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authorSimon Ochsenreither <simon@ochsenreither.de>2013-05-13 00:03:56 +0200
committerSimon Ochsenreither <simon@ochsenreither.de>2013-05-13 00:03:56 +0200
commit0ee92042601b07f31cfeba5aac1a247f14c52005 (patch)
tree7f73d03064dc795af823c57950c8ab582d57f799
parentda91728a0b1d5e449eb13b697993d056e7ad53d6 (diff)
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SI-7469 Remove @deprecated scala.util.parsing.ast
-rw-r--r--src/library/scala/util/parsing/ast/AbstractSyntax.scala33
-rw-r--r--src/library/scala/util/parsing/ast/Binders.scala348
2 files changed, 0 insertions, 381 deletions
diff --git a/src/library/scala/util/parsing/ast/AbstractSyntax.scala b/src/library/scala/util/parsing/ast/AbstractSyntax.scala
deleted file mode 100644
index 3a2e990036..0000000000
--- a/src/library/scala/util/parsing/ast/AbstractSyntax.scala
+++ /dev/null
@@ -1,33 +0,0 @@
-/* __ *\
-** ________ ___ / / ___ Scala API **
-** / __/ __// _ | / / / _ | (c) 2006-2013, LAMP/EPFL **
-** __\ \/ /__/ __ |/ /__/ __ | **
-** /____/\___/_/ |_/____/_/ | | **
-** |/ **
-\* */
-
-package scala
-package util.parsing.ast
-
-import scala.util.parsing.input.Positional
-
-/** This component provides the core abstractions for representing an Abstract Syntax Tree
- *
- * @author Adriaan Moors
- */
-@deprecated("This class will be removed", "2.10.0")
-trait AbstractSyntax {
- /** The base class for elements of the abstract syntax tree.
- */
- trait Element extends Positional
-
- /** The base class for elements in the AST that represent names [[scala.util.parsing.ast.Binders]].
- */
- trait NameElement extends Element {
- def name: String
- override def equals(that: Any): Boolean = that match {
- case n: NameElement => n.name == name
- case _ => false
- }
- }
-}
diff --git a/src/library/scala/util/parsing/ast/Binders.scala b/src/library/scala/util/parsing/ast/Binders.scala
deleted file mode 100644
index 990c603ac5..0000000000
--- a/src/library/scala/util/parsing/ast/Binders.scala
+++ /dev/null
@@ -1,348 +0,0 @@
-/* __ *\
-** ________ ___ / / ___ Scala API **
-** / __/ __// _ | / / / _ | (c) 2006-2013, LAMP/EPFL **
-** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
-** /____/\___/_/ |_/____/_/ | | **
-** |/ **
-\* */
-
-package scala
-package util.parsing.ast
-
-import scala.collection.AbstractIterable
-import scala.collection.mutable
-import scala.language.implicitConversions
-
-//DISCLAIMER: this code is highly experimental!
-
- // TODO: avoid clashes when substituting
- // TODO: check binders in the same scope are distinct
-
-/** This trait provides the core ''Scrap-Your-Boilerplate'' abstractions as
- * well as implementations for common datatypes.
- *
- * (Based on Ralf Lämmel's [[http://homepages.cwi.nl/~ralf/syb3/ SYB papers]].)
- *
- * @author Adriaan Moors
- */
-@deprecated("This class will be removed", "2.10.0")
-trait Mappable {
- trait Mapper { def apply[T <% Mappable[T]](x: T): T } /* TODO: having type `Forall T. T => T` is too strict:
- sometimes we want to allow `Forall T >: precision. T => T` for some type `precision`, so that,
- beneath a certain threshold, we have some leeway.
- concretely: to use gmap for substitution, we simply require that ast nodes are mapped to ast nodes,
- we can't require that the type is preserved precisely: a Name may map to e.g., a MethodCall
- */
-
- trait Mappable[T] {
- // one-layer traversal
- def gmap(f: Mapper): T
- // everywhere f x = f (gmapT (everywhere f) x)
- def everywhere(f: Mapper)(implicit c: T => Mappable[T]): T =
- f(gmap(new Mapper { def apply[T <% Mappable[T]](x: T): T = x.everywhere(f)}))
- }
-
- implicit def StringIsMappable(s: String): Mappable[String] =
- new Mappable[String] {
- def gmap(f: Mapper): String = f(s)
- }
-
- implicit def ListIsMappable[t <% Mappable[t]](xs: List[t]): Mappable[List[t]] =
- new Mappable[List[t]] {
- def gmap(f: Mapper): List[t] = (for (x <- xs) yield f(x)).toList
- }
-
- implicit def OptionIsMappable[t <% Mappable[t]](xs: Option[t]): Mappable[Option[t]] =
- new Mappable[Option[t]] {
- def gmap(f: Mapper): Option[t] = (for (x <- xs) yield f(x))
- }
-}
-
-/** 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?)
