package SpreadSheetJ.Model;

import java.util.Enumeration;
import java.util.Vector;


// Expressions can be thought of as trees.  Each non-leaf node of the tree
// contains an operator, and the children of that node are the subexpressions
// (operands) that the operator operates upon.  Constants, cell references,
// and the like form the leaves of the tree.
// 
// For example, the expression (a2 + 2) * c26 is equivalent to the tree:
// 
//                *
//               / \
//              +   c26
//             / \
//           a2   2

public abstract class Expression implements Cloneable
{
  // How many operands does this expression node have?
  public abstract int arity();
  
  // Get the k_th operand
  public abstract Expression operand(int k);
  //pre: k < arity()




  // Evaluate this expression
  public abstract Value evaluate(SpreadSheet usingSheet);



  // Copy this expression (deep copy), altering any cell references
  // by the indicated offsets except where the row or column is "fixed"
  // by a preceding $. E.g., if e is  2*D4+C$2/$A$1, then
  // e.copy(1,2) is 2*E6+D$2/$A$1, e.copy(-1,4) is 2*C8+B$2/$A$1
  public abstract Expression clone (int colOffset, int rowOffset);

  public Object clone ()
  {
    return clone(0,0);
  }



  public Sequence collectReferences()
  {
    Sequence refs = new Sequence();
    for (int i = 0; i < arity(); ++i)
      {
	Sequence refsi = operand(i).collectReferences();
	for (Enumeration p = refsi.front(); p.hasMoreElements(); ) {
	  CellName cn = (CellName)p.nextElement();
	  refs.addToBack (cn);
	}
      }
    return refs;
  }


  public static Expression get (String in)
  {
    return new ExprParser().doParse(in);
  }


  public String toString ()
  {
    String out = "";
    if (isInline() && arity() == 0) {
      out = getOperator();
    }
    else if (isInline() && arity() == 1) {
      out = getOperator();
      Expression opnd = operand(0);
      if (precedence() > opnd.precedence()) {
	out = out + '(' + opnd + ')';
      }
      else
	out = out + opnd;
    }
    else if (isInline() && arity() == 2) {
      Expression left = operand(0);
      Expression right = operand(1);

      if (precedence() > left.precedence()) {
	out = "(" + left + ')';
      }
      else
	out = left.toString();

      out = out + getOperator();

      if (precedence() > right.precedence()) {
	  out = out + '(' + right + ')';
      }
      else
	out = out + right;
    }
    else {
      // write in prefix function-call form
      out = getOperator() + '(';
      for (int k = 0; k < arity(); ++k)	{
	if (k > 0)
	  out = out + ", ";
	out = out + operand(k);
      }
      out = out + ')';
    }
    return out;
  }



  // The following control how the expression gets printed by 
  // the default implementation of put(ostream&)
  
  public abstract boolean isInline();
  // if false, print as functionName(comma-separated-list)
  // if true, print in inline form

  public abstract int precedence();
  // Parentheses are placed around an expression whenever its precedence
  // is lower than the precedence of an operator (expression) applied to it.
  // E.g., * has higher precedence than +, so we print 3*(a1+1) but not
  // (3*a1)+1

  public abstract String getOperator();
  // Returns the name of the operator for printing purposes.
  // For constants, this is the string version of the constant value.



}

package SpreadSheetJ.Model;


//
// Represents a value that might be obtained for some spreadsheet cell
// when its formula was evaluated.
// 
// Values may come in many forms. At the very least, we can expect that
// our spreadsheet will support numeric and string values, and will
// probably need an "error" or "invalid" value type as well. Later we may 
// want to add addiitonal value kinds, such as currency or dates.
//
public abstract
class Value implements Cloneable
{
    public abstract String valueKind();
    // Indicates what kind of value this is. For any two values, v1 and v2,
    // v1.valueKind() == v2.valueKind() if and only if they are of the
    // same kind (e.g., two numeric values). The actual character string
    // pointed to by valueKind() may be anything, but should be set to
    // something descriptive as an aid in identification and debugging.
    
    
    public abstract String render (int maxWidth);
    // Produce a string denoting this value such that the
    // string's length() <= maxWidth (assuming maxWidth > 0)
    // If maxWidth==0, then the output string may be arbitrarily long.
    // This function is intended to supply the text for display in the
    // cells of a spreadsheet.

    public String toString()
    {
	return render(0);
    }
    
    public boolean equals (Object value)
    {
	Value v = (Value)value;
	return (valueKind() == v.valueKind()) && isEqual(v);
    }
	

    abstract boolean isEqual (Value v);
    //pre: valueKind() == v.valueKind()
    //  Returns true iff this value is equal to v, using a comparison
    //  appropriate to the kind of value.

