A method that should be called from every well-designed equals method that is open to be overridden in a subclass.
A method that should be called from every well-designed equals method that is open to be overridden in a subclass. See Programming in Scala, Chapter 28 for discussion and design.
the value being probed for possible equality
true if this instance can possibly equal that
, otherwise false
The size of this product.
The nth element of this product, 0-based.
The nth element of this product, 0-based. In other words, for a
product A(x1, ..., xk)
, returns x(n+1)
where 0 < n < k
.
the index of the element to return
the element n
elements after the first element
Test two objects for inequality.
Test two objects for inequality.
true
if !(this == that), false otherwise.
Equivalent to x.hashCode
except for boxed numeric types and null
.
Equivalent to x.hashCode
except for boxed numeric types and null
.
For numerics, it returns a hash value which is consistent
with value equality: if two value type instances compare
as true, then ## will produce the same hash value for each
of them.
For null
returns a hashcode where null.hashCode
throws a
NullPointerException
.
a hash value consistent with ==
Test two objects for equality.
Test two objects for equality.
The expression x == that
is equivalent to if (x eq null) that eq null else x.equals(that)
.
true
if the receiver object is equivalent to the argument; false
otherwise.
Cast the receiver object to be of type T0
.
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 expression 1.asInstanceOf[String]
will throw a ClassCastException
at
runtime, while the expression List(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 type.
the receiver object.
if the receiver object is not an instance of the erasure of type T0
.
Create a copy of the receiver object.
Create a copy of the receiver object.
The default implementation of the clone
method is platform dependent.
a copy of the receiver object.
not specified by SLS as a member of AnyRef
Tests whether the argument (arg0
) is a reference to the receiver object (this
).
Tests whether the argument (arg0
) is a reference to the receiver object (this
).
The eq
method implements an equivalence relation on
non-null instances of AnyRef
, and has three additional properties:
x
and y
of type AnyRef
, multiple invocations of
x.eq(y)
consistently returns true
or consistently returns false
.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
).
true
if the argument is a reference to the receiver object; false
otherwise.
The equality method for reference types.
Called by the garbage collector on the receiver object when there are no more references to the object.
Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the finalize
method is invoked, as
well as the interaction between finalize
and non-local returns
and exceptions, are all platform dependent.
not specified by SLS as a member of AnyRef
Returns string formatted according to given format
string.
Returns string formatted according to given format
string.
Format strings are as for String.format
(@see java.lang.String.format).
A representation that corresponds to the dynamic class of the receiver object.
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.
not specified by SLS as a member of AnyRef
The hashCode method for reference types.
.
.
Test whether the dynamic type of the receiver object is T0
.
Test whether the dynamic type of the receiver object is T0
.
Note that the result of the test is modulo Scala's erasure semantics.
Therefore the expression 1.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 specified type.
true
if the receiver object is an instance of erasure of type T0
; false
otherwise.
The canonical way to test if a Tree represents a term.
The canonical way to test if a Tree represents a type.
Equivalent to !(this eq that)
.
Equivalent to !(this eq that)
.
true
if the argument is not a reference to the receiver object; false
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.
not specified by SLS as a member of AnyRef
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.
not specified by SLS as a member of AnyRef
An iterator over all the elements of this product.
An iterator over all the elements of this product.
in the default implementation, an Iterator[Any]
A string used in the toString
methods of derived classes.
A string used in the toString
methods of derived classes.
Implementations may override this method to prepend a string prefix
to the result of toString
methods.
in the default implementation, the empty string
Obtains string representation of a tree
(tree: StringAdd).self
(tree: StringFormat).self
(tree: ArrowAssoc[Tree]).x
(Since version 2.10.0) Use leftOfArrow
instead
(tree: Ensuring[Tree]).x
(Since version 2.10.0) Use resultOfEnsuring
instead
Tree is the basis for scala's abstract syntax. The nodes are implemented as case classes, and the parameters which initialize a given tree are immutable: however Trees have several mutable fields which are manipulated in the course of typechecking, including pos, symbol, and tpe.
Newly instantiated trees have tpe set to null (though it may be set immediately thereafter depending on how it is constructed.) When a tree is passed to the typer, typically via
typer.typed(tree)
, under normal circumstances the tpe must be null or the typer will ignore it. Furthermore, the typer is not required to return the same tree it was passed.Trees can be easily traversed with e.g. foreach on the root node; for a more nuanced traversal, subclass Traverser. Transformations can be considerably trickier: see the numerous subclasses of Transformer found around the compiler.
Copying Trees should be done with care depending on whether it need be done lazily or strictly (see LazyTreeCopier and StrictTreeCopier) and on whether the contents of the mutable fields should be copied. The tree copiers will copy the mutable attributes to the new tree; calling Tree#duplicate will copy symbol and tpe, but all the positions will be focused.
Trees can be coarsely divided into four mutually exclusive categories:
TypTree
, notTypeTree
.SymTrees include important nodes Ident and Select, which are used as both terms and types; they are distinguishable based on whether the Name is a TermName or TypeName. The correct way for to test for a type or a term (on any Tree) are the isTerm/isType methods on Tree.
"Others" are mostly syntactic or short-lived constructs. Examples include CaseDef, which wraps individual match cases: they are neither terms nor types, nor do they carry a symbol. Another example is Parens, which is eliminated during parsing.