package dotty.tools.dotc
package core
import util.HashSet
import Symbols._
import Flags._
import Names._
import Scopes._
import Constants._
import Contexts._
import Annotations._
import Denotations._
import References._
import Periods._
import References.{Reference, RefSet, RefUnion, ErrorRef}
import scala.util.hashing.{MurmurHash3 => hashing}
import collection.immutable.BitSet
import collection.mutable
import collection.mutable
trait Types { self: Context =>
import Types._
private val initialUniquesCapacity = 50000
private[Types] val uniques = new util.HashSet[Type]("uniques", initialUniquesCapacity) {
override def hash(x: Type): Int = x.hash
}
/** A set for hash consing superclass bitsets */
private[Types] val uniqueBits = new util.HashSet[BitSet]("superbits", 1024)
}
object Types {
/** A hash value indicating that the underlying type is not
* cached in unbiques.
*/
final val NotCached = 0
/** An alternative value returned from `hash` if the
* computed hashCode would be `NotCached`.
*/
final val NotCachedAlt = Int.MinValue
abstract class Type extends DotClass {
def <:< (that: Type): Boolean = ???
def hash = NotCached
/** The type symbol associated with the type
*/
def typeSymbol(implicit ctx: Context): Symbol = NoSymbol
/** The term symbol associated with the type
*/
def termSymbol(implicit ctx: Context): Symbol = NoSymbol
/** Does this type denote a stable reference (i.e. singleton type)? */
def isStable(implicit ctx: Context): Boolean = false
/** Is this type dangerous (i.e. it might contain conflicting
* type information when empty, so that it can be constructed
* so that type unsoundness results.) A dangerous type has an underlying
* type of the form T_1 with T_n { decls }, where one of the
* T_i (i > 1) is an abstract type.
*/
def isVolatile: Boolean = false
/** Is this type guaranteed not to have `null` as a value? */
def isNotNull: Boolean = false
/** Is this type produced as a repair for an error? */
def isError(implicit ctx: Context): Boolean = (typeSymbol hasFlag Error) || (termSymbol hasFlag Error)
/** Is some part of this type produced as a repair for an error? */
def isErroneous(implicit ctx: Context): Boolean = exists(_.isError)
/** Returns true if there is a part of this type that satisfies predicate `p`.
*/
def exists(p: Type => Boolean): Boolean =
new ExistsAccumulator(p)(false, this)
/** For a class or intersection type, its parents.
* For a TypeBounds type, the parents of its hi bound.
* inherited by typerefs, singleton types, and refinement types,
* The empty list for all other types */
def parents(implicit ctx: Context): List[Type] = List()
def bounds(implicit ctx: Context): TypeBounds = TypeBounds(this, this)
def member(name: Name)(implicit ctx: Context): Reference =
findMember(name, this, Flags.Empty)
def decls(implicit ctx: Context): Scope = unsupported("decls")
def decl(name: Name)(implicit ctx: Context): Reference =
decls.refsNamed(name).toRef
def nonPrivateMember(name: Name)(implicit ctx: Context): Reference =
findMember(name, this, Flags.Private)
def findMember(name: Name, pre: Type, excluded: FlagSet)(implicit ctx: Context): Reference =
unsupported("findMember")
protected def findMemberAmong(candidates: RefSet, pre: Type, owner: ClassSymbol, excluded: FlagSet)(implicit ctx: Context): Reference = {
val resultSyms = candidates
.filterAccessibleFrom(pre)
.filterExcluded(excluded)
.asSeenFrom(pre, owner)
if (resultSyms.exists) resultSyms.toRef
else ErrorRef // todo: refine
}
def memberType(sym: Symbol): Type = ???
def memberInfo(sym: Symbol): Type = ???
def widen: Type = ???
def deconst: Type = ???
def prefix: Type = ???
def isTrivial: Boolean = ???
def resultType: Type = ???
def baseClasses: List[ClassSymbol] = ???
def typeArgs: List[Type] = ???
def isCachable: Boolean = false
def asSeenFrom(pre: Type, clazz: Symbol)(implicit ctx: Context): Type =
if (this.isTrivial || clazz.isStaticMono) this
else new AsSeenFromMap(pre, clazz) apply (this)
def subst(from: List[Symbol], to: List[Type]): Type = ???
def subst(from: PolyType, to: PolyType): Type = ???
def subst(from: MethodType, to: MethodType): Type = ???
def substSym(from: List[Symbol], to: List[Symbol]): Type = ???
def substThis(clazz: ClassSymbol, tp: Type): Type = ???
def substThis(from: RefinedType, tp: Type): Type = ???
def baseType(base: Symbol)(implicit ctx: Context): Type = base.info match {
case cinfo: ClassInfoType => cinfo.baseTypeOf(this)
case _ => NoType
}
def typeParams: List[TypeSymbol] = ???
def effectiveBounds: TypeBounds = ???
def isWrong: Boolean = ???
def exists: Boolean = true
def & (that: Type)(implicit ctx: Context): Type =
if (this eq that) this
else if (this.isWrong) that
else if (that.isWrong) this
else that match {
case OrType(that1, that2) =>
this & that1 | this & that2
case _ =>
this match {
case OrType(this1, this2) =>
this1 & that | this2 & that
case _ =>
val t1 = mergeIfSub(this, that)
if (t1.exists) t1
else {
val t2 = mergeIfSub(that, this)
if (t2.exists) t2
else AndType(this, that)
}
}
}
def | (that: Type)(implicit ctx: Context): Type =
if (this eq that) this
else if (this.isWrong) this
else if (that.isWrong) that
else {
val t1 = mergeIfSuper(this, that)
if (t1.exists) t1
else {
val t2 = mergeIfSuper(that, this)
if (t2.exists) t2
else OrType(this, that)
}
}
/** Merge `t1` into `t2` if t1 is a subtype of some part of t2.
