Decode arbitrary arity tuple

zio · Apr 15, 2024 · 3193853 · 3193853
1 parent 420e2c6
commit 3193853
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diff --git a/quill-sql/src/main/scala/io/getquill/generic/GenericDecoder.scala b/quill-sql/src/main/scala/io/getquill/generic/GenericDecoder.scala
@@ -192,6 +192,11 @@ object GenericDecoder {
     TypeRepr.of[T] <:< TypeRepr.of[Option[Any]]
   }
 
+  private def isTuple[T: Type](using Quotes) = {
+    import quotes.reflect._
+    TypeRepr.of[T] <:< TypeRepr.of[Tuple]
+  }
+
   private def isBuiltInType[T: Type](using Quotes) = {
     import quotes.reflect._
     isOption[T] || (TypeRepr.of[T] <:< TypeRepr.of[Seq[_]])
@@ -207,6 +212,22 @@ object GenericDecoder {
         case '[Option[tpe]] =>
           decodeOptional[tpe, ResultRow, Session](index, baseIndex, resultRow, session)
       }
+    } else if (isTuple[T]) {
+      val decoderIndex = overriddenIndex.getOrElse(elementIndex)
+      Type.of[T] match {
+        case '[EmptyTuple] =>
+          FlattenData(Type.of[T], '{ EmptyTuple }, '{false}, index)
+        case '[h *: t] =>
+          val FlattenData(htpe, hvalue, hnullCheck, headIndex) = decode[h, ResultRow, Session](    index, baseIndex, resultRow, session, overriddenIndex)
+          val nextIndex = headIndex + 1
+          val FlattenData(ttpe, tvalue, tnullCheck, lastIndex) = decode[t, ResultRow, Session](nextIndex, baseIndex, resultRow, session, overriddenIndex)
+          val hhvalue = hvalue.asExprOf[h]
+          val ttvalue = tvalue.asExprOf[t]
+          // TODO speedup construction via ConstructDecoded
+          // val m = Expr.summon[Mirror.ProductOf[T]]
+          // ConstructDecoded(types, terms, m)
+          FlattenData(Type.of[h *: t], '{$hhvalue *: $ttvalue}, '{$hnullCheck || $tnullCheck}, lastIndex)
+      }
     } else {
       // specifically if there is a decoder found, allow optional override of the index via a resolver
       val decoderIndex = overriddenIndex.getOrElse(elementIndex)

diff --git a/quill-sql/src/test/scala/io/getquill/ArbitraryTupleSpec.scala b/quill-sql/src/test/scala/io/getquill/ArbitraryTupleSpec.scala
@@ -0,0 +1,36 @@
+package io.getquill
+
+import io.getquill.context.mirror.{MirrorSession, Row}
+import io.getquill.generic.TupleMember
+
+class ArbitraryTupleSpec extends Spec {
+
+  val ctx = new MirrorContext(PostgresDialect, Literal)
+  import ctx._
+
+  type MyRow1 = (Int, String)
+  type MyRow2 = Int *: String *: EmptyTuple
+
+  "ordinary tuple" in {
+    inline def q = quote{
+      querySchema[MyRow1]("my_table", t => t._1 -> "int_field", t => t._2 -> "string_field")
+    }
+
+    val result = ctx.run(q)
+
+    result.extractor(Row(123, "St"), MirrorSession.default) mustEqual
+      (123, "St")
+  }
+
+  "arbitrary long tuple" in {
+    inline def q = quote{
+      querySchema[MyRow2]("my_table", t => t._1 -> "int_field", t => t._2 -> "string_field")
+    }
+
+    val result = ctx.run(q)
+
+    result.extractor(Row(123, "St"), MirrorSession.default) mustEqual
+      (123, "St")
+  }
+
+}