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author | Jason Zaugg <jzaugg@gmail.com> | 2013-05-15 07:33:16 -0700 |
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committer | Jason Zaugg <jzaugg@gmail.com> | 2013-05-15 07:33:16 -0700 |
commit | 44ad31761a31457f863976f748aa688da5c334c9 (patch) | |
tree | 089f22b51c4592a2c03f3fc736cbb51bc1b7cb48 /test/files/neg | |
parent | c587bdf0db0dc88c8e6cc6db109a7fd4a368e8f1 (diff) | |
parent | 966f51c9cb23c788f22dc0b71a534508e3eed4e3 (diff) | |
download | scala-44ad31761a31457f863976f748aa688da5c334c9.tar.gz scala-44ad31761a31457f863976f748aa688da5c334c9.tar.bz2 scala-44ad31761a31457f863976f748aa688da5c334c9.zip |
Merge pull request #2514 from scalamacros/topic/5923-master
makes sense of implicit macros! now in master
Diffstat (limited to 'test/files/neg')
3 files changed, 30 insertions, 0 deletions
diff --git a/test/files/neg/macro-divergence-controlled.check b/test/files/neg/macro-divergence-controlled.check new file mode 100644 index 0000000000..4876f7cf96 --- /dev/null +++ b/test/files/neg/macro-divergence-controlled.check @@ -0,0 +1,4 @@ +Test_2.scala:2: error: could not find implicit value for parameter e: Complex[Foo] + println(implicitly[Complex[Foo]]) + ^ +one error found diff --git a/test/files/neg/macro-divergence-controlled/Impls_Macros_1.scala b/test/files/neg/macro-divergence-controlled/Impls_Macros_1.scala new file mode 100644 index 0000000000..59acaede65 --- /dev/null +++ b/test/files/neg/macro-divergence-controlled/Impls_Macros_1.scala @@ -0,0 +1,23 @@ +import scala.reflect.macros.Context +import language.experimental.macros + +trait Complex[T] + +class Foo(val foo: Foo) + +object Complex { + def impl[T: c.WeakTypeTag](c: Context): c.Expr[Complex[T]] = { + import c.universe._ + val tpe = weakTypeOf[T] + for (f <- tpe.declarations.collect{case f: TermSymbol if f.isParamAccessor && !f.isMethod => f}) { + val trecur = appliedType(typeOf[Complex[_]], List(f.typeSignature)) + if (c.openImplicits.tail.exists(ic => ic.pt =:= trecur)) c.abort(c.enclosingPosition, "diverging implicit expansion. reported by a macro!") + val recur = c.inferImplicitValue(trecur, silent = true) + if (recur == EmptyTree) c.abort(c.enclosingPosition, s"couldn't synthesize $trecur") + } + c.literalNull + } + + implicit object ComplexString extends Complex[String] + implicit def genComplex[T]: Complex[T] = macro impl[T] +} diff --git a/test/files/neg/macro-divergence-controlled/Test_2.scala b/test/files/neg/macro-divergence-controlled/Test_2.scala new file mode 100644 index 0000000000..dcc4593335 --- /dev/null +++ b/test/files/neg/macro-divergence-controlled/Test_2.scala @@ -0,0 +1,3 @@ +object Test extends App { + println(implicitly[Complex[Foo]]) +}
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