diff options
| -rw-r--r-- | src/dotty/tools/dotc/core/TypeOps.scala | 48 | ||||
| -rw-r--r-- | src/dotty/tools/dotc/core/Types.scala | 14 | ||||
| -rw-r--r-- | src/dotty/tools/dotc/typer/Inferencing.scala | 46 | ||||
| -rw-r--r-- | src/dotty/tools/dotc/typer/Typer.scala | 4 |
4 files changed, 39 insertions, 73 deletions
diff --git a/src/dotty/tools/dotc/core/TypeOps.scala b/src/dotty/tools/dotc/core/TypeOps.scala index 6070b4f49..272e93dd3 100644 --- a/src/dotty/tools/dotc/core/TypeOps.scala +++ b/src/dotty/tools/dotc/core/TypeOps.scala @@ -113,54 +113,6 @@ trait TypeOps { this: Context => } } - type VarianceMap = SimpleMap[TypeVar, Integer] - - /** Add occurrences of type variables in type `tp` to variance map `vmap` */ - final def addVariances(vmap: VarianceMap, tp: Type, variance: Int, include: TypeVar => Boolean, accu: VariancesAccumulator): VarianceMap = tp match { - case tp: TypeRef => - if (tp.symbol.isStatic) vmap - else { - val prefix = tp.prefix - val tp1 = tp.lookupRefined(prefix, tp.name) - addVariances(vmap, if (tp1.exists) tp1 else prefix, variance, include, accu) - } - case tp: TermRef => - if (tp.symbol.isStatic) vmap - else addVariances(vmap, tp.prefix, variance, include, accu) - - case _: ThisType - | _: BoundType - | NoPrefix => vmap - - case tp: RefinedType => - addVariances( - addVariances(vmap, tp.parent, variance, include, accu), - tp.refinedInfo, variance, include, accu) - - case bounds @ TypeBounds(lo, hi) if lo eq hi => - addVariances(vmap, lo, variance * bounds.variance, include, accu) - - case tp: TypeVar if !tp.isInstantiated && (typerState.constraint contains tp) && include(tp) => - val v = vmap(tp) - if (v == null) vmap.updated(tp, variance) - else if (v == variance) vmap - else vmap.updated(tp, 0) - - case _ => - (if (accu != null) accu else new VariancesAccumulator(include)).runOver(vmap, tp, variance) - } - - class VariancesAccumulator(include: TypeVar => Boolean) extends TypeAccumulator[VarianceMap] { - def apply(vmap: VarianceMap, tp: Type): VarianceMap = addVariances(vmap, tp, variance, include, this) - def runOver(vmap: VarianceMap, tp: Type, variance: Int): VarianceMap = { - val saved = this.variance - this.variance = variance - val result = foldOver(vmap, tp) - this.variance = saved - result - } - } - private def enterArgBinding(formal: Symbol, info: Type, cls: ClassSymbol, decls: Scope) = { val lazyInfo = new LazyType { // needed so we do not force `formal`. def complete(denot: SymDenotation)(implicit ctx: Context): Unit = { diff --git a/src/dotty/tools/dotc/core/Types.scala b/src/dotty/tools/dotc/core/Types.scala index 00d719acb..5c65b7ede 100644 --- a/src/dotty/tools/dotc/core/Types.scala +++ b/src/dotty/tools/dotc/core/Types.scala @@ -838,7 +838,19 @@ object Types { * 0 means: mixed or non-variant occurrences */ def variances(include: TypeVar => Boolean)(implicit ctx: Context): VarianceMap = track("variances") { - ctx.addVariances(SimpleMap.Empty, this, +1, include, null) + val accu = new TypeAccumulator[VarianceMap] { + def apply(vmap: VarianceMap, t: Type): VarianceMap = t match { + case t: TypeVar + if !t.isInstantiated && (ctx.typerState.constraint contains t) && include(t) => + val v = vmap(t) + if (v == null) vmap.updated(t, variance) + else if (v == variance) vmap + else vmap.updated(t, 0) + case _ => + foldOver(vmap, t) + } + } + accu(SimpleMap.Empty, this) } /** A simplified version of this type which is equivalent wrt =:= to this type. diff --git a/src/dotty/tools/dotc/typer/Inferencing.scala