我正在使用Xtext的语言服务器上工作。我要实现的功能之一是使语言服务器解析包含字母数字字符和符号的字符串的能力。
最初，我定义了一个终端TEXT，其中包含字母和一些符号，如下所示：
terminal TEXT:
('a'..'z'|'A'..'Z'|'_'|'-'|'.')
;
当我为TEXT调用终止规则时，通常使用：
string+=TEXT+
或者类似表示“ abcd”之类的东西。但是，此实现导致与其他规则存在一些冲突，即我的UDouble规则，该规则允许用户键入双精度字符为“ 1e-10”。因此，我试图找出一种方法来制作类似“ message2！”的内容。允许同时不干扰我的UDouble规则。我尝试的其他方法是创建两个附加的终端规则：
terminal ALPHA:
('a'..'Z'|'A'..'Z'|'0'..'9')
;
terminal PUNCT:
('!'|'.'|'*'|',')
;
然后创建一个解析器规则，该规则接受任意ALPHA或PUNCT列表，定义为：
Char_str:
(ALPHA
| PUNCT)+
;
但是在使用单元测试运行此语法时，使用字符串“ test2”会导致此错误跟踪：
java.lang.AssertionError: Expected no errors, but got :ERROR (org.eclipse.xtext.diagnostics.Diagnostic.Syntax) 'required (...)+ loop did not match anything at input 'sd'' on File, offset 51, length 2
at org.junit.Assert.fail(Assert.java:88)
at org.eclipse.xtext.testing.validation.ValidationTestHelper.assertNoErrors(ValidationTestHelper.java:186)
at org.eclipse.xtext.testing.validation.ValidationTestHelper.assertNoErrors(ValidationTestHelper.java:92)
at gov.lanl.mcnp.tests.McnpParsingMiscTest.testFileCreation2(McnpParsingMiscTest.java:485)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.eclipse.xtext.testing.XtextRunner$1.evaluate(XtextRunner.java:49)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
at org.junit.vintage.engine.execution.RunnerExecutor.execute(RunnerExecutor.java:40)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(Unknown Source)
at java.util.stream.ReferencePipeline$3$1.accept(Unknown Source)
at java.util.Iterator.forEachRemaining(Unknown Source)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Unknown Source)
at java.util.stream.AbstractPipeline.copyInto(Unknown Source)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(Unknown Source)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(Unknown Source)
at java.util.stream.AbstractPipeline.evaluate(Unknown Source)
at java.util.stream.ReferencePipeline.forEach(Unknown Source)
at org.junit.vintage.engine.VintageTestEngine.executeAllChildren(VintageTestEngine.java:80)
at org.junit.vintage.engine.VintageTestEngine.execute(VintageTestEngine.java:71)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:229)
at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$6(DefaultLauncher.java:197)
at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:211)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:191)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:137)
at org.eclipse.jdt.internal.junit5.runner.JUnit5TestReference.run(JUnit5TestReference.java:89)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)