package dotty.tools.dotc
package core
import Types._
import Contexts._
import Symbols._
import SymDenotations.{LazyType, TypeParamsCompleter}
import Decorators._
import util.Stats._
import util.common._
import Names._
import NameOps._
import Flags._
import StdNames.tpnme
import util.Positions.Position
import config.Printers._
import collection.mutable
import dotty.tools.dotc.config.Config
import java.util.NoSuchElementException
object TypeApplications {
/** Assert type is not a TypeBounds instance and return it unchanged */
val noBounds = (tp: Type) => tp match {
case tp: TypeBounds => throw new AssertionError("no TypeBounds allowed")
case _ => tp
}
/** If `tp` is a TypeBounds instance return its lower bound else return `tp` */
val boundsToLo = (tp: Type) => tp match {
case tp: TypeBounds => tp.lo
case _ => tp
}
/** If `tp` is a TypeBounds instance return its upper bound else return `tp` */
val boundsToHi = (tp: Type) => tp match {
case tp: TypeBounds => tp.hi
case _ => tp
}
/** Does variance `v1` conform to variance `v2`?
* This is the case if the variances are the same or `sym` is nonvariant.
*/
def varianceConforms(v1: Int, v2: Int)(implicit ctx: Context): Boolean =
v1 == v2 || v2 == 0
/** Does the variance of type parameter `tparam1` conform to the variance of type parameter `tparam2`?
*/
def varianceConforms(tparam1: TypeParamInfo, tparam2: TypeParamInfo)(implicit ctx: Context): Boolean =
varianceConforms(tparam1.paramVariance, tparam2.paramVariance)
/** Doe the variances of type parameters `tparams1` conform to the variances
* of corresponding type parameters `tparams2`?
* This is only the case of `tparams1` and `tparams2` have the same length.
*/
def variancesConform(tparams1: List[TypeParamInfo], tparams2: List[TypeParamInfo])(implicit ctx: Context): Boolean =
tparams1.corresponds(tparams2)(varianceConforms)
/** Extractor for
*
* [v1 X1: B1, ..., vn Xn: Bn] -> C[X1, ..., Xn]
*
* where v1, ..., vn and B1, ..., Bn are the variances and bounds of the type parameters
* of the class C.
*
* @param tycon C
*/
object EtaExpansion {
def apply(tycon: Type)(implicit ctx: Context) = {
assert(tycon.typeParams.nonEmpty, tycon)
tycon.EtaExpand(tycon.typeParamSymbols)
}
def unapply(tp: Type)(implicit ctx: Context): Option[TypeRef] = tp match {
case tp @ TypeLambda(tparams, AppliedType(fn: TypeRef, args)) if (args == tparams.map(_.toArg)) => Some(fn)
case _ => None
}
}
/** Extractor for type application T[U_1, ..., U_n]. This is the refined type
*
* T { type p_1 v_1= U_1; ...; type p_n v_n= U_n }
*
* where v_i, p_i are the variances and names of the type parameters of T.
*/
object AppliedType {
def apply(tp: Type, args: List[Type])(implicit ctx: Context): Type = tp.appliedTo(args)
def unapply(tp: Type)(implicit ctx: Context): Option[(Type, List[Type])] = tp match {
case tp: RefinedType =>
var refinements: List[RefinedType] = Nil
var tycon = tp.stripTypeVar
while (tycon.isInstanceOf[RefinedType]) {
val rt = tycon.asInstanceOf[RefinedType]
refinements = rt :: refinements
tycon = rt.parent.stripTypeVar
}
def collectArgs(tparams: List[TypeParamInfo],
refinements: List[RefinedType],
argBuf: mutable.ListBuffer[Type]): Option[(Type, List[Type])] = refinements match {
case Nil if tparams.isEmpty && argBuf.nonEmpty =>
Some((tycon, argBuf.toList))
case RefinedType(_, rname, rinfo) :: refinements1
if tparams.nonEmpty && rname == tparams.head.paramName =>
collectArgs(tparams.tail, refinements1, argBuf += rinfo.argInfo)
case _ =>
None
}
collectArgs(tycon.typeParams, refinements, new mutable.ListBuffer[Type])
case HKApply(tycon, args) =>
Some((tycon, args))
case _ =>
None
}
}
/** Adapt all arguments to possible higher-kinded type parameters using etaExpandIfHK
*/
def etaExpandIfHK(tparams: List[TypeParamInfo], args: List[Type])(implicit ctx: Context): List[Type] =
if (tparams.isEmpty) args
else {
def bounds(tparam: TypeParamInfo) = tparam match {
case tparam: Symbol => tparam.infoOrCompleter
case tparam: LambdaParam => tparam.paramBounds
}
args.zipWithConserve(tparams)((arg, tparam) => arg.etaExpandIfHK(bounds(tparam)))
}
/** A type map that tries to reduce a (part of) the result type of the type lambda `tycon`
* with the given `args`(some of which are wildcard arguments represented by type bounds).
