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CanBuildFrom: Add support for Class and simple form for To (fix #135) #136

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Merged
merged 1 commit into from
Aug 6, 2018
Merged

CanBuildFrom: Add support for Class and simple form for To (fix #135) #136

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7 changes: 7 additions & 0 deletions scalafix/input/src/main/scala/fix/CanBuildFromSrc.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -33,4 +33,11 @@ object CanBuildFromSrc {
cbf2("")
()
}

def f2[T, That](implicit cbf: CanBuildFrom[Nothing, T, That]): Foo[T, That] =
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Previously it would only take CanBuildFrom[Nothing, A, CC[B]] now it accepts CanBuildFrom[Nothing, A, B], but it won't rewrite e.to[CC] => cbf.fromSpecific(e)

new Foo

class Foo[T, That](implicit cbf: CanBuildFrom[Nothing, T, That]) {
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We now support Classes and Def. I don't see another place where we could insert a CanBuildFrom. Maybe on a type alias (type Foo = CanBuildFrom[Bar, Buz, Qux])?

val b = cbf()
}
}
7 changes: 7 additions & 0 deletions scalafix/output/src/main/scala/fix/CanBuildFromSrc.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -33,4 +33,11 @@ object CanBuildFromSrc {
cbf2.newBuilder("")
()
}

def f2[T, That](implicit cbf: Factory[T, That]): Foo[T, That] =
new Foo

class Foo[T, That](implicit cbf: Factory[T, That]) {
val b = cbf.newBuilder
}
}
132 changes: 70 additions & 62 deletions scalafix/rules/src/main/scala/fix/CanBuildFrom.scala
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Expand Up @@ -8,19 +8,21 @@ import scala.collection.mutable

object CanBuildFrom {
def apply(paramss: List[List[Term.Param]],
body: Term,
stats: List[Tree],
ctx: RuleCtx,
collectionCanBuildFrom: SymbolMatcher,
nothing: SymbolMatcher)(implicit index: SemanticdbIndex): Patch = {
// CanBuildFrom has def apply() but not CanBuild
def emptyApply(param: Name): Boolean = {
import scala.meta.contrib._
val matchCbf = SymbolMatcher.exact(ctx.index.symbol(param).get)
body.exists {
case Term.Apply(Term.Select(matchCbf(_), _), Nil) => true
case Term.Apply(matchCbf(_), Nil) => true
case _ => false
}
stats.exists(
_.exists {
case Term.Apply(Term.Select(matchCbf(_), _), Nil) => true
case Term.Apply(matchCbf(_), Nil) => true
case _ => false
}
)
}

paramss.flatten
Expand All @@ -38,7 +40,7 @@ object CanBuildFrom {
) if !nothing.matches(p1) && !emptyApply(param) =>
new CanBuildFrom(param, cbf)
}
.map(_.toBuildFrom(body, ctx))
.map(_.toBuildFrom(stats, ctx))
.asPatch
}
}
Expand All @@ -48,7 +50,7 @@ object CanBuildFrom {
// param: cbf
// cbf : collection.generic.CanBuildFrom
case class CanBuildFrom(param: Name, cbf: Type) {
def toBuildFrom(body: Term, ctx: RuleCtx)(implicit index: SemanticdbIndex): Patch = {
def toBuildFrom(stats: List[Tree], ctx: RuleCtx)(implicit index: SemanticdbIndex): Patch = {

val matchCbf = SymbolMatcher.exact(ctx.index.symbol(param).get)

Expand All @@ -60,15 +62,17 @@ case class CanBuildFrom(param: Name, cbf: Type) {
)

val cbfCalls =
body.collect {
// cbf.apply(x)
case ap @ Term.Apply(sel @ Term.Select(cbf2 @ matchCbf(_), apply), List(x)) =>
replaceNewBuilder(ap, cbf2, x)

// cbf(x)
case ap @ Term.Apply(cbf2 @ matchCbf(_), List(x)) =>
replaceNewBuilder(ap, cbf2, x)
}.asPatch
stats
.map(_.collect {
// cbf.apply(x)
case ap @ Term.Apply(sel @ Term.Select(cbf2 @ matchCbf(_), apply), List(x)) =>
replaceNewBuilder(ap, cbf2, x)

// cbf(x)
case ap @ Term.Apply(cbf2 @ matchCbf(_), List(x)) =>
replaceNewBuilder(ap, cbf2, x)
}.asPatch)
.asPatch

val parameterType =
ctx.replaceTree(cbf, "BuildFrom")
Expand All @@ -79,12 +83,13 @@ case class CanBuildFrom(param: Name, cbf: Type) {

object CanBuildFromNothing {
def apply(paramss: List[List[Term.Param]],
body: Term,
stats: List[Tree],
ctx: RuleCtx,
collectionCanBuildFrom: SymbolMatcher,
nothing: SymbolMatcher,
toTpe: SymbolMatcher,
handledTo: mutable.Set[Tree])(implicit index: SemanticdbIndex): Patch = {

paramss.flatten
.collect {
case Term.Param(
Expand All @@ -96,16 +101,13 @@ object CanBuildFromNothing {
List(
nothing(_),
t,
cct @ Type.Apply(
cc,
_
)
toT
)
)
),
_
) =>
new CanBuildFromNothing(param, tpe, t, cct, cc, body, ctx, toTpe, handledTo)
new CanBuildFromNothing(param, tpe, t, toT, stats, ctx, toTpe, handledTo)
}
.map(_.toFactory)
.asPatch
Expand All @@ -119,14 +121,12 @@ object CanBuildFromNothing {
// tpe : collection.generic.CanBuildFrom[Nothing, Int, CC[Int]]
// cbf : CanBuildFrom
// v : Int
// cct : CC[Int]
// cc : CC
// toT : CC[Int]
case class CanBuildFromNothing(param: Name,
tpe: Type.Apply,
t: Type,
cct: Type.Apply,
cc: Type,
body: Term,
toT: Type,
stats: List[Tree],
ctx: RuleCtx,
toTpe: SymbolMatcher,
handledTo: mutable.Set[Tree]) {
Expand All @@ -141,53 +141,61 @@ case class CanBuildFromNothing(param: Name,
val visitedCbfCalls = mutable.Set[Tree]()

