为什么我的antlr lexer java类是“代码太大”？ [英] Why my antlr lexer java class is "code too large"?

问题描述

这是Antlr中的词法分析器（对不起长文件）：

This is the lexer in Antlr (sorry for a long file):

lexer grammar SqlServerDialectLexer;
/* T-SQL words */
AND: 'AND';
BIGINT: 'BIGINT';
BIT: 'BIT';
CASE: 'CASE';
CHAR: 'CHAR';
COUNT: 'COUNT';
CREATE: 'CREATE';
CURRENT_TIMESTAMP: 'CURRENT_TIMESTAMP';
DATETIME: 'DATETIME';
DECLARE: 'DECLARE';
ELSE: 'ELSE';
END: 'END';
FLOAT: 'FLOAT';
FROM: 'FROM';
GO: 'GO';
IMAGE: 'IMAGE';
INNER: 'INNER';
INSERT: 'INSERT';
INT: 'INT';
INTO: 'INTO';
IS: 'IS';
JOIN: 'JOIN';
NOT: 'NOT';
NULL: 'NULL';
NUMERIC: 'NUMERIC';
NVARCHAR: 'NVARCHAR';
ON: 'ON';
OR: 'OR';
SELECT: 'SELECT';
SET: 'SET';
SMALLINT: 'SMALLINT';
TABLE: 'TABLE';
THEN: 'THEN';
TINYINT: 'TINYINT';
UPDATE: 'UPDATE';
USE: 'USE';
VALUES: 'VALUES';
VARCHAR: 'VARCHAR';
WHEN: 'WHEN';
WHERE: 'WHERE';

QUOTE: '\'' { textMode = !textMode; };
QUOTED: {textMode}?=> ~('\'')*;

EQUALS: '=';
NOT_EQUALS: '!=';
SEMICOLON: ';';
COMMA: ',';
OPEN: '(';
CLOSE: ')';
VARIABLE: '@' NAME;
NAME:
    ( LETTER | '#' | '_' ) ( LETTER | NUMBER | '#' | '_' | '.' )*
    ;
NUMBER: DIGIT+;

fragment LETTER: 'a'..'z' | 'A'..'Z';
fragment DIGIT: '0'..'9';
SPACE
    :
    ( ' ' | '\t' | '\n' | '\r' )+
    { skip(); }
    ;

JDK 1.6说代码太大并且可以编译它。为什么以及如何解决这个问题？

JDK 1.6 says code too large and can't compile it. Why and how to solve the problem?

推荐答案

实际上我不会说这是一个很大的语法，而且必须有一个之所以没有产生合理大小的代码。

Actually I wouldn't say this is a big grammar, and there must be a reason why it doesn't produce reasonably sized code.

我认为这个问题直接与此规则有关：

I think the problem is directly related to this rule:

QUOTED: {textMode}?=> ~('\'')*;

您是否有任何特殊原因要将QUOTED零件作为单独的标记，而不是将其合并引用，巴特也把它放在他的语法中？这也会使 textMode 变量过时。

Is there any particular reason why you want the QUOTED part as a separate token, rather than leaving it combined with the quote, as Bart also put it in his grammar? This would also make the textMode variable obsolete.

删除QUOTE并用

QUOTED: '\'' (~'\'')* '\'';

最有可能解决问题，即使没有拆分语法。

most probably will solve the problem, even without splitting the grammar.

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