* Non-wildcard arguments are substituted everywhere as usual. A wildcard argument
* `>: L <: H` is substituted for a type lambda parameter `X` only if `X` appears
* in a toplevel refinement of the form
*
* { type A = X }
*
* and there are no other occurrences of `X` in the reduced type. In that case
* the refinement above is replaced by
*
* { type A >: L <: U }
*
* The `allReplaced` field indicates whether all occurrences of type lambda parameters
* in the reduced type have been replaced with arguments.
*/
class Reducer(tycon: TypeLambda, args: List[Type])(implicit ctx: Context) extends TypeMap {
private var available = Set((0 until args.length): _*)
var allReplaced = true
def hasWildcardArg(p: PolyParam) =
p.binder == tycon && args(p.paramNum).isInstanceOf[TypeBounds]
def apply(t: Type) = t match {
case t @ TypeAlias(p: PolyParam) if hasWildcardArg(p) && available.contains(p.paramNum) =>
available -= p.paramNum
args(p.paramNum)
case p: PolyParam if p.binder == tycon =>
if (hasWildcardArg(p)) { allReplaced = false; p }
else args(p.paramNum)
case _: TypeBounds | _: HKApply =>
val saved = available
available = Set()
try mapOver(t)
finally available = saved
case _ =>
mapOver(t)
}
}
}
import TypeApplications._
/** A decorator that provides methods for modeling type application */
class TypeApplications(val self: Type) extends AnyVal {
/** The type parameters of this type are:
* For a ClassInfo type, the type parameters of its class.
* For a typeref referring to a class, the type parameters of the class.
* For a typeref referring to a Lambda class, the type parameters of
* its right hand side or upper bound.
* For a refinement type, the type parameters of its parent, dropping
* any type parameter that is-rebound by the refinement. "Re-bind" means:
* The refinement contains a TypeAlias for the type parameter, or
* it introduces bounds for the type parameter, and we are not in the
* special case of a type Lambda, where a LambdaTrait gets refined
* with the bounds on its hk args. See `LambdaAbstract`, where these
* types get introduced, and see `isBoundedLambda` below for the test.
*/
final def typeParams(implicit ctx: Context): List[TypeParamInfo] = /*>|>*/ track("typeParams") /*<|<*/ {
self match {
case self: ClassInfo =>
self.cls.typeParams
case self: TypeLambda =>
self.typeParams
case self: TypeRef =>
val tsym = self.symbol
if (tsym.isClass) tsym.typeParams
else if (!tsym.isCompleting) tsym.info.typeParams
else Nil
case self: RefinedType =>
self.parent.typeParams.filterNot(_.paramName == self.refinedName)
case self: RecType =>
self.parent.typeParams
case _: HKApply | _: SingletonType =>
Nil
case self: WildcardType =>
self.optBounds.typeParams
case self: TypeProxy =>
self.underlying.typeParams
case _ =>
Nil
}
}
/** If `self` is a higher-kinded type, its type parameters $hk_i, otherwise Nil */
final def hkTypeParams(implicit ctx: Context): List[TypeParamInfo] =
if (isHK) typeParams else Nil
/** If `self` is a generic class, its type parameter symbols, otherwise Nil */
final def typeParamSymbols(implicit ctx: Context): List[TypeSymbol] = typeParams match {
case (_: Symbol) :: _ =>
assert(typeParams.forall(_.isInstanceOf[Symbol]))
typeParams.asInstanceOf[List[TypeSymbol]]
case _ => Nil
}
/** The named type parameters declared or inherited by this type.
