Bug 362651

Description Meinte Boersma 2011-11-02 06:30:18 EDT

Build Identifier: 20110615-0604

Use of Java's Object#getClass() method leads to creation of statement "Class<? extends Object> _class = item.getClass();" after compilation to Java. This may shadow a pre-existing method parameter without chance of accessing the original one in the Xtend code when using closures, which is hard to debug. As an example:

	def <T> Iterable<T> asIterable(JSONArray jsonArray, Class<T> _class) {
		jsonArray.asIterableInternal( [ item, list |
			if( _class.isAssignableFrom(item.^class) ) {
				list.add(_class.cast(item))
			} else {
				throw new IllegalArgumentException('''item is of type «item.^class.name» and cannot be cast to «_class.name»'''.toString)
			}
		] )
	}

And the dependency:

	def <T> Iterable<T> asIterableInternal(JSONArray jsonArray, org.eclipse.xtext.xbase.lib.Functions$Function2<Object, List<T>, ?> action) {
		val len = jsonArray.length
		val iterable = new ArrayList<T>(len)
		var i = 0
		while( i < len ) {
			try {
				val item = jsonArray.get(i)
				action.apply(item, iterable)
			} catch( Exception e ) {
				throw new RuntimeException('''cannot obtain item with index «i» from JSONArray'''.toString, e)
			}
			i = i+1
		}
		iterable
	}

(Renaming the parameter '_class' to e.g. 'clazz' resolves the problem.)

Reproducible: Always

Steps to Reproduce:
1. see details
2.
3.