b/src/dotty/tools/dotc/typer/Inferencing.scala index 763904ac4..986ddf570 100644 --- a/src/dotty/tools/dotc/typer/Inferencing.scala +++ b/src/dotty/tools/dotc/typer/Inferencing.scala @@ -602,31 +602,33 @@ object Inferencing { * approximate it by its lower bound. Otherwise, if it appears contravariantly * in type `tp` approximate it by its upper bound. */ - def interpolateUndetVars(tree: Tree)(implicit ctx: Context): Unit = Stats.track("interpolateUndetVars") { - val tp = tree.tpe.widen + def interpolateUndetVars(tree: Tree)(implicit ctx: Context): Unit = { val constraint = ctx.typerState.constraint - - constr.println(s"interpolate undet vars in ${tp.show}, pos = ${tree.pos}, mode = ${ctx.mode}, undets = ${constraint.uninstVars map (tvar => s"${tvar.show}@${tvar.owningTree.pos}")}") - constr.println(s"qualifying undet vars: ${constraint.uninstVars filter qualifies map (tvar => s"$tvar / ${tvar.show}")}, constraint: ${constraint.show}") - - def qualifies(tvar: TypeVar) = tree contains tvar.owningTree - val vs = tp.variances(qualifies) - var changed = false - vs foreachBinding { (tvar, v) => - if (v != 0) { - typr.println(s"interpolate ${if (v == 1) "co" else "contra"}variant ${tvar.show} in ${tp.show}") - tvar.instantiate(fromBelow = v == 1) - changed = true + val qualifies = (tvar: TypeVar) => tree contains tvar.owningTree + def interpolate() = Stats.track("interpolateUndetVars") { + val tp = tree.tpe.widen + constr.println(s"interpolate undet vars in ${tp.show}, pos = ${tree.pos}, mode = ${ctx.mode}, undets = ${constraint.uninstVars map (tvar => s"${tvar.show}@${tvar.owningTree.pos}")}") + constr.println(s"qualifying undet vars: ${constraint.uninstVars filter qualifies map (tvar => s"$tvar / ${tvar.show}")}, constraint: ${constraint.show}") + + val vs = tp.variances(qualifies) + var changed = false + vs foreachBinding { (tvar, v) => + if (v != 0) { + typr.println(s"interpolate ${if (v == 1) "co" else "contra"}variant ${tvar.show} in ${tp.show}") + tvar.instantiate(fromBelow = v == 1) + changed = true + } } + if (changed) // instantiations might have uncovered new typevars to interpolate + interpolateUndetVars(tree) + else + for (tvar <- constraint.uninstVars) + if (!(vs contains tvar) && qualifies(tvar)) { + typr.println(s"instantiating non-occurring ${tvar.show} in ${tp.show}") + tvar.instantiate(fromBelow = true) + } } - if (changed) // instantiations might have uncovered new typevars to interpolate - interpolateUndetVars(tree) - else - for (tvar <- constraint.uninstVars) - if (!(vs contains tvar) && qualifies(tvar)) { - typr.println(s"instantiating non-occurring ${tvar.show} in ${tp.show}") - tvar.instantiate(fromBelow = true) - } + if (constraint.uninstVars exists qualifies) interpolate() } /** Instantiate undetermined type variables to that type `tp` is diff --git a/src/dotty/tools/dotc/typer/Typer.scala b/src/dotty/tools/dotc/typer/Typer.scala index 49792cb73..7e44f6a76 100644 --- a/src/dotty/tools/dotc/typer/Typer.scala +++ b/src/dotty/tools/dotc/typer/Typer.scala @@ -84,8 +84,8 @@ class Typer extends Namer with Applications with Implicits { /** The type of a selection with `name` of a tree with type `site`. */ def selectionType(site: Type, name: Name, pos: Position)(implicit ctx: Context): Type = { - val refDenot = site.member(name) - if (reallyExists(refDenot)) site.select(name, refDenot) + val mbr = site.member(name) + if (reallyExists(mbr)) site.select(name, mbr) else { if (!site.isErroneous) { typr.println(s"site = $site, baseClasses = ${site.baseClasses}") |