
+        local max_rating, best_enemy = - math.huge, {}
         for _,enemy in ipairs(enemies) do
             local rating, defender_rating, attacker_rating =
                 battle_calcs.attack_rating(unit, enemy, { unit.x, unit.y }, { enemy_leader_weight = 1 }, cache)
@@ -1262,7 +1262,7 @@ function battle_calcs.relative_damage_map(units, enemies, cache)
     -- Then we want the same thing for all of the enemy units (for the counter attack on enemy turn)
     local enemy_ratings = {}
     for i,enemy in ipairs(enemies) do
-        local max_rating, best_unit = -9e99, {}
+        local max_rating, best_unit = - math.huge, {}
         for _,unit in ipairs(units) do
             local rating, defender_rating, attacker_rating =
                 battle_calcs.attack_rating(enemy, unit, { enemy.x, enemy.y }, { enemy_leader_weight = 1 }, cache)
@@ -1323,7 +1323,7 @@ function battle_calcs.best_defense_map(units, cfg)
         for _,loc in ipairs(reach) do
             local defense = 100 - unit:defense(wesnoth.get_terrain(loc[1], loc[2]))
 
-            if (defense > (defense_map:get(loc[1], loc[2]) or -9e99)) then
+            if (defense > (defense_map:get(loc[1], loc[2]) or - math.huge)) then
                 defense_map:insert(loc[1], loc[2], defense)
             end
         end
@@ -1373,7 +1373,7 @@ function battle_calcs.get_attack_combos_subset(units, enemy, cfg)
 
     cfg = cfg or {}
     cfg.order_matters = cfg.order_matters or false
-    cfg.max_combos = cfg.max_combos or 9e99
+    cfg.max_combos = cfg.max_combos or math.huge
     cfg.max_time = cfg.max_time or false
     cfg.skip_presort = cfg.skip_presort or 5
 

data/ai/lua/generic_rush_engine.lua

@@ -298,7 +298,7 @@ return {
             local enemy_attack_map = BC.get_attack_map(enemies).units
 
             -- Now we go through the villages and units
-            local max_rating, best_village, best_unit = -9e99, {}, {}
+            local max_rating, best_village, best_unit = - math.huge, {}, {}
             local village_ratings = {}
             for j,v in ipairs(villages) do
                 -- First collect all information that only depends on the village
@@ -322,7 +322,7 @@ return {
                 local enemy_distance_from_village = AH.get_closest_enemy(v)
 
                 -- Now we go on to the unit-dependent rating
-                local best_unit_rating = -9e99
+                local best_unit_rating = - math.huge
                 local reachable = false
                 for i,u in ipairs(units) do
                     -- Skip villages that have units other than 'u' itself on them
@@ -370,7 +370,7 @@ return {
                 end
             end
 
-            if (max_rating > -9e99) then
+            if (max_rating > - math.huge) then
                 self.data.unit, self.data.village = best_unit, best_village
                 if (max_rating >= 1000) then
                     if AH.print_eval() then AH.done_eval_messages(start_time, ca_name) end
@@ -423,7 +423,7 @@ return {
             end
 
             -- Go through all possible attacks with poisoners
-            local max_rating, best_attack = -9e99, {}
+            local max_rating, best_attack = - math.huge, {}
             for i,a in ipairs(attacks) do
                 local attacker = wesnoth.get_unit(a.src.x, a.src.y)
                 local defender = wesnoth.get_unit(a.target.x, a.target.y)
@@ -465,7 +465,7 @@ return {
                 end
             end
 
-            if (max_rating > -9e99) then
+            if (max_rating > - math.huge) then
                 self.data.attack = best_attack
                 if AH.print_eval() then AH.done_eval_messages(start_time, ca_name) end
                 return 190000

data/ai/lua/retreat.lua

@@ -114,7 +114,7 @@ function retreat_functions.get_retreat_injured_units(healees, regenerates)
 
     local healing_locs = retreat_functions.get_healing_locations()
 
-    local max_rating, best_loc, best_unit = -9e99, nil, nil
+    local max_rating, best_loc, best_unit = - math.huge, nil, nil
     for i,u in ipairs(healees) do
         local possible_locations = wesnoth.find_reach(u)
         -- TODO: avoid ally's villages (may be preferable to lower rating so they will

data/ai/micro_ais/cas/ca_big_animals.lua

@@ -58,7 +58,7 @@ function ca_big_animals:execution(cfg)
     end)
 
     -- Now find the one of these hexes that is closest to the goal
-    local max_rating, best_hex = -9e99
+    local max_rating, best_hex = - math.huge
     reach_map:iter( function(x, y, v)
         local rating = -wesnoth.map.distance_between(x, y, goal.goal_x, goal.goal_y)
 
