o != arg0 is the same as !(o == (arg0)).
o != arg0 is the same as !(o == (arg0)).
the object to compare against this object for dis-equality.
false if the receiver object is equivalent to the argument; true otherwise.
Efficient (and slightly tricky) overload of ++ on parameters which are
specifically of type Group[_].
Efficient (and slightly tricky) overload of ++ on parameters which are
specifically of type Group[_].
Efficient (and slightly tricky) overload of +: on parameters which are
specifically of type Node.
Efficient (and slightly tricky) overload of +: on parameters which are
specifically of type Node.
Efficient (and slightly tricky) overload of :+ on parameters which are
specifically of type Node.
Efficient (and slightly tricky) overload of :+ on parameters which are
specifically of type Node.
o == arg0 is the same as if (o eq null) arg0 eq null else o.equals(arg0).
o == arg0 is the same as if (o eq null) arg0 eq null else o.equals(arg0).
the object to compare against this object for equality.
true if the receiver object is equivalent to the argument; false otherwise.
o == arg0 is the same as o.equals(arg0).
o == arg0 is the same as o.equals(arg0).
the object to compare against this object for equality.
true if the receiver object is equivalent to the argument; false otherwise.
[use case] Performs a shallow-select on the XML tree according to the specified selector function.
Performs a shallow-select on the XML tree according to the specified selector function. Shallow selection is defined according to the following expression:
Performs a shallow-select on the XML tree according to the specified selector function.
Performs a shallow-select on the XML tree according to the specified selector function. Shallow selection is defined according to the following expression:
nodes flatMap {
case Elem(_, _, children) => children collect selector
case _ => Group()
}
In English, this means that a shallow selection works by first selectingonly the Elem(s) at the top level and then filtering their children according to the selector. The results of these filtrations are concatenated together, producing a single flattened result.
Very important: This is not the same as the XPath / operator!
(nor does it strive to be) XPath is inconsistent in its selection semantics,
varying them slightly depending on whether or not you are selecting from
the top level or in the middle of a compound expression. As a result, it
is categorically impossible to implement XPath in a combinatorial
fashion. Rather than give up on combinators, we chose to give up on XPath.
In practice, this "select child Elem(s), then filter their children" behavior
tends to be the most useful variant of the XPath selection. The "missed"
case here is applying a filter to the top-level set of nodes. This is
currently not handled by the API (perhaps in future). For now, if you need
this functionality, it's pretty easy to get it using the filter method.
The results of this function will be a collection of some variety, but the exact type is determined by the selector itself. For example:
val ns: Group[Node] = ... ns \ "name" ns \ * ns \ text
The three selection expressions here produce very different results. The
first will produce a collection of type Zipper[Elem],
the second will produce Zipper[Node],
while the third will produce
scala.collection.Traversable[scala.String].
This reflects the fact that the selector produced (by implicit conversion)
from a String will only filter for nodes of type Elem.
However, the * selector will filter for all nodes (as the wildcard
symbol would suggest) and thus it must return a collection containing the
fully-generic Node. Finally, the text selector
specifically pulls out the textual contents of nodes, and thus its results
will not be nodes at all, but raw String(s).
Whenever supported by the resulting collection type, the selection operation will preserve a "backtrace", or an "undo log" of sorts. This backtrace is known as a zipper context. This context makes it possible to operate on the collection resulting from performing a selection, then unselect to rebuild the original collection around it (modulo the changes made). This provides a very clean and powerful way of drilling down into an XML tree, making some changes and then realizing those changes within the context of the full tree. In a sense, it solves the major inconvenience associated with immutable tree structures: the need to manually rebuild the entire ancestry of the tree after making a change somewhere within.
[use case] Performs a deep-select on the XML tree according to the specified selector function.
Performs a deep-select on the XML tree according to the specified selector function. Deep selection is defined according to the following recursion:
Performs a deep-select on the XML tree according to the specified selector function.
Performs a deep-select on the XML tree according to the specified selector function. Deep selection is defined according to the following recursion:
val recursive = nodes flatMap {
case Elem(_, _, _, children) => children \\ selector
case _ => Group()
}
(this \ selector) ++ recursive
In English, this means that deep selection is defined simply as the recursive
application of shallow selection (\), all the way from the root down to the
leaves. Note that the recursion does not short circuit when a result is
found. Thus, if a parent node matches the selector as well as one of its
children, then both the parent and the child will be returned, with the
parent preceeding the child in the results.
Just as with shallow selection, the very outermost level of the group is not
considered in the selection. Thus, deep selection is not exactly the
same as the XPath // operator, since // will consider the outermost level,
while Anti-XML's deep selection \\ will not.
