Scala 3 support (#11)

Closes #2 ## Macros Just like @KuceraMartin in #3, I ran into scala/scala3#19493 and scala/scala3#19436 when trying to resolve a `TypeMapper` by importing from a `DialectTypeMappers`. As a workaround, I introduced [additional `implicit def`s in the `TableMapper` companion object](https://github.com/com-lihaoyi/scalasql/blob/a7d6c531bf7b9cc2f5e2c175906d2a1e961de206/scalasql/core/src/TypeMapper.scala#L58-L121) that instead rely on an implicit instance of `DialectTypeMappers`, i.e. in a macro: ```scala // bad, causes a compiler crash // TableMacro.scala (dialect: DialectTypeMappers) => { import dialect.* summonInline[TypeMapper[t]] } // good // TypeMapper.scala implicit def stringFromDialectTypeMappers(implicit d: DialectTypeMappers): TypeMapper[String] = d.StringType // TableMacro.scala (dialect: DialectTypeMappers) => { given d: DialectTypeMappers = dialect summonInline[TypeMapper[t]] } ``` ## Supporting changes In addition to building out the macros in Scala 3, the following changes were necessary: 1. Update the generated code to ensure `def`s aren't too far to the left -- this is to silence Scala 3 warnings 2. Convert `CharSequence`s to `String`s explicitly -- see the [error the Scala 3 compiler reported here](9ffeb06) 3. Remove `try` block without a corresponding `catch` -- see the [warning the Scala 3 compiler reported here](011c3f6) 4. Add types to implicit definitions 5. Mark `renderSql` as `private[scalasql]` instead of `protected` -- see the [error the Scala 3 compiler reported here](8e767e3) 6. Use Scala 3.4 -- this is a little unfortunate since it's not the LTS but it's necessary for the Scala 3 macros to [match on higher kinded types like this](https://github.com/com-lihaoyi/scalasql/blob/a7d6c531bf7b9cc2f5e2c175906d2a1e961de206/scalasql/query/src-3/TableMacro.scala#L48-L52). This type of match doesn't work in Scala 3.3 7. Replace `_` wildcards with `?` -- this is to silence Scala 3 warnings 8. Replace `Foo with Bar` in types with `Foo & Bar` -- this is to silence Scala 3 warnings 9. Add the `-Xsource:3` compiler option for Scala 2 -- this is necessary to use the language features mentioned in points 7 and 8 10. Add a number of type annotations to method overrides -- this is to silence warnings reported by the Scala 2 compiler as a result of enabling `-Xsource:3`. All of the warnings relate to the inferred type of the method changing between Scala 2 and 3
com-lihaoyi · May 25, 2024 · 7cbc5cc · 7cbc5cc
1 parent 7318f00
commit 7cbc5cc
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diff --git a/.scalafmt.conf b/.scalafmt.conf
@@ -1,4 +1,4 @@
-version = "3.7.15"
+version = "3.8.1"
 
 align.preset = none
 align.openParenCallSite = false
@@ -15,5 +15,10 @@ docstrings.wrap = no
 
 maxColumn = 100
 newlines.implicitParamListModifierPrefer = before
-runner.dialect = scala213
+runner.dialect = scala3
 
+fileOverride {
+  "glob:**/src-2/**" {
+    runner.dialect = scala213source3
+  }
+}
diff --git a/build.sc b/build.sc
@@ -1,12 +1,12 @@
 import $file.docs.generateDocs
 import $ivy.`de.tototec::de.tobiasroeser.mill.vcs.version::0.4.0`
 import $ivy.`com.github.lolgab::mill-mima::0.1.0`
-import $ivy.`com.goyeau::mill-scalafix::0.3.1`
+import $ivy.`com.goyeau::mill-scalafix::0.4.0`
 import de.tobiasroeser.mill.vcs.version.VcsVersion
 import com.goyeau.mill.scalafix.ScalafixModule
 import mill._, scalalib._, publish._
 
-val scalaVersions = Seq("2.13.12"/*, "3.3.1"*/)
+val scalaVersions = Seq("2.13.12", "3.4.2")
 
 trait Common extends CrossScalaModule with PublishModule with ScalafixModule{
   def scalaVersion = crossScalaVersion
@@ -27,12 +27,15 @@ trait Common extends CrossScalaModule with PublishModule with ScalafixModule{
     )
   )
 