*/
private def mergeIfSub(t1: Type, t2: Type)(implicit ctx: Context): Type =
if (t1 <:< t2)
if (t2 <:< t1) t2 else t1
else t2 match {
case t2 @ AndType(t21, t22) =>
val lower1 = mergeIfSub(t1, t21)
if (lower1 eq t21) t2
else if (lower1.exists) lower1 & t22
else {
val lower2 = mergeIfSub(t1, t22)
if (lower2 eq t22) t2
else if (lower2.exists) t21 & lower2
else NoType
}
case _ =>
NoType
}
/** Merge `t1` into `t2` if t1 is a supertype of some part of t2.
*/
private def mergeIfSuper(t1: Type, t2: Type)(implicit ctx: Context): Type =
if (t2 <:< t1)
if (t1 <:< t2) t2 else t1
else t2 match {
case t2 @ OrType(t21, t22) =>
val higher1 = mergeIfSuper(t1, t21)
if (higher1 eq t21) t2
else if (higher1.exists) higher1 | t22
else {
val higher2 = mergeIfSuper(t1, t22)
if (higher2 eq t22) t2
else if (higher2.exists) t21 | higher2
else NoType
}
case _ =>
NoType
}
// hashing
protected def hashSeed = getClass.hashCode
private def finishHash(hashCode: Int, arity: Int): Int = {
val h = hashing.finalizeHash(hashCode, arity)
if (h == NotCached) NotCachedAlt else h
}
private def finishHash(seed: Int, arity: Int, tp: Type): Int = {
val elemHash = tp.hash
if (elemHash == NotCached) return NotCached
finishHash(hashing.mix(seed, elemHash), arity + 1)
}
private def finishHash(seed: Int, arity: Int, tps: List[Type]): Int = {
var h = seed
var xs = tps
var len = arity
while (xs.nonEmpty) {
val elemHash = xs.head.hash
if (elemHash == NotCached) return NotCached
h = hashing.mix(h, elemHash)
xs = xs.tail
len += 1
}
finishHash(h, len)
}
private def finishHash(seed: Int, arity: Int, tp: Type, tps: List[Type]): Int = {
val elemHash = tp.hash
if (elemHash == NotCached) return NotCached
finishHash(hashing.mix(seed, elemHash), arity + 1, tps)
}
protected def doHash(x: Any): Int =
finishHash(hashing.mix(hashSeed, x.hashCode), 1)
protected def doHash(tp: Type): Int =
finishHash(hashSeed, 0, tp)
protected def doHash(tp1: Type, tp2: Type): Int = {
val elemHash = tp1.hash
if (elemHash == NotCached) return NotCached
finishHash(hashing.mix(hashSeed, elemHash), 1, tp2)
}
protected def doHash(x1: Any, tp2: Type): Int =
finishHash(hashing.mix(hashSeed, x1.hashCode), 1, tp2)
protected def doHash(tp1: Type, tps2: List[Type]): Int =
finishHash(hashSeed, 0, tp1, tps2)
protected def doHash(x1: Any, tp2: Type, tps3: List[Type]): Int =
finishHash(hashing.mix(hashSeed, x1.hashCode), 1, tp2, tps3)
} // end Type
abstract class UniqueType extends Type {
final override val hash = computeHash
override def hashCode = hash
def computeHash: Int
}
def unique[T <: Type](tp: T)(implicit ctx: Context): T = {
if (tp.hash == NotCached) tp
else ctx.root.uniques.findEntryOrUpdate(tp).asInstanceOf[T]
}
trait TypeProxy extends Type {
def underlying(implicit ctx: Context): Type
override def findMember(name: Name, pre: Type, excluded: FlagSet)(implicit ctx: Context): Reference =
underlying.findMember(name, pre, excluded)
override def parents(implicit ctx: Context) = underlying.parents
override def decls(implicit ctx: Context) = underlying.decls
}
trait TransformingProxy extends TypeProxy {
}
trait SubType extends UniqueType with TypeProxy {
}
trait SingletonType extends SubType
// --- NamedTypes ------------------------------------------------------------------
/** A NamedType of the form Prefix # name
*/
abstract class NamedType extends UniqueType with TypeProxy {
val name: Name
private[this] var referencedVar: Reference = null
protected[this] var validPeriods = Nowhere
private def needsStablePrefix(sym: Symbol) =
sym.isAbstractType || sym.isClass && !sym.isJava
def referenced(implicit ctx: Context): Reference = {
if (!containsPeriod(validPeriods, ctx.period)) {
referencedVar = prefix.member(name)
validPeriods = ctx.stableInterval
if (needsStablePrefix(referencedVar.symbol) && !prefix.isStable)
throw new MalformedType(prefix, referencedVar.symbol)
}
referencedVar
}
def isType = name.isTypeName
def isTerm = name.isTermName
def symbol(implicit ctx: Context): Symbol = referenced.symbol
def info(implicit ctx: Context): Type = referenced.info
def underlying(implicit ctx: Context): Type = info
override def parents(implicit ctx: Context) = {
val ps = info.parents
val sym = symbol
if (sym.isClass) ps.mapConserve(_.substThis(sym.asClass, prefix)) else ps
}
def derivedNamedType(pre: Type, name: Name)(implicit ctx: Context): Type =
if (pre eq prefix) this
else NamedType(pre, name)
override def computeHash = doHash(name, prefix)
}
abstract case class TermRef(override val prefix: Type, name: TermName) extends NamedType with SingletonType {
override def termSymbol(implicit ctx: Context): Symbol = symbol
override def isStable(implicit ctx: Context) = prefix.isStable && termSymbol.isStable
}
abstract case class TypeRef(override val prefix: Type, name: TypeName) extends NamedType {
override def typeSymbol(implicit ctx: Context): Symbol = symbol
}
trait NamedNoPrefix extends NamedType {
protected val fixedSym: Symbol
override def symbol(implicit ctx: Context): Symbol = fixedSym
override def info(implicit ctx: Context): Type = fixedSym.info
