An environment that maps a NameElement' to the scope in which it is bound.
This can be used to model scoping during parsing.
(This class is similar to Burak's ECOOP paper on pattern matching, except that we use
=='
instead of eq', thus types can't be unified in general)
TODO: more documentation
A BoundElement' is bound in a certain scope
scope', which keeps track of the actual element that
el' stands for.
A
BoundElement' is represented textually by its bound element, followed by its scope's id'.
For example:
x@1' represents the variable x' that is bound in the scope with
id' 1'.
The base class for elements of the abstract syntax tree.
The base class for elements in the AST that represent names {@see Binders}.
Returns a given result, but executes the supplied closure before returning.
A Scope' keeps track of one or more syntactic elements that represent bound names.
The elements it contains share the same scope and must all be distinct (wrt. ==)
A
NameElement' n' in the AST that is conceptually bound by a
Scope' s', is replaced by a
BoundElement(n, s)'.
A variable that escaped its scope (i.
Represents an element with variables that are bound in a certain scope.
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.
Equivalent to x.hashCode
except for boxed numeric types.
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.
a hash value consistent with ==
Test two objects for equality.
Test two objects for equality.
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.
Create a copy of the receiver object.
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.
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.
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.
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.
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.
If a list of UnderBinder's all have the same scope, they can be turned in to an UnderBinder
containing a list of the elements in the original
UnderBinder'.
If a list of UnderBinder's all have the same scope, they can be turned in to an UnderBinder
containing a list of the elements in the original
UnderBinder'.
The name sequence' comes from the fact that this method's type is equal to the type of monadic sequence.
Creates a String representation of this object.
Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.
a String representation of the object.
This component provides functionality for enforcing variable binding during parse-time.
When parsing simple languages, like Featherweight Scala, these parser combinators will fully enforce the binding discipline. When names are allowed to be left unqualified, these mechanisms would have to be complemented by an extra phase that resolves names that couldn't be resolved using the naive binding rules. (Maybe some machinery to model
implicit' binders (e.g.,
this' and imported qualifiers) and selection on a binder will suffice?)