* These are all uninstantiated named type parameters of this type or one
* of its base types.
*/
final def namedTypeParams(implicit ctx: Context): Set[TypeSymbol] = self match {
case self: ClassInfo =>
self.cls.namedTypeParams
case self: RefinedType =>
self.parent.namedTypeParams.filterNot(_.name == self.refinedName)
case self: SingletonType =>
Set()
case self: TypeProxy =>
self.underlying.namedTypeParams
case _ =>
Set()
}
/** The smallest supertype of this type that instantiated none of the named type parameters
* in `params`. That is, for each named type parameter `p` in `params`, either there is
* no type field named `p` in this type, or `p` is a named type parameter of this type.
* The first case is important for the recursive case of AndTypes, because some of their operands might
* be missing the named parameter altogether, but the AndType as a whole can still
* contain it.
*/
final def widenToNamedTypeParams(params: Set[TypeSymbol])(implicit ctx: Context): Type = {
/** Is widening not needed for `tp`? */
def isOK(tp: Type) = {
val ownParams = tp.namedTypeParams
def isMissingOrOpen(param: TypeSymbol) = {
val ownParam = tp.nonPrivateMember(param.name).symbol
!ownParam.exists || ownParams.contains(ownParam.asType)
}
params.forall(isMissingOrOpen)
}
/** Widen type by forming the intersection of its widened parents */
def widenToParents(tp: Type) = {
val parents = tp.parents.map(p =>
tp.baseTypeWithArgs(p.symbol).widenToNamedTypeParams(params))
parents.reduceLeft(ctx.typeComparer.andType(_, _))
}
if (isOK(self)) self
else self match {
case self @ AppliedType(tycon, args) if !isOK(tycon) =>
widenToParents(self)
case self: TypeRef if self.symbol.isClass =>
widenToParents(self)
case self: RefinedType =>
val parent1 = self.parent.widenToNamedTypeParams(params)
if (params.exists(_.name == self.refinedName)) parent1
else self.derivedRefinedType(parent1, self.refinedName, self.refinedInfo)
case self: TypeProxy =>
self.superType.widenToNamedTypeParams(params)
case self: AndOrType =>
self.derivedAndOrType(
self.tp1.widenToNamedTypeParams(params), self.tp2.widenToNamedTypeParams(params))
}
}
/** Is self type higher-kinded (i.e. of kind != "*")? */
def isHK(implicit ctx: Context): Boolean = self.dealias match {
case self: TypeRef => self.info.isHK
case self: RefinedType => false
case self: TypeLambda => true
case self: HKApply => false
case self: SingletonType => false
case self: TypeVar => self.origin.isHK // discrepancy with typeParams, why?
case self: WildcardType => self.optBounds.isHK
case self: TypeProxy => self.underlying.isHK
case _ => false
}
/** Computes the kind of `self` without forcing anything.
* @return 1 if type is known to be higher-kinded
* -1 if type is known to be a * type
* 0 if kind of `self` is unknown (because symbols have not yet completed)
*/
def knownHK(implicit ctx: Context): Int = self match {
case self: TypeRef =>
val tsym = self.symbol
if (tsym.isClass) -1
else tsym.infoOrCompleter match {
case completer: TypeParamsCompleter =>
if (completer.completerTypeParams(tsym).nonEmpty) 1 else -1
case _ =>
if (!tsym.isCompleting || tsym.isAliasType) tsym.info.knownHK
else 0
}
case self: RefinedType => -1
case self: TypeLambda => 1
case self: HKApply => -1
case self: SingletonType => -1
case self: TypeVar => self.origin.knownHK
case self: WildcardType => self.optBounds.knownHK
case self: TypeProxy => self.underlying.knownHK
case NoType | _: LazyType => 0
case _ => -1
}
/** True if it can be determined without forcing that the class symbol
* of this application exists. Equivalent to
*
* self.classSymbol.exists
*
* but without forcing anything.
