如何在Xtext DSL中嵌入XBase表达式

Question

我正在编写一个简单的小领域特定语言来指定对消息的约束，并且已经尝试了一段时间将XBase表达式嵌入到该语言中，但没有成功。

语法看起来像这样：

grammar org.xtext.businessrules.BusinessRules with org.eclipse.xtext.xbase.Xbase
//import "http://www.eclipse.org/xtext/xbase/Xbase" as xbase
import "http://www.eclipse.org/xtext/common/JavaVMTypes" as jvmTypes
generate businessRules "http://www.xtext.org/businessrules/BusinessRules"

Start:
    rules+=Constraint*;

Constraint:
    {Constraint}
    'FOR' 'PAYLOAD' payload=PAYLOAD 'ELEMENT' element=ID 'CONSTRAINED BY' constraint=XExpression;



PAYLOAD:
    "SimulationSessionEvents"
    |"stacons"
    |"any"
;



Range:
    'above' min=INT ('below' max=INT)?
    |'below' max=INT ('above' min=INT)?
;

当尝试解析文件时，例如：

对于受...约束的有效负载SimulationSessionEvents元素矩阵

我无法让它适用于...=任何类型的算术表达式，尽管它适用于...=循环或if表达式，甚至只适用于一个数字。我一做类似'-5‘或'4-5’的事情，它就会说Couldn't resolve reference to JvmIdentifiableElement '-'，尽管Xbase.xtext语法看起来允许这些表达式。

我不认为我遗漏了任何Jars，因为当我运行mwe工作流时，它不会报错，只是在尝试解析输入文件时。

任何帮助都将不胜感激。

编辑:项目的buildpath如下：

C:\Program Files\eclipse\plugins\org.eclipse.xtext_2.2.1.v201112130541.jar
C:\Program Files\eclipse\plugins\org.eclipse.emf.ecore.xmi_2.7.0.v20120127-1122.jar
C:\Program Files\eclipse\plugins\org.eclipse.emf.ecore_2.7.0.v20120127-1122.jar
C:\Program Files\eclipse\plugins\org.eclipse.emf.common_2.7.0.v20120127-1122.jar
C:\Program Files\eclipse\plugins\org.eclipse.xtext.util_2.2.1.v201112130541.jar
C:\Program Files\eclipse\plugins\com.google.guava_10.0.1.1.jar
C:\Program Files\eclipse\plugins\com.google.inject_3.0.0.no_aop.jar
C:\Program Files\eclipse\plugins\javax.inject_1.0.0.v20091030.jar
C:\Program Files\eclipse\plugins\org.antlr.runtime_3.2.0.v201101311130.jar
C:\Program Files\eclipse\plugins\org.eclipse.emf.mwe.core_1.2.1.v201112070431.jar
C:\Program Files\eclipse\plugins\org.apache.commons.cli_1.2.0.v201105210650.jar
C:\Program Files\eclipse\plugins\org.eclipse.emf.mwe2.runtime_2.2.0.v201112070431.jar
C:\Program Files\eclipse\plugins\org.eclipse.emf.mwe.utils_1.2.1.v201112070431.jar
C:\Program Files\eclipse\plugins\org.eclipse.xtext.xbase_2.2.1.v201112130541.jar
C:\Program Files\eclipse\plugins\org.eclipse.xtext.common.types_2.2.1.v201112130541.jar
C:\Program Files\eclipse\plugins\org.apache.log4j_1.2.15.v201012070815.jar
C:\Program Files\eclipse\plugins\org.apache.commons.logging_1.0.4.v201101211617.jar
C:\Program Files\eclipse\plugins\org.eclipse.xtext.generator_2.2.1.v201112130541.jar
C:\Program Files\eclipse\plugins\org.eclipse.xtend_1.1.0.v201108020519.jar
C:\Program Files\eclipse\plugins\com.ibm.icu_4.4.2.v20110823.jar
C:\Program Files\eclipse\plugins\org.eclipse.xpand_1.1.0.v201108020519.jar
C:\Program Files\eclipse\plugins\org.eclipse.xtend.typesystem.emf_1.0.1.v201108020519.jar
C:\Program Files\eclipse\plugins\org.eclipse.emf.codegen.ecore_2.7.0.v20120130-0943.jar
C:\Program Files\eclipse\plugins\org.eclipse.emf.codegen_2.6.0.v20120130-0943.jar
C:\Program Files\eclipse\plugins\de.itemis.xtext.antlr_2.0.0.v201108011202.jar
C:\Program Files\eclipse\plugins\org.antlr.generator_3.2.0.v201108011202.jar
C:\Program Files\eclipse\plugins\org.eclipse.emf.mwe2.lib_2.2.0.v201112070431.jar
C:\Program Files\eclipse\plugins\org.eclipse.xtext.xbase.lib_2.2.1.v201112130541.jar
C:\Program Files\eclipse\plugins\org.eclipse.xtend2.lib_2.2.1.v201112130541.jar
C:\Program Files\eclipse\plugins\org.eclipse.emf.mwe2.launch_2.2.0.v201112071250.jar
C:\Program Files\eclipse\plugins\org.eclipse.emf.mwe2.language_2.2.0.v201112071250.jar

Answer 1

问题修复后，您需要在实际声明xbase.lib模型的项目的构建路径中包含DSL。

Answer 2

您必须将Xtend库放在包含DSL文件的项目的类路径中。

从上下文菜单中选择“构建路径”，然后选择“添加库”。选择Xtend库，它应该可以为您工作。