possibleinheritbug.nim

## Original: https://nim-by-example.github.io/oop/

## Running the above with non ref objects errors ##

type Animal = object of RootObj
  name: string
  age: int
method vocalize(this: Animal): string = "..."
method ageHumanYrs(this: Animal): int = this.age

type Dog = object of Animal

method vocalize(this: Dog): string = "woof"
method ageHumanYrs(this: Dog): int = this.age * 7

type Cat = object of Animal

method vocalize(this: Cat): string = "meow"


var animals: seq[Animal] = newSeq[Animal]()

animals.add(Dog(name: "Sparky", age: 10)) # <- Error here
animals.add(Cat(name: "Mitten", age: 10))

for a in animals:
  echo a.vocalize()
  echo a.ageHumanYrs()

#[ Running this gives: ]
test.nim(19)             test
assign.nim(96)           genericAssign
assign.nim(75)           genericAssignAux
assign.nim(24)           genericAssignAux
assign.nim(21)           genericAssignAux
assign.nim(51)           genericAssignAux
SIGSEGV: Illegal storage access. (Attempt to read from nil?)
]#

## Assigning first to a var runs but has wrong results ##

type Animal = object of RootObj
  name: string
  age: int
  
method vocalize(this: Animal): string = "..."
method ageHumanYrs(this: Animal): int = this.age

type Dog = object of Animal

method vocalize(this: Dog): string = "woof"
method ageHumanYrs(this: Dog): int = this.age * 7

type Cat = object of Animal

method vocalize(this: Cat): string = "meow"


var animals: seq[Animal] = newSeq[Animal]()
var d = Dog(name: "Sparky", age: 10)
var c = Cat(name: "Mitten", age: 10)
animals.add(d)
animals.add(c)

for a in animals:
  echo a.vocalize()
  echo a.ageHumanYrs()

#[ This results in: ]
 ... -> should be woof
 10  -> should be 70
 ... -> should be meow
 10
]#