org.lsmp.djep.xjep
Class PrintVisitor

java.lang.Object
  org.lsmp.djep.xjep.DoNothingVisitor
      org.lsmp.djep.xjep.ErrorCatchingVisitor
          org.lsmp.djep.xjep.PrintVisitor

All Implemented Interfaces:

ParserVisitor

Direct Known Subclasses:

DPrintVisitor

public class PrintVisitor

extends ErrorCatchingVisitor

Prints an expression. Prints the expression with lots of brackets. ((-1.0)/sqrt((1.0-(x^2.0)))). To use

 JEP j = ...; Node in = ...;
 TreeUtils tu = new TreeUtils(j);
 PrintVisitor pv = new PrintVisitor(tu);
 pv.print(in,"x");
 

Author:

Rich Morris Created on 20-Jun-2003

Nested Class Summary

static interface

PrintVisitor.PrintRulesI This interface specifies the method needed to implement a special print rule.

Field Summary

static int	FULL_BRACKET All brackets are printed.
protected int	mode The current mode for printing.
protected java.lang.StringBuffer	sb

Constructor Summary

PrintVisitor()
Creates a visitor to create and print string representations of an expression tree.

Method Summary

void	addSpecialRule(Operator op, PrintVisitor.PrintRulesI rules) Adds a special print rule to be added for a given operator.
void	append(java.lang.String s) Add a string to buffer.
int	getMaxLen()
int	getMode() Return the current print mode.
void	print(Node node) Prints on System.out.
void	print(Node node, java.io.PrintStream out) Prints the tree decending from node with lots of brackets or specified stream.
void	println(Node node) Prints on System.out.
void	println(Node node, java.io.PrintStream out) Prints the tree decending from node with a newline at end.
void	setMaxLen(int i) Sets the maximium length printed per line.
void	setMode(int mode, boolean flag) Set printing mode.
java.lang.String	toString(Node node) returns a String representation of the equation.
java.lang.Object	visit(ASTConstant node, java.lang.Object data)
java.lang.Object	visit(ASTFunNode node, java.lang.Object data)
java.lang.Object	visit(ASTVarNode node, java.lang.Object data)

Methods inherited from class org.lsmp.djep.xjep.ErrorCatchingVisitor

acceptCatchingErrors, addError, clearErrors, getError, getErrorsMessage, hasErrors

Methods inherited from class org.lsmp.djep.xjep.DoNothingVisitor

acceptChildrenAsArray, visit, visit

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

FULL_BRACKET

public static final int FULL_BRACKET

All brackets are printed. Removes all ambiguity.

See Also:

Constant Field Values

sb

protected java.lang.StringBuffer sb

mode

protected int mode

The current mode for printing.

Constructor Detail

PrintVisitor

public PrintVisitor()

Creates a visitor to create and print string representations of an expression tree.

Method Detail

print

public void print(Node node,
                  java.io.PrintStream out)

Prints the tree decending from node with lots of brackets or specified stream.

print

public void print(Node node)

Prints on System.out.

println

public void println(Node node,
                    java.io.PrintStream out)

Prints the tree decending from node with a newline at end.

println

public void println(Node node)

Prints on System.out.

toString

public java.lang.String toString(Node node)

returns a String representation of the equation.

append

public void append(java.lang.String s)

Add a string to buffer. Classes implementing PrintRulesI should call this add the

addSpecialRule

public void addSpecialRule(Operator op,
                           PrintVisitor.PrintRulesI rules)

Adds a special print rule to be added for a given operator. TODO Allow special rules for other functions, i.e. not operators.

visit

public java.lang.Object visit(ASTFunNode node,
                              java.lang.Object data)
                       throws ParseException

Specified by:

visit in interface ParserVisitor

Overrides:

visit in class DoNothingVisitor

Throws:

ParseException

visit

public java.lang.Object visit(ASTVarNode node,
                              java.lang.Object data)
                       throws ParseException

Specified by:

visit in interface ParserVisitor

Overrides:

visit in class DoNothingVisitor

Throws:

ParseException

visit

public java.lang.Object visit(ASTConstant node,
                              java.lang.Object data)

Specified by:

visit in interface ParserVisitor

Overrides:

visit in class DoNothingVisitor

getMode

public int getMode()

Return the current print mode.

setMode

public void setMode(int mode,
                    boolean flag)

Set printing mode. In full bracket mode the brackets each element in the tree will be suronded by brackets to indicate the tree structure. In the default mode, (full bracket off) the number of brackets is minimised so (x+y)+z will be printed as x+y+z.

Parameters:

mode - which flags to change, typically FULL_BRACKET

flag - whether to switch this mode on or off

getMaxLen

public int getMaxLen()

Returns:

the maximum length printed per line

setMaxLen

public void setMaxLen(int i)

Sets the maximium length printed per line. If the value is not -1 then the string will be broken into chunks each of which is less than the max lenght.

Parameters:

i - the maximum length