Description
= problem =
When transforming XML, it is often necessary to transform attribute values as well as elements. It would be nice to be able to write something like:
case elem: Elem => elem.copy(attributes=
for (attr <- elem.attributes) yield attr match {
case attr@Attribute("attrToChange", _, _) => attr.copy(value=Text("newValue"))
case other => other
}
)= analysis =
This doesn't work in Scala 2.8.1 because xml.Attribute.copy only allows the next attribute to be changed, and because map over an xml.MetaData yields an Iterable[MetaData] not a MetaData.
= enhancement recommendation =
To solve the copying problem, xml.Attribute could grow a method like one of the xml.Attribute.apply methods, e.g.:
def copy(pre: String = this.pre, key: String = this.key, value: Seq[Node] = this.value, next: MetaData = this.next): AttributeSolving the map problem probably means updating Attribute to use the new collections APIs better - e.g. it should probably implement IterableLike[MetaData, MetaData] which I think means it needs a simple Builder that sets the next attributes appropriately.