- *
- * @author Adriaan Moors
- */
-trait Binders extends AbstractSyntax with Mappable {
- /** 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, as determined by `==`.
- *
- * A `NameElement` `n` in the AST that is conceptually bound by a `Scope` `s`, is replaced by a
- * `BoundElement(n, s)`. (For example, in `val x:Int=x+1`, the first `x` is modelled by a
- * Scope `s` that contains `x` and the second `x` is represented by a `BoundElement(x, s)`)
- * The term (`x+1`) in scope of the Scope becomes an `UnderBinder(s, x+1)`.
- *
- * A `NameElement` `n` is bound by a `Scope` `s` if it is wrapped as a `BoundElement(n, s)`, and
- * `s` has a binder element that is semantically equal (`equals` or `==`) to `n`.
- *
- * A `Scope` is represented textually by its list of binder elements, followed by the scope's `id`.
- * For example: `[x, y]!1` represents the scope with `id` `1` and binder elements `x` and `y`.
- * (`id` is solely used for this textual representation.)
- */
- class Scope[binderType <: NameElement] extends AbstractIterable[binderType] with Iterable[binderType] {
- private val substitution: mutable.Map[binderType, Element] =
- new mutable.LinkedHashMap[binderType, Element] // a LinkedHashMap is ordered by insertion order -- important!
-
- /** Returns a unique number identifying this Scope (only used for representation purposes). */
- val id: Int = _Binder.genId
-
- /** Returns the binders in this scope.
- * For a typical let-binding, this is just the variable name. For an argument list to a method body,
- * there is one binder per formal argument.
- */
- def iterator = substitution.keysIterator
-
- /** Return the `i`th binder in this scope. */
- def apply(i: Int): binderType = this.iterator.toList(i)
-
- /** Returns true if this container has a binder equal (as determined by `==`) to `b`. */
- def binds(b: binderType): Boolean = substitution.contains(b)
-
- def indexFor(b: binderType): Option[Int] = {
- val iter = this.iterator.zipWithIndex
- for ((that, count) <- iter) {
- if (that.name == b.name) // TODO: why do name equals and structural equals differ?
- return Some(count + 1)
- else
- Console.println(that+"!="+b)
- }
-
- None
- }
-
- /** Adds a new binder, for example the variable name in a local variable declaration.
- *
- * @param b a new binder that is distinct from the existing binders in this scope,
- * and shares their conceptual scope. `canAddBinder(b)` must hold.
- * @return `binds(b)` and `getElementFor(b) eq b` will hold.
- */
- def addBinder(b: binderType) { substitution += Pair(b, b) }
-
- // TODO: strengthen this condition so that no binders may be added after this scope has been
- // linked to its `UnderBinder` (i.e., while parsing, BoundElements may be added to the Scope
- // associated to the UnderBinder, but after that, no changes are allowed, except for substitution)?
- /** `canAddElement` indicates whether `b` may be added to this scope.
- *
- *
- * @return true if `b` had not been added yet
- */
- def canAddBinder(b: binderType): Boolean = !binds(b)
-
- /** ''Replaces'' the bound occurrences of a contained binder by their new value.
- * The bound occurrences of `b` are not actually replaced; the scope keeps track
- * of a substitution that maps every binder to its current value. Since a `BoundElement` is
- * a proxy for the element it is bound to by its binder, `substitute` may thus be thought of
- * as replacing all the bound occurrences of the given binder `b` by their new value `value`.
- *
- * @param b the binder whose bound occurrences should be given a new value. `binds(b)` must hold.
- * @param value the new value for the bound occurrences of `b`
- * @return `getElementFor(b) eq value` will hold.
- */
- def substitute(b: binderType, value: Element): Unit = substitution(b) = value
-
- /** Returns the current value for the bound occurrences of `b`.
- *
- * @param b the contained binder whose current value should be returned `binds(b)` must hold.
- */
- def getElementFor(b: binderType): Element = substitution(b)
-
- override def toString: String = this.iterator.toList.mkString("[",", ","]")+"!"+id // TODO show substitution?
