An environment that maps a NameElement' to the scope in which it is bound
A BoundElement' is bound in a certain scope
scope', which keeps track of the actual element thatel' stands for
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
A variable that escaped its scope (i
Represents an element with variables that are bound in a certain scope
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 equivalence relation:
x
of type Any
,
x.equals(x)
should return true
.x
and y
of type
Any
, x.equals(y)
should return true
if and only
if y.equals(x)
returns true
.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 Int
(o1.hashCode.equals(o2.hashCode)
).
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
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.
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.
Returns a string representation of the object
Returns a string representation of the object.
The default representation is platform dependent.
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?)