Brian. The original post tried to filter a string by filtering (without) that actual string, and was interested in why that did not yield empty. Intuitively, the result of such a filter operation ought always to be empty. The presence of the char “[“ is the “culprit”. That is as far as I took it.
Anyway, you state that the char “[“ is a regex special character, which explains a lot. The other two, “?” and “*” filter without issue, though, and I guess one has to be a regex user to see why. I am not. Craig > On Jan 24, 2024, at 2:53 PM, Brian Milby via use-livecode > <use-livecode@lists.runrev.com> wrote: > > Your test misses the actual issue: > > on mouseup > local tStr > local tFilter > put "a*b" into tFilter > put "anything bold" into tStr > filter tStr with tFilter > put tStr > end mouseup > > Will yield "anything bold" > > while using the following 2 lines: > put "a?b" into tFilter > put "a*b" into tStr > will yield "a*b" > > Finally, using the following 2 lines: > put "a[?]b" into tFilter > put "a?b" into tStr > will yield "a?b" > > The point is that you can end up with issues if you are counting on "*" and > "?" to filter literally. They don't - they are wildcards and can match > anything (multiple char or single char respectively). The "[" is also > special. > > To ensure that your filters work properly if you do not want to use any > wildcards (i.e. match * and ? literally) would require you to change *, ?, > and [ to [*], [?], and [[]. > > On Wed, Jan 24, 2024 at 1:19 PM Craig Newman via use-livecode < > use-livecode@lists.runrev.com> wrote: > >> OK, instead of working I did this: >> >> on mouseUp >> >> repeat with y = 1 to 255 >> >> put "XX" & numToChar(y) & "XX" into temp >> >> filter temp without temp >> >> if temp <> "" then put y & return after accum >> >> end repeat >> >> answer accum >> >> end mouseUp >> >> There are two characters that prevent the filter command from doing its >> job: ASCII 91 (“[“) and ASCII 10, the return char. >> >> >> >> Craig >> >> >>> On Jan 24, 2024, at 12:51 PM, Craig Newman via use-livecode < >> use-livecode@lists.runrev.com> wrote: >>> >>> Brian. >>> >>> Nope. Those two chars pass through the filter, er, filtered. >>> >>> Again, I did not test the entire character set. >>> >>> Craig >>> >>>> On Jan 24, 2024, at 11:05 AM, Brian Milby via use-livecode < >> use-livecode@lists.runrev.com> wrote: >>>> >>>> The only other two that would cause issues are ? and * which are single >> and multiple char wildcards respectively. >>>> >>>> Brian Milby >>>> br...@milby7.com >>>> >>>>> On Jan 24, 2024, at 10:21 AM, Craig Newman via use-livecode < >> use-livecode@lists.runrev.com> wrote: >>>>> >>>>> I did not test the ASCII set exhaustively, but the culprit is the >> char “[“ (ASCII 91). Any other char (including “]”) in the string works >> correctly, that is, nothing is left after the filter command executes. >>>>> >>>>> I do not know enough to say whether that particular char does >> something to the filter command, which may use regex somehow in its inner >> workings. >>>>> >>>>> Craig >>>>> >>>>> Craig >>>>> >>>>>> On Jan 23, 2024, at 9:45 PM, Brian Milby via use-livecode < >> use-livecode@lists.runrev.com> wrote: >>>>>> >>>>>> Not sure this is really a bug. The default is to match a >> wildcardPattern. If you want to match [ then you must use [[] in the >> pattern. >>>>>> >>>>>> Brian Milby >>>>>> br...@milby7.com >>>>>> >>>>>>>> On Jan 23, 2024, at 9:02 PM, Neville Smythe via use-livecode < >> use-livecode@lists.runrev.com> wrote: >>>>>>> >>>>>>> Try this in the msg box: >>>>>>> >>>>>>> put "aaa[bbb" into tStr; put line 1 of tStr into tLine; filter tStr >> without tLine; put tStr >>>>>>> I get (using MacOS, LC 9.6.11) >>>>>>> >>>>>>> aaa[bbb >>>>>>> >>>>>>> That is to say, the line is not filtered out. >>>>>>> >>>>>>> And: >>>>>>> >>>>>>> put "aaa[bbb" into tStr; filter tStr with tStr; put tStr >>>>>>> >>>>>>> produces an empty string instead of the original string. >>>>>>> >>>>>>> The bug occurs if the line contains the character “[“ anywhere; any >> lines containing that character are ignored by both filter with and filter >> without. >>>>>>> >>>>>>> This is really serious, because I rely on the filter command a lot, >> as I would think do many other developers! >>>>>>> >>>>>>> Don’t know if it occurs with other characters, but I have never seen >> it before. I discovered it when filtering lines with regular expressions. >> Other special regexp characters I have tested do not trigger the bug. >>>>>>> >>>>>>> Neville Smythe >>>>>>> >>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> use-livecode mailing list >>>>>>> use-livecode@lists.runrev.com >>>>>>> Please visit this url to subscribe, unsubscribe and manage your >> subscription preferences: >>>>>>> http://lists.runrev.com/mailman/listinfo/use-livecode >>>>>> >>>>>> _______________________________________________ >>>>>> use-livecode mailing list >>>>>> use-livecode@lists.runrev.com >>>>>> Please visit this url to subscribe, unsubscribe and manage your >> subscription preferences: >>>>>> http://lists.runrev.com/mailman/listinfo/use-livecode >>>>> >>>>> >>>>> _______________________________________________ >>>>> use-livecode mailing list >>>>> use-livecode@lists.runrev.com >>>>> Please visit this url to subscribe, unsubscribe and manage your >> subscription preferences: >>>>> http://lists.runrev.com/mailman/listinfo/use-livecode >>>> >>>> _______________________________________________ >>>> use-livecode mailing list >>>> use-livecode@lists.runrev.com >>>> Please visit this url to subscribe, unsubscribe and manage your >> subscription preferences: >>>> http://lists.runrev.com/mailman/listinfo/use-livecode >>> >>> >>> _______________________________________________ >>> use-livecode mailing list >>> use-livecode@lists.runrev.com >>> Please visit this url to subscribe, unsubscribe and manage your >> subscription preferences: >>> http://lists.runrev.com/mailman/listinfo/use-livecode >> >> _______________________________________________ >> use-livecode mailing list >> use-livecode@lists.runrev.com >> Please visit this url to subscribe, unsubscribe and manage your >> subscription preferences: >> http://lists.runrev.com/mailman/listinfo/use-livecode >> > _______________________________________________ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your subscription > preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
