/*****************************************************************************
* *
* This file is part of the BeanShell Java Scripting distribution. *
* Documentation and updates may be found at http://www.beanshell.org/ *
* *
* Sun Public License Notice: *
* *
* The contents of this file are subject to the Sun Public License Version *
* 1.0 (the "License"); you may not use this file except in compliance with *
* the License. A copy of the License is available at http://www.sun.com *
* *
* The Original Code is BeanShell. The Initial Developer of the Original *
* Code is Pat Niemeyer. Portions created by Pat Niemeyer are Copyright *
* (C) 2000. All Rights Reserved. *
* *
* GNU Public License Notice: *
* *
* Alternatively, the contents of this file may be used under the terms of *
* the GNU Lesser General Public License (the "LGPL"), in which case the *
* provisions of LGPL are applicable instead of those above. If you wish to *
* allow use of your version of this file only under the terms of the LGPL *
* and not to allow others to use your version of this file under the SPL, *
* indicate your decision by deleting the provisions above and replace *
* them with the notice and other provisions required by the LGPL. If you *
* do not delete the provisions above, a recipient may use your version of *
* this file under either the SPL or the LGPL. *
* *
* Patrick Niemeyer (pat@pat.net) *
* Author of Learning Java, O'Reilly & Associates *
* http://www.pat.net/~pat/ *
* *
*****************************************************************************/
package org.gjt.sp.jedit.bsh;
class BSHAssignment extends SimpleNode implements ParserConstants
{
public int operator;
BSHAssignment(int id) { super(id); }
public Object eval(
CallStack callstack, Interpreter interpreter)
throws EvalError
{
BSHPrimaryExpression lhsNode =
(BSHPrimaryExpression)jjtGetChild(0);
if ( lhsNode == null )
throw new InterpreterError( "Error, null LHSnode" );
boolean strictJava = interpreter.getStrictJava();
LHS lhs = lhsNode.toLHS( callstack, interpreter);
if ( lhs == null )
throw new InterpreterError( "Error, null LHS" );
// For operator-assign operations save the lhs value before evaluating
// the rhs. This is correct Java behavior for postfix operations
// e.g. i=1; i+=i++; // should be 2 not 3
Object lhsValue = null;
if ( operator != ASSIGN ) // assign doesn't need the pre-value
try {
lhsValue = lhs.getValue();
} catch ( UtilEvalError e ) {
throw e.toEvalError( this, callstack );
}
SimpleNode rhsNode = (SimpleNode)jjtGetChild(1);
Object rhs;
// implement "blocks" foo = { };
// if ( rhsNode instanceof BSHBlock )
// rsh =
// else
rhs = rhsNode.eval(callstack, interpreter);
if ( rhs == Primitive.VOID )
throw new EvalError("Void assignment.", this, callstack );
try {
switch(operator)
{
case ASSIGN:
return lhs.assign( rhs, strictJava );
case PLUSASSIGN:
return lhs.assign(
operation(lhsValue, rhs, PLUS), strictJava );
case MINUSASSIGN:
return lhs.assign(
operation(lhsValue, rhs, MINUS), strictJava );
case STARASSIGN:
return lhs.assign(
operation(lhsValue, rhs, STAR), strictJava );
case SLASHASSIGN:
return lhs.assign(
operation(lhsValue, rhs, SLASH), strictJava );
case ANDASSIGN:
case ANDASSIGNX:
return lhs.assign(
operation(lhsValue, rhs, BIT_AND), strictJava );
case ORASSIGN:
case ORASSIGNX:
return lhs.assign(
operation(lhsValue, rhs, BIT_OR), strictJava );
case XORASSIGN:
return lhs.assign(
operation(lhsValue, rhs, XOR), strictJava );
case MODASSIGN:
return lhs.assign(
operation(lhsValue, rhs, MOD), strictJava );
case LSHIFTASSIGN:
case LSHIFTASSIGNX:
return lhs.assign(
operation(lhsValue, rhs, LSHIFT), strictJava );
case RSIGNEDSHIFTASSIGN:
case RSIGNEDSHIFTASSIGNX:
return lhs.assign(
operation(lhsValue, rhs, RSIGNEDSHIFT ), strictJava );
case RUNSIGNEDSHIFTASSIGN:
case RUNSIGNEDSHIFTASSIGNX:
return lhs.assign(
operation(lhsValue, rhs, RUNSIGNEDSHIFT),
strictJava );
default:
throw new InterpreterError(
"unimplemented operator in assignment BSH");
}
} catch ( UtilEvalError e ) {
throw e.toEvalError( this, callstack );
}
}
private Object operation( Object lhs, Object rhs, int kind )
throws UtilEvalError
{
/*
Implement String += value;
According to the JLS, value may be anything.
In BeanShell, we'll disallow VOID (undefined) values.
(or should we map them to the empty string?)
*/
if ( lhs instanceof String && rhs != Primitive.VOID ) {
if ( kind != PLUS )
throw new UtilEvalError(
"Use of non + operator with String LHS" );
return (String)lhs + rhs;
}
if ( lhs instanceof Primitive || rhs instanceof Primitive )
if(lhs == Primitive.VOID || rhs == Primitive.VOID)
throw new UtilEvalError(
"Illegal use of undefined object or 'void' literal" );
else if ( lhs == Primitive.NULL || rhs == Primitive.NULL )
throw new UtilEvalError(
"Illegal use of null object or 'null' literal" );
if( (lhs instanceof Boolean || lhs instanceof Character ||
lhs instanceof Number || lhs instanceof Primitive) &&
(rhs instanceof Boolean || rhs instanceof Character ||
rhs instanceof Number || rhs instanceof Primitive) )
{
return Primitive.binaryOperation(lhs, rhs, kind);
}
throw new UtilEvalError("Non primitive value in operator: " +
lhs.getClass() + " " + tokenImage[kind] + " " + rhs.getClass() );
}
}