The following code will result in a compile error
func(:any) : false = false
This function returns a value of type false, but the function body's result is an incompatible value of type logic.(3510)
Possible bugs are one of the following
1: It is not a compile error even if “false” is written as the type of the variable.
2: “false” cannot be stored in a variable of type false.
Is " false" a type?
I thought the type was “logic” which can be true/false. So if you change it to
func(:any) : logic = false
That shouldn’t return errors.
Thank you very much.
Yes, you are right, the type of the variable should be “logic”.
However, specifying “false” as the type of the variable does not cause a compile error. The error message also says “type false”.
I wanted to know if this is a compiler bug or not.
See also.
Thanks for the clarification! That’s interesting to check out indeed 
Apart from being a value of the type logic, false is also a type that has no possible values. As a return type, it indicates that the function doesn’t return a value. The only way to do this right now is using the Err function, which is defined as:
# Halts the Verse runtime with error `Message`.
Err(Message:string)<computes>:false
The reason why it’s valuable to have such a type with no possible values is that it’s a subtype of all other types, also known as the bottom type. You can use a value from :false without regard for what value is expected, and an expression like or or if that joins possible results from different branches into a single type can ignore unreachable branches. For example:
MaybeInt:?int=...
MyInt:int = MaybeInt? or Err("expected MaybeInt to be set")
The left-hand-side of the or yields a value from :int, and the right-hand-side of the or yields a value from :false. This means the combined expression will yield a value from the join :int | :false, but because :false has no possible values this simplifies to :int, and the compiler accepts binding the result to MyInt:int.
I would think that someone in the Reasonable Names department would see that:
André