LisaNov2004TutorialW3 < CF

CF Web>CscfSpecific>LisaNovember2004>LisaNov2004TutorialW3 (2005-06-04, MikePatterson) (raw view)

I didn't take very many notes at this session, as the tutorial notes are fairly straightforward.  I will give page numbers that refer to the notes, and these notes likely won't make much sense without them.

8 - cursor = |

18 - note, two states before it hits the start of the string.

26 - difference between Perl and POSIX - with Perl one can be flexible by changing order in the regex.

34, 35 - possible use of non-greedy matching.

39 - no, it's not more efficient to "just" reverse both the string and the regex (class question).  Boyer-Moore search.

43 - DFA.  Are there engines that choose NFA vs DFA based on the regex?  Yes - GNU regex does this.

49 - n(?!\s) succeeds at the end of the string.  n(?=\s) does not.  So they're not just reverses of each other.

56 - NB parenthesis numbering, it's a bit tricky here.

65 - with a fence, you can go in, then leave, but never go back in again.  (Think of it as a museum admission, he says.)

66 - is it faster to lowercase first?  "It depends," he says.  Depends on the string, and depends on the full regex.

-- Main.MikePatterson - 04 Jun 2005

Topic revision: r1 - 2005-06-04 - MikePatterson

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