Negation of a regular expression in a Pattern

[Raffaello Giulietti]

I'm not sure what's unclear in "any character except a, b, or c" or "any 
character except one in the Greek block".
A line terminator is neither 'a' nor 'b' nor 'c', nor is it in the Greek 
block.

Your example works the same in JDK 8, 11, 17, 21, 22, with or without 
the additional MULTILINE or DOTALL flags.

(BTW, if you look carefully, the example in the Stack Overflow 
discussion you are referring to builds a matcher over a string that does 
_not_ contain any line terminator.)

As documented (and implied by the name), DOTALL refers to the pattern "."

Similarly, MULTILINE refers to the "^" and "$" boundary matchers.



If you feel the doc is incorrect, you might consider filing a bug report
https://bugs.java.com/bugdatabase/




On 2024-08-11 11:42, Olivier Cailloux wrote:
> Dear list,
> 
> The Pattern Javadoc <https://docs.oracle.com/en/java/javase/22/docs/api/ 
> java.base/java/util/regex/Pattern.html> does not specify whether “Any 
> character” includes line terminators in “Any character except |a|, |b|, 
> or |c| (negation)” ([^abc]) or “Any character except one in the Greek 
> block (negation)” (\P{InGreek}), or whether it depends on DOTALL or 
> MULTILINE being set.
> 
> As a result, it seems to me impossible from the doc to deduce, for 
> example, whether the Pattern "[^a]" will match a line terminator 
> (spoiler alert: it does <https://onecompiler.com/java/42nuaa4bd>). This 
> discussion <https://stackoverflow.com/questions/64383917/> illustrates 
> the confusion.
> 
> Would an addition to the doc be considered?
>