The syntax parsing time and performance did not meet my expectations

[cmmjxh]

Hello, I have customized the syntax using Antlr4 (4.13.2), but when using the parser to parse, I found that the general performance loss for each syntax parsing is about 50ms. Our project can only allow us to control it within about 5ms. I am not sure if it is because our syntax definition is inaccurate, and the performance supported by Antlr4 can only reach this limit. Can you help answer my question?（java） `grammar DataFusion;

@header{ package org.example.code; }

options { language = Java; }

// DataFusion 语法定义jql jql: elements end ;

elements: element (',' element)* ; // Simplified to allow for easier parsing of multiple elements

element: ID ':' (strings | constant | function | expr) // Simplified and removed unnecessary alternatives | all | ignore ;

expr: term (op=('+'|'-') term) | factor (op=(''|'/') factor)* | number | strings | function | '(' expr ')' ;

term: factor (op=('+'|'-') factor) *; factor: number | strings | function | '(' expr ')' | ID;

function: AGGOPER '(' argument ')' | IFNULL '(' number ',' strings ',' argument ')' | CONCAT '(' strings (',' strings)* ')' ;

argument: strings | number | expr | constant ;

number: INTEGER | FLOAT ;

strings : ID ;

end : ';';

constant: '\'' ID '\'' | '\'''\'' | '\'' (INTEGER | FLOAT) '\'';

all : '' | ID '' ;

ignore : '-$'ID | '-$'all;

AGGOPER: 'SUM' | 'sum' | 'AVG' | 'avg' | 'COUNT' | 'count' | 'MAX' | 'max' | 'MIN' | 'min' ;

IFNULL: 'IFNULL' | 'ifnull' ;

CONCAT: 'CONCAT' | 'concat';

FLOAT : '-'? DIGIT+ '.' DIGIT+ ; fragment DIGIT : [0-9] ; ID : [a-zA-Z0-9_$\u0080-\uffff.]+ ; Grammar_EOF: ';' ; WS: [ \t\r\n]+ -> skip;` 解析耗时：57ms

[kaby76]

The grammar you provide is not valid. It doesn't pass the Antlr Tool. Please use correct Markdown syntax for code blocks.

[jimidle]

The grammar looks highly ambiguous and precedence looks incorrect. Use the recognizer options to report ambiguities s you parse then fix the grammar. Then you can use SLL mode and should teach your required parsing times easily. You have to work at a grammar and understand it to get good performance

On Mon, Aug 26, 2024 at 06:41 Ken Domino @.***> wrote:

The grammar you provide is not valid. It doesn't pass the Antlr Tool. Please use correct Markdown syntax for code blocks.

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