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package dotty.tools.dotc.core
import Types._, Symbols._, Contexts._, Names._
/** Substitution operations on types. See the corresponding `subst` and
* `substThis` methods on class Type for an explanation.
*/
trait Substituters { this: Context =>
final def subst(tp: Type, from: BindingType, to: BindingType, theMap: SubstBindingMap): Type =
tp match {
case tp: BoundType =>
if (tp.binder eq from) tp.copyBoundType(to.asInstanceOf[tp.BT]) else tp
case tp: NamedType =>
if (tp.currentSymbol.isStatic) tp
else tp.derivedSelect(subst(tp.prefix, from, to, theMap))
case _: ThisType | NoPrefix =>
tp
case tp: RefinedType =>
tp.derivedRefinedType(subst(tp.parent, from, to, theMap), tp.refinedName, subst(tp.refinedInfo, from, to, theMap))
case tp: TypeAlias =>
tp.derivedTypeAlias(subst(tp.alias, from, to, theMap))
case _ =>
(if (theMap != null) theMap else new SubstBindingMap(from, to))
.mapOver(tp)
}
final def subst1(tp: Type, from: Symbol, to: Type, theMap: Subst1Map): Type = {
tp match {
case tp: NamedType =>
val sym = tp.symbol
if (sym eq from) return to
if (sym.isStatic && !from.isStatic) tp
else tp.derivedSelect(subst1(tp.prefix, from, to, theMap))
case _: ThisType | _: BoundType | NoPrefix =>
tp
case tp: RefinedType =>
tp.derivedRefinedType(subst1(tp.parent, from, to, theMap), tp.refinedName, subst1(tp.refinedInfo, from, to, theMap))
case tp: TypeAlias =>
tp.derivedTypeAlias(subst1(tp.alias, from, to, theMap))
case _ =>
(if (theMap != null) theMap else new Subst1Map(from, to))
.mapOver(tp)
}
}
final def subst2(tp: Type, from1: Symbol, to1: Type, from2: Symbol, to2: Type, theMap: Subst2Map): Type = {
tp match {
case tp: NamedType =>
val sym = tp.symbol
if (sym eq from1) return to1
if (sym eq from2) return to2
if (sym.isStatic && !from1.isStatic && !from2.isStatic) tp
else tp.derivedSelect(subst2(tp.prefix, from1, to1, from2, to2, theMap))
case _: ThisType | _: BoundType | NoPrefix =>
tp
case tp: RefinedType =>
tp.derivedRefinedType(subst2(tp.parent, from1, to1, from2, to2, theMap), tp.refinedName, subst2(tp.refinedInfo, from1, to1, from2, to2, theMap))
case tp: TypeAlias =>
tp.derivedTypeAlias(subst2(tp.alias, from1, to1, from2, to2, theMap))
case _ =>
(if (theMap != null) theMap else new Subst2Map(from1, to1, from2, to2))
.mapOver(tp)
}
}
final def subst(tp: Type, from: List[Symbol], to: List[Type], theMap: SubstMap): Type = {
tp match {
case tp: NamedType =>
val sym = tp.symbol
var fs = from
var ts = to
while (fs.nonEmpty) {
if (fs.head eq sym) return ts.head
fs = fs.tail
ts = ts.tail
}
if (sym.isStatic && !existsStatic(from)) tp
else tp.derivedSelect(subst(tp.prefix, from, to, theMap))
case _: ThisType | _: BoundType | NoPrefix =>
tp
case tp: RefinedType =>
tp.derivedRefinedType(subst(tp.parent, from, to, theMap), tp.refinedName, subst(tp.refinedInfo, from, to, theMap))
case tp: TypeAlias =>
tp.derivedTypeAlias(subst(tp.alias, from, to, theMap))
case _ =>
(if (theMap != null) theMap else new SubstMap(from, to))
.mapOver(tp)
}
}
final def substDealias(tp: Type, from: List[Symbol], to: List[Type], theMap: SubstDealiasMap): Type = {
tp match {
case tp: NamedType =>
val sym = tp.symbol
var fs = from
var ts = to
while (fs.nonEmpty) {