-  def scalacOptions = Seq("-Xlint:unused")
+  def scalacOptions = T {
+    Seq("-Wunused:privates,locals,explicits,implicits,params") ++
+      Option.when(scalaVersion().startsWith("2."))("-Xsource:3")
+  }
 }
 
 
 object scalasql extends Cross[ScalaSql](scalaVersions)
-trait ScalaSql extends Common{
+trait ScalaSql extends Common{ common =>
   def moduleDeps = Seq(query, operations)
   def ivyDeps = Agg(
     ivy"org.apache.logging.log4j:log4j-api:2.20.0",
@@ -45,7 +48,7 @@ trait ScalaSql extends Common{
 
 
   object test extends ScalaTests with ScalafixModule{
-    def scalacOptions = Seq("-Xlint:unused")
+    def scalacOptions = common.scalacOptions
     def ivyDeps = Agg(
       ivy"com.github.vertical-blank:sql-formatter:2.0.4",
       ivy"com.lihaoyi::mainargs:0.4.0",
@@ -66,6 +69,9 @@ trait ScalaSql extends Common{
     def forkArgs = Seq("-Duser.timezone=Asia/Singapore")
   }
 
+  private def indent(code: Iterable[String]): String =
+    code.map(_.split("\n").map("  " + _).mkString("\n")).mkString("\n")
+
   object core extends Common with CrossValue {
     def ivyDeps = Agg(
       ivy"com.lihaoyi::geny:1.0.0",
@@ -100,7 +106,7 @@ trait ScalaSql extends Common{
         s"""package scalasql.core.generated
            |import scalasql.core.Queryable
            |trait QueryableRow{
-           |  ${queryableRowDefs.mkString("\n")}
+           |${indent(queryableRowDefs)}
            |}
            |""".stripMargin
       )
@@ -147,7 +153,6 @@ trait ScalaSql extends Common{
            |    implicit
            |    ${commaSep(j => s"q$j: Queryable.Row[Q$j, R$j]")}
            |): Queryable.Row[(${commaSep(j => s"Q$j")}), (${commaSep(j => s"R$j")})] = {
-           |  import scalasql.core.SqlStr.SqlStringSyntax
            |  new Queryable.Row.TupleNQueryable(
            |    Seq(${commaSep(j => s"q$j.walkLabels()")}),
            |    t => Seq(${commaSep(j => s"q$j.walkExprs(t._$j)")}),
@@ -166,7 +171,7 @@ trait ScalaSql extends Common{
         s"""
            |implicit def append$i[$commaSepQ, QA, $commaSepR, RA](
            |      implicit qr0: Queryable.Row[($commaSepQ, QA), ($commaSepR, RA)],
-           |      qr20: Queryable.Row[QA, RA]): $joinAppendType = new $joinAppendType {
+           |      @annotation.nowarn("msg=never used") qr20: Queryable.Row[QA, RA]): $joinAppendType = new $joinAppendType {
            |    override def appendTuple(t: ($commaSepQ), v: QA): ($commaSepQ, QA) = (${commaSep(j => s"t._$j")}, v)
            |
            |    def qr: Queryable.Row[($commaSepQ, QA), ($commaSepR, RA)] = qr0
@@ -179,23 +184,23 @@ trait ScalaSql extends Common{
            |import scalasql.core.{Queryable, Expr}
            |import scalasql.query.Column
            |trait Insert[V[_[_]], R]{
-           |  ${defs(false).mkString("\n")}
+           |${indent(defs(false))}
            |}
            |trait InsertImpl[V[_[_]], R] extends Insert[V, R]{ this: scalasql.query.Insert[V, R] =>
            |  def newInsertValues[R](
            |        insert: scalasql.query.Insert[V, R],
-           |        columns: Seq[Column[_]],
-           |        valuesLists: Seq[Seq[Expr[_]]]
+           |        columns: Seq[Column[?]],
+           |        valuesLists: Seq[Seq[Expr[?]]]
            |    )(implicit qr: Queryable[V[Column], R]): scalasql.query.InsertColumns[V, R]
-           |  ${defs(true).mkString("\n")}
+           |${indent(defs(true))}
            |}
            |
            |trait QueryableRow{
-           |  ${queryableRowDefs.mkString("\n")}
+           |${indent(queryableRowDefs)}
            |}
            |
            |trait JoinAppend extends scalasql.query.JoinAppendLowPriority{
-           |  ${joinAppendDefs.mkString("\n")}
+           |${indent(joinAppendDefs)}
            |}
            |""".stripMargin
       )

diff --git a/docs/reference.md b/docs/reference.md
@@ -440,7 +440,7 @@ dbClient.transaction { implicit db =>
   db.run(Purchase.delete(_.id <= 3)) ==> 3
   db.run(Purchase.select.size) ==> 4
 