@@ -95,7 +95,7 @@ function ca_big_animals:execution(cfg)
     end
 
     -- Finally, if the unit ended up next to enemies, attack the weakest of those
-    local min_hp, target = 9e99
+    local min_hp, target = math.huge
     for xa,ya in H.adjacent_tiles(unit.x, unit.y) do
         local enemy = wesnoth.get_unit(xa, ya)
         if AH.is_attackable_enemy(enemy) then

data/ai/micro_ais/cas/ca_bottleneck_attack.lua

@@ -11,7 +11,7 @@ function ca_bottleneck_attack:evaluation(cfg, data)
     }
     if (not attackers[1]) then return 0 end
 
-    local max_rating, best_attacker, best_target, best_weapon = -9e99
+    local max_rating, best_attacker, best_target, best_weapon = - math.huge
     for _,attacker in ipairs(attackers) do
         local targets = AH.get_attackable_enemies { { "filter_adjacent", { id = attacker.id } } }
 

data/ai/micro_ais/cas/ca_bottleneck_move.lua

@@ -25,7 +25,7 @@ local function bottleneck_is_my_territory(map, enemy_map)
                 dummy_unit.x, dummy_unit.y = x, y
 
                 -- Find lowest movement cost to own front-line hexes
-                local min_cost, best_path = 9e99
+                local min_cost, best_path = math.huge
                 map:iter(function(xm, ym, v)
                     local path, cost = AH.find_path_with_shroud(dummy_unit, xm, ym, { ignore_units = true })
                     if (cost < min_cost) then
@@ -34,7 +34,7 @@ local function bottleneck_is_my_territory(map, enemy_map)
                 end)
 
                 -- And the same to the enemy front line
-                local min_cost_enemy, best_path_enemy = 9e99
+                local min_cost_enemy, best_path_enemy = math.huge
                 enemy_map:iter(function(xm, ym, v)
                     local path, cost = AH.find_path_with_shroud(dummy_unit, xm, ym, { ignore_units = true })
                     if (cost < min_cost_enemy) then
@@ -192,7 +192,7 @@ local function bottleneck_move_out_of_way(unit_in_way, data)
         occ_hexes:insert(unit.x, unit.y)
     end
 
-    local best_reach, best_hex = -9e99
+    local best_reach, best_hex = - math.huge
     for _,loc in ipairs(reach) do
         if data.BD_is_my_territory:get(loc[1], loc[2]) and (not occ_hexes:get(loc[1], loc[2])) then
             -- Criterion: MP left after the move has been done
@@ -273,7 +273,7 @@ function ca_bottleneck_move:evaluation(cfg, data)
         for xa,ya in H.adjacent_tiles(healer.x, healer.y) do
             -- Cannot be on the line, and needs to be in own territory
             if data.BD_is_my_territory:get(xa, ya) then
-                local min_dist = 9e99
+                local min_dist = math.huge
                 data.BD_def_map:iter( function(xd, yd, vd)
                     local dist_line = M.distance_between(xa, ya, xd, yd)
                     if (dist_line < min_dist) then min_dist = dist_line end

data/ai/micro_ais/cas/ca_coward.lua

@@ -52,7 +52,7 @@ function ca_coward:execution(cfg)
             -- Store this weighting in the third field of each 'reach' element
             reach[i][3] = rating
         else
-            reach[i][3] = -9e99
+            reach[i][3] = - math.huge
         end
     end
 
@@ -76,7 +76,7 @@ function ca_coward:execution(cfg)
 
     -- As final step, if there are more than one remaining locations,
     -- we take the one with the minimum score in the distance-from-enemy criterion
-    local max_rating, best_hex = -9e99
+    local max_rating, best_hex = - math.huge
     for _,pos in ipairs(best_overall) do
         if (pos[3] > max_rating) then
             max_rating, best_hex = pos[3], pos
@@ -88,7 +88,7 @@ function ca_coward:execution(cfg)
 
