用 unicode 编写语法规则名称 [ANTLR 4] [英] write a grammar rule name in unicode [ANTLR 4]
问题描述
我仍然是 ANTLR 4 的初学者,我想知道是否有办法用 unicode 编写语法规则名称.例如,以下规则很好:
I am still a beginner in ANTLR 4 and I was wondering if there is a way to write a grammar rule name in unicode. For example, the following rule is fine:
atomExp 返回 [double value]: n=Number {$value = Double.parseDouble($n.text);}|'(' exp=additionExp ')' {$value = $exp.value;};
但是,假设我想编写相同的规则,但不是将其名称写为 "atomExp" ,而是将名称写为阿拉伯语单词 "تعبير"
However, let's say I want to write the same rule but instead of writing its name as "atomExp" , I want to write the name as an Arabic word "تعبير"
تعبير 返回 [double value]: n=Number {$value = Double.parseDouble($n.text);}|'(' exp=additionExp ')' {$value = $exp.value;};
但是当我尝试以这种方式编写它时,出现没有可行的替代方案"错误.有人可以解决我的问题吗?提前致谢
but when I try to write it that way I get "no viable alternative" error. Can someone solve my problem please. Thanks in advance
推荐答案
查看时 ANTLR4 的词法分析器语法,可以看到词法分析器和解析器名称支持某些 Unicode 字符:
When looking at the lexer grammar for ANTLR4, you can see that lexer and parser names support certain Unicode chars:
/** Allow unicode rule/token names */
ID : NameStartChar NameChar*;
fragment
NameChar
: NameStartChar
| '0'..'9'
| '_'
| '\u00B7'
| '\u0300'..'\u036F'
| '\u203F'..'\u2040'
;
fragment
NameStartChar
: 'A'..'Z'
| 'a'..'z'
| '\u00C0'..'\u00D6'
| '\u00D8'..'\u00F6'
| '\u00F8'..'\u02FF'
| '\u0370'..'\u037D'
| '\u037F'..'\u1FFF'
| '\u200C'..'\u200D'
| '\u2070'..'\u218F'
| '\u2C00'..'\u2FEF'
| '\u3001'..'\uD7FF'
| '\uF900'..'\uFDCF'
| '\uFDF0'..'\uFFFD'
; // ignores | ['\u10000-'\uEFFFF] ;
INT : [0-9]+
;
但您的 ID تعبير
似乎不符合 ID
规则的 NameChar*
部分.
But it appears that your ID تعبير
does not comply with the NameChar*
part of the ID
rule.
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