edu.mit.ai.psg.jevaES
Interface IExpressionNode

All Known Subinterfaces:

IExpressionStoreNode

All Known Implementing Classes:

ExpressionNode

public interface IExpressionNode

extends IJevaNode

Interface to nodes for Java expressions. Don't call this interface's methods directly, but instead use EvalMethods to capture errors.

See Also:

EvalMethods, ExpressionNode

Method Summary

Class	getType(IEnv env) Verifies the type correctness of the expression and returns the static type of the expression (nodes should not call this interface directly, but should call EvalMethods.getType).
Object	getValue(IEnv env) Get the value of this node (nodes should not call this interface directly, but should call EvalMethods.eval).
boolean	isConstant(IEnv env) Predicate testing whether this is a constant expression (nodes should not call this interface directly, but should call EvalMethods.getType).

Methods inherited from interface edu.mit.ai.psg.jevaES.IJevaNode

getBeginToken, getEndToken, print, print, printToString, printToString, setBeginToken, setEndToken

Methods inherited from interface edu.mit.ai.psg.jevaES.Node

jjtAddChild, jjtClose, jjtGetChild, jjtGetNumChildren, jjtGetParent, jjtOpen, jjtSetParent

Method Detail

getType

public Class getType(IEnv env)
              throws VerifyingException

Verifies the type correctness of the expression and returns the static type of the expression (nodes should not call this interface directly, but should call EvalMethods.getType). Value may be cached.

Parameters:

env - environment of name bindings, etc.

Throws:

VerifyingException - if expression is illegal

See Also:

EvalMethods.getType(IExpressionNode, IEnv)

isConstant

public boolean isConstant(IEnv env)
                   throws VerifyingException

Predicate testing whether this is a constant expression (nodes should not call this interface directly, but should call EvalMethods.getType). Value may be cached. This predicate is sometimes required for determining type (see [JavaLangSpec sec 15.27, 5.2, 15.24, 14.9])

Parameters:

env - environment of name bindings, etc.

Throws:

VerifyingException - if expression is illegal

See Also:

EvalMethods.isConstant(IExpressionNode, IEnv)

getValue

public Object getValue(IEnv env)
                throws ThrowException

Get the value of this node (nodes should not call this interface directly, but should call EvalMethods.eval). Value may be cached if it is constant.

Parameters:

env - environment of name bindings, etc.

Throws:

ThrowException - if completes abruptly with an exception

See Also:

EvalMethods.eval(IExpressionNode, IEnv)