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.

-- MikePatterson - 04 Jun 2005

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