override def referenced(implicit ctx: Context): Reference = new UniqueSymRef(fixedSym, info)
}
final class TermRefNoPrefix(val fixedSym: TermSymbol)(implicit ctx: Context)
extends TermRef(NoPrefix, fixedSym.name) with NamedNoPrefix {
validPeriods = allPeriods(ctx.runId)
}
final class TypeRefNoPrefix(val fixedSym: TypeSymbol)(implicit ctx: Context)
extends TypeRef(NoPrefix, fixedSym.name) with NamedNoPrefix {
validPeriods = allPeriods(ctx.runId)
}
final class UniqueTermRef(prefix: Type, name: TermName) extends TermRef(prefix, name)
final class UniqueTypeRef(prefix: Type, name: TypeName) extends TypeRef(prefix, name)
object NamedType {
def apply(prefix: Type, name: Name)(implicit ctx: Context) =
if (name.isTermName) TermRef(prefix, name.asTermName)
else TypeRef(prefix, name.asTypeName)
}
object TermRef {
def apply(prefix: Type, name: TermName)(implicit ctx: Context) =
unique(new UniqueTermRef(prefix, name))
def apply(sym: TermSymbol)(implicit ctx: Context) =
unique(new TermRefNoPrefix(sym))
}
object TypeRef {
def apply(prefix: Type, name: TypeName)(implicit ctx: Context) =
unique(new UniqueTypeRef(prefix, name))
def apply(sym: TypeSymbol)(implicit ctx: Context) =
unique(new TypeRefNoPrefix(sym))
}
// --- Other SingletonTypes: ThisType/SuperType/ConstantType ---------------------------
abstract case class ThisType(clazz: ClassSymbol) extends SingletonType {
def underlying(implicit ctx: Context) = clazz.typeOfThis
override def isStable(implicit ctx: Context) = true
override def computeHash = doHash(clazz)
}
final class UniqueThisType(clazz: ClassSymbol) extends ThisType(clazz)
object ThisType {
def apply(clazz: ClassSymbol)(implicit ctx: Context) =
unique(new UniqueThisType(clazz))
}
abstract case class SuperType(thistpe: Type, supertpe: Type) extends SingletonType {
def underlying(implicit ctx: Context) = supertpe
override def isStable(implicit ctx: Context) = true
override def computeHash = doHash(thistpe, supertpe)
def derivedSuperType(thistp: Type, supertp: Type)(implicit ctx: Context) =
if ((thistp eq thistpe) && (supertp eq supertpe)) this
else SuperType(thistp, supertp)
}
final class UniqueSuperType(thistpe: Type, supertpe: Type) extends SuperType(thistpe, supertpe)
object SuperType {
def apply(thistpe: Type, supertpe: Type)(implicit ctx: Context) =
unique(new UniqueSuperType(thistpe, supertpe))
}
abstract case class ConstantType(value: Constant) extends SingletonType {
def underlying(implicit ctx: Context) = value.tpe
override def computeHash = doHash(value)
}
final class UniqueConstantType(value: Constant) extends ConstantType(value)
object ConstantType {
def apply(value: Constant)(implicit ctx: Context) =
unique(new UniqueConstantType(value))
}
// --- AppliedType -----------------------------------------------------------------
abstract case class AppliedType(tycon: Type, override val typeArgs: List[Type]) extends UniqueType {
assert(tycon.typeParams.length == typeArgs.length)
def derivedAppliedType(tc: Type, args: List[Type])(implicit ctx: Context): Type =
if ((tc eq tycon) && (args eq typeArgs)) this
else AppliedType(tc, args)
override def computeHash = doHash(tycon, typeArgs)
}
final class UniqueAppliedType(tycon: Type, typeArgs: List[Type]) extends AppliedType(tycon, typeArgs)
object AppliedType {
def apply(tycon: Type, typeArgs: List[Type])(implicit ctx: Context) =
unique(new UniqueAppliedType(tycon, typeArgs))
}
// --- Refined Type ---------------------------------------------------------
case class RefinedType(parent: Type, names: List[Name])(infosExpr: RefinedType => List[Type]) extends UniqueType with TypeProxy {
def underlying(implicit ctx: Context) = parent
lazy val infos = infosExpr(this)
def derivedRefinedType(parent1: Type, names1: List[Name], infos1: List[Type]): RefinedType =
if ((parent1 eq parent) && (names1 eq names) && (infos1 eq infos)) this
else
RefinedType(parent1, names1) { rt =>
val thistp = RefinedThis(rt)
infos1 map (_.substThis(this, thistp))
}
def findDecl(name: Name, pre: Type)(implicit ctx: Context): Reference = {
var ns = names
var is = infos
var ref: Reference = NoRef
while (ns.nonEmpty && (ref eq NoRef)) {
if (ns.head == name)
ref = new JointSymRef(NoSymbol, is.head.substThis(this, pre))
ns = ns.tail
is = is.tail
}
ref
}
override def findMember(name: Name, pre: Type, excluded: FlagSet)(implicit ctx: Context): Reference =
parent.findMember(name, pre, excluded | Flags.Private) &
findDecl(name, pre)
def computeHash = doHash(names, parent, infos)
}
// --- ClassInfo Type ---------------------------------------------------------
case class ClassInfoType(_parents: List[Type], _decls: Scope, clazz: ClassSymbol) extends UniqueType {
import NameFilter._
import util.LRU8Cache
override def parents(implicit ctx: Context) = _parents
override def decls(implicit ctx: Context) = _decls
private var memberCacheVar: LRU8Cache[Name, RefSet] = null
private def memberCache: LRU8Cache[Name, RefSet] = {
if (memberCacheVar == null) memberCacheVar = new LRU8Cache
memberCacheVar
}
def thisType: Type = ???