*/
def safeIsClassRef(implicit ctx: Context): Boolean = self.stripTypeVar match {
case self: RefinedOrRecType =>
self.parent.safeIsClassRef
case self: TypeRef =>
self.denot.exists && {
val sym = self.symbol
sym.isClass ||
sym.isCompleted && self.info.isAlias
}
case _ =>
false
}
/** Dealias type if it can be done without forcing the TypeRef's info */
def safeDealias(implicit ctx: Context): Type = self match {
case self: TypeRef if self.denot.exists && self.symbol.isAliasType =>
self.info.bounds.hi.stripTypeVar.safeDealias
case _ =>
self
}
/** Lambda abstract `self` with given type parameters. Examples:
*
* type T[X] = U becomes type T = [X] -> U
* type T[X] >: L <: U becomes type T >: L <: ([X] -> U)
*
* TODO: Handle parameterized lower bounds
*/
def LambdaAbstract(tparams: List[Symbol])(implicit ctx: Context): Type = {
def expand(tp: Type) =
TypeLambda(
tpnme.syntheticLambdaParamNames(tparams.length), tparams.map(_.variance))(
tl => tparams.map(tparam => tl.lifted(tparams, tparam.info).bounds),
tl => tl.lifted(tparams, tp))
assert(!isHK, self)
self match {
case self: TypeAlias =>
self.derivedTypeAlias(expand(self.alias))
case self @ TypeBounds(lo, hi) =>
self.derivedTypeBounds(lo, expand(hi))
case _ => expand(self)
}
}
/** Convert a type constructor `TC` which has type parameters `T1, ..., Tn`
* in a context where type parameters `U1,...,Un` are expected to
*
* LambdaXYZ { Apply = TC[hk$0, ..., hk$n] }
*
* Here, XYZ corresponds to the variances of
* - `U1,...,Un` if the variances of `T1,...,Tn` are pairwise compatible with `U1,...,Un`,
* - `T1,...,Tn` otherwise.
* v1 is compatible with v2, if v1 = v2 or v2 is non-variant.
*/
def EtaExpand(tparams: List[TypeSymbol])(implicit ctx: Context): Type = {
val tparamsToUse = if (variancesConform(typeParams, tparams)) tparams else typeParamSymbols
self.appliedTo(tparams map (_.typeRef)).LambdaAbstract(tparamsToUse)
//.ensuring(res => res.EtaReduce =:= self, s"res = $res, core = ${res.EtaReduce}, self = $self, hc = ${res.hashCode}")
}
/** Eta expand the prefix in front of any refinements. */
def EtaExpandCore(implicit ctx: Context): Type = self.stripTypeVar match {
case self: RefinedType =>
self.derivedRefinedType(self.parent.EtaExpandCore, self.refinedName, self.refinedInfo)
case _ =>
self.EtaExpand(self.typeParamSymbols)
}
/** If self is not higher-kinded, eta expand it. */
def ensureHK(implicit ctx: Context): Type =
if (isHK) self else EtaExpansion(self)
/** Eta expand if `self` is a (non-lambda) class reference and `bound` is a higher-kinded type */
def etaExpandIfHK(bound: Type)(implicit ctx: Context): Type = {
val hkParams = bound.hkTypeParams
if (hkParams.isEmpty) self
else self match {
case self: TypeRef if self.symbol.isClass && self.typeParams.length == hkParams.length =>
EtaExpansion(self)
case _ => self
}
}
/** If argument A and type parameter P are higher-kinded, adapt the variances
* of A to those of P, ensuring that the variances of the type lambda A
* agree with the variances of corresponding higher-kinded type parameters of P. Example:
*
* class GenericCompanion[+CC[X]]
* GenericCompanion[List]
*
* with adaptHkVariances, the argument `List` will expand to
*
* [X] => List[X]
*
* instead of
*
* [+X] => List[X]
*
* even though `List` is covariant. This adaptation is necessary to ignore conflicting
* variances in overriding members that have types of hk-type parameters such as
* `GenericCompanion[GenTraversable]` or `GenericCompanion[ListBuffer]`.