-  db.savepoint { sp =>
+  db.savepoint { _ =>
     db.run(Purchase.delete(_ => true)) ==> 4
     db.run(Purchase.select.size) ==> 0
   }
@@ -499,7 +499,7 @@ dbClient.transaction { implicit db =>
   db.run(Purchase.select.size) ==> 4
 
   try {
-    db.savepoint { sp =>
+    db.savepoint { _ =>
       db.run(Purchase.delete(_ => true)) ==> 4
       db.run(Purchase.select.size) ==> 0
       throw new FooException
@@ -533,11 +533,11 @@ dbClient.transaction { implicit db =>
   db.run(Purchase.delete(_.id <= 2)) ==> 2
   db.run(Purchase.select.size) ==> 5
 
-  db.savepoint { sp1 =>
+  db.savepoint { _ =>
     db.run(Purchase.delete(_.id <= 4)) ==> 2
     db.run(Purchase.select.size) ==> 3
 
-    db.savepoint { sp2 =>
+    db.savepoint { _ =>
       db.run(Purchase.delete(_.id <= 6)) ==> 2
       db.run(Purchase.select.size) ==> 1
     }

diff --git a/scalasql/core/src/DbApi.scala b/scalasql/core/src/DbApi.scala
@@ -27,7 +27,7 @@ trait DbApi extends AutoCloseable {
    * Runs the given [[SqlStr]] of the form `sql"..."` and returns a value of type [[R]]
    */
   def runSql[R](query: SqlStr, fetchSize: Int = -1, queryTimeoutSeconds: Int = -1)(
-      implicit qr: Queryable.Row[_, R],
+      implicit qr: Queryable.Row[?, R],
       fileName: sourcecode.FileName,
       lineNum: sourcecode.Line
   ): IndexedSeq[R]
@@ -48,7 +48,7 @@ trait DbApi extends AutoCloseable {
    * arbitrary [[SqlStr]] of the form `sql"..."` and  streams the results back to you
    */
   def streamSql[R](sql: SqlStr, fetchSize: Int = -1, queryTimeoutSeconds: Int = -1)(
-      implicit qr: Queryable.Row[_, R],
+      implicit qr: Queryable.Row[?, R],
       fileName: sourcecode.FileName,
       lineNum: sourcecode.Line
   ): Generator[R]
@@ -63,7 +63,7 @@ trait DbApi extends AutoCloseable {
       fetchSize: Int = -1,
       queryTimeoutSeconds: Int = -1
   )(
-      implicit qr: Queryable.Row[_, R],
+      implicit qr: Queryable.Row[?, R],
       fileName: sourcecode.FileName,
       lineNum: sourcecode.Line
   ): IndexedSeq[R]
@@ -78,7 +78,7 @@ trait DbApi extends AutoCloseable {
       fetchSize: Int = -1,
       queryTimeoutSeconds: Int = -1
   )(
-      implicit qr: Queryable.Row[_, R],
+      implicit qr: Queryable.Row[?, R],
       fileName: sourcecode.FileName,
       lineNum: sourcecode.Line
   ): Generator[R]
@@ -104,7 +104,7 @@ trait DbApi extends AutoCloseable {
   )(implicit fileName: sourcecode.FileName, lineNum: sourcecode.Line): Int
 