Note: For certain selectors (such as an element name selector defined
using a String or Symbol), the result of this method will be a zipper,
similar to the results from the shallow-select operator (\). This zipper
will not be valid! Zipper context synthesis for deep selection is
currently unimplemented. Thus, any attempt to use the unselect method on
the resulting zipper will likely throw an exception. At the very least, it
won't return a useful result. The implementation of this feature is ongoing.
This method is used to cast the receiver object to be of type T0.
This method is used to cast the receiver object to be of type T0.
Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expressionList(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as
part of compilation it is not possible to check whether the contents of the list are of the requested typed.
the receiver object.
Merges adjacent Text as well as adjacentCDATA nodes to produce a Group which represents
an identical XML fragment but with a minimized structure.
Merges adjacent Text as well as adjacentCDATA nodes to produce a Group which represents
an identical XML fragment but with a minimized structure. Slightly more
formally, for any XML fragment with n characters of textual data, there
are 2n possible ways of representing that fragment as a Group. All
of these representations are semantically distinct (i.e. structurally different
in memory) but logically equivalent in that they will all generate the same
XML fragment if serialized. Of these 2n distinct representations,
there will be exactly one representation which is minimal, in that the
smallest possible number
of Text and CDATA nodes
are used to represent the textual data. This form may be considered
"canonical". This method converts an arbitrary Group into its canonical
form, a logically equivalent Group which represents the same XML fragment
in its structurally minimized form.
This method is perhaps best explained by an example:
val xml = Group(Text("Daniel "), Text("Spiewak"))
xml.canonicalize // => Group(Text("Daniel Spiewak"))
The Group resulting from the canonicalize invocation will produce exactly
the same result as would xml were we to invoke the toString method on
each of them. However, the canonicalized result has only one text node for
the entire character block, while xml (the original Group) has two.
This is actually a very common gotcha in scala.xml. The issue comes up
most frequently in the area of equality. As you can see in the example above,xml clearly will not be equivalent (according to the equals method)
to xml.canonicalize. However, it is very natural to assume that these
two structures are in fact equal due to their logical equivalence in
that they represent the same textual XML fragment. Oftentimes, people will
get around this issue in scala.xml by converting all NodeSeq(s) into
strings prior to comparison. In Anti-XML, all that is necessary to handle
potential semantic divergence in cases of logical equality is to simply
invoke the canonicalize method on each of the two equality operands.
This method creates and returns a copy of the receiver object.
This method creates and returns a copy of the receiver object.
The default implementation of the clone method is platform dependent.
a copy of the receiver object.
use iterator' instead
This method is used to test whether the argument (arg0) is a reference to the
receiver object (this).
This method is used to test whether the argument (arg0) is a reference to the
receiver object (this).
The eq method implements an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation] on
non-null instances of AnyRef:
* It is reflexive: for any non-null instance x of type AnyRef, x.eq(x) returns true.
* It is symmetric: for any non-null instances x and y of type AnyRef, x.eq(y) returns true if and
only if y.eq(x) returns true.
* It is transitive: for any non-null instances x, y, and z of type AnyRef if x.eq(y) returns true and y.eq(z) returns true, then x.eq(z) returns true.
Additionally, the eq method has three other properties.
* It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of
x.eq(y) consistently returns true or consistently returns false.
* For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false.
* null.eq(null) returns true.
When overriding the equals or hashCode methods, it is important to ensure that their behavior is
consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they
should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).
the object to compare against this object for reference equality.
true if the argument is a reference to the receiver object; false otherwise.
This method is used to compare the receiver object (this) with the argument object (arg0) for equivalence.
This method is used to compare the receiver object (this) with the argument object (arg0) for equivalence.
The default implementations of this method is an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence
relation]:
* It is reflexive: for any instance x of type Any, x.equals(x) should return true.
* It is symmetric: for any instances x and y of type Any, x.equals(y) should return true if and
only if y.equals(x) returns true.
* It is transitive: for any instances x, y, and z of type AnyRef if x.equals(y) returns true and
y.equals(z) returns true, then x.equals(z) should return true.
If you override this method, you should verify that your implementation remains an equivalence relation.
Additionally, when overriding this method it is often necessary to override hashCode to ensure that objects
that are "equal" (o1.equals(o2) returns true) hash to the same
scala.Int
(o1.hashCode.equals(o2.hashCode)).
true if the receiver object is equivalent to the argument; false otherwise.
use corresponds instead
This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.
This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.