private var baseClassesVar: List[ClassSymbol] = null
private var superClassBitsVar: BitSet = null
private def computeSuperClassBits(implicit ctx: Context): Unit = {
val seen = new mutable.BitSet
val locked = new mutable.BitSet
def addBaseClasses(bcs: List[ClassSymbol], to: List[ClassSymbol])
: List[ClassSymbol] = bcs match {
case bc :: bcs1 =>
val id = bc.superId
if (seen contains id) to
else if (locked contains id) throw new CyclicReference(clazz)
else {
locked += id
val bcs1added = addBaseClasses(bcs1, to)
seen += id
if (bcs1added eq bcs1) bcs else bc :: bcs1added
}
case _ =>
to
}
def addParentBaseClasses(ps: List[Type], to: List[ClassSymbol]): List[ClassSymbol] = ps match {
case p :: ps1 =>
addBaseClasses(p.baseClasses, addParentBaseClasses(ps1, to))
case _ =>
to
}
baseClassesVar = clazz :: addParentBaseClasses(parents, Nil)
superClassBitsVar = ctx.root.uniqueBits.findEntryOrUpdate(seen.toImmutable)
}
def superClassBits(implicit ctx: Context): BitSet = {
if (superClassBitsVar == null) computeSuperClassBits
superClassBitsVar
}
def baseClasses(implicit ctx: Context): List[ClassSymbol] = {
if (baseClassesVar == null) computeSuperClassBits
baseClassesVar
}
/** Is this class a subclass of `clazz`? */
final def isSubClass(clazz: ClassSymbol)(implicit ctx: Context): Boolean = {
superClassBits contains clazz.superId
}
private var definedFingerPrintCache: FingerPrint = null
private def computeDefinedFingerPrint(implicit ctx: Context): FingerPrint = {
var bits = newNameFilter
var e = decls.lastEntry
while (e != null) {
includeName(bits, clazz.name)
e = e.prev
}
var ps = parents
while (ps.nonEmpty) {
val parent = ps.head.typeSymbol
parent.info match {
case cinfo: ClassInfoType =>
includeFingerPrint(bits, cinfo.definedFingerPrint)
parent.deref setFlag Frozen
case _ =>
}
ps = ps.tail
}
definedFingerPrintCache = bits
bits
}
/** Enter a symbol in current scope.
* Note: We require that this does not happen after the first time
* someone does a findMember on a subclass.
*/
def enter(sym: Symbol)(implicit ctx: Context) = {
require((clazz.flags & Frozen) == Flags.Empty)
decls enter sym
if (definedFingerPrintCache != null)
includeName(definedFingerPrintCache, sym.name)
if (memberCacheVar != null)
memberCache invalidate sym.name
}
/** Delete symbol from current scope.
* Note: We require that this does not happen after the first time
* someone does a findMember on a subclass.
