What does '#' mean in SML?

Question

I have a function, that creates a new tree, based on an old one, and the min/max values of each node from the old one. using the datatypes:

datatype 'a Tree = LEAF of 'a | NODE of ('a Tree) * ('a Tree)

and

datatype 'a myTree = myLEAF of 'a | myNODE of 'a*'a*('a myTree)*('a myTree)

for instance,

(NODE(NODE(NODE(LEAF(0),LEAF(9)),LEAF(6)),NODE(LEAF(3),LEAF(10))))

should produce:

(myNODE(0,10,myNODE(0,9,myNODE(0,9,myLEAF(0),myLEAF(9)),myLEAF(6)),myNODE(3,10,myLEAF(3),myLEAF(10))))

Everything seems to work. Except, the values in the leaf and internal nodes are replaced with '#'.

example:

 minmaxTree t1;
val it =
  myNODE (1,2,myNODE (1,2,myNODE #,myLEAF #),myNODE (1,2,myNODE #,myNODE #))
  : int myTree

Im confused why the sml compiler is replacing with '#', where the values are clearly ints. Thank you kindly!

Answer 1

As pointed out by molbdnilo, this was a duplicate question, the answer to my question is found here: here There was an output restriction, the compiler was not set to print out in depth, as i need it to. after applying the solution here,

my output is:

- minmaxTree t1;
val it =
  myNODE
    (1,2,myNODE (1,2,myNODE (1,2,myLEAF 1,myLEAF 2),myLEAF 1),
     myNODE
       (1,2,myNODE (1,2,myLEAF 1,myLEAF 2),
        myNODE (1,2,myNODE (1,2,myLEAF 1,myLEAF 2),myLEAF 1))) : int myTree