ANTLR如何执行角色操作？

Question

ANTLR 3似乎在其规则中使用某种正则表达式操作，有人知道它是否使用自定义语法以及文档的位置在哪里？

Answer 1

来自ANTLR wiki：

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ANTLR Symbols

另请参阅Grammars和Special symbols in actions。

Symbol          | Description
----------------+--------------------------------------------------------
$               | Attribute
@               | Action
::              | action or dynamically-scoped attribute scope specifier
:               | rule definition
;               | end rule
|               | alternative
's'             | char or string literal
.               | wildcard
=               | label assignment
+=              | list label assignment
[..]            | argument or return value spec
{...}           | action
...             | forced action; execute even while backtracking
(...)           | subrule
+               | 1 or more
*               | 0 or more
?               | optional or semantic predicate
~               | match not
!               | don't include in AST
^               | make AST root node
=>              | always execute predicate
->              | rewrite rule
<token options> | token option spec like ID<node=VarNode>
^(...)          | tree grammar or rewrite element
// ...          | single-line comment
/* ... */       | multi-line comment