Oniguruma question

[Kenneth McDonald]

For those adventurous souls who are already using Oniguruma...

With the following Oniguruma re:

print "aabb".index(/.+?(?<!a)/)
print "\n"

My reasoning tells me I should be getting 3, but I'm getting 0.
Basically, the .+ should force the re 'cursor' past at least the first
a; after that, the negative lookback should force it past the first b.
Could someone explain where I'm misunderstanding?

Thanks,
Ken

 

[Kenneth McDonald]

'Cause I'm a Ruby newbie who's still learning this stuff

Ken

 

[Robert Klemme]

I'm writing a library to make re's easier to use This is in the
test suite.

Thanks for the feedback, that comes as a real surprise to me. So maybe
I'll try /..+?/

This one won't match after "aa". Instead it will match "aa". I do not
know what you intend to match so I cannot really comment. This is
clearly a toy example, isn't it? There are multiple ways to match "bb"
in "aabb" and it is completely unclear to me what you are after.

Your original RX literally translated means "match anything which is not
preceded by a" which is especially true for every character at the
beginning of a string.

Btw, I can recommend "Mastering Regular Expressions" - it is a really
good book on the matter.

Kind regards

robert

 

[Kenneth McDonald]

It was part of a unit testing suite. I did figure out where I was
going wrong, a silly mistake on my part which I should've been past
years ago. Thanks for the help.

Ken