Question

This is my first question , please correct me if anything is wrong.
I have some set of old rules in one of document system , im trying to convert them into new document system.
I have lot of IF-ENDIF and IF-ELSE-ENDIF nested inside each other like below. Need some logic which works on converting below input to corresponding output.
Need help for algo. Thanks

INPUT:  
IF (Cond 1)  
    IF(Cond 2)  
    ENDIF  
    IF(Cond3)  
    ELSE  
    ENDIF  
ELSE  
    IF(Cond4)  
    ELSE  
        IF(Cond5)  
        ELSE  
        ENDIF  
    ENDIF  
    IF(Cond6)  
    ENDIF  
ENDIF  

Required OUTPUT:

    IF(Cond1) AND (Cond2)  
    IF(Cond1) AND (Cond3)  
    IF(Cond1) AND !(Cond3)  
    IF!(Cond1) AND (Cond4)  
    IF!(Cond1) AND !(Cond4)  AND (Cond5)  
    IF!(Cond1) AND !(Cond4) AND !(Cond5)  
    IF!(Cond1) AND (Cond6)  

Answer 1

I will assume that you have logic that can parse the file in the first place. If so, then you should end up with an abstract syntax tree where each node looks something like this:

If
  |
  +--- Condition
  |
  +--- Positive statement
  |
  +--- Negative statement

or

Sequence
  |
  +--- Statement 1
  |
  +--- Statement 2
  |
  ...
  |
  +--- Statement n

or

Terminal

where Terminal represents a concrete statement. They are implicit in your original input file. For example, “IF(COND2) ENDIF” would be represented as follows:

If
  |
  +--- Cond2
  |
  +--- Terminal
  |
  +--- (null)

In your case, your actual tree would look something like this:

If
  |
  +--- Cond1
  |
  +--- Sequence
  |      |
  |      +--- If
  |      |      |
  |      |      +--- Cond2
  |      |      |
  |      |      +--- Terminal
  |      |      |
  |      |      +--- (null)
  |      |
  |      +--- If
  |             |
  |             +--- Cond3
  |             |
  |             +--- Terminal
  |             |
  |             +--- Terminal
  |
  +--- If
       ...

To generate the output, you would simply recursively walk down the tree, building a stack of conditions along the way, then when you get to a statement, output the whole stack of conditions with ANDs between them. Here is some pseudocode:

void treeWalk(root):
    treeWalk(root, []);

void treeWalk(root, conditions):
    case root of:
        If(cond, positive, negative):
            if (positive is not null):
                treeWalk(positive, conditions + cond)
            if (negative is not null):
                treeWalk(negative, conditions + !cond)
        Sequence(statements):
            for each statement in statements:
                treeWalk(statements, conditions)
        Terminal:
            print "IF "
            for each condition in conditions:
                if (condition is not the last condition):
                    print " AND "
                print condition

Here I am using + to indicate appending an item to a list. It is assumed that !cond results in a condition that prints itself out with a “!” at the front.

I hope that helps!