   def updateGetGeneratedKeysSql[R](sql: SqlStr, fetchSize: Int = -1, queryTimeoutSeconds: Int = -1)(
-      implicit qr: Queryable.Row[_, R],
+      implicit qr: Queryable.Row[?, R],
       fileName: sourcecode.FileName,
       lineNum: sourcecode.Line
   ): IndexedSeq[R]
@@ -115,7 +115,7 @@ trait DbApi extends AutoCloseable {
       fetchSize: Int = -1,
       queryTimeoutSeconds: Int = -1
   )(
-      implicit qr: Queryable.Row[_, R],
+      implicit qr: Queryable.Row[?, R],
       fileName: sourcecode.FileName,
       lineNum: sourcecode.Line
   ): IndexedSeq[R]
@@ -202,22 +202,20 @@ object DbApi {
           .asInstanceOf[R]
       else if (qr.isExecuteUpdate(query)) updateSql(flattened).asInstanceOf[R]
       else {
-        try {
-          val res = stream(query, fetchSize, queryTimeoutSeconds)(
-            qr.asInstanceOf[Queryable[Q, Seq[_]]],
-            fileName,
-            lineNum
+        val res = stream(query, fetchSize, queryTimeoutSeconds)(
+          qr.asInstanceOf[Queryable[Q, Seq[?]]],
+          fileName,
+          lineNum
+        )
+        if (qr.isSingleRow(query)) {
+          val results = res.take(2).toVector
+          assert(
+            results.size == 1,
+            s"Single row query must return 1 result, not ${results.size}"
           )
-          if (qr.isSingleRow(query)) {
-            val results = res.take(2).toVector
-            assert(
-              results.size == 1,
-              s"Single row query must return 1 result, not ${results.size}"
-            )
-            results.head.asInstanceOf[R]
-          } else {
-            res.toVector.asInstanceOf[R]
-          }
+          results.head.asInstanceOf[R]
+        } else {
+          res.toVector.asInstanceOf[R]
         }
       }
     }
@@ -248,7 +246,7 @@ object DbApi {
         fetchSize: Int = -1,
         queryTimeoutSeconds: Int = -1
     )(
-        implicit qr: Queryable.Row[_, R],
+        implicit qr: Queryable.Row[?, R],
         fileName: sourcecode.FileName,
         lineNum: sourcecode.Line
     ): IndexedSeq[R] = streamSql(sql, fetchSize, queryTimeoutSeconds).toVector
@@ -258,7 +256,7 @@ object DbApi {
         fetchSize: Int = -1,
         queryTimeoutSeconds: Int = -1
     )(
-        implicit qr: Queryable.Row[_, R],
+        implicit qr: Queryable.Row[?, R],
         fileName: sourcecode.FileName,
         lineNum: sourcecode.Line
     ): Generator[R] = {
@@ -292,7 +290,7 @@ object DbApi {
         fetchSize: Int = -1,
         queryTimeoutSeconds: Int = -1
     )(
-        implicit qr: Queryable.Row[_, R],
+        implicit qr: Queryable.Row[?, R],
         fileName: sourcecode.FileName,
         lineNum: sourcecode.Line
     ): IndexedSeq[R] = {
@@ -314,7 +312,7 @@ object DbApi {
         fetchSize: Int = -1,
         queryTimeoutSeconds: Int = -1
     )(
-        implicit qr: Queryable.Row[_, R],
+        implicit qr: Queryable.Row[?, R],
         fileName: sourcecode.FileName,
         lineNum: sourcecode.Line
     ): IndexedSeq[R] = {
@@ -327,7 +325,7 @@ object DbApi {
         fetchSize: Int = -1,
         queryTimeoutSeconds: Int = -1
     )(
-        implicit qr: Queryable.Row[_, R],
+        implicit qr: Queryable.Row[?, R],
         fileName: sourcecode.FileName,
         lineNum: sourcecode.Line
     ): Generator[R] = {
@@ -362,7 +360,7 @@ object DbApi {
         fetchSize: Int = -1,
         queryTimeoutSeconds: Int = -1
     )(
-        implicit qr: Queryable.Row[_, R],
+        implicit qr: Queryable.Row[?, R],
         fileName: sourcecode.FileName,
         lineNum: sourcecode.Line
     ): IndexedSeq[R] = runRawUpdateGetGeneratedKeys0(
@@ -466,7 +464,7 @@ object DbApi {
         queryTimeoutSeconds: Int,
         fileName: sourcecode.FileName,
         lineNum: sourcecode.Line,
-        qr: Queryable.Row[_, R]
+        qr: Queryable.Row[?, R]
     ): IndexedSeq[R] = {
       val statement = connection.prepareStatement(sql, java.sql.Statement.RETURN_GENERATED_KEYS)
       for ((v, i) <- variables.iterator.zipWithIndex) v(statement, i + 1)

