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author | Eugene Burmako <xeno.by@gmail.com> | 2013-01-07 07:42:38 +0300 |
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committer | Eugene Burmako <xeno.by@gmail.com> | 2013-01-09 08:10:46 +0100 |
commit | 66acf364ae3003dd1abb4eeb8759afc6e12aa1a1 (patch) | |
tree | 853fc3cf39bd34ec32887843fb98f05bad8f1fb7 /test | |
parent | d17e3fc29cd48a3d4cbbbfc1fc9eb021d787d4d7 (diff) | |
download | scala-66acf364ae3003dd1abb4eeb8759afc6e12aa1a1.tar.gz scala-66acf364ae3003dd1abb4eeb8759afc6e12aa1a1.tar.bz2 scala-66acf364ae3003dd1abb4eeb8759afc6e12aa1a1.zip |
SI-5903 extractor macros do work
Apparently it is already possible to use macros to customize pattern
matching as described in the comments to the aforementioned JIRA issue.
What's even better - with the incoming addition of c.introduceTopLevel
it becomes possible to generate arbitrarily complex unappliers, even
with heterogeneous types of arguments varying from expansion to expansion
Diffstat (limited to 'test')
-rw-r--r-- | test/files/run/macro-expand-unapply-a.check | 2 | ||||
-rw-r--r-- | test/files/run/macro-expand-unapply-a.flags | 1 | ||||
-rw-r--r-- | test/files/run/macro-expand-unapply-a/Impls_Macros_1.scala | 15 | ||||
-rw-r--r-- | test/files/run/macro-expand-unapply-a/Test_2.scala | 6 | ||||
-rw-r--r-- | test/files/run/macro-expand-unapply-b.check | 2 | ||||
-rw-r--r-- | test/files/run/macro-expand-unapply-b.flags | 1 | ||||
-rw-r--r-- | test/files/run/macro-expand-unapply-b/Impls_Macros_1.scala | 37 | ||||
-rw-r--r-- | test/files/run/macro-expand-unapply-b/Test_2.scala | 8 |
8 files changed, 72 insertions, 0 deletions
diff --git a/test/files/run/macro-expand-unapply-a.check b/test/files/run/macro-expand-unapply-a.check new file mode 100644 index 0000000000..7c2976e51e --- /dev/null +++ b/test/files/run/macro-expand-unapply-a.check @@ -0,0 +1,2 @@ +(1,2) +(1,2,3) diff --git a/test/files/run/macro-expand-unapply-a.flags b/test/files/run/macro-expand-unapply-a.flags new file mode 100644 index 0000000000..cd66464f2f --- /dev/null +++ b/test/files/run/macro-expand-unapply-a.flags @@ -0,0 +1 @@ +-language:experimental.macros
\ No newline at end of file diff --git a/test/files/run/macro-expand-unapply-a/Impls_Macros_1.scala b/test/files/run/macro-expand-unapply-a/Impls_Macros_1.scala new file mode 100644 index 0000000000..61d6345f16 --- /dev/null +++ b/test/files/run/macro-expand-unapply-a/Impls_Macros_1.scala @@ -0,0 +1,15 @@ +import scala.reflect.macros.Context + +object Helper { + def unapplySeq[T](x: List[T]): Option[Seq[T]] = List.unapplySeq[T](x) +} + +object Macros { + def impl[T: c.WeakTypeTag](c: Context)(x: c.Expr[List[T]]) = { + c.universe.reify(Helper.unapplySeq(x.splice)) + } + + object UnapplyMacro { + def unapplySeq[T](x: List[T]): Option[Seq[T]] = macro impl[T] + } +}
\ No newline at end of file diff --git a/test/files/run/macro-expand-unapply-a/Test_2.scala b/test/files/run/macro-expand-unapply-a/Test_2.scala new file mode 100644 index 0000000000..6169d86b19 --- /dev/null +++ b/test/files/run/macro-expand-unapply-a/Test_2.scala @@ -0,0 +1,6 @@ +import Macros._ + +object Test extends App { + List(1, 2) match { case UnapplyMacro(x, y) => println((x, y)) } + List(1, 2, 3) match { case UnapplyMacro(x, y, z) => println((x, y, z)) } +}
