|
| 1 | +import scala.util.parsing.combinator._ |
| 2 | +import scala.util.DynamicVariable |
| 3 | + |
| 4 | +import org.junit.Test |
| 5 | + |
| 6 | +class t9010 { |
| 7 | + @Test |
| 8 | + def test: Unit = { |
| 9 | + val p = new grammar |
| 10 | + val lastNoSuccessVar = getLastNoSuccessVar(p) |
| 11 | + import p._ |
| 12 | + |
| 13 | + val res1 = parse(x, "x") |
| 14 | + assert(res1.successful) |
| 15 | + assert(lastNoSuccessVar.value == None) |
| 16 | + |
| 17 | + val res2 = parse(x, "y") |
| 18 | + assert(!res2.successful) |
| 19 | + assert(lastNoSuccessVar.value == None) |
| 20 | + |
| 21 | + val res3 = parseAll(x, "x") |
| 22 | + assert(res3.successful) |
| 23 | + assert(lastNoSuccessVar.value == None) |
| 24 | + |
| 25 | + val res4 = parseAll(x, "y") |
| 26 | + assert(!res4.successful) |
| 27 | + assert(lastNoSuccessVar.value == None) |
| 28 | + } |
| 29 | + |
| 30 | + private def getLastNoSuccessVar(p: Parsers): DynamicVariable[Option[_]] = { |
| 31 | + // use java reflection instead of scala (see below) because of |
| 32 | + // https://issues.scala-lang.org/browse/SI-9306 |
| 33 | + val fn = "scala$util$parsing$combinator$Parsers$$lastNoSuccessVar" |
| 34 | + val f = p.getClass.getDeclaredMethod(fn) |
| 35 | + f.setAccessible(true) |
| 36 | + f.invoke(p).asInstanceOf[DynamicVariable[Option[_]]] |
| 37 | + |
| 38 | + /* |
| 39 | + val ru = scala.reflect.runtime.universe |
| 40 | + val mirror = ru.runtimeMirror(getClass.getClassLoader) |
| 41 | + val lastNoSuccessVarField = |
| 42 | + ru.typeOf[Parsers].decl(ru.TermName("lastNoSuccessVar")).asTerm.accessed.asTerm |
| 43 | + mirror.reflect(p).reflectField(lastNoSuccessVarField).get. |
| 44 | + asInstanceOf[DynamicVariable[Option[_]]] |
| 45 | + */ |
| 46 | + } |
| 47 | + |
| 48 | + private final class grammar extends RegexParsers { |
| 49 | + val x: Parser[String] = "x" |
| 50 | + } |
| 51 | +} |
0 commit comments