val cbfCalls =
body.collect {
// cbf.apply()
case ap @ Term.Apply(sel @ Term.Select(cbf2 @ matchCbf(_), apply), Nil) =>
visitedCbfCalls += sel
replaceNewBuilder(ap, cbf2)

// cbf.apply
case sel @ Term.Select(cbf2 @ matchCbf(_), ap) if (!visitedCbfCalls.contains(sel)) =>
replaceNewBuilder(sel, cbf2)

// cbf()
case ap @ Term.Apply(cbf2 @ matchCbf(_), Nil) =>
replaceNewBuilder(ap, cbf2)
}.asPatch

val matchCC = SymbolMatcher.exact(ctx.index.symbol(cc).get)
stats
.map(_.collect {
// cbf.apply()
case ap @ Term.Apply(sel @ Term.Select(cbf2 @ matchCbf(_), apply), Nil) =>
visitedCbfCalls += sel
replaceNewBuilder(ap, cbf2)

// cbf.apply
case sel @ Term.Select(cbf2 @ matchCbf(_), ap) if (!visitedCbfCalls.contains(sel)) =>
replaceNewBuilder(sel, cbf2)

// cbf()
case ap @ Term.Apply(cbf2 @ matchCbf(_), Nil) =>
replaceNewBuilder(ap, cbf2)
}.asPatch)
.asPatch

// e.to[CC] => cbf.fromSpecific(e)
val toCalls =
body.collect {
case ap @ Term.ApplyType(Term.Select(e, to @ toTpe(_)), List(cc2 @ matchCC(_))) =>
handledTo += to
val toCalls = toT match {
case cct @ Type.Apply(cc, _) => {
val matchCC = SymbolMatcher.exact(ctx.index.symbol(cc).get)

stats
.map(_.collect {
case ap @ Term.ApplyType(Term.Select(e, to @ toTpe(_)), List(cc2 @ matchCC(_))) =>
handledTo += to

// e.to[CC](*cbf*) extract implicit parameter
val synth = ctx.index.synthetics.find(_.position.end == ap.pos.end).get
val Term.Apply(_, List(implicitCbf)) = synth.text.parse[Term].get
// e.to[CC](*cbf*) extract implicit parameter
val synth = ctx.index.synthetics.find(_.position.end == ap.pos.end).get
val Term.Apply(_, List(implicitCbf)) = synth.text.parse[Term].get

// This is a bit unsafe
// https://github.com/scalameta/scalameta/issues/1636
if (implicitCbf.syntax == param.syntax) {
// This is a bit unsafe
// https://github.com/scalameta/scalameta/issues/1636
if (implicitCbf.syntax == param.syntax) {

// .to[CC]
val apToRemove = ap.tokens.slice(e.tokens.end - ap.tokens.start, ap.tokens.size)
// .to[CC]
val apToRemove = ap.tokens.slice(e.tokens.end - ap.tokens.start, ap.tokens.size)

ctx.removeTokens(apToRemove) +
ctx.addLeft(e, implicitCbf.syntax + ".fromSpecific(") +
ctx.addRight(e, ")")
} else Patch.empty
ctx.removeTokens(apToRemove) +
ctx.addLeft(e, implicitCbf.syntax + ".fromSpecific(") +
ctx.addRight(e, ")")
} else Patch.empty

}.asPatch
}.asPatch)
.asPatch
}
case _ => Patch.empty
}

// implicit cbf: collection.generic.CanBuildFrom[Nothing, Int, CC[Int]] =>
// implicit cbf: Factory[Int, CC[Int]]
val parameterType =
ctx.replaceTree(
tpe,
Type.Apply(Type.Name("Factory"), List(t, cct)).syntax
Type.Apply(Type.Name("Factory"), List(t, toT)).syntax
)

parameterType + cbfCalls + toCalls
Expand Down
19 changes: 17 additions & 2 deletions scalafix/rules/src/main/scala/fix/Stable212Base.scala
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Expand Up @@ -234,8 +234,23 @@ trait Stable212Base extends CrossCompatibility { self: SemanticRule =>
val useSites =
ctx.tree.collect {
case Defn.Def(_, _, _, paramss, _, body) =>
CanBuildFromNothing(paramss, body, ctx, collectionCanBuildFrom, nothing, toTpe, handledTo) +
CanBuildFrom(paramss, body, ctx, collectionCanBuildFrom, nothing)
CanBuildFromNothing(paramss,
List(body),
ctx,
collectionCanBuildFrom,
nothing,
toTpe,
handledTo) +
CanBuildFrom(paramss, List(body), ctx, collectionCanBuildFrom, nothing)
case Defn.Class(_, _, _, Ctor.Primary(_, _, paramss), Template(_, _, _, stats)) =>
CanBuildFromNothing(paramss,
stats,
ctx,
collectionCanBuildFrom,
nothing,
toTpe,
handledTo) +
CanBuildFrom(paramss, stats, ctx, collectionCanBuildFrom, nothing)
}.asPatch

val imports =
Expand Down