Addings/modifications to help files

[sidki3003]

(Jul. 20, 2009 03:35 AM)whenever Wrote:  No, "+" doesn't look ahead, it just repeats the preceding expression blindly. The help file has below words:

Sure it doesn't. It *removes* look ahead capatibility from subexpressions like "*>". Have a look at the examples below that statement.

Quote:I think "*" is equal to "?++" in prox language while the help file has:

Effectively yes. Speedwise the difference is around an order of magnitude.

Quote:So, The "*" itself looks ahead.

Right. That's what we need to get rid of in mentioned example situations.

Quote:To match a string until meet a ">", "[^>]+>" is faster than "*>" because "+" just blindly repeat the "[^>]" while "*" has to check after each character match if it is followed by a ">".

Now that we have made "*" blind, it's much faster than "[^>]+>".

A more accurate expression for "making blind" is: Limiting the subexpression's scope, so that - after the initial match - there is nothing left to look ahead.

Quote:I don't understand what the examples are trying to show.

\*\*\*+{98} instead of \*+{100} makes the expression start with two unique chars, which is what we want.

Quote:A more detailed example might help.

I couldn't think of any.


I should also note that techniques.txt is addressing advanced filter writers, who know the help files (i know them too ), as well as the prox-list discussions. That allows it to go straight to the point, without repeating any Proxomitron basics.
(No one else would be interested in such things anyway.)

Thanks for looking at that draft.
I assume that its content is logically correct (all statements have been tested, of course), but maybe some wordings and/or examples could be improved to make it easier to understand.