     -- If 'attack_if_trapped' is set, the coward attacks the weakest unit it ends up next to
     if cfg.attack_if_trapped then
-        local max_rating, best_target = -9e99
+        local max_rating, best_target = - math.huge
         for xa,ya in H.adjacent_tiles(coward.x, coward.y) do
             local target = wesnoth.get_unit(xa, ya)
             if target and wesnoth.is_enemy(coward.side, target.side) then

data/ai/micro_ais/cas/ca_fast_combat.lua

@@ -84,7 +84,7 @@ function ca_fast_combat:evaluation(cfg, data)
             local attacks = AH.get_attacks({ unit }, { include_occupied = cfg.include_occupied_attack_hexes, viewing_side = viewing_side })
 
             if (#attacks > 0) then
-                local max_rating, best_target, best_dst = -9e99
+                local max_rating, best_target, best_dst = - math.huge
                 for _,attack in ipairs(attacks) do
                     if enemy_map:get(attack.target.x, attack.target.y)
                         and (not avoid_map:get(attack.dst.x, attack.dst.y))

data/ai/micro_ais/cas/ca_fast_combat_leader.lua

@@ -119,7 +119,7 @@ function ca_fast_combat_leader:evaluation(cfg, data)
     local attacks = AH.get_attacks({ leader }, { include_occupied = cfg.include_occupied_attack_hexes, viewing_side = viewing_side })
 
     if (#attacks > 0) then
-        local max_rating, best_target, best_dst = -9e99
+        local max_rating, best_target, best_dst = - math.huge
         for _,attack in ipairs(attacks) do
             if enemy_map:get(attack.target.x, attack.target.y)
                 and (not avoid_map:get(attack.dst.x, attack.dst.y))

data/ai/micro_ais/cas/ca_fast_move.lua

@@ -143,7 +143,7 @@ function ca_fast_move:execution(cfg)
         if (next_goal > #goals) then next_goal = 1 end
         local goal = goals[next_goal]
 
-        local max_rating, best_unit_info = -9e99
+        local max_rating, best_unit_info = - math.huge
         for _,unit_info in ipairs(goal) do
             if (not unit_info.cost) then
                 local _,cost =
@@ -198,7 +198,7 @@ function ca_fast_move:execution(cfg)
             local reach = wesnoth.find_reach(unit)
 
             local pre_ratings = {}
-            local max_rating, best_hex = -9e99
+            local max_rating, best_hex = - math.huge
             for _,loc in ipairs(reach) do
                 if (not avoid_map:get(loc[1], loc[2])) then
                     local rating = -M.distance_between(loc[1], loc[2], short_goal[1], short_goal[2])
@@ -246,7 +246,7 @@ function ca_fast_move:execution(cfg)
                 unit:extract()
                 local old_x, old_y = unit.x, unit.y
 
-                local max_rating = -9e99
+                local max_rating = - math.huge
                 for _,pre_rating in ipairs(pre_ratings) do
                     -- If pre_rating is worse than the full rating, we are done because the
                     -- move cost can never be less than the distance, so we cannot possibly do

data/ai/micro_ais/cas/ca_forest_animals_move.lua

@@ -96,7 +96,7 @@ function ca_forest_animals_move:execution(cfg)
                 AH.checked_move(ai, unit, reachable_wander_terrain[rand][1], reachable_wander_terrain[rand][2])
             end
         else  -- Or if no close reachable terrain was found, move toward the closest
-            local min_dist, best_hex = 9e99
+            local min_dist, best_hex = math.huge
             for _,loc in ipairs(wander_locs) do
                 local dist = M.distance_between(loc[1], loc[2], unit.x, unit.y)
                 if dist < min_dist then

data/ai/micro_ais/cas/ca_forest_animals_tusker_attack.lua

@@ -32,7 +32,7 @@ function ca_forest_animals_tusker_attack:execution(cfg)
     local adjacent_enemies = get_adjacent_enemies(cfg)
 
     -- Find the closest enemy to any tusker
-    local min_dist, attacker, target = 9e99
+    local min_dist, attacker, target = math.huge
     for _,tusker in ipairs(tuskers) do
         for _,enemy in ipairs(adjacent_enemies) do
             local dist = M.distance_between(tusker.x, tusker.y, enemy.x, enemy.y)

data/ai/micro_ais/cas/ca_forest_animals_tusklet_move.lua

@@ -33,7 +33,7 @@ function ca_forest_animals_tusklet_move:execution(cfg)
     local tusklet = get_tusklets(cfg)[1]
     local tuskers = get_tuskers(cfg)
 
-    local goto_tusker, min_dist = {}, 9e99
+    local goto_tusker, min_dist = {}, math.huge
     for _,tusker in ipairs(tuskers) do
         local dist = M.distance_between(tusker.x, tusker.y, tusklet.x, tusklet.y)
         if (dist < min_dist) then

data/ai/micro_ais/cas/ca_goto.lua

@@ -118,7 +118,7 @@ function ca_goto:execution(cfg, data)
         enemy_attack_map = BC.get_attack_map(live_enemies)
     end
 