*/
def delete(sym: Symbol)(implicit ctx: Context) = {
require((clazz.flags & Frozen) == Flags.Empty)
decls unlink sym
if (definedFingerPrintCache != null)
computeDefinedFingerPrint
if (memberCacheVar != null)
memberCache invalidate sym.name
}
def definedFingerPrint(implicit ctx: Context): FingerPrint = {
val fp = definedFingerPrintCache
if (fp != null) fp else computeDefinedFingerPrint
}
final def memberRefsNamed(name: Name)(implicit ctx: Context): RefSet = {
var refs: RefSet = memberCache lookup name
if (refs == null) {
if (containsName(definedFingerPrint, name)) {
val ownRefs = decls.refsNamed(name)
refs = ownRefs
var ps = parents
while (ps.nonEmpty) {
val parentSym = ps.head.typeSymbol
parentSym.info match {
case pinfo: ClassInfoType =>
refs = refs union
pinfo.memberRefsNamed(name)
.filterExcluded(Flags.Private)
.asSeenFrom(thisType, parentSym)
.filterDisjoint(ownRefs)
case _ =>
}
}
} else {
refs = NoRef
}
memberCache enter (name, refs)
}
refs
}
private var baseTypeCache: java.util.HashMap[UniqueType, Type] = null
final def baseTypeOf(tp: Type)(implicit ctx: Context): Type = {
def computeBaseTypeOf(tp: Type): Type = tp match {
case tp: NamedType =>
val sym = tp.symbol
val bt = baseTypeOf(tp.info)
if (sym.isClass) bt.substThis(sym.asClass, tp.prefix)
else bt
case AppliedType(tycon, args) =>
baseTypeOf(tycon).subst(tycon.typeParams, args)
case AndType(tp1, tp2) =>
baseTypeOf(tp1) & baseTypeOf(tp2)
case OrType(tp1, tp2) =>
baseTypeOf(tp1) | baseTypeOf(tp2)
case ClassInfoType(parents, _, _) =>
def reduce(bt: Type, ps: List[Type]): Type = ps match {
case p :: ps1 => reduce(bt & baseTypeOf(p), ps1)
case _ => bt
}
reduce(NoType, parents)
case tp: TypeProxy =>
baseTypeOf(tp.underlying)
}
if (clazz.isStatic && clazz.typeParams.isEmpty) clazz.tpe
else tp match {
case tp: UniqueType =>
if (baseTypeCache == null)
baseTypeCache = new java.util.HashMap[UniqueType, Type]
var basetp = baseTypeCache get tp
if (basetp == null) {
baseTypeCache.put(tp, NoType)
basetp = computeBaseTypeOf(tp)
baseTypeCache.put(tp, basetp)
} else if (basetp == NoType) {
throw new CyclicReference(clazz)
}
basetp
case _ =>
computeBaseTypeOf(tp)
}
}
override def typeSymbol(implicit ctx: Context) = clazz
override def findMember(name: Name, pre: Type, excluded: FlagSet)(implicit ctx: Context): Reference =
findMemberAmong(memberRefsNamed(name), pre, clazz, excluded)
def computeHash = clazz.hashCode
}
// --- AndType/OrType ---------------------------------------------------------------
abstract case class AndType(tp1: Type, tp2: Type) extends UniqueType {
type This <: AndType
def derivedAndType(t1: Type, t2: Type)(implicit ctx: Context) =
if ((t1 eq tp1) && (t2 eq tp2)) this
else AndType(t1, t2)
override def findMember(name: Name, pre: Type, excluded: FlagSet)(implicit ctx: Context): Reference =
(tp1 findMember (name, pre, excluded)) & (tp2 findMember (name, pre, excluded))
override def computeHash = doHash(tp1, tp2)
}
final class UniqueAndType(tp1: Type, tp2: Type) extends AndType(tp1, tp2)
object AndType {
def apply(tp1: Type, tp2: Type)(implicit ctx: Context) =
unique(new UniqueAndType(tp1, tp2))
}
abstract case class OrType(tp1: Type, tp2: Type) extends UniqueType {
def derivedOrType(t1: Type, t2: Type)(implicit ctx: Context) =
if ((t1 eq tp1) && (t2 eq tp2)) this
else OrType(t1, t2)
override def findMember(name: Name, pre: Type, excluded: FlagSet)(implicit ctx: Context): Reference = {
(tp1.findMember(name, pre, excluded) | tp2.findMember(name, pre, excluded))(pre)
}
override def computeHash = doHash(tp1, tp2)
}
final class UniqueOrType(tp1: Type, tp2: Type) extends OrType(tp1, tp2)
object OrType {
def apply(tp1: Type, tp2: Type)(implicit ctx: Context) =
unique(new UniqueOrType(tp1, tp2))
}
// ----- Method types: MethodType/ExprType/PolyType/MethodParam/PolyParam ---------------
abstract case class MethodType(paramNames: List[TermName], paramTypes: List[Type])(resultTypeExp: MethodType => Type) extends UniqueType {
override lazy val resultType = resultTypeExp(this)
lazy val isDependent = resultType exists {
case MethodParam(mt, _) => mt eq this
case _ => false
}
def paramSig(tp: Type): TypeName = ???
lazy val signature: Signature = {
val sig = paramTypes map paramSig
resultType match {
case mt: MethodType => sig ++ mt.signature
case _ => sig
}
}
def instantiate(argTypes: List[Type])(implicit ctx: Context): Type =
if (isDependent) new InstMethodMap(this, argTypes) apply resultType
else resultType
override def computeHash = doHash(paramNames, resultType, paramTypes)
}
final class UniqueMethodType(paramNames: List[TermName], paramTypes: List[Type])(resultTypeExp: MethodType => Type) extends MethodType(paramNames, paramTypes)(resultTypeExp)
object MethodType {
def apply(paramNames: List[TermName], paramTypes: List[Type], resultTypeExp: MethodType => Type)(implicit ctx: Context) =
unique(new UniqueMethodType(paramNames, paramTypes)(resultTypeExp))
}
