/*****************************************************************************
* *
* 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 BSHSwitchStatement
extends SimpleNode
implements ParserConstants
{
public BSHSwitchStatement(int id) { super(id); }
public Object eval( CallStack callstack, Interpreter interpreter )
throws EvalError
{
int numchild = jjtGetNumChildren();
int child = 0;
SimpleNode switchExp = ((SimpleNode)jjtGetChild(child++));
Object switchVal = switchExp.eval( callstack, interpreter );
/*
Note: this could be made clearer by adding an inner class for the
cases and an object context for the child traversal.
*/
// first label
BSHSwitchLabel label;
Object node;
ReturnControl returnControl=null;
// get the first label
if ( child >= numchild )
throw new EvalError("Empty switch statement.", this, callstack );
label = ((BSHSwitchLabel)jjtGetChild(child++));
// while more labels or blocks and haven't hit return control
while ( child < numchild && returnControl == null )
{
// if label is default or equals switchVal
if ( label.isDefault
|| primitiveEquals(
switchVal, label.eval( callstack, interpreter ),
callstack, switchExp )
)
{
// execute nodes, skipping labels, until a break or return
while ( child < numchild )
{
node = jjtGetChild(child++);
if ( node instanceof BSHSwitchLabel )
continue;
// eval it
Object value =
((SimpleNode)node).eval( callstack, interpreter );
// should check to disallow continue here?
if ( value instanceof ReturnControl ) {
returnControl = (ReturnControl)value;
break;
}
}
} else
{
// skip nodes until next label
while ( child < numchild )
{
node = jjtGetChild(child++);
if ( node instanceof BSHSwitchLabel ) {
label = (BSHSwitchLabel)node;
break;
}
}
}
}
if ( returnControl != null && returnControl.kind == RETURN )
return returnControl;
else
return Primitive.VOID;
}
/**
Helper method for testing equals on two primitive or boxable objects.
yuck: factor this out into Primitive.java
*/
private boolean primitiveEquals(
Object switchVal, Object targetVal,
CallStack callstack, SimpleNode switchExp )
throws EvalError
{
if ( switchVal instanceof Primitive || targetVal instanceof Primitive )
try {
// binaryOperation can return Primitive or wrapper type
Object result = Primitive.binaryOperation(
switchVal, targetVal, ParserConstants.EQ );
result = Primitive.unwrap( result );
return result.equals( Boolean.TRUE );
} catch ( UtilEvalError e ) {
throw e.toEvalError(
"Switch value: "+switchExp.getText()+": ",
this, callstack );
}
else
return switchVal.equals( targetVal );
}
}