Field Detail

• root

  protected ShuntingYardExpressionTree.Node root

  Root node of the expression tree.

• postfix

  protected Stack<Token> postfix

  Stack to hold the postfix (RPN) expression.

• operatorStack

  protected Stack<Operator> operatorStack

  Stack to hold the operators.

Constructor Detail

• ShuntingYardExpressionTree

  public ShuntingYardExpressionTree()

  No-Argument Constructor.

Method Detail

• init

  protected void init(String expr)

  Method to create the postfix expression from the infix expression.

  Parameters:

  expr - Expression string

• evaluateParenthesis

  protected void evaluateParenthesis()

  Method to evaluate operators at the top of the operator stack until a left parenthesis is encountered.

• formTree

  protected boolean formTree(ShuntingYardExpressionTree.Node node,
                             Token token)

  Method to form the expression tree recursively.

  Parameters:

  node - Current node of the expression tree

  token - Token to be inserted

  Returns:

  true if token could be inserted, otherwise false

• formTree

  protected void formTree()

  Method to form the expression tree.

• evaluate

  protected Operand evaluate(ShuntingYardExpressionTree.Node node)

  Method to recursively evaluate the expression tree and return the result as an operand.

  Parameters:

  node - Current node of the expression tree

  Returns:

  Result of expression evaluation as an operand

• evaluate

  public double evaluate(String expr)

  Method to evaluate an expression.
  This method acts as the single point of access for expression evaluation.

  Specified by:

  evaluate in class ShuntingYard

  Parameters:

  expr - Expression string

  Returns:

  Result of expression evaluation as a double