-
- /** Returns a list of strings that represent the binder elements, each tagged with this scope's id. */
- def bindersToString: List[String] = (for(b <- this.iterator) yield b+"!"+id).toList
-
- /** Return a new inheriting scope that won't check whether binding is respected until the scope is left (so as to support forward references). */
- def allowForwardRef: Scope[binderType] = this // TODO
-
- /** Return a nested scope -- binders entered into it won't be visible in this scope, but if this scope allows forward references,
- * the binding in the returned scope also does, and thus the check that all variables are bound is deferred until this scope is left.
- */
- def nested: Scope[binderType] = this // TODO
-
- def onEnter() {}
- def onLeft() {}
- }
-
-
- trait BindingSensitive {
- // would like to specify this as one method:
- // def alpha_==[t <: NameElement](other: BoundElement[t]): Boolean
- // def alpha_==[bt <: binderType, st <: elementT](other: UnderBinder[bt, st]): Boolean
- }
-
- /** 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`.
- *
- * @note `scope.binds(el)` holds before and after.
- */
- case class BoundElement[boundElement <: NameElement](el: boundElement, scope: Scope[boundElement]) extends NameElement with Proxy with BindingSensitive {
- /** Returns the element this `BoundElement` stands for.
- * The `Proxy` trait ensures `equals`, `hashCode` and `toString` are forwarded to
- * the result of this method.
- */
- def self: Element = scope.getElementFor(el)
-
- def name = self.asInstanceOf[NameElement].name // TODO: this is only safe when substituted to a NameElement, which certainly isn't required -- I want dynamic inheritance! :)
-
- // decorate element's representation with the id of the scope it's bound in
- override def toString: String = super.toString+"@"+scope.id
-
- def alpha_==[t <: NameElement](other: BoundElement[t]): Boolean = scope.indexFor(el) == other.scope.indexFor(other.el)
- }
-
- /** A variable that escaped its scope (i.e., a free variable) -- we don't deal very well with these yet. */
- class UnboundElement[N <: NameElement](private val el: N) extends NameElement {
- def name = el.name+"@??"
- }
-
- // this is useless, as Element is a supertype of BoundElement --> the coercion will never be inferred
- // if we knew a more specific type for the element that the bound element represents, this could make sense
- // implicit def BoundElementProxy[t <: NameElement](e: BoundElement[t]): Element = e.self
-
- /** Represents an element with variables that are bound in a certain scope. */
- class UnderBinder[binderType <: NameElement, elementT <% Mappable[elementT]](val scope: Scope[binderType], private[Binders] val element: elementT) extends Element with BindingSensitive {
- override def toString: String = "(" + scope.toString + ") in { "+element.toString+" }"
-
- /** Alpha-equivalence -- TODO
- * Returns true if the `element` of the `other` `UnderBinder` is equal to this `element` up to alpha-conversion.
- *
- * That is, regular equality is used for all elements but `BoundElement`s: such an element is
- * equal to a `BoundElement` in `other` if their binders are equal. Binders are equal if they
- * are at the same index in their respective scope.
- *
- * Example:
- * {{{
- * UnderBinder([x, y]!1, x@1) alpha_== UnderBinder([a, b]!2, a@2)
- * ! (UnderBinder([x, y]!1, y@1) alpha_== UnderBinder([a, b]!2, a@2))
- * }}}
- */
- /*def alpha_==[bt <: binderType, st <: elementT](other: UnderBinder[bt, st]): Boolean = {
- var result = true
-
- // TODO: generic zip or gmap2
- element.gmap2(other.element, new Mapper2 {
- def apply[s <% Mappable[s], t <% Mappable[t]](x :{s, t}): {s, t} = x match {
- case {be1: BoundElement[_], be2: BoundElement[_]} => result == result && be1.alpha_==(be2) // monadic gmap (cheating using state directly)
- case {ub1: UnderBinder[_, _], ub2: UnderBinder[_, _]} => result == result && be1.alpha_==(be2)
- case {a, b} => result == result && a.equals(b)
- }; x
- })
- }*/
-
- def cloneElementWithSubst(subst: Map[NameElement, NameElement]) = element.gmap(new Mapper { def apply[t <% Mappable[t]](x :t): t = x match{