}

package SpreadSheetJ.Model;



//
// Numeric values in the spreadsheet.
//
public
class NumericValue extends Value
{
  private double d;
  private static final String theValueKindName = new String("Numeric");
  
  public NumericValue()
  {
	d =0.0;
  }
  
  public NumericValue (double x)
  {
	d = x;
  }
  
  // The string used to identify numeric value kinds.
  public static String valueKindName()
  {
	return theValueKindName;
  }
  
  // Indicates what kind of value this is. For any two values, v1 and v2,
  // v1.valueKind() == v2.valueKind() if and only if they are of the
  // same kind (e.g., two numeric values). The actual character string
  // pointed to by valueKind() may be anything, but should be set to
  // something descriptive as an aid in identification and debugging.
  public String valueKind()
  {
	return theValueKindName;
  }
  
  
  // Produce a string denoting this value such that the
  // string's length() <= maxWidth (assuming maxWidth > 0)
  // If maxWidth==0, then the output string may be arbitrarily long.
  // This function is intended to supply the text for display in the
  // cells of a spreadsheet.
  public String render (int maxWidth)
  {
	String rendering = "" + d;
	if (rendering.indexOf('.') >= 0 &&
	    rendering.indexOf('E') < 0 &&
	    rendering.indexOf('e') < 0) {
	    while (rendering.charAt(rendering.length()-1) == '0') {
          rendering = rendering.substring(0, rendering.length()-1);
	    }
	    if (rendering.charAt(rendering.length()-1) == '.') {
          rendering = rendering.substring(0, rendering.length()-1);
	    }
	}
	if (maxWidth > 0 && rendering.length() > maxWidth) {
      String discarded = rendering.substring(maxWidth);
      rendering = rendering.substring(0, maxWidth);
      if (discarded.indexOf('.') >= 0) {
		// We have a problem - can't fit the decimal point into
		// the allowed width
		rendering = "****************************";
		rendering = rendering.substring(0, maxWidth);
      }
	}
	return rendering;
  }
  
  
    public Object clone()
  {
	return new NumericValue(d);
  }

  
  public double getNumericValue()
    {
      return d;
    }
  
    boolean isEqual (Value v)
	//pre: valueKind() == v.valueKind()
	//  Returns true iff this value is equal to v, using a comparison
	//  appropriate to the kind of value.
  {
	NumericValue nv = (NumericValue)v;
	return d == nv.d;
  }
  
}

public class Book {
  public Book ()
    {
      authorName = new String();
      title = new String();
    }
 
  public String getAuthorName() {return authorName;}
  public void   setAuthorName(String a) {authorName = a;}
 
  public String getTitle() {return title;}
  public void   setTitle(String t) {title = t;}
 
    public boolean equals(Object right) {
     Book b = (Book)right;
     return authorName.equals(b.authorName) &&
       title.equals(b.title);
  }

  private String authorName;
  private String title;

}

public class Book {
  public Book ()
    {
      authorName = new String();
      title = new String();
    }
 
  public String getAuthorName() {return authorName;}
  public void   setAuthorName(String a) {authorName = a;}
 
  public String getTitle() {return title;}
  public void   setTitle(String t) {title = t;}
 
  public boolean equals(Object right) {
     Book b = (Book)right;
     return authorName.equals(b.authorName) &&
       title.equals(b.title);
  }

  public int hashCode() {
     return 7 * authorName.hashCode()
        + title.hashCode();
  }

  private String authorName;
  private String title;

}

public class Book {
  public Book ()
    {
      authorName = new String();
      title = new String();
    }
 
  public String getAuthorName() {return authorName;}
  public void   setAuthorName(String a) {authorName = a;}
 
  public String getTitle() {return title;}
  public void   setTitle(String t) {title = t;}
 
  public boolean equals(Object right) {
     Book b = (Book)right;
     return authorName.equals(b.authorName) &&
       title.equals(b.title);
  }

  public int hashCode() {
     return 7 * authorName.hashCode()
        + title.hashCode();
  }

  public String toString() {
     return "'" + title.toString() + "' by "
       + authorName.toString();
  }

  private String authorName;
  private String title;

}