-- @preview-file on clear

_ENV = Dora

hpGroup = Group {"hp"}

spGroup = Group {"sp"}

observer = Observer "Change", {"hp", "mp"}

observer1 = Observer "Remove", {"hp", "sp"}

Entity

hp: 100

mp: 998

id: 0

entity0 = hpGroup\find => @id == 0

Entity

hp: 119

sp: 233

id: 1

entity1 = hpGroup\find => @id == 1

print "-- {hp} group"

hpGroup\each =>

print "entity", @id

print "-- {sp} group"

spGroup\each =>

print "entity", @id

print "-- {hp mp} observer"

entity0.hp += 20

entity0.hp -= 34

entity1.hp -= 1

entity1.hp -= 99

observer

\watch (hp, mp) =>

if oldHP := @oldValues.hp

assert @oldValues.hp == 100

assert hp == 86

print "hp change [from #{oldHP} to #{hp}]: entity #{@id}"

if oldMP := @oldValues.mp

print "mp change [from #{oldMP} to #{mp}]: entity #{@id}"

observer1

\watch (hp, sp) =>

if hp == nil

assert @oldValues.hp == 119

print "hp removed from entity #{@id}, old value: #{@oldValues.hp}"

if sp == nil

print "sp removed from entity #{@id}, old value: #{@oldValues.sp}"

print "-- {hp} group"

hpGroup\each =>

print "entity", @id, @hp

print "remove hp from entity", entity1.id

entity1.hp = nil

print "-- {hp} group"

hpGroup\each =>

print "entity", @index, @hp

assert hpGroup.count == 1

print "-- {sp} group"

spGroup\each =>

print "entity", @index, @sp

assert spGroup.count == 1