* When checking overriding, we need to validate the subtype relationship
*
* GenericCompanion[[X] -> ListBuffer[X]] <: GenericCompanion[[+X] -> GenTraversable[X]]
*
* Without adaptation, this would be false, and hence an overriding error would
* result. But with adaptation, the rhs argument will be adapted to
*
* [X] -> GenTraversable[X]
*
* which makes the subtype test succeed. The crucial point here is that, since
* GenericCompanion only expects a non-variant CC, the fact that GenTraversable
* is covariant is irrelevant, so can be ignored.
*/
def adaptHkVariances(bound: Type)(implicit ctx: Context): Type = {
val hkParams = bound.hkTypeParams
if (hkParams.isEmpty) self
else {
def adaptArg(arg: Type): Type = arg match {
case arg @ TypeLambda(tparams, body) if
!tparams.corresponds(hkParams)(_.paramVariance == _.paramVariance) &&
tparams.corresponds(hkParams)(varianceConforms) =>
TypeLambda(tparams.map(_.paramName), hkParams.map(_.paramVariance))(
tl => arg.paramBounds.map(_.subst(arg, tl).bounds),
tl => arg.resultType.subst(arg, tl)
)
case arg @ TypeAlias(alias) =>
arg.derivedTypeAlias(adaptArg(alias))
case arg @ TypeBounds(lo, hi) =>
arg.derivedTypeBounds(lo, adaptArg(hi))
case _ =>
arg
}
adaptArg(self)
}
}
/** Encode
*
* T[U1, ..., Un]
*
* where
* @param self = `T`
* @param args = `U1,...,Un`
* performing the following simplifications
*
* 1. If `T` is an eta expansion `[X1,..,Xn] -> C[X1,...,Xn]` of class `C` compute
* `C[U1, ..., Un]` instead.
* 2. If `T` is some other type lambda `[X1,...,Xn] -> S` none of the arguments
* `U1,...,Un` is a wildcard, compute `[X1:=U1, ..., Xn:=Un]S` instead.
* 3. If `T` is a polytype, instantiate it to `U1,...,Un`.
*/
final def appliedTo(args: List[Type])(implicit ctx: Context): Type = /*>|>*/ track("appliedTo") /*<|<*/ {
val typParams = self.typeParams
def matchParams(t: Type, tparams: List[TypeParamInfo], args: List[Type])(implicit ctx: Context): Type = args match {
case arg :: args1 =>
try {
val tparam :: tparams1 = tparams
matchParams(RefinedType(t, tparam.paramName, arg.toBounds(tparam)), tparams1, args1)
} catch {
case ex: MatchError =>
println(s"applied type mismatch: $self with underlying ${self.underlyingIfProxy}, args = $args, typeParams = $typParams") // !!! DEBUG
//println(s"precomplete decls = ${self.typeSymbol.unforcedDecls.toList.map(_.denot).mkString("\n ")}")
throw ex
}
case nil => t
}
if (args.isEmpty || ctx.erasedTypes) self
else self.stripTypeVar.safeDealias match {
case self: TypeLambda =>
if (!args.exists(_.isInstanceOf[TypeBounds])) self.instantiate(args)
else {
val reducer = new Reducer(self, args)
val reduced = reducer(self.resType)
if (reducer.allReplaced) reduced
else HKApply(self, args)
}
case self: PolyType =>
self.instantiate(args)
case self: AndOrType =>
self.derivedAndOrType(self.tp1.appliedTo(args), self.tp2.appliedTo(args))
case self: TypeAlias =>
self.derivedTypeAlias(self.alias.appliedTo(args))
case self: TypeBounds =>
self.derivedTypeBounds(self.lo, self.hi.appliedTo(args))
case self: LazyRef =>
LazyRef(() => self.ref.appliedTo(args))
case self: WildcardType =>
self
case self: TypeRef if self.symbol == defn.NothingClass =>
self
case _ if typParams.isEmpty || typParams.head.isInstanceOf[LambdaParam] =>
HKApply(self, args)
