code / tomo

   1 # Tests for ensuring immutable value nature in various contexts
   2 struct Inner(xs:[Int32])
   3 
   4 struct Outer(inner:Inner)
   5 
   6 enum HoldsList(HasList(xs:[Int32]))
   7 
   8 func sneaky(outer:Outer)
   9     (&outer.inner.xs)[1] = 99
  10 
  11 func sneaky2(outer:&Outer)
  12     (&outer.inner.xs)[1] = 99
  13 
  14 func main()
  15     do
  16         xs := [10, 20, 30]
  17         copy := xs
  18         (&xs)[1] = 99
  19         assert xs == [99, 20, 30]
  20         assert copy == [10, 20, 30]
  21 
  22     do
  23         t := {"A":10, "B":20}
  24         copy := t
  25         (&t)["A"] = 99
  26         assert t == {"A":99, "B":20}
  27         assert copy == {"A":10, "B":20}
  28 
  29     do
  30         foo := Outer(Inner([10, 20, 30]))
  31         copy := foo
  32         (&foo.inner.xs)[1] = 99
  33         assert foo.inner.xs == [99, 20, 30]
  34         assert copy.inner.xs == [10, 20, 30]
  35 
  36     do
  37         foo := Outer(Inner([10, 20, 30]))
  38         copy := foo
  39         sneaky(foo)
  40         assert foo.inner.xs == [10, 20, 30]
  41         assert copy.inner.xs == [10, 20, 30]
  42 
  43     do
  44         foo := Outer(Inner([10, 20, 30]))
  45         copy := foo
  46         sneaky2(&foo)
  47         assert foo.inner.xs == [99, 20, 30]
  48         assert copy.inner.xs == [10, 20, 30]
  49 
  50     do
  51         x := HoldsList.HasList([10, 20, 30])
  52         when x is HasList(list)
  53             (&list)[1] = 99
  54 
  55         assert x == HoldsList.HasList([10, 20, 30])