abstract case class ExprType(override val resultType: Type) extends UniqueType {
def derivedExprType(rt: Type)(implicit ctx: Context) =
if (rt eq resultType) this else ExprType(rt)
override def computeHash = doHash(resultType)
}
final class UniqueExprType(resultType: Type) extends ExprType(resultType)
object ExprType {
def apply(resultType: Type)(implicit ctx: Context) =
unique(new UniqueExprType(resultType))
}
case class PolyType(paramNames: List[TypeName])(paramBoundsExp: PolyType => List[TypeBounds], resultTypeExp: PolyType => Type) extends Type {
lazy val paramBounds = paramBoundsExp(this)
override lazy val resultType = resultTypeExp(this)
def instantiate(argTypes: List[Type])(implicit ctx: Context): Type =
new InstPolyMap(this, argTypes) apply resultType
override def hashCode = System.identityHashCode(this)
override def equals(other: Any) = other match {
case that: PolyType => this eq that
case _ => false
}
}
case class MethodParam(mt: MethodType, paramNum: Int) extends SingletonType {
def underlying(implicit ctx: Context) = mt.paramTypes(paramNum)
override def computeHash = NotCached
}
case class RefinedThis(rt: RefinedType) extends SingletonType {
def underlying(implicit ctx: Context) = rt.parent
override def computeHash = NotCached
}
case class PolyParam(pt: PolyType, paramNum: Int) extends TypeProxy {
def underlying(implicit ctx: Context) = pt.paramBounds(paramNum).hi
}
// ------ Type Bounds ------------------------------------------------------------
abstract case class TypeBounds(lo: Type, hi: Type) extends UniqueType with TypeProxy {
def underlying(implicit ctx: Context): Type = hi
def derivedTypeBounds(lo1: Type, hi1: Type)(implicit ctx: Context) =
if ((lo1 eq lo) && (hi1 eq hi)) this
else TypeBounds(lo, hi)
def & (that: TypeBounds)(implicit ctx: Context): TypeBounds =
TypeBounds(this.lo | that.lo, this.hi & that.hi)
def | (that: TypeBounds)(implicit ctx: Context): TypeBounds =
TypeBounds(this.lo & that.lo, this.hi | that.hi)
def map(f: Type => Type)(implicit ctx: Context): TypeBounds =
TypeBounds(f(lo), f(hi))
override def computeHash = doHash(lo, hi)
}
final class UniqueTypeBounds(lo: Type, hi: Type) extends TypeBounds(lo, hi)
object TypeBounds {
def apply(lo: Type, hi: Type)(implicit ctx: Context) =
unique(new UniqueTypeBounds(lo, hi))
}
// ----- AnnotatedTypes -----------------------------------------------------------
case class AnnotatedType(annots: List[AnnotationInfo], tpe: Type) extends TypeProxy {
def underlying(implicit ctx: Context): Type = tpe
def derivedAnnotatedType(annots1: List[AnnotationInfo], tpe1: Type) =
if ((annots1 eq annots) && (tpe1 eq tpe)) this
else AnnotatedType.make(annots1, tpe1)
}
object AnnotatedType {
def make(annots: List[AnnotationInfo], underlying: Type) =
if (annots.isEmpty) underlying
else AnnotatedType(annots, underlying)
}
// Special type objects ------------------------------------------------------------
case object NoType extends Type {
override def prefix = NoPrefix
def symbol = NoSymbol
def info = NoType
}
case object NoPrefix extends UniqueType {
override def computeHash = hashSeed
}
abstract class ErrorType extends Type
object ErrorType extends ErrorType
case object WildcardType extends Type
// ----- TypeMaps --------------------------------------------------------------------
abstract class TypeMap(implicit ctx: Context) extends (Type => Type) {
def apply(tp: Type): Type
/** Map this function over given type */
def mapOver(tp: Type): Type = tp match {
case tp: NamedType =>
tp.derivedNamedType(this(tp.prefix), tp.name)
case ThisType(_)
| MethodParam(_, _)
| PolyParam(_, _)
| ConstantType(_) => tp
case tp @ AppliedType(tycon, targs) =>
tp.derivedAppliedType(this(tycon), targs mapConserve this)
case tp @ PolyType(pnames) =>
val pbounds = tp.paramBounds
val pbounds1 = pbounds mapConserve (_ map this)
val restpe = tp.resultType
val restpe1 = this(restpe)
if ((pbounds1 eq pbounds) && (restpe1 eq restpe))
tp
else PolyType(pnames)(
x => pbounds1 mapConserve (_ map (_.subst(tp, x))),
x => restpe1.subst(tp, x))
case tp @ MethodType(pnames, ptypes) =>
val ptypes1 = ptypes mapConserve this
val restpe = tp.resultType
val restpe1 = this(restpe)
if ((ptypes1 eq ptypes) && (restpe1 eq restpe)) tp
else MethodType(pnames, ptypes1, x => restpe1.subst(tp, x))
case tp @ ExprType(restpe) =>
tp.derivedExprType(this(restpe))
case tp @ SuperType(thistp, supertp) =>
tp.derivedSuperType(this(thistp), this(supertp))
case tp @ TypeBounds(lo, hi) =>
if (lo eq hi) {
val lo1 = this(lo)
tp.derivedTypeBounds(lo1, lo1)
} else {
tp.derivedTypeBounds(this(lo), this(hi))
}
case tp @ RefinedType(parent, names) =>
tp.derivedRefinedType(this(parent), names, tp.infos mapConserve this)
case tp @ AnnotatedType(annots, underlying) =>
tp.derivedAnnotatedType(mapOverAnnotations(annots), this(underlying))
case _ =>
tp
}
def mapOverAnnotations(annots: List[AnnotationInfo]): List[AnnotationInfo] = ???