-    local max_rating, closest_hex, best_path, best_unit = -9e99
+    local max_rating, closest_hex, best_path, best_unit = - math.huge
     for _,unit in ipairs(units) do
         for _,loc in ipairs(locs) do
             -- If cfg.use_straight_line is set, we simply find the closest

data/ai/micro_ais/cas/ca_hang_out.lua

@@ -83,11 +83,11 @@ function ca_hang_out:execution(cfg)
         avoid_map = LS.of_pairs(wesnoth.get_locations { terrain = 'C*,C*^*,*^C*' })
     end
 
-    local max_rating, best_hex, best_unit = -9e99
+    local max_rating, best_hex, best_unit = - math.huge
     for _,unit in ipairs(units) do
         -- Only consider units that have not been marked yet
         if (not MAIUV.get_mai_unit_variables(unit, cfg.ai_id, "moved")) then
-            local max_rating_unit, best_hex_unit = -9e99
+            local max_rating_unit, best_hex_unit = - math.huge
 
             -- Check out all unoccupied hexes the unit can reach
             local reach_map = AH.get_reachable_unocc(unit)

data/ai/micro_ais/cas/ca_healer_move.lua

@@ -63,7 +63,7 @@ function ca_healer_move:evaluation(cfg, data)
 
     local avoid_map = LS.of_pairs(ai.aspects.avoid)
 
-    local max_rating = -9e99
+    local max_rating = - math.huge
     for _,healer in ipairs(healers) do
         local reach = wesnoth.find_reach(healer)
 

data/ai/micro_ais/cas/ca_herding_attack_close_enemy.lua

@@ -48,7 +48,7 @@ function ca_herding_attack_close_enemy:execution(cfg)
     local radius = cfg.attack_distance or 4
     local enemies = get_enemies(cfg, radius)
 
-    max_rating, best_dog, best_enemy, best_hex = -9e99
+    max_rating, best_dog, best_enemy, best_hex = - math.huge
     for _,enemy in ipairs(enemies) do
         for _,dog in ipairs(dogs) do
             local reach_map = AH.get_reachable_unocc(dog)
@@ -90,7 +90,7 @@ function ca_herding_attack_close_enemy:execution(cfg)
     if (not dogs[1]) then return end
 
     -- Find closest sheep/enemy pair first
-    local min_dist, closest_sheep, closest_enemy = 9e99
+    local min_dist, closest_sheep, closest_enemy = math.huge
     for _,enemy in ipairs(enemies) do
         for _,single_sheep in ipairs(sheep) do
             local dist = M.distance_between(enemy.x, enemy.y, single_sheep.x, single_sheep.y)
@@ -102,7 +102,7 @@ function ca_herding_attack_close_enemy:execution(cfg)
     end
 
     -- Move dogs in between enemies and sheep
-    max_rating, best_dog, best_hex = -9e99
+    max_rating, best_dog, best_hex = - math.huge
     for _,dog in ipairs(dogs) do
         local reach_map = AH.get_reachable_unocc(dog)
         reach_map:iter( function(x, y, v)

data/ai/micro_ais/cas/ca_herding_herd_sheep.lua

@@ -42,7 +42,7 @@ function ca_herding_herd_sheep:execution(cfg)
     local dogs = get_dogs(cfg)
     local sheep_to_herd = get_sheep_to_herd(cfg)
 
-    local max_rating, best_dog, best_hex = -9e99
+    local max_rating, best_dog, best_hex = - math.huge
     local c_x, c_y = cfg.herd_x, cfg.herd_y
     for _,single_sheep in ipairs(sheep_to_herd) do
         -- Farthest sheep goes first

data/ai/micro_ais/cas/ca_hunter.lua

@@ -12,7 +12,7 @@ local function hunter_attack_weakest_adj_enemy(ai, hunter)
 
     if (hunter.attacks_left == 0) then return 'no_attack' end
 
-    local min_hp, target = 9e99
+    local min_hp, target = math.huge
     for xa,ya in H.adjacent_tiles(hunter.x, hunter.y) do
         local enemy = wesnoth.get_unit(xa, ya)
         if AH.is_attackable_enemy(enemy) then
@@ -74,7 +74,7 @@ function ca_hunter:execution(cfg)
         local reach_map = AH.get_reachable_unocc(hunter)
 
         -- Now find the one of these hexes that is closest to the goal
-        local max_rating, best_hex = -9e99
+        local max_rating, best_hex = - math.huge
         reach_map:iter( function(x, y, v)
             -- Distance from goal is first rating
             local rating = -M.distance_between(x, y, hunter_vars.goal_x, hunter_vars.goal_y)