从多文件RelaxNG模式生成DTD

Question

我有一个RelaxNG模式，它被分解成几个.rnc文件。我希望能够将它们转换为DTD，但是trang抱怨我使用了external指令：

$ trang schema/text.rnc schema/text.dtd
[...]/schema/text.rnc:3:6: error: sorry, "externalRef" is not supported
[...]/schema/text.rnc:4:9: error: sorry, "externalRef" is not supported
[...]/grcxml/schema/text.rnc:6:15: error: sorry, "externalRef" is not supported
[...]/schema/text.rnc:3:6: error: sorry, "externalRef" is not supported
Exception in thread "main" java.lang.NullPointerException
        at com.thaiopensource.relaxng.output.dtd.ContentType.ref(ContentType.java:138)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.visitRef(Analysis.java:232)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.visitRef(Analysis.java:78)
        at com.thaiopensource.relaxng.edit.RefPattern.accept(RefPattern.java:9)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.analyzeContentType(Analysis.java:336)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.visitGroup(Analysis.java:216)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.visitGroup(Analysis.java:78)
        at com.thaiopensource.relaxng.edit.GroupPattern.accept(GroupPattern.java:5)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.analyzeContentType(Analysis.java:336)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.visitElement(Analysis.java:118)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.visitElement(Analysis.java:78)
        at com.thaiopensource.relaxng.edit.ElementPattern.accept(ElementPattern.java:9)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.analyzeContentType(Analysis.java:336)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.visitRef(Analysis.java:232)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.visitRef(Analysis.java:78)
        at com.thaiopensource.relaxng.edit.RefPattern.accept(RefPattern.java:9)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.analyzeContentType(Analysis.java:336)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.visitDefine(Analysis.java:288)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.visitDefine(Analysis.java:78)
        at com.thaiopensource.relaxng.edit.DefineComponent.accept(DefineComponent.java:39)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.visitContainer(Analysis.java:278)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.visitGrammar(Analysis.java:258)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.visitGrammar(Analysis.java:78)
        at com.thaiopensource.relaxng.edit.GrammarPattern.accept(GrammarPattern.java:14)
        at com.thaiopensource.relaxng.output.dtd.Analysis$Analyzer.analyzeContentType(Analysis.java:336)
        at com.thaiopensource.relaxng.output.dtd.Analysis.<init>(Analysis.java:534)
        at com.thaiopensource.relaxng.output.dtd.DtdOutputFormat.output(DtdOutputFormat.java:22)
        at com.thaiopensource.relaxng.translate.Driver.run(Driver.java:144)
        at com.thaiopensource.relaxng.translate.Driver.main(Driver.java:44)

Trang将一个像RelaxNG这样的表达模式填充到一个昏暗的DTD中的能力似乎是不可思议的，这一障碍让我感到惊讶。external包含对于跨模式共享定义是如此的好，我不想失去它们。那么，怎样才能使这一切成为可能呢？

Answer 1

如果您不关心DTD不会将除法复制到源文件中，那么可以首先使用jing：

$ jing -s source.rng > intermediate.rng
$ trang intermediate.rng final.dtd

第一步将所有内容合并到一个文件中。第二个人将皈依。

Answer 2

我认为您可以使用Trang将.rnc紧凑模式转换为.rng，这应该将外部模式合并到主模式中。一旦您有了一个.rng文件，您就可以将其转换为DTD。

另见https://code.google.com/p/jing-trang/issues/detail?id=51和https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=264706。