check if a tree is complete standard ml
- by aizen92
I want to make a function in standard ml that checks if a tree is complete or not, the function somehow works, but its giving me the wrong type and a warning of non-exhaustive cases
The tree code:
datatype 'data tree =
EMPTY
| NODE of 'data tree * 'data * 'data tree;
fun isComplete EMPTY = true
| isComplete (NODE(x, y, z)) = if (x = EMPTY andalso z <> EMPTY) orelse (x <> EMPTY andalso z = EMPTY) then false else true;
Now the above function's type is: ''a tree -> bool but the required type is 'a tree -> bool
The warning I'm having is:
stdIn:169.8 Warning: calling polyEqual
stdIn:169.26 Warning: calling polyEqual
stdIn:169.45-169.47 Warning: calling polyEqual
stdIn:169.64-169.66 Warning: calling polyEqual
stdIn:124.1-169.94 Warning: match nonexhaustive
NODE (x,y,z) => ...
What is the problem I'm having?