}
class InstMethodMap(mt: MethodType, argtypes: List[Type])(implicit ctx: Context) extends TypeMap {
def apply(tp: Type) = tp match {
case MethodParam(`mt`, n) => argtypes(n)
case _ => mapOver(tp)
}
}
class InstPolyMap(pt: PolyType, argtypes: List[Type])(implicit ctx: Context) extends TypeMap {
def apply(tp: Type) = tp match {
case PolyParam(`pt`, n) => argtypes(n)
case _ => mapOver(tp)
}
}
class InstRefinedMap(rt: RefinedType)(implicit ctx: Context) extends TypeMap {
def apply(tp: Type) = tp match {
case RefinedThis(`rt`) => rt.parent
case _ => mapOver(tp)
}
}
class AsSeenFromMap(pre: Type, clazz: Symbol)(implicit ctx: Context) extends TypeMap {
private def skipPrefixOf(pre: Type, clazz: Symbol) =
(pre eq NoType) || (pre eq NoPrefix) || clazz.isPackageClass
private def toPrefix(pre: Type, clazz: Symbol, thisclazz: ClassSymbol, tp: Type): Type =
if (skipPrefixOf(pre, clazz))
tp
else if ((thisclazz isNonBottomSubClass clazz) &&
(pre.widen.typeSymbol isNonBottomSubClass thisclazz))
pre match {
case SuperType(thistp, _) => thistp
case _ => pre
}
else
toPrefix(pre.baseType(clazz).prefix, clazz.owner, thisclazz, tp)
private def toInstance(pre: Type, clazz: Symbol, tparam: Symbol, tp: Type): Type = {
if (skipPrefixOf(pre, clazz)) tp
else {
val tparamOwner = tparam.owner
def throwError =
if (tparamOwner.tpe.parents exists (_.isErroneous))
ErrorType // don't be overzealous with throwing exceptions, see #2641
else
throw new Error(
s"something is wrong (wrong class file?): tp ${tparam.locationString} cannot be instantiated from ${pre.widen}")
def prefixMatches = pre.typeSymbol isNonBottomSubClass tparamOwner
val basePre = pre.baseType(clazz)
def instParamFrom(typeInst: Type): Type = typeInst match {
case ConstantType(_) =>
// have to deconst because it may be a Class[T].
instParamFrom(typeInst.deconst)
case AppliedType(tycon, baseArgs) =>
instParam(tycon.typeParams, baseArgs)
case _ =>
throwError
}
def instParam(ps: List[Symbol], as: List[Type]): Type =
if (ps.isEmpty || as.isEmpty) throwError
else if (tparam eq ps.head) as.head
else throwError
if (tparamOwner == clazz && prefixMatches) instParamFrom(basePre)
else toInstance(basePre.prefix, clazz.owner, tparam, tp)
}
}
def apply(tp: Type) = tp match {
case ThisType(thisclazz) =>
toPrefix(pre, clazz, thisclazz, tp)
case _ =>
tp.widen match {
case tp: TypeRef if tp.typeSymbol.isTypeParameter =>
toInstance(pre, clazz, tp.typeSymbol, tp)
case _ =>
if (tp.isTrivial) tp else mapOver(tp)
}
}
}
// todo: prevent unstable prefixes in variables?
// ----- TypeAccumulators ----------------------------------------------------
abstract class TypeAccumulator[T] extends ((T, Type) => T) {
def apply(x: T, tp: Type): T
def apply(x: T, annot: AnnotationInfo): T = ???
def foldOver(x: T, tp: Type): T = tp match {
case tp: NamedType =>
this(x, tp.prefix)
case ThisType(_)
| MethodParam(_, _)
| PolyParam(_, _)
| ConstantType(_) => x
case AppliedType(tycon, targs) =>
(this(x, tycon) /: targs) (this)
case tp @ PolyType(pnames) =>
this((x /: tp.paramBounds) (this), tp.resultType)
case MethodType(pnames, ptypes) =>
this((x /: ptypes) (this), tp.resultType)
case ExprType(restpe) =>
this(x, restpe)
case SuperType(thistp, supertp) =>
this(this(x, thistp), supertp)
case TypeBounds(lo, hi) =>
this(this(x, lo), hi)
case tp @ RefinedType(parent, names) =>
(this(x, parent) /: tp.infos) (apply)
case AnnotatedType(annots, underlying) =>
this((x /: annots) (apply), underlying)
case _ => x
}
}
class ExistsAccumulator(p: Type => Boolean) extends TypeAccumulator[Boolean] {
def apply(x: Boolean, tp: Type) = x || p(tp) || foldOver(x, tp)
}
// ----- Subtyping -----------------------------------------------------------
type Constraints = Map[PolyParam, TypeBounds]
class SubTyper(val constraints: Constraints = Map(), explain: Boolean = false) {
/**
* isSubRefinement(T1, T2) =
* val clazz = T1.clazz
*
*
*/
def isSubRefinement(tp1: Type, tp2: Type)(implicit ctx: Context): Boolean = {
val clazz = tp1.typeSymbol
assert(clazz eq tp2.typeSymbol)
if (tp1.prefix != tp2.prefix) return false
tp1 match {
case AppliedType(tycon2, args2) =>
isSubArgs(clazz.typeParams, tp1.typeArgs, args2) &&
isSubRefinement(tp1, tycon2)
case RefinedType(tycon2, names) =>
???
}
}
def isSubArgs(tparams: List[TypeSymbol], subargs: List[Type], superargs: List[Type]): Boolean = ???
/**
* NoType is not a sub or superType of Anything
*
* T <: ?
* ? <: T
* T <: Error
* Error <: T
*
* T1 <: T2[U2s] :-
* T1 <: T2 /\
* val T[U1s] = T1 baseType T2.typeSymbol
* and for all i:
* if !(Ui contravariant in T) U1i <: U2i
* if !(Ui covariant in T) U2i <: U1i
*
* T1[U1s] <: T2 if
* T1 <: T2
*
* P#A <: P#A if A is no a class, or both types have same symbol
*
* T1 <: T2 if class C = T2.typeSymbol
* /\ T1' = t1 baseType C
* /\ T1' isSubRefinement T2
*
* T1 <: T2 { Ds }
* if T1 <: T2 and forall i, T1 specializesSym Di
*
*
*/
def isSubType(tp1: Type, tp2: Type)(implicit ctx: Context): Boolean = {
???
