openjava.ptree
Class BinaryExpression

java.lang.Object
  |
  +--openjava.ptree.ParseTreeObject
        |
        +--openjava.ptree.NonLeaf
              |
              +--openjava.ptree.BinaryExpression

All Implemented Interfaces:

Cloneable, Expression, ParseTree, VariableInitializer

public class BinaryExpression

extends NonLeaf

implements Expression

The BinaryExpression class represents an expression which consists of an operators and two operands.
This doesn't includes the expression whose operator is the instanceof operator nor the expression whose operator is one of the assignment operators.
If the operator in the expression of the left operand or the right operand has week unity, this automatically produces the code in which the left operand is enclosed by parenthesises.
In the case the left is a + b, the operator is * the right is c + d, this produces the code :

     (a + b) * (c + d)
 

See Also:

Expression, InstanceofExpression, AssignmentExpression

Field Summary

static int	BITAND
static int	BITOR
static int	DIVIDE
static int	EQUAL
static int	GREATER
static int	GREATEREQUAL
static int	IN
static int	INSTANCEOF
static int	INTERSECT
static int	LESS
static int	LESSEQUAL
static int	LOGICAL_AND
static int	LOGICAL_OR
static int	MINUS
static int	MOD
static int	NOTEQUAL
private int	opr the operator
(package private) static String[]	opr_string
private static int	OTHER
static int	PLUS
static int	REL_MINUS
static int	SHIFT_L
static int	SHIFT_R
static int	SHIFT_RR
private static int	STRING
static int	TIMES
static int	UNION
static int	XOR

Fields inherited from class openjava.ptree.NonLeaf

Fields inherited from class openjava.ptree.ParseTreeObject

debugFlag, debugLevel, LN, out, writerStack

Constructor Summary

(package private)	BinaryExpression()
	BinaryExpression(Expression lexp, int opr, Expression rexp) Allocates a new object.
	BinaryExpression(Expression lexp, String opr, Expression rexp)

Method Summary

void	accept(ParseTreeVisitor v) Accepts a ParseTreeVisitor object as the role of a Visitor in the Visitor pattern, as the role of an Element in the Visitor pattern.
(package private) static OJClass	chooseType(OJClass left, OJClass right)
Expression	getLeft() Gets the expression of the left operand.
int	getOperator() Gets the id number of the operator.
Expression	getRight() Gets the expression of the right operand.
OJClass	getType(Environment env)
ParseTree	makeCopy() Makes a new copy of this nonleaf-node as a ptree-node.
ParseTree	makeRecursiveCopy() Makes a new copy (another object) of this nonleaf-node recursively.
private boolean	needsLeftPar(Expression leftexpr)
private boolean	needsRightPar(Expression rightexpr)
String	operatorString()
void	setLeft(Expression lexpr) Sets the expression of the left operand.
void	setOperator(int opr) Sets the id number of the operator.
void	setRight(Expression rexpr) Sets the expression of the right operand.
protected static int	strength(int op) Returns the strength of the union of the operator.
private static int	strength(OJClass type)
void	writeCode() Writes the code this parse-tree presents for.

Methods inherited from class openjava.ptree.NonLeaf

childrenAccept, childrenAreEqual, elementAt, equals, getComment, getContents, getLength, getRowType, replaceChildWith, set, set, set, set, set, set, set, set, set, setComment, setElementAt

Methods inherited from class openjava.ptree.ParseTreeObject

clone, eq, eq, equal, flushPrintWriter, getDebugFlag, getNest, getObjectID, getParent, getPrintWriter, getTab, hashCode, lastObjectID, popNest, popPrintWriter, pushNest, pushPrintWriter, replace, setDebugFlag, setDebugLevel, setNest, setParent, setPrintStream, setTab, toFlattenString, toString, writeDebug, writeDebugL, writeDebugLln, writeDebugln, writeDebugLR, writeDebugR, writeDebugRln, writeTab

Methods inherited from class java.lang.Object

equals, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface openjava.ptree.Expression

getRowType

Methods inherited from interface openjava.ptree.ParseTree

childrenAccept, eq, equals, getObjectID, replace, toFlattenString, toString

Field Detail

TIMES

public static final int TIMES

See Also:

Constant Field Values

DIVIDE

public static final int DIVIDE

See Also:

Constant Field Values

MOD

public static final int MOD

See Also:

Constant Field Values

PLUS

public static final int PLUS

See Also:

Constant Field Values

MINUS

public static final int MINUS

See Also:

Constant Field Values

SHIFT_L

public static final int SHIFT_L

See Also:

Constant Field Values

SHIFT_R

public static final int SHIFT_R

See Also:

Constant Field Values

SHIFT_RR

public static final int SHIFT_RR

See Also:

Constant Field Values

LESS

public static final int LESS

See Also:

Constant Field Values

GREATER

public static final int GREATER

See Also:

Constant Field Values

LESSEQUAL

public static final int LESSEQUAL

See Also:

Constant Field Values

GREATEREQUAL

public static final int GREATEREQUAL

See Also:

Constant Field Values

INSTANCEOF

public static final int INSTANCEOF

See Also:

Constant Field Values

EQUAL

public static final int EQUAL

See Also:

Constant Field Values

NOTEQUAL

public static final int NOTEQUAL

See Also:

Constant Field Values

BITAND

public static final int BITAND

See Also:

Constant Field Values

XOR

public static final int XOR

See Also:

Constant Field Values

BITOR

public static final int BITOR

See Also:

Constant Field Values

LOGICAL_AND

public static final int LOGICAL_AND

See Also:

Constant Field Values

LOGICAL_OR

public static final int LOGICAL_OR

See Also:

Constant Field Values

IN

public static final int IN

See Also:

Constant Field Values

UNION

public static final int UNION

See Also:

Constant Field Values

REL_MINUS

public static final int REL_MINUS

See Also:

Constant Field Values

INTERSECT

public static final int INTERSECT

See Also:

Constant Field Values

opr_string

static final String[] opr_string

opr

private int opr

the operator

STRING

private static final int STRING

See Also:

Constant Field Values

OTHER

private static final int OTHER

See Also:

Constant Field Values

Constructor Detail

BinaryExpression

public BinaryExpression(Expression lexp,
                        int opr,
                        Expression rexp)

Allocates a new object.

Parameters:

lexp - the expression of the left operand.

opr - the id number of operator.

rexp - the expression of the right operand.

BinaryExpression

public BinaryExpression(Expression lexp,
                        String opr,
                        Expression rexp)

BinaryExpression

BinaryExpression()

Method Detail

makeRecursiveCopy

public ParseTree makeRecursiveCopy()

Description copied from interface: ParseTree

Makes a new copy (another object) of this nonleaf-node recursively. The objects contained by this object will also be copied.

Specified by:

makeRecursiveCopy in interface ParseTree

Overrides:

makeRecursiveCopy in class NonLeaf

Returns:

the copy of this nonleaf-node as a ptree-node.

makeCopy

public ParseTree makeCopy()

Description copied from interface: ParseTree

Makes a new copy of this nonleaf-node as a ptree-node. The objects contained by the new object are same as these contained by the original object.

Specified by:

makeCopy in interface ParseTree

Overrides:

makeCopy in class ParseTreeObject

Returns:

the copy of this nonleaf-node as a ptree-node.

writeCode

public void writeCode()

Description copied from class: NonLeaf

Writes the code this parse-tree presents for.

Specified by:

writeCode in interface ParseTree

Overrides:

writeCode in class NonLeaf

needsLeftPar

private final boolean needsLeftPar(Expression leftexpr)

needsRightPar

private final boolean needsRightPar(Expression rightexpr)

strength

protected static final int strength(int op)

Returns the strength of the union of the operator.

Parameters:

op - the id number of operator.

Returns:

the strength of the union.

getLeft

public Expression getLeft()

Gets the expression of the left operand.

Returns:

the left expression.

setLeft

public void setLeft(Expression lexpr)

Sets the expression of the left operand.

Parameters:

lexpr - the left expression.

getRight

public Expression getRight()

Gets the expression of the right operand.

Returns:

the right expression.

setRight

public void setRight(Expression rexpr)

Sets the expression of the right operand.

Parameters:

rexpr - the right expression.

getOperator

public int getOperator()

Gets the id number of the operator.

Returns:

the id number of the operator.

See Also:

TIMES, DIVIDE, MOD, PLUS, MINUS, SHIFT_L, SHIFT_R, SHIFT_RR, LESS, GREATER, LESSEQUAL, GREATEREQUAL, INSTANCEOF, EQUAL, NOTEQUAL, BITAND, XOR, BITOR, LOGICAL_AND, LOGICAL_OR, IN

setOperator

public void setOperator(int opr)

Sets the id number of the operator.

Parameters:

opr - the id number of the operator.

See Also:

TIMES, DIVIDE, MOD, PLUS, MINUS, SHIFT_L, SHIFT_R, SHIFT_RR, LESS, GREATER, LESSEQUAL, GREATEREQUAL, INSTANCEOF, EQUAL, NOTEQUAL, BITAND, XOR, BITOR, LOGICAL_AND, LOGICAL_OR, IN

operatorString

public String operatorString()

accept

public void accept(ParseTreeVisitor v)
            throws ParseTreeException

Description copied from interface: ParseTree

Accepts a ParseTreeVisitor object as the role of a Visitor in the Visitor pattern, as the role of an Element in the Visitor pattern.

This invoke an appropriate visit() method on the accepted visitor.

Specified by:

accept in interface ParseTree

Specified by:

accept in class ParseTreeObject

Parameters:

v - a visitor

ParseTreeException

getType

public OJClass getType(Environment env)
                throws Exception

Specified by:

getType in interface Expression

Exception

chooseType

static OJClass chooseType(OJClass left,
                          OJClass right)

strength

private static int strength(OJClass type)