if (fs.head eq sym) return ts.head
fs = fs.tail
ts = ts.tail
}
if (sym.isStatic && !existsStatic(from)) tp
else {
tp.info match {
case TypeAlias(alias) =>
val alias1 = substDealias(alias, from, to, theMap)
if (alias1 ne alias) return alias1
case _ =>
}
tp.derivedSelect(substDealias(tp.prefix, from, to, theMap))
}
case _: ThisType | _: BoundType | NoPrefix =>
tp
case tp: RefinedType =>
tp.derivedRefinedType(substDealias(tp.parent, from, to, theMap), tp.refinedName, substDealias(tp.refinedInfo, from, to, theMap))
case tp: TypeAlias =>
tp.derivedTypeAlias(substDealias(tp.alias, from, to, theMap))
case _ =>
(if (theMap != null) theMap else new SubstDealiasMap(from, to))
.mapOver(tp)
}
}
final def substSym(tp: Type, from: List[Symbol], to: List[Symbol], theMap: SubstSymMap): Type =
tp match {
case tp: NamedType =>
val sym = tp.symbol
var fs = from
var ts = to
while (fs.nonEmpty) {
if (fs.head eq sym)
return tp match {
case tp: WithFixedSym => NamedType.withFixedSym(tp.prefix, ts.head)
case _ => substSym(tp.prefix, from, to, theMap) select ts.head
}
fs = fs.tail
ts = ts.tail
}
if (sym.isStatic && !existsStatic(from)) tp
else tp.derivedSelect(substSym(tp.prefix, from, to, theMap))
case tp: ThisType =>
val sym = tp.cls
var fs = from
var ts = to
while (fs.nonEmpty) {
if (fs.head eq sym) return ts.head.asClass.thisType
fs = fs.tail
ts = ts.tail
}
tp
case _: ThisType | _: BoundType | NoPrefix =>
tp
case tp: RefinedType =>
tp.derivedRefinedType(substSym(tp.parent, from, to, theMap), tp.refinedName, substSym(tp.refinedInfo, from, to, theMap))
case tp: TypeAlias =>
tp.derivedTypeAlias(substSym(tp.alias, from, to, theMap))
case _ =>
(if (theMap != null) theMap else new SubstSymMap(from, to))
.mapOver(tp)
}
final def substThis(tp: Type, from: ClassSymbol, to: Type, theMap: SubstThisMap): Type =
tp match {
case tp: ThisType =>
if (tp.cls eq from) to else tp
case tp: NamedType =>
if (tp.currentSymbol.isStaticOwner) tp
else tp.derivedSelect(substThis(tp.prefix, from, to, theMap))
case _: BoundType | NoPrefix =>
tp
case tp: RefinedType =>
tp.derivedRefinedType(substThis(tp.parent, from, to, theMap), tp.refinedName, substThis(tp.refinedInfo, from, to, theMap))
case tp: TypeAlias =>
tp.derivedTypeAlias(substThis(tp.alias, from, to, theMap))
case _ =>
(if (theMap != null) theMap else new SubstThisMap(from, to))
.mapOver(tp)
}
final def substRecThis(tp: Type, from: Type, to: Type, theMap: SubstRecThisMap): Type =
tp match {
case tp @ RecThis(binder) =>
if (binder eq from) to else tp
case tp: NamedType =>
if (tp.currentSymbol.isStatic) tp
else tp.derivedSelect(substRecThis(tp.prefix, from, to, theMap))
case _: ThisType | _: BoundType | NoPrefix =>
tp
case tp: RefinedType =>
tp.derivedRefinedType(substRecThis(tp.parent, from, to, theMap), tp.refinedName, substRecThis(tp.refinedInfo, from, to, theMap))
case tp: TypeAlias =>
tp.derivedTypeAlias(substRecThis(tp.alias, from, to, theMap))
case _ =>
(if (theMap != null) theMap else new SubstRecThisMap(from, to))
.mapOver(tp)
}
final def substParam(tp: Type, from: ParamRef, to: Type, theMap: SubstParamMap): Type =
tp match {
case tp: BoundType =>
if (tp == from) to else tp
case tp: NamedType =>
if (tp.currentSymbol.isStatic) tp