\ No newline at end of file diff --git a/test/files/run/macro-expand-unapply-b.check b/test/files/run/macro-expand-unapply-b.check new file mode 100644 index 0000000000..5272f0d00a --- /dev/null +++ b/test/files/run/macro-expand-unapply-b.check @@ -0,0 +1,2 @@ +(1,List(2)) +List(1) diff --git a/test/files/run/macro-expand-unapply-b.flags b/test/files/run/macro-expand-unapply-b.flags new file mode 100644 index 0000000000..cd66464f2f --- /dev/null +++ b/test/files/run/macro-expand-unapply-b.flags @@ -0,0 +1 @@ +-language:experimental.macros
\ No newline at end of file diff --git a/test/files/run/macro-expand-unapply-b/Impls_Macros_1.scala b/test/files/run/macro-expand-unapply-b/Impls_Macros_1.scala new file mode 100644 index 0000000000..d0300bdf7e --- /dev/null +++ b/test/files/run/macro-expand-unapply-b/Impls_Macros_1.scala @@ -0,0 +1,37 @@ +import language.experimental.macros +import scala.reflect.macros.Context + +object Macros { + implicit class ContextExtensions(c: StringContext) { + object q { + def unapply(x: Any): Option[Any] = macro impl + } + } + + def impl(c: Context)(x: c.Expr[Any]): c.Expr[Option[Any]] = { + import c.universe._ + import Flag._ + + // parts here will be string literals - static parts of the string interpolation + // e.g. for q"$x, $y" parts will be Literal(Constant("")), Literal(Constant(", ")) and Literal(Constant("")) + val Apply(Select(Select(Apply(_, List(Apply(_, parts))), _), _), _) = c.macroApplication + val nresults = parts.length - 1 + + def results() = + ((1 to (nresults - 1)).toList map (i => Literal(Constant(i)))) :+ // (n - 1) results of type Int + Apply(Ident(TermName("List")), List(Literal(Constant(nresults)))) // and also one result of a different type + def extractorBody() = + if (nresults == 0) Literal(Constant(true)) + else if (nresults == 1) Apply(Ident(TermName("Some")), results()) + else Apply(Ident(TermName("Some")), List(Apply(Ident(TermName("Tuple" + nresults)), results()))) + + val name = TermName(java.util.UUID.randomUUID().toString.replace("-", "")) + val mdef = ModuleDef(NoMods, name, Template(List(Select(Ident(TermName("scala")), TypeName("AnyRef"))), emptyValDef, List( + DefDef(Modifiers(), nme.CONSTRUCTOR, List(), List(List()), TypeTree(), + Block(List(pendingSuperCall), Literal(Constant(())))), + DefDef(Modifiers(), TermName("unapply"), List(), List(List(ValDef(Modifiers(PARAM), TermName("x"), Ident(TypeName("Any")), EmptyTree))), TypeTree(), + extractorBody())))) + c.introduceTopLevel(nme.EMPTY_PACKAGE_NAME.toString, mdef) + c.Expr[Option[Any]](Apply(Select(Ident(name), TermName("unapply")), List(x.tree))) + } +}
\ No newline at end of file diff --git a/test/files/run/macro-expand-unapply-b/Test_2.scala b/test/files/run/macro-expand-unapply-b/Test_2.scala new file mode 100644 index 0000000000..5352160dfe --- /dev/null +++ b/test/files/run/macro-expand-unapply-b/Test_2.scala @@ -0,0 +1,8 @@ +object Test extends App { + import Macros._ + def whatever() = null + val q"$x1, $y1" = whatever() + println(x1, y1) + val q"$x2" = whatever() + println(x2) +} |