jeops.expressions
Class JavaExpr

java.lang.Object
  |
  +--jeops.expressions.JavaExpr

Direct Known Subclasses:

BinaryJavaExpr, ConstJavaExpr, ConstructorJavaExpr, FieldJavaExpr, MethodJavaExpr, UnaryJavaExpr, VarJavaExpr

public abstract class JavaExpr

extends java.lang.Object

This class models an expression of (our subset of) the java language.

Version:

0.04 23 Fev 1999 First version with the comments in English.

Author:

Carlos Figueira Filho (csff@di.ufpe.br)

Field Summary

static int	BOOL Constant used to indicate that this expression's type is boolean.
static int	INT Constant used to indicate that this expression's type is int.
static int	OBJ Constant used to indicate that this expression's type is Object.

Constructor Summary

JavaExpr()

Method Summary

void	dump() Prints the tree for the expression of this precondition.
abstract void	dump(int spaces) Prints the tree for the expression of this precondition.
boolean	evaluateBool(SymbolicTable table) Returns the boolean result of this expression.
int	evaluateInt(SymbolicTable table) Returns the int result of this expression.
java.lang.Object	evaluateObj(SymbolicTable table) Returns in an object the result of the evaluation of this expression.
abstract java.lang.Class	getClasse() Returns an object representing the class of this expression.
java.util.Enumeration	identObjetos() Returns all object variable identifiers that are used in this expression.
int	numIdentObjetos() Returns the number of object identifiers (variables) in this expression.
int	tipo() Returns the type of this expression.

Methods inherited from class java.lang.Object

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

Field Detail

INT

public static final int INT

Constant used to indicate that this expression's type is int.

BOOL

public static final int BOOL

Constant used to indicate that this expression's type is boolean.

OBJ

public static final int OBJ

Constant used to indicate that this expression's type is Object. (or any of this subclasses).

Constructor Detail

JavaExpr

public JavaExpr()

Method Detail

dump

public void dump()

Prints the tree for the expression of this precondition. Useful for debugging.

dump

public abstract void dump(int spaces)

Prints the tree for the expression of this precondition. Useful for debugging.

Parameters:

spaces - the identation for the printed output.

evaluateBool

public boolean evaluateBool(SymbolicTable table)
                     throws MethodEvaluationException,
                            FieldAccessException

Returns the boolean result of this expression. If this is not a boolean expression, the value false will be returned.

Parameters:

table - the symbolic table where the values of the variables used within this rule are stored.

Throws:

MethodEvaluationException - if an exception was thrown while evaluating a method that may occur within this expression.

FieldAccessException - if an exception was thrown while accessing a field of an object that may occur in this expression.

Since:

0.03

evaluateInt

public int evaluateInt(SymbolicTable table)
                throws MethodEvaluationException,
                       FieldAccessException

Returns the int result of this expression. If this is not an integer expression, the value 0 (zero) will be returned.

Parameters:

table - the symbolic table where the values of the variables used within this rule are stored.

Throws:

MethodEvaluationException - if an exception was thrown while evaluating a method that may occur within this expression.

FieldAccessException - if an exception was thrown while accessing a field of an object that may occur in this expression.

Since:

0.03

evaluateObj

public java.lang.Object evaluateObj(SymbolicTable table)
                             throws MethodEvaluationException,
                                    FieldAccessException

Returns in an object the result of the evaluation of this expression. If needed, the result will be wrapped in one of the language wrapper classes for the primitive types.

Parameters:

table - the symbolic table where the values of the variables used within this rule are stored.

Throws:

MethodEvaluationException - if an exception was thrown while evaluating a method that may occur within this expression.

FieldAccessException - if an exception was thrown while accessing a field of an object that may occur in this expression.

getClasse

public abstract java.lang.Class getClasse()

Returns an object representing the class of this expression.

identObjetos

public java.util.Enumeration identObjetos()

Returns all object variable identifiers that are used in this expression.

numIdentObjetos

public int numIdentObjetos()

Returns the number of object identifiers (variables) in this expression.

tipo

public int tipo()

Returns the type of this expression.