We tried a lot to find a way to store arithmetic operation in an array and then use them for processing.

eg. get + or - or / or * in an array like say array opp = [+,+.-,*,/,+] and then use them like 5 opp[1] 10 = to get 15. or like opp[1](5,10) to get 15

We are able to do it for normal variable but not on array. 

eg. as below

builtin-num-bin-op: opp = "+";

int: val = opp(5,10);

We are able to get the expected result in val. 

But can't declare an array of that type builtin-num-bin-op, and thus can't solve the our problem to get the operations as input.

Please advice.

The actual code that worked before is below. But now even after removing array it is not working. I am also getting the same error as yours. 

int: boardSize = 7;
% tried to parameterize operator. It worked initially but now not working. Especially not working with array so harcoded operators.
builtin-num-bin-op : opp = "-";
int: val = opp(boardSize,boardSize+1);
output["\(val)"];

 

This is the code worked like an hour ago. It seems I have modified a lot after that and now this initial one not working at all. I was able to pring -1. 

Then I do not have the output and the exact item i had while initial writing it and then creating the modal based on it. 

Is there any other way to parameterize operation or operators like +, -, *  and /, 

So that I need not hard code these values and get them as input from User and work for all different puzzles.

As far as I know, there is no way to do what you want to do. There is no type in MiniZinc for functions. So you can't assign a function to a variable as you can in Haskell, Python, etc. The closest you can come is to do this:

output ["\('+'(3, 4))  \('+'(3, 4) == '+'(5, 2))"];   % => 7 true

But you can't even use that trick to put '+' into an enum.

 

You might want to look at something like this.

enum OP = {plus, minus, times, divided_by}; 

predicate eval_op(var SMALL_INT: v1, var  OP: op, var SMALL_INT: v2, var  SMALL_INT: v3) =

    op == plus /\ v1 + v2 == v3 \/

    op == minus /\ v1 - v2 == v3 \/

    op == times /\ v1 * v2 == v3 \/

    op == divided_by /\ v1 div v2 == v3;

set of int: SMALL_INT = 1..10;

set of int: VERY_SMALL_INT = 3..5;

var VERY_SMALL_INT: val_1;

var OP: op;

var VERY_SMALL_INT: val_2;

var SMALL_INT: val_3;

constraint eval_op(val_1, op, val_2, val_3);

solve satisfy;

output ["\(val_1) \(op) \(val_2) == \(val_3)"];

 

Set the Configuration Editor (top right icon) to User-defined behavior and Stop after this many solutions to, say, 20.

I got the following output.

 

Running untitled_model.mzn
3 plus 3 == 6

----------

3 times 3 == 9

----------

3 divided_by 3 == 1

----------

4 plus 3 == 7

----------

4 minus 3 == 1

----------

4 divided_by 3 == 1

----------

5 plus 3 == 8

----------

5 minus 3 == 2

----------

5 divided_by 3 == 1

----------

3 plus 4 == 7

----------

4 plus 4 == 8

----------

4 divided_by 4 == 1

----------

5 plus 4 == 9

----------

5 minus 4 == 1

----------

5 divided_by 4 == 1

----------

3 plus 5 == 8

----------

4 plus 5 == 9

----------

5 plus 5 == 10

----------

5 divided_by 5 == 1

----------

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Finished in 218msec