带有空字符的字符串

Question

假设我们有两个词汇定义：

  lexical DQChr = ![\"] | [\"][\"];
  lexical String = "\"" DQChr* "\"";

那么下面的案例就很好解析了：

  parse(#String,"\"a\"");
  parse(#String,"\"\u0001\"");

但是，空字符会给出解析错误：

  parse(#String,"\u0000");

如何在引用的字符串中允许空字符？

Answer 1

看来你可以将

\u0000

添加到正则表达式中：

Version: 0.28.2
rascal>lexical DQChr = ([\u0000] | ![\"]) | [\"][\"];
ok
rascal>lexical String = "\"" DQChr* "\"";
ok
rascal>parse(#String,"\"a\"");
String: (String) `"a"`
rascal>parse(#String,"\"\u0001\"");
String: (String) `""`
rascal>parse(#String,"\"\u0000\"");
String: (String) `""`