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RE: [NTS] regular expression to find anything up to two spaces in a row ...

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  • John Shotsky
    Negative classes work by individual characters only. You could change any instance of two spaces to a token character, then negate class that, but that s
    Message 1 of 13 , Jun 18, 2011
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      Negative classes work by individual characters only. You could change any instance of two spaces to a token character,
      then negate class that, but that's probably even more work.



      Regards,

      John

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      From: ntb-scripts@yahoogroups.com [mailto:ntb-scripts@yahoogroups.com] On Behalf Of Don
      Sent: Saturday, June 18, 2011 09:26
      To: ntb-scripts@yahoogroups.com
      Subject: Re: [NTS] regular expression to find anything up to two spaces in a row ...





      Hi Axel,

      It is part of a longer expression. It is on a single line.
      (.+?) {2,}

      Don't know why I was struggling I guess ... other than I was trying to
      say "anything but two spaces". This works fine -- but is there a way to
      actually say anything but two spaces? Things inside of [ and ] continue
      to baffle me at the moment. How do I say not something specific?

      Thank you for the prompt help!

      On 6/18/2011 11:21 AM, Axel Berger wrote:
      > Don wrote:>
      >> I want to find and capture everything and anything unless until I
      >> encounter two spaces in a row ...
      >
      > You don't specify how general you need it to be. There may be more than
      > one of those several space markers or none and the marker may be more
      > than two spaces in a row. And you will need to find more than one line,
      > I think. This caters for all of these:
      >
      > ^!Jump TEXT_START
      > :loop
      > ^!Find "(?s)(.+?)( {2,})" RSTI1
      > ^!IfError rest
      > ^!Continue
      > ;^!MoveCursor 2
      > ^!Find "(?s)( {2,})" RSTI
      > ^!Jump SELECT_END
      > ^!Goto loop
      > :rest
      > ^!Find "(?s)(.+)" RSTI
      > ^!Continue
      >
      > Axel
      >
      >
      > ------------------------------------
      >
      > Fookes Software: http://www.fookes.com/
      > NoteTab website: http://www.notetab.com/
      > NoteTab Discussion Lists: http://www.notetab.com/groups.php
      >
      > ***
      > Yahoo! Groups Links
      >
      >
      >
      >





      [Non-text portions of this message have been removed]
    • Eb
      Move the quatifier outside of the class, Inside the class you re just adding the {2} characters to the class. ([^ ]{2}) If you want to expand this to mean 2
      Message 2 of 13 , Jun 20, 2011
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        Move the quatifier outside of the class, Inside the class you're just adding the "{2}" characters to the class.

        ([^ ]{2})

        If you want to expand this to mean 2 or more spaces, just change the quantifier to {2,}

        --- In ntb-scripts@yahoogroups.com, Don <don@...> wrote:
        >
        > I want to find and capture everything and anything unless until I
        > encounter two spaces in a row ...
        >
        > I was trying this:
        > ([^ {2}]*)
        >
      • Axel Berger
        ... Nope. What you suggest equals two instances of not space . What Don wants is anything but two spaces in row . Quite different. All your finds will have
        Message 3 of 13 , Jun 20, 2011
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          Eb wrote:
          > Move the quatifier outside of the class, Inside the class you're
          > just adding the "{2}" characters to the class.
          > ([^ ]{2})

          Nope. What you suggest equals "two instances of 'not space'". What Don
          wants is "anything but two spaces in row". Quite different.

          All your finds will have a length of exactly two and they can't include
          even a single space.

          There really is no single-step solution for this, but then, as long as
          clips is doing all the work and I don't have to, I really don't mind how
          many steps it takes.

          Axel
        • Don
          I am actually exporting this one to another purpose, but testing in both notetab and regex buddy.
          Message 4 of 13 , Jun 20, 2011
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            I am actually exporting this one to another purpose, but testing in both
            notetab and regex buddy.

            On 6/20/2011 2:33 PM, Axel Berger wrote:
            > Eb wrote:
            >> Move the quatifier outside of the class, Inside the class you're
            >> just adding the "{2}" characters to the class.
            >> ([^ ]{2})
            >
            > Nope. What you suggest equals "two instances of 'not space'". What Don
            > wants is "anything but two spaces in row". Quite different.
            >
            > All your finds will have a length of exactly two and they can't include
            > even a single space.
            >
            > There really is no single-step solution for this, but then, as long as
            > clips is doing all the work and I don't have to, I really don't mind how
            > many steps it takes.
            >
            > Axel
          • Eb
            Right you are. I started out commenting on the placement of quatifiers. Then I was on a roll, but forgot about the _not_ two spaces. ... Actually, I would
            Message 5 of 13 , Jun 21, 2011
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              Right you are.