case dealiased =>
matchParams(dealiased, typParams, args)
}
}
final def appliedTo(arg: Type)(implicit ctx: Context): Type = appliedTo(arg :: Nil)
final def appliedTo(arg1: Type, arg2: Type)(implicit ctx: Context): Type = appliedTo(arg1 :: arg2 :: Nil)
final def applyIfParameterized(args: List[Type])(implicit ctx: Context): Type =
if (typeParams.nonEmpty) appliedTo(args) else self
/** A cycle-safe version of `appliedTo` where computing type parameters do not force
* the typeconstructor. Instead, if the type constructor is completing, we make
* up hk type parameters matching the arguments. This is needed when unpickling
* Scala2 files such as `scala.collection.generic.Mapfactory`.
*/
final def safeAppliedTo(args: List[Type])(implicit ctx: Context) = self match {
case self: TypeRef if !self.symbol.isClass && self.symbol.isCompleting =>
HKApply(self, args)
case _ =>
appliedTo(args)
}
/** Turn this type, which is used as an argument for
* type parameter `tparam`, into a TypeBounds RHS
*/
final def toBounds(tparam: TypeParamInfo)(implicit ctx: Context): TypeBounds = self match {
case self: TypeBounds => // this can happen for wildcard args
self
case _ =>
val v = tparam.paramVariance
/* Not neeeded.
if (v > 0 && !(tparam is Local) && !(tparam is ExpandedTypeParam)) TypeBounds.upper(self)
else if (v < 0 && !(tparam is Local) && !(tparam is ExpandedTypeParam)) TypeBounds.lower(self)
else
*/
TypeAlias(self, v)
}
/** The type arguments of this type's base type instance wrt. `base`.
* Existential types in arguments are returned as TypeBounds instances.
*/
final def baseArgInfos(base: Symbol)(implicit ctx: Context): List[Type] =
if (self derivesFrom base)
self match {
case self: HKApply => self.superType.baseArgInfos(base)
case _ => base.typeParams.map(param => self.member(param.name).info.argInfo)
}
else
Nil
/** The type arguments of this type's base type instance wrt.`base`.
* Existential types in arguments are disallowed.
*/
final def baseArgTypes(base: Symbol)(implicit ctx: Context): List[Type] =
baseArgInfos(base) mapConserve noBounds
/** The type arguments of this type's base type instance wrt.`base`.
* Existential types in arguments are approximated by their lower bound.
*/
final def baseArgTypesLo(base: Symbol)(implicit ctx: Context): List[Type] =
baseArgInfos(base) mapConserve boundsToLo
/** The type arguments of this type's base type instance wrt.`base`.
* Existential types in arguments are approximated by their upper bound.
*/
final def baseArgTypesHi(base: Symbol)(implicit ctx: Context): List[Type] =
baseArgInfos(base) mapConserve boundsToHi
/** The first type argument of the base type instance wrt `base` of this type */
final def firstBaseArgInfo(base: Symbol)(implicit ctx: Context): Type = base.typeParams match {
case param :: _ if self derivesFrom base =>
self match {
case self: HKApply => self.superType.firstBaseArgInfo(base)
case _ => self.member(param.name).info.argInfo
}
case _ =>
NoType
}
/** The base type including all type arguments and applicable refinements
* of this type. Refinements are applicable if they refine a member of
* the parent type which furthermore is not a name-mangled type parameter.
* Existential types in arguments are returned as TypeBounds instances.