The details of when and if the finalize method are invoked, as well as the interaction between finalizeand non-local returns and exceptions, are all platform dependent.
use lastIndexWhere instead
use head' instead
use headOption' instead
Returns a representation that corresponds to the dynamic class of the receiver object.
Returns a representation that corresponds to the dynamic class of the receiver object.
The nature of the representation is platform dependent.
a representation that corresponds to the dynamic class of the receiver object.
Returns a hash code value for the object.
Returns a hash code value for the object.
The default hashing algorithm is platform dependent.
Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)) yet
not be equal (o1.equals(o2) returns false). A degenerate implementation could always return 0.
However, it is required that if two objects are equal (o1.equals(o2) returns true) that they have
identical hash codes (o1.hashCode.equals(o2.hashCode)). Therefore, when overriding this method, be sure
to verify that the behavior is consistent with the equals method.
the hash code value for the object.
This method is used to test whether the dynamic type of the receiver object is T0.
This method is used to test whether the dynamic type of the receiver object is T0.
Note that the test result of the test is modulo Scala's erasure semantics. Therefore the expression1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will
return true. In the latter example, because the type argument is erased as part of compilation it is not
possible to check whether the contents of the list are of the requested typed.
true if the receiver object is an instance of erasure of type T0; false otherwise.
o.ne(arg0) is the same as !(o.eq(arg0)).
o.ne(arg0) is the same as !(o.eq(arg0)).
the object to compare against this object for reference dis-equality.
false if the argument is not a reference to the receiver object; true otherwise.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
use view' instead
use reverseIterator' instead
Serializes the nodes in this Group into their most compact XML representation
and concatenates the result.
Serializes the nodes in this Group into their most compact XML representation
and concatenates the result. Note that the result of this method may not
be well-formed XML, since well-formed XML is required to have only a single
parent element (whereas a Group may contain multiple nodes at its top level).
This is not a pretty-print. The resulting XML will not be formatted in any
way. It will be precisely the XML fragment represented by this Group,
no more and no less.
The XML fragment represented by this Group in String form
Produces a
scala.collection.immutable.Vector
which contains all of the
nodes in this Group.
Produces a
scala.collection.immutable.Vector
which contains all of the
nodes in this Group. This function is guaranteed to run in constant time.
Efficient (and slightly tricky) overload of updated on parameters which are
specifically of type Node.
Efficient (and slightly tricky) overload of updated on parameters which are
specifically of type Node.
Represents a collection of arbitrary nodes (Node)). Note that this collection need not have a single root parent element. Thus, a valid
Groupcould be as follows:Group(EntityRef("quot"), Text("Daniel is "), Elem(None, "em", Attributes(), Map(), Group(Text("delusional!"))), EntityRef("quot"))This would correspond to the following XML fragment (note: not actually well-formed XML, since it is lacking a single root element):
Note that unlike
scala.xml,Groupis not a special type of Node! This design decision has a very profound impact on the framework as a whole. In general, the result is an API which is more consistent and more predictable than it otherwise would have been. However, it also resulted in some unfortunate sacrifices: specifically, full XPath semantics. The exact semantics of the\and\\operators are defined in their respective scaladocs.Groupis parameterized based on the type ofNodeit contains. In the general case (such as the one illustrated above), this will be exactlyNode. However, there are some very common cases wherein aGroupmay have a more specific type than justNode. For example:In this example,
resultswill have typeGroup[Elem]. This is because the selector employed ("name") can only produce results of typeElem. This mechanism forms the basis for the typed selectors mechanism, which is extremely powerful and serves to eliminate a great deal of boiler-plate casting when traversing XML hierarchies.In the general case,
Groupis backed by an instance of scala.collection.immutable.Vector . This implementation detail is significant as it implies two things. First, the implementation ofGroupis truly immutable, meaning that there are no tricky concurrency semantics to worry about. Second, unlikescala.xml(which backs its sequences by eitherListorArrayBuffer, depending on phase of the moon), it is possible to perform efficient random-access and updates across the entireGroup. Random access is implemented by theapplymethod, while random "updates" are implemented by theupdatedmethod. Fast prepend and append operations are also available.Beyond this, all standard collection operations are available on
Group(e.g.flatMap,exists,collect,slice, etc). The appropriate incantations have been spoken to allow these methods to return the correct type. Thus, if youmapover aGroupand your function returns something which extendsNode, the result will be aGroup. If your function returns something which does not extendNode(e.g.Int), then the result will be something else (probably a genericIndexedSeqbacked byVector).Groupitself extends scala.collection.immutable.IndexedSeq and thus can be used in situations which require this abstraction.