Fixed infinite loop in whitespace with no comments in LanguageDef (#…

…119) * Fixed bug where whitespace with no comments does not advance program counter * Added unit test
j-mie6 · Apr 25, 2022 · 7f2fb16 · 7f2fb16
1 parent 13f2d25
commit 7f2fb16
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Showing 2 changed files with 13 additions and 2 deletions.
diff --git a/src/main/scala/parsley/internal/machine/instructions/TokenInstrs.scala b/src/main/scala/parsley/internal/machine/instructions/TokenInstrs.scala
@@ -77,8 +77,13 @@ private [instructions] abstract class WhiteSpaceLike(start: String, end: String,
         else ctx.pushAndContinue(())
     }
 
+    final def spacesAndContinue(ctx: Context): Unit = {
+        spaces(ctx)
+        ctx.pushAndContinue(())
+    }
+
     private final val impl = {
-        if (!lineAllowed && !multiAllowed) spaces(_)
+        if (!lineAllowed && !multiAllowed) spacesAndContinue(_)
         else if (!lineAllowed) multisOnly(_)
         else if (!multiAllowed) singlesOnly(_)
         else singlesAndMultis(_)
@@ -235,4 +240,4 @@ private [internal] final class TokenMaxOp(operator: String, _ops: Set[String]) e
     // $COVERAGE-OFF$
     override def toString: String = s"TokenMaxOp(${operator})"
     // $COVERAGE-ON$
-}
+}
diff --git a/src/test/scala/parsley/TokeniserTests.scala b/src/test/scala/parsley/TokeniserTests.scala
@@ -397,4 +397,10 @@ class TokeniserTests extends ParsleyTest {
         p.parse("bye") shouldBe a [Success[_]]
         p.parse("Bye") shouldBe a [Success[_]]
     }
+
+    "issue #199" should "not regress: whitespace should work without comments defined" in {
+        val lang = token.LanguageDef.plain.copy(space = token.Predicate(_.isWhitespace))
+        val lexer = new token.Lexer(lang)
+        lexer.whiteSpace.parse("[") shouldBe a [Success[_]]
+    }
 }