*/
final def baseTypeWithArgs(base: Symbol)(implicit ctx: Context): Type = ctx.traceIndented(s"btwa ${self.show} wrt $base", core, show = true) {
def default = self.baseTypeRef(base).appliedTo(baseArgInfos(base))
self match {
case tp: TypeRef =>
tp.info match {
case TypeBounds(_, hi) => hi.baseTypeWithArgs(base)
case _ => default
}
case tp @ RefinedType(parent, name, _) if !tp.member(name).symbol.is(ExpandedTypeParam) =>
tp.wrapIfMember(parent.baseTypeWithArgs(base))
case tp: TermRef =>
tp.underlying.baseTypeWithArgs(base)
case tp: HKApply =>
tp.superType.baseTypeWithArgs(base)
case AndType(tp1, tp2) =>
tp1.baseTypeWithArgs(base) & tp2.baseTypeWithArgs(base)
case OrType(tp1, tp2) =>
tp1.baseTypeWithArgs(base) | tp2.baseTypeWithArgs(base)
case _ =>
default
}
}
/** Translate a type of the form From[T] to To[T], keep other types as they are.
* `from` and `to` must be static classes, both with one type parameter, and the same variance.
* Do the same for by name types => From[T] and => To[T]
*/
def translateParameterized(from: ClassSymbol, to: ClassSymbol)(implicit ctx: Context): Type = self match {
case self @ ExprType(tp) =>
self.derivedExprType(tp.translateParameterized(from, to))
case _ =>
if (self.derivesFrom(from))
if (ctx.erasedTypes) to.typeRef
else RefinedType(to.typeRef, to.typeParams.head.name, self.member(from.typeParams.head.name).info)
else self
}
/** If this is repeated parameter type, its underlying Seq type,
* or, if isJava is true, Array type, else the type itself.
*/
def underlyingIfRepeated(isJava: Boolean)(implicit ctx: Context): Type =
if (self.isRepeatedParam) {
val seqClass = if (isJava) defn.ArrayClass else defn.SeqClass
translateParameterized(defn.RepeatedParamClass, seqClass)
}
else self
/** If this is an encoding of a (partially) applied type, return its arguments,
* otherwise return Nil.
* Existential types in arguments are returned as TypeBounds instances.
*/
final def argInfos(implicit ctx: Context): List[Type] = self match {
case AppliedType(tycon, args) => args
case _ => Nil
}
/** Argument types where existential types in arguments are disallowed */
def argTypes(implicit ctx: Context) = argInfos mapConserve noBounds
/** Argument types where existential types in arguments are approximated by their lower bound */
def argTypesLo(implicit ctx: Context) = argInfos mapConserve boundsToLo
/** Argument types where existential types in arguments are approximated by their upper bound */
def argTypesHi(implicit ctx: Context) = argInfos mapConserve boundsToHi
/** The core type without any type arguments.
* @param `typeArgs` must be the type arguments of this type.
*/
final def withoutArgs(typeArgs: List[Type]): Type = self match {
case HKApply(tycon, args) => tycon
case _ =>
typeArgs match {
case _ :: typeArgs1 =>
val RefinedType(tycon, _, _) = self
tycon.withoutArgs(typeArgs1)
case nil =>
self
}
}
final def typeConstructor(implicit ctx: Context): Type = self.stripTypeVar match {
case AppliedType(tycon, _) => tycon
case self => self
}
/** If this is the image of a type argument; recover the type argument,
* otherwise NoType.
*/
final def argInfo(implicit ctx: Context): Type = self match {
case self: TypeAlias => self.alias
case self: TypeBounds => self
case _ => NoType
}
/** If this is a type alias, its underlying type, otherwise the type itself */
def dropAlias(implicit ctx: Context): Type = self match {
case TypeAlias(alias) => alias
case _ => self
}
/** The element type of a sequence or array */
def elemType(implicit ctx: Context): Type = self match {
case defn.ArrayOf(elemtp) => elemtp
case JavaArrayType(elemtp) => elemtp
case _ => firstBaseArgInfo(defn.SeqClass)
}
}
