Add evidence of subtyping to Match visitor method

jeffmay · Feb 17, 2022 · 8dac009 · 8dac009
1 parent 80561fb
commit 8dac009
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Showing 4 changed files with 6 additions and 0 deletions.
diff --git a/core-v1/src/main/scala/algebra/Expr.scala b/core-v1/src/main/scala/algebra/Expr.scala
@@ -328,6 +328,7 @@ object Expr {
     def visitMatch[I, S, B : ExtractValue.AsBoolean, O](
       expr: Match[I, S, B, O, OP],
     )(implicit
+      ev: S <:< I,
       opO: OP[Option[O]],
     ): I ~:> Option[O]
 
@@ -514,6 +515,7 @@ object Expr {
     override def visitMatch[I, S, B : ExtractValue.AsBoolean, O](
       expr: Match[I, S, B, O, OP],
     )(implicit
+      ev: S <:< I,
       opO: OP[Option[O]],
     ): H[I, Option[O]] =
       proxy(underlying.visitMatch(expr))
@@ -1317,6 +1319,7 @@ object Expr {
     branches: IndexedSeq[MatchCase[I, _ <: S, B, O, OP]],
     override private[v1] val debugging: Debugging[Nothing, Nothing] = NoDebugging,
   )(implicit
+    ev: S <:< I,
     opO: OP[Option[O]],
   ) extends Expr[I, Option[O], OP]("matching") {
     override def visit[G[-_, +_]](v: Visitor[G, OP]): G[I, Option[O]] = v.visitMatch(this)

diff --git a/core-v1/src/main/scala/engine/ImmutableCachingEngine.scala b/core-v1/src/main/scala/engine/ImmutableCachingEngine.scala
@@ -382,6 +382,7 @@ object ImmutableCachingEngine {
     override def visitMatch[I, S, B : AsBoolean, O](
       expr: Expr.Match[I, S, B, O, OP],
     )(implicit
+      ev: S <:< I,
       opO: OP[Option[O]],
     ): I => CachedResult[Option[O]] = memoize(expr, _) { i =>
       val CachedResult(maybeMatch, cacheState) =

diff --git a/core-v1/src/main/scala/engine/SimpleEngine.scala b/core-v1/src/main/scala/engine/SimpleEngine.scala
@@ -206,6 +206,7 @@ object SimpleEngine {
     override def visitMatch[I, S, B : ExtractValue.AsBoolean, O](
       expr: Expr.Match[I, S, B, O, OP],
     )(implicit
+      ev: S <:< I,
       opO: OP[Option[O]],
     ): I => Option[O] = { i =>
       val maybeMatch = expr.branches.zipWithIndex.foldLeft(None: Option[(O, Int)]) {

diff --git a/core-v1/src/main/scala/engine/StandardEngine.scala b/core-v1/src/main/scala/engine/StandardEngine.scala
@@ -236,6 +236,7 @@ object StandardEngine {
     override def visitMatch[I, S, B : ExtractValue.AsBoolean, O](
       expr: Expr.Match[I, S, B, O, OP],
     )(implicit
+      ev: S <:< I,
       opO: OP[Option[O]],
     ): PO <:< I => ExprResult[PO, I, Option[O], OP] = ???