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Diffstat (limited to 'core/src/main/scala/magnolia.scala')
| -rw-r--r-- | core/src/main/scala/magnolia.scala | 22 |
1 files changed, 10 insertions, 12 deletions
diff --git a/core/src/main/scala/magnolia.scala b/core/src/main/scala/magnolia.scala index 27172d3..66d59d0 100644 --- a/core/src/main/scala/magnolia.scala +++ b/core/src/main/scala/magnolia.scala @@ -161,18 +161,6 @@ class Macros(val c: whitebox.Context) { val reduction = components.reduce { (left, right) => q"$impl.combine($left, $right)" } q"$impl.call($reduction, sourceParameter)" - case ContravariantDerivation1Implicit(impl) => - val parts = subtypes.tail.zip(components.tail) - val base = q""" - $impl.call(${components.head}, sourceParameter.asInstanceOf[${subtypes.head}]) - """ - parts.foldLeft(base) { case (aggregated, (componentType, derivedImplicit)) => - q""" - if(sourceParameter.isInstanceOf[$componentType]) - $impl.call($derivedImplicit, sourceParameter.asInstanceOf[$componentType]) - else $aggregated""" - } - case ContravariantDerivation2Implicit(impl) => val parts = subtypes.tail.zip(components.tail) val base = q""" @@ -184,6 +172,16 @@ class Macros(val c: whitebox.Context) { $impl.call($derivedImplicit, sourceParameter1.asInstanceOf[$componentType], sourceParameter2.asInstanceOf[$componentType]) else $aggregated""" } + case ContravariantDerivation1Implicit(impl) => + val parts = subtypes.zip(components) + + val caseClauses = parts.map { case (subtype, component) => + cq"(value: $subtype) => $impl.call($component, value)" + } + + q"""(sourceParameter: @_root_.scala.annotation.switch) match { + case ..$caseClauses + }""" } } } else None |