|Why is flex pattern-matching of NULs slow? firstname.lastname@example.org (Roger L Costello) (2022-04-08)|
|Why is flex pattern-matching of NULs slow? email@example.com (Christopher F Clark) (2022-04-09)|
|From:||Roger L Costello <firstname.lastname@example.org>|
|Date:||Fri, 8 Apr 2022 11:06:00 +0000|
|Injection-Info:||gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="77256"; mail-complaints-to="email@example.com"|
|Keywords:||lex, performance, question, comment|
|Posted-Date:||08 Apr 2022 11:48:17 EDT|
The Flex manual says this:
Pattern-matching of NULs is substantially slower
than matching other characters.
Why is that?
[My recollection is that zero is used as a flag value in internal
tables and there is some slow kludge to say that this is a nul not the
flag, but perhaps someone who has looked at the code more recently
will remember the details. -John]
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