else tp.derivedSelect(substParam(tp.prefix, from, to, theMap))
case _: ThisType | NoPrefix =>
tp
case tp: RefinedType =>
tp.derivedRefinedType(substParam(tp.parent, from, to, theMap), tp.refinedName, substParam(tp.refinedInfo, from, to, theMap))
case tp: TypeAlias =>
tp.derivedTypeAlias(substParam(tp.alias, from, to, theMap))
case _ =>
(if (theMap != null) theMap else new SubstParamMap(from, to))
.mapOver(tp)
}
final def substParams(tp: Type, from: BindingType, to: List[Type], theMap: SubstParamsMap): Type =
tp match {
case tp: ParamRef =>
if (tp.binder == from) to(tp.paramNum) else tp
case tp: NamedType =>
if (tp.currentSymbol.isStatic) tp
else tp.derivedSelect(substParams(tp.prefix, from, to, theMap))
case _: ThisType | NoPrefix =>
tp
case tp: RefinedType =>
tp.derivedRefinedType(substParams(tp.parent, from, to, theMap), tp.refinedName, substParams(tp.refinedInfo, from, to, theMap))
case tp: TypeAlias =>
tp.derivedTypeAlias(substParams(tp.alias, from, to, theMap))
case _ =>
(if (theMap != null) theMap else new SubstParamsMap(from, to))
.mapOver(tp)
}
private def existsStatic(syms: List[Symbol]): Boolean = syms match {
case sym :: syms1 => sym.isStatic || existsStatic(syms1)
case nil => false
}
final class SubstBindingMap(from: BindingType, to: BindingType) extends DeepTypeMap {
def apply(tp: Type) = subst(tp, from, to, this)
}
final class Subst1Map(from: Symbol, to: Type) extends DeepTypeMap {
def apply(tp: Type) = subst1(tp, from, to, this)
}
final class Subst2Map(from1: Symbol, to1: Type, from2: Symbol, to2: Type) extends DeepTypeMap {
def apply(tp: Type) = subst2(tp, from1, to1, from2, to2, this)
}
final class SubstMap(from: List[Symbol], to: List[Type]) extends DeepTypeMap {
def apply(tp: Type): Type = subst(tp, from, to, this)
}
final class SubstDealiasMap(from: List[Symbol], to: List[Type]) extends DeepTypeMap {
override def apply(tp: Type): Type = substDealias(tp, from, to, this)
}
final class SubstSymMap(from: List[Symbol], to: List[Symbol]) extends DeepTypeMap {
def apply(tp: Type): Type = substSym(tp, from, to, this)
}
final class SubstThisMap(from: ClassSymbol, to: Type) extends DeepTypeMap {
def apply(tp: Type): Type = substThis(tp, from, to, this)
}
final class SubstRecThisMap(from: Type, to: Type) extends DeepTypeMap {
def apply(tp: Type): Type = substRecThis(tp, from, to, this)
}
final class SubstParamMap(from: ParamRef, to: Type) extends DeepTypeMap {
def apply(tp: Type) = substParam(tp, from, to, this)
}
final class SubstParamsMap(from: BindingType, to: List[Type]) extends DeepTypeMap {
def apply(tp: Type) = substParams(tp, from, to, this)
}
/** A map for "cycle safe substitutions" which do not force the denotation
* of a TypeRef unless the name matches up with one of the substituted symbols.
*/
final class SafeSubstMap(from: List[Symbol], to: List[Type]) extends TypeMap {
def apply(tp: Type): Type = tp match {
case tp: NamedType =>
try {
var sym: Symbol = null
var fs = from
var ts = to
while (fs.nonEmpty) {
if (fs.head.name == tp.name) {
if (sym == null) sym = tp.symbol
if (fs.head eq sym) return ts.head
}
fs = fs.tail
ts = ts.tail
}
tp.newLikeThis(apply(tp.prefix))
}
catch {
case ex: CyclicReference => tp.derivedSelect(apply(tp.prefix))
}
case _ => mapOver(tp)
}
}
}
|
