INVALID_SYNTAX_CANNOT_PARSE for at sign (@)

Description

Since release 9.1.0, Lucene’s SyntaxParser have been uncapable to parse @ in a query, throwing a Syntax Error (INVALID_SYNTAX_CANNOT_PARSE). Version 9.0.0 is the last I tested that still can parse this character.

Two similar examples that throw INVALID_SYNTAX_CANNOT_PARSE in 9.1.0, but not in 9.0.0:

• \\ an@tomy
• \\ @natomy

Leaving some log dump here:

Syntax Error, cannot parse \\ an@tomy:  
INVALID_SYNTAX_CANNOT_PARSE: Syntax Error, cannot parse \\ an@tomy:  
	at org.apache.lucene.queryparser.flexible.standard.parser.StandardSyntaxParser.generateParseException(StandardSyntaxParser.java:2093)
	at org.apache.lucene.queryparser.flexible.standard.parser.StandardSyntaxParser.jj_consume_token(StandardSyntaxParser.java:1961)
	at org.apache.lucene.queryparser.flexible.standard.parser.StandardSyntaxParser.TopLevelQuery(StandardSyntaxParser.java:115)
	at org.apache.lucene.queryparser.flexible.standard.parser.StandardSyntaxParser.parse(StandardSyntaxParser.java:92)
	at org.apache.lucene.queryparser.flexible.core.QueryParserHelper.parse(QueryParserHelper.java:214)
	at org.apache.lucene.queryparser.flexible.standard.StandardQueryParser.parse(StandardQueryParser.java:280)
        ...

Version and environment details

• JDK: temurin-17.0.3
• OS: MacOS Monterey 12.6 and alpine-java17:latest (docker image)
• Lucene: 9.1.0

[rmuir]

not a bug, but related to new features added to the parser. see the associated message in MIGRATE.txt:

## Minor syntactical changes in StandardQueryParser (Lucene 9.1)

LUCENE-10223 adds interval functions and min-should-match support to StandardQueryParser. This
means that interval function prefixes ("fn:") and the '@' character after parentheses will
parse differently than before. If you need the exact previous behavior, clone the StandardSyntaxParser from the previous version of Lucene and create a custom query parser
with that parser.

[gcbaptista]

OK, thank you very much for the clarification 👍