diff --git a/scalasql/core/src/Expr.scala b/scalasql/core/src/Expr.scala
@@ -7,7 +7,7 @@ import scalasql.core.SqlStr.SqlStringSyntax
  * a Scala value of a particular type [[T]]
  */
 trait Expr[T] extends SqlStr.Renderable {
-  protected final def renderSql(ctx: Context): SqlStr = {
+  private[scalasql] final def renderSql(ctx: Context): SqlStr = {
     ctx.exprNaming.get(this.exprIdentity).getOrElse(renderToSql0(ctx))
   }
 
@@ -37,15 +37,15 @@ object Expr {
   def identity[T](e: Expr[T]): Identity = e.exprIdentity
   class Identity()
 
-  implicit def ExprQueryable[E[_] <: Expr[_], T](
+  implicit def ExprQueryable[E[_] <: Expr[?], T](
       implicit mt: TypeMapper[T]
   ): Queryable.Row[E[T], T] = new ExprQueryable[E, T]()
 
-  class ExprQueryable[E[_] <: Expr[_], T](
+  class ExprQueryable[E[_] <: Expr[?], T](
       implicit tm: TypeMapper[T]
   ) extends Queryable.Row[E[T], T] {
-    def walkLabels() = Seq(Nil)
-    def walkExprs(q: E[T]) = Seq(q)
+    def walkLabels(): Seq[List[String]] = Seq(Nil)
+    def walkExprs(q: E[T]): Seq[Expr[?]] = Seq(q)
 
     override def construct(args: Queryable.ResultSetIterator): T = args.get(tm)
 

diff --git a/scalasql/core/src/ExprsToSql.scala b/scalasql/core/src/ExprsToSql.scala
@@ -39,7 +39,7 @@ object ExprsToSql {
     }
   }
 
-  def booleanExprs(prefix: SqlStr, exprs: Seq[Expr[_]])(implicit ctx: Context) = {
+  def booleanExprs(prefix: SqlStr, exprs: Seq[Expr[?]])(implicit ctx: Context) = {
     SqlStr.optSeq(exprs.filter(!Expr.isLiteralTrue(_))) { having =>
       prefix + SqlStr.join(having.map(Renderable.renderSql(_)), sql" AND ")
     }

diff --git a/scalasql/core/src/JoinNullable.scala b/scalasql/core/src/JoinNullable.scala
@@ -8,8 +8,8 @@ import scalasql.core.SqlStr.SqlStringSyntax
  */
 trait JoinNullable[Q] {
   def get: Q
-  def isEmpty[T](f: Q => Expr[T])(implicit qr: Queryable[Q, _]): Expr[Boolean]
-  def nonEmpty[T](f: Q => Expr[T])(implicit qr: Queryable[Q, _]): Expr[Boolean]
+  def isEmpty[T](f: Q => Expr[T])(implicit qr: Queryable[Q, ?]): Expr[Boolean]
+  def nonEmpty[T](f: Q => Expr[T])(implicit qr: Queryable[Q, ?]): Expr[Boolean]
   def map[V](f: Q => V): JoinNullable[V]
 
 }
@@ -19,11 +19,11 @@ object JoinNullable {
 
   def apply[Q](t: Q): JoinNullable[Q] = new JoinNullable[Q] {
     def get: Q = t
-    def isEmpty[T](f: Q => Expr[T])(implicit qr: Queryable[Q, _]): Expr[Boolean] = Expr {
+    def isEmpty[T](f: Q => Expr[T])(implicit qr: Queryable[Q, ?]): Expr[Boolean] = Expr {
       implicit ctx =>
         sql"(${f(t)} IS NULL)"
     }
-    def nonEmpty[T](f: Q => Expr[T])(implicit qr: Queryable[Q, _]): Expr[Boolean] = Expr {
+    def nonEmpty[T](f: Q => Expr[T])(implicit qr: Queryable[Q, ?]): Expr[Boolean] = Expr {
       implicit ctx =>
         sql"(${f(t)} IS NOT NULL)"
     }