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author | Jason Zaugg <jzaugg@gmail.com> | 2012-09-08 18:37:59 +0200 |
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committer | Jason Zaugg <jzaugg@gmail.com> | 2012-09-08 18:47:49 +0200 |
commit | c619f94a9cfbddc12c9c5df3affb4636f8982a0a (patch) | |
tree | 8f0b988c9ab4cdb10723118453a4bda76d753457 /src/partest | |
parent | 5b9b394d99bd7e4446e0f15475b34ec287d91685 (diff) | |
download | scala-c619f94a9cfbddc12c9c5df3affb4636f8982a0a.tar.gz scala-c619f94a9cfbddc12c9c5df3affb4636f8982a0a.tar.bz2 scala-c619f94a9cfbddc12c9c5df3affb4636f8982a0a.zip |
SI-6331 Avoid typing an If tree with a constant type.
The fast path in typedIf added in 8552740b avoided lubbing the if/else branch types
if they are identical, but this fails to deconst the type. This could lead to the entire
if expression being replaced by a constant.
Also introduces a new tool in partest for nicer checkfiles.
// in Test.scala
trace(if (t) -0d else 0d)
// in Test.check
trace> if (Test.this.t)
-0.0
else
0.0
res: Double = -0.0
Diffstat (limited to 'src/partest')
-rw-r--r-- | src/partest/scala/tools/partest/package.scala | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/src/partest/scala/tools/partest/package.scala b/src/partest/scala/tools/partest/package.scala index 08934ef143..49d3ed301c 100644 --- a/src/partest/scala/tools/partest/package.scala +++ b/src/partest/scala/tools/partest/package.scala @@ -73,4 +73,31 @@ package object partest { def isPartestDebug: Boolean = propOrEmpty("partest.debug") == "true" + + + import language.experimental.macros + + /** + * `trace("".isEmpty)` will return `true` and as a side effect print the following to standard out. + * {{{ + * trace> "".isEmpty + * res: Boolean = true + * + * }}} + * + * An alternative to [[scala.tools.partest.ReplTest]] that avoids the inconvenience of embedding + * test code in a string. + */ + def trace[A](a: A) = macro traceImpl[A] + + import scala.reflect.macros.Context + def traceImpl[A: c.AbsTypeTag](c: Context)(a: c.Expr[A]): c.Expr[A] = { + import c.universe._ + val exprCode = c.literal(show(a.tree)) + val exprType = c.literal(show(a.actualType)) + reify { + println(s"trace> ${exprCode.splice}\nres: ${exprType.splice} = ${a.splice}\n") + a.splice + } + } } |