              I started out commenting on the placement of quatifiers.

              Then I was on a roll, but forgot about the _not_ two spaces.

              --- In ntb-scripts@yahoogroups.com, Axel Berger <Axel-Berger@...> wrote:
              > Nope. What you suggest equals "two instances of 'not space'". What Don
              > wants is "anything but two spaces in row". Quite different.
              >
              > All your finds will have a length of exactly two and they can't include
              > even a single space.
              >
              > There really is no single-step solution for this, but then, as long


              Actually, I would expect the assertion:

              (?= )

              to find a string ending in 2 spaces, without including the two spaces in the match.

              Eb
            • Axel Berger
              ... Yes, you re right and that s probably better than my ^!Find (?s)(.+?)( {2,}) RSTI1 but it has the same problem. Don specified ... which I took to mean
              Message 6 of 13 , Jun 21, 2011
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                Eb wrote:
                > Actually, I would expect the assertion:
                > (?= )
                > to find a string ending in 2 spaces, without including the
                > two spaces in the match.

                Yes, you're right and that's probably better than my

                ^!Find "(?s)(.+?)( {2,})" RSTI1

                but it has the same problem. Don specified
                > everything and anything unless until I
                > encounter two spaces in a row ...
                which I took to mean the two spaces may or may not occur, as is usual
                when using negative classes. If they're certain to do, then things get
                much easier.

                Axel
              • Don
                Yes the two spaces are certain to occur :-) I am limited I supposed in my understanding so I didn t make the assumption you made. Now that you explain it like
                Message 7 of 13 , Jun 21, 2011
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                  Yes the two spaces are certain to occur :-)

                  I am limited I supposed in my understanding so I didn't make the
                  assumption you made. Now that you explain it like that I guess it makes
                  sense. What I am trying to do is use two spaces as a delimiter in
                  essence. I will actually be discarding the spaces as unnecessary in
                  what I am doing.

                  Off to look up (?= ) and see what it means.

                  On 6/21/2011 7:54 PM, Axel Berger wrote:
                  > Eb wrote:
                  >> Actually, I would expect the assertion:
                  >> (?= )
                  >> to find a string ending in 2 spaces, without including the
                  >> two spaces in the match.
                  >
                  > Yes, you're right and that's probably better than my
                  >
                  > ^!Find "(?s)(.+?)( {2,})" RSTI1
                  >
                  > but it has the same problem. Don specified
                  >> everything and anything unless until I
                  >> encounter two spaces in a row ...
                  > which I took to mean the two spaces may or may not occur, as is usual
                  > when using negative classes. If they're certain to do, then things get
                  > much easier.
                  >
                  > Axel
                  >
                  >
                  > ------------------------------------
                  >
                  > Fookes Software: http://www.fookes.com/
                  > NoteTab website: http://www.notetab.com/
                  > NoteTab Discussion Lists: http://www.notetab.com/groups.php
                  >
                  > ***
                  > Yahoo! Groups Links
                  >
                  >
                  >
                  >
                • Don
                  From Regex Buddy (my newest friend ...): Positive lookahead works just the same. q(?=u) matches a q that is followed by a u, without making the u part of the
                  Message 8 of 13 , Jun 21, 2011
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                    From Regex Buddy (my newest friend ...):

                    "Positive lookahead works just the same. q(?=u) matches a q that is
                    followed by a u, without making the u part of the match. The positive
                    lookahead construct is a pair of round brackets, with the opening
                    bracket followed by a question mark and an equals sign. You can use any
                    regular expression inside the lookahead. Any valid regular expression
                    can be used inside the lookahead."

                    If I understand correctly, I can then actually do this:
                    (?=( ))
                    and create a back-reference if I wish?

                    Learning as I go here :-) and it's fun. Thanks Axel and Eb!


