An Algorithm for Generating Boolean Expressions in VHDL Based on Ladder Diagrams

Algorithm 5

The interpretation algorithm.

Function-5: TranslateAndOrTreeIntoBooleanExpression

Input: the root node of the And-Or tree named “root”

Output: the Boolean expression of the And-Or Tree

expression ← new string()

if (root.children.count == 0)

  Return expression ← root.toString()

end // if

if (the type of root is AND-Node)

  for childNode: root.children

    subExpression ← TranslateAndOrTreeIntoBooleanExpression(childNode)

    Expression ← expression + “AND” + subExpression

  end for

else

  for childNode: root.children

    subExpression ← TranslateAndOrTreeIntoBooleanExpression(childNode)

    Expression ← expression + “OR” + subExpression

  end // for

end // if

Expression ← “(“+ expression +”)”

return expression