com.caucho.quercus.expr
Class LiteralNullExpr

java.lang.Object
  extended by com.caucho.quercus.expr.Expr
      extended by com.caucho.quercus.expr.LiteralNullExpr
Direct Known Subclasses:
LiteralNullExprPro

public class LiteralNullExpr
extends Expr

Represents a PHP null expression.


Field Summary
static LiteralNullExpr NULL
           
 
Fields inherited from class com.caucho.quercus.expr.Expr
COMPILE_ARG_MAX
 
Constructor Summary
protected LiteralNullExpr()
           
 
Method Summary
 Value eval(Env env)
          Evaluates the expression.
 Value evalConstant()
          Evaluates the expression as a constant.
 boolean isLiteral()
          Returns true for a literal expression.
 java.lang.String toString()
           
 
Methods inherited from class com.caucho.quercus.expr.Expr
assign, canRead, createAssign, createAssignFrom, createAssignRef, createCall, createClassConst, createClassField, createClassField, createCopy, createDeref, createFieldGet, createFieldGet, createIsset, createRef, createUnset, evalArg, evalArgs, evalArray, evalArrayAssign, evalAssignRef, evalAssignValue, evalBoolean, evalChar, evalConstantPrefix, evalConstantSuffix, evalCopy, evalDirty, evalDouble, evalIsset, evalLong, evalObject, evalPostIncrement, evalPreIncrement, evalRef, evalString, evalStringValue, evalTop, evalUnsetArray, evalValue, evalVar, getFileName, getFunctionLocation, getLine, getLocation, getLocationLine, isArray, isAssign, isBoolean, isConstant, isDouble, isFalse, isLong, isNumber, isRef, isString, isTrue, isVar, print
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

NULL

public static final LiteralNullExpr NULL
Constructor Detail

LiteralNullExpr

protected LiteralNullExpr()
Method Detail

evalConstant

public Value evalConstant()
Evaluates the expression as a constant.

Overrides:
evalConstant in class Expr
Returns:
the expression value.

isLiteral

public boolean isLiteral()
Returns true for a literal expression.

Overrides:
isLiteral in class Expr

eval

public Value eval(Env env)
Evaluates the expression.

Specified by:
eval in class Expr
Parameters:
env - the calling environment.
Returns:
the expression value.

toString

public java.lang.String toString()
Overrides:
toString in class Expr