/*
if (tp1 == NoType || tp2 == NoType) return false
if (tp1 eq tp2) return true
tp2 match {
case tp2 @ NamedType(pre2, name2) =>
val ref2 = tp2.referenced
if (name2.isTerm && ref2.isStable) return isSubType(tp1, ref2.info)
}
tp1 match {
case tp1 @ NamedType(pre1, name1) =>
val ref1 = tp1.referenced
val sym1 = ref1.symbol
if (sym1 != NoSymbol) {
tp2 match {
case tp2 @ NamedType(pre2, name2) =>
val ref2 = tp2.referenced
val sym2 = ref2.symbol
if (sym1 eq sym2) return true
if (sym1.isTerm) {
val expanded2 = if (ref2.info.isStable) return ref2.info else tp2
return isSubType(ref1.info, expanded2)
}
}
}
}
(tp1, tp2) match {
case (tp1 @ NamedType(pre1, name1), tp2 @ NamedType(pre2, name2)) =>
if (!(pre1 =:= pre2)) return false
val ref1 = tp1.referenced
val ref2 = tp2.referenced
val sym1 = ref1.symbol
val sym2 = ref2.symbol
if (sym1 != NoSymbol && sym2 != NoSymbol) {
if (sym1 eq sym2) return true
if (sym2.isTerm && ref2.isStable) return isSubType(tp1, ref2.info)
if (sym1.isTerm) return isSubType(ref1.info, tp2)
if (sym1.isClass) {
if (sym1 == NothingClass) return true
if (sym2.isClass) return sym1.isNonBottomSubClass(sym2) || sym1 == NullClass
} else if (isSubType(ref1.upperBound, tp2)) return true
// !sym1.isClass || !sym2.isClass
if (name1 == name2) return true
val lo = ref2.info.lowerBound
return lo.typeSymbol != NothingClass && isSubType(tp1, lo)
}
if (sym1 == NothingClass) return true
if ()
if (sym1.isClass)
if (sym1 == NothingClass) true
if (sym2.isClass) sym1 isSubClass sym2
else if (name1 eq name2) true
else if
}
if (name1 == name2)
}
(!(tp1.symbol.isClass && tp2.symbol.isClass) || tp1.symbol == tp2.symbol)
}
}
/** First try, on the right:
* - unwrap Annotated types, BoundedWildcardTypes,
* - bind TypeVars on the right, if lhs is not Annotated nor BoundedWildcard
* - handle common cases for first-kind TypeRefs on both sides as a fast path.
*/
def firstTry(tp1: Type, tp2: Type)(implicit ctx: Context): Boolean = tp2 match {
case tp2: NamedType =>
firstTry(tp1, tp2.underlying)
case tp2: TypeRef =>
case tr2: TypeRef =>
tp1 match {
case tr1: TypeRef =>
val sym1 = tr1.sym
val sym2 = tr2.sym
val pre1 = tr1.pre
val pre2 = tr2.pre
(((if (sym1 == sym2) phase.erasedTypes || sym1.owner.hasPackageFlag || isSubType(pre1, pre2, depth)
else (sym1.name == sym2.name && !sym1.isModuleClass && !sym2.isModuleClass &&
(isUnifiable(pre1, pre2) ||
isSameSpecializedSkolem(sym1, sym2, pre1, pre2) ||
sym2.isAbstractType && isSubPre(pre1, pre2, sym2)))) &&
isSubArgs(tr1.args, tr2.args, sym1.typeParams, depth))
||
sym2.isClass && {
val base = tr1 baseType sym2
(base ne tr1) && isSubType(base, tr2, depth)
}
||
thirdTryRef(tr1, tr2))
case _ =>
secondTry
}
case AnnotatedType(_, _, _) =>
isSubType(tp1.withoutAnnotations, tp2.withoutAnnotations, depth) &&
annotationsConform(tp1, tp2)
case BoundedWildcardType(bounds) =>
isSubType(tp1, bounds.hi, depth)
case tv2 @ TypeVar(_, constr2) =>
tp1 match {
case AnnotatedType(_, _, _) | BoundedWildcardType(_) =>
secondTry
case _ =>
tv2.registerBound(tp1, true)
}
case _ =>
secondTry*/
}
}
// ----- Exceptions -------------------------------------------------------------
class TypeError(msg: String) extends Exception(msg)
class FatalTypeError(msg: String) extends TypeError(msg)
class MalformedType(pre: Type, sym: Symbol) extends FatalTypeError(s"malformed type: $pre.$sym")
class CyclicReference(sym: Symbol) extends FatalTypeError("cyclic reference involving $sym")
// ----- Misc utilities ---------------------------------------------------------
/** like map2, but returns list `xs` itself - instead of a copy - if function
* `f` maps all elements to themselves.
*/
def map2Conserve[A <: AnyRef, B](xs: List[A], ys: List[B])(f: (A, B) => A): List[A] =
if (xs.isEmpty) xs
else {
val x1 = f(xs.head, ys.head)
val xs1 = map2Conserve(xs.tail, ys.tail)(f)
if ((x1 eq xs.head) && (xs1 eq xs.tail)) xs
else x1 :: xs1
}
def NothingType(implicit ctx: Context) = ctx.root.definitions.NothingType
def AnyType(implicit ctx: Context) = ctx.root.definitions.AnyType
lazy val SingletonType: Type = ???
}