- case substable: NameElement if subst.contains(substable) => subst.get(substable).asInstanceOf[t] // TODO: wrong... substitution is not (necessarily) the identity function
- //Console.println("substed: "+substable+"-> "+subst.get(substable)+")");
- case x => x // Console.println("subst: "+x+"(keys: "+subst.keys+")");x
- }})
-
- // TODO
- def cloneElementNoBoundElements = element.gmap(new Mapper { def apply[t <% Mappable[t]](x :t): t = x match{
- case BoundElement(el, _) => new UnboundElement(el).asInstanceOf[t] // TODO: precision stuff
- case x => x
- }})
-
- def extract: elementT = cloneElementNoBoundElements
- def extract(subst: Map[NameElement, NameElement]): elementT = cloneElementWithSubst(subst)
-
- /** Get a string representation of element, normally we don't allow direct access to element, but just getting a string representation is ok. */
- def elementToString: String = element.toString
- }
-
- //SYB type class instances
- implicit def UnderBinderIsMappable[bt <: NameElement <% Mappable[bt], st <% Mappable[st]](ub: UnderBinder[bt, st]): Mappable[UnderBinder[bt, st]] =
- new Mappable[UnderBinder[bt, st]] {
- def gmap(f: Mapper): UnderBinder[bt, st] = UnderBinder(f(ub.scope), f(ub.element))
- }
-
- implicit def ScopeIsMappable[bt <: NameElement <% Mappable[bt]](scope: Scope[bt]): Mappable[Scope[bt]] =
- new Mappable[Scope[bt]] {
- def gmap(f: Mapper): Scope[bt] = { val newScope = new Scope[bt]()
- for(b <- scope) newScope.addBinder(f(b))
- newScope
- }
- }
-
- implicit def NameElementIsMappable(self: NameElement): Mappable[NameElement] = new Mappable[NameElement] {
- def gmap(f: Mapper): NameElement = self match {
- case BoundElement(el, scope) => BoundElement(f(el), f(scope))
- case _ => UserNameElementIsMappable(self).gmap(f)
- }
- }
-
- def UserNameElementIsMappable[t <: NameElement](self: t): Mappable[t]
-
- object UnderBinder {
- def apply[binderType <: NameElement, elementT <% Mappable[elementT]](scope: Scope[binderType], element: elementT) = new UnderBinder(scope, element)
- def unit[bt <: NameElement, elementT <% Mappable[elementT]](x: elementT) = UnderBinder(new Scope[bt](), x)
- }
-
- /** 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.
- *
- * @note `!orig.isEmpty` implies `orig.forall(ub => ub.scope eq orig(0).scope)`
- *
- */
- def sequence[bt <: NameElement, st <% Mappable[st]](orig: List[UnderBinder[bt, st]]): UnderBinder[bt, List[st]] =
- if(orig.isEmpty) UnderBinder.unit(Nil)
- else UnderBinder(orig(0).scope, orig.map(_.element))
-
- // couldn't come up with a better name...
- def unsequence[bt <: NameElement, st <% Mappable[st]](orig: UnderBinder[bt, List[st]]): List[UnderBinder[bt, st]] =
- orig.element.map(sc => UnderBinder(orig.scope, sc))
-
- //TODO: more documentation
- /** An environment that maps a `NameElement` to the scope in which it is bound.
- * This can be used to model scoping during parsing.
- *
- * @note This class uses similar techniques as described by ''Burak Emir'' in
- * [[http://library.epfl.ch/theses/?nr=3899 Object-oriented pattern matching]],
- * but uses `==` instead of `eq`, thus types can't be unified in general.
- */
- abstract class BinderEnv {
- def apply[A <: NameElement](v: A): Option[Scope[A]]
- def extend[a <: NameElement](v : a, x : Scope[a]) = new BinderEnv {
- def apply[b <: NameElement](w : b): Option[Scope[b]] =
- if(w == v) Some(x.asInstanceOf[Scope[b]])
- else BinderEnv.this.apply(w)
- }
- }
-
- object EmptyBinderEnv extends BinderEnv {
- def apply[A <: NameElement](v: A): Option[Scope[A]] = None
- }
-
- // TODO: move this to some utility object higher in the scala hierarchy?
- /** Returns a given result, but executes the supplied closure before returning.
- * (The effect of this closure does not influence the returned value.)
- */
- trait ReturnAndDo[T]{
- /**
- * @param block code to be executed, purely for its side-effects
- */
- def andDo(block: => Unit): T
- }
-
- def return_[T](result: T): ReturnAndDo[T] =
- new ReturnAndDo[T] {
- val r = result
- def andDo(block: => Unit): T = {block; r}
- }
-
- private object _Binder {
- private var currentId = 0
- private[Binders] def genId = return_(currentId) andDo {currentId=currentId+1}
- }
-}