/*****************************************************************************
* Licensed to the Apache Software Foundation (ASF) under one *
* or more contributor license agreements. See the NOTICE file *
* distributed with this work for additional information *
* regarding copyright ownership. The ASF licenses this file *
* to you under the Apache License, Version 2.0 (the *
* "License"); you may not use this file except in compliance *
* with the License. You may obtain a copy of the License at *
* *
* http://www.apache.org/licenses/LICENSE-2.0 *
* *
* Unless required by applicable law or agreed to in writing, *
* software distributed under the License is distributed on an *
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY *
* KIND, either express or implied. See the License for the *
* specific language governing permissions and limitations *
* under the License. *
* *
* *
* This file is part of the BeanShell Java Scripting distribution. *
* Documentation and updates may be found at http://www.beanshell.org/ *
* Patrick Niemeyer (pat@pat.net) *
* Author of Learning Java, O'Reilly & Associates *
* *
*****************************************************************************/
package bsh;
/**
* Implementation of the enhanced for(:) statement.
* This statement uses BshIterable to support iteration over a wide variety
* of iterable types. Under JDK 1.1 this statement supports primitive and
* Object arrays, Vectors, and enumerations. Under JDK 1.2 and later it
* additionally supports collections.
*
* @author Daniel Leuck
* @author Pat Niemeyer
*/
class
BSHEnhancedForStatement extends
SimpleNode implements
ParserConstants {
String varName;
BSHEnhancedForStatement(int
id) {
super(
id);
}
public
Object eval(
CallStack callstack,
Interpreter interpreter) throws
EvalError {
Class elementType = null;
SimpleNode expression;
SimpleNode statement = null;
NameSpace enclosingNameSpace =
callstack.
top();
SimpleNode firstNode = ((
SimpleNode)
jjtGetChild(0));
int
nodeCount =
jjtGetNumChildren();
if (
firstNode instanceof
BSHType) {
elementType = ((
BSHType)
firstNode).
getType(
callstack,
interpreter);
expression = ((
SimpleNode)
jjtGetChild(1));
if (
nodeCount > 2) {
statement = ((
SimpleNode)
jjtGetChild(2));
}
} else {
expression =
firstNode;
if (
nodeCount > 1) {
statement = ((
SimpleNode)
jjtGetChild(1));
}
}
BlockNameSpace eachNameSpace = new
BlockNameSpace(
enclosingNameSpace);
callstack.
swap(
eachNameSpace);
final
Object iteratee =
expression.
eval(
callstack,
interpreter);
if (
iteratee ==
Primitive.
NULL) {
throw new
EvalError("The collection, array, map, iterator, or " + "enumeration portion of a for statement cannot be null.", this,
callstack);
}
CollectionManager cm =
CollectionManager.
getCollectionManager();
if (!
cm.
isBshIterable(
iteratee)) {
throw new
EvalError("Can't iterate over type: " +
iteratee.
getClass(), this,
callstack);
}
BshIterator iterator =
cm.
getBshIterator(
iteratee);
Object returnControl =
Primitive.
VOID;
while (
iterator.
hasNext()) {
try {
Object value =
iterator.
next();
if (
value == null) {
value =
Primitive.
NULL;
}
if (
elementType != null) {
eachNameSpace.
setTypedVariable(
varName/*name*/,
elementType/*type*/,
value/*value*/, new
Modifiers()/*none*/);
} else {
eachNameSpace.
setVariable(
varName,
value, false);
}
} catch (
UtilEvalError e) {
throw
e.
toEvalError("for loop iterator variable:" +
varName, this,
callstack);
}
boolean
breakout = false; // switch eats a multi-level break here?
if (
statement != null) {
// not empty statement
Object ret =
statement.
eval(
callstack,
interpreter);
if (
ret instanceof
ReturnControl) {
switch (((
ReturnControl)
ret).
kind) {
case
RETURN:
returnControl =
ret;
breakout = true;
break;
case
CONTINUE:
break;
case
BREAK:
breakout = true;
break;
}
}
}
if (
breakout) {
break;
}
}
callstack.
swap(
enclosingNameSpace);
return
returnControl;
}
}