                    On 6/21/2011 7:54 PM, Axel Berger wrote:
                    > Eb wrote:
                    >> Actually, I would expect the assertion:
                    >> (?= )
                    >> to find a string ending in 2 spaces, without including the
                    >> two spaces in the match.
                    >
                    > Yes, you're right and that's probably better than my
                    >
                    > ^!Find "(?s)(.+?)( {2,})" RSTI1
                    >
                    > but it has the same problem. Don specified
                    >> everything and anything unless until I
                    >> encounter two spaces in a row ...
                    > which I took to mean the two spaces may or may not occur, as is usual
                    > when using negative classes. If they're certain to do, then things get
                    > much easier.
                    >
                    > Axel
                    >
                    >
                    > ------------------------------------
                    >
                    > Fookes Software: http://www.fookes.com/
                    > NoteTab website: http://www.notetab.com/
                    > NoteTab Discussion Lists: http://www.notetab.com/groups.php
                    >
                    > ***
                    > Yahoo! Groups Links
                    >
                    >
                    >
                    >
                  • John Shotsky
                    [Off to look up (?= ) and see what it means.] I use it often. It is the inverse of K - which doesn t capture anything before, but it evaluates it. (?=), when
                    Message 9 of 13 , Jun 21, 2011
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                      [Off to look up (?= ) and see what it means.]

                      I use it often. It is the inverse of \K - which doesn't capture anything before, but it evaluates it. (?=), when used in
                      a regex, is exactly the same, meaning anything that follows is not captured, but is evaluated.



                      So, this:

                      "this that"

                      Run on:

                      ^!Replace "this\x20\K(?=that)" >> "with\x20" ARSW

                      Produces "this with that"

                      Pretty handy for inserting something without any capturing.

                      Regards,

                      John



                      From: ntb-scripts@yahoogroups.com [mailto:ntb-scripts@yahoogroups.com] On Behalf Of Don
                      Sent: Tuesday, June 21, 2011 18:23
                      To: ntb-scripts@yahoogroups.com
                      Subject: Re: [NTS] Re: regular expression to find anything up to two spaces in a row ...





                      Yes the two spaces are certain to occur :-)

                      I am limited I supposed in my understanding so I didn't make the
                      assumption you made. Now that you explain it like that I guess it makes
                      sense. What I am trying to do is use two spaces as a delimiter in
                      essence. I will actually be discarding the spaces as unnecessary in
                      what I am doing.

                      Off to look up (?= ) and see what it means.

                      On 6/21/2011 7:54 PM, Axel Berger wrote:
                      > Eb wrote:
                      >> Actually, I would expect the assertion:
                      >> (?= )
                      >> to find a string ending in 2 spaces, without including the
                      >> two spaces in the match.
                      >
                      > Yes, you're right and that's probably better than my
                      >
                      > ^!Find "(?s)(.+?)( {2,})" RSTI1
                      >
                      > but it has the same problem. Don specified
                      >> everything and anything unless until I
                      >> encounter two spaces in a row ...
                      > which I took to mean the two spaces may or may not occur, as is usual
                      > when using negative classes. If they're certain to do, then things get
                      > much easier.
                      >
                      > Axel
                      >
                      >
                      > ------------------------------------
                      >
                      > Fookes Software: http://www.fookes.com/
                      > NoteTab website: http://www.notetab.com/
                      > NoteTab Discussion Lists: http://www.notetab.com/groups.php
                      >
                      > ***
                      > Yahoo! Groups Links
                      >
                      >
                      >
                      >





                      [Non-text portions of this message have been removed]
                    • Art Kocsis
                      John, Not quite. Look ahead and look behind assertions are very useful, I agree but K and (?
                      Message 10 of 13 , Jun 22, 2011
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                        John,

                        Not quite. Look ahead and look behind assertions are very useful, I agree but
                        \K and (?<=...) [the positive look behind assertion] are NOT EXACTLY the
                        same. The big difference (and what makes \K so much better), is that the
                        escape sequence \K allows variable length sub patterns whereas the positive/
                        negative look ahead/look behind assertions all require fixed length sub
                        patterns.

                        Namaste', Art

                        At 06/21/2011 19:12, John wrote:
                        >[Off to look up (?= ) and see what it means.]
                        >
                        >I use it often. It is the inverse of \K - which doesn't capture anything
                        >before, but it evaluates it.
                        >(?=), when used in a regex, is exactly the same, meaning anything that
                        >follows is not captured,
                        > but is evaluated.
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