Perfect, thanks Devin - I was hoping to see ‘offsets’ in the docs under ‘offset’, so this will do nicely! :-) Best, Keith
> On 29 Oct 2018, at 15:49, Devin Asay via use-livecode > <use-livecode@lists.runrev.com> wrote: > > On Oct 29, 2018, at 9:32 AM, Keith Clarke via use-livecode > <use-livecode@lists.runrev.com> wrote: >> >> Folks, >> Is there a simple way to find the offset of a character from the ‘right’ end >> of a string, rather than the beginning - or alternatively get a list of all >> occurrences? >> >> I’m trying to separate paths & pages from a list of URLs and so looking to >> identify the position of the last ‘/‘ character. >> >> Thanks & regards, >> Keith > > > There was a discussion on this topic on the list a few years ago, and I saved > these functions in my script library: > > From Peter Brigham: > These are utility functions I use constantly for text processing. > Offsets(str,cntr) returns a comma-delimited list of all the offsets of str in > ctnr. Lineoffsets(str,cntr) does the same with lineoffsets. Then you can > interate over the list of offsets to do whatever you want to each instance of > str in cntr. I keep them in a utility stack that is in the stackinuse, so it > is available to all stacks. I don't use regex, as I have never gotten the > regex syntax to stick in my head firmly enough to find it natural, and in any > case doing it by script turns out to be as fast or faster. > > Peter's lineOffsets function returns a line number for each found char > offset. I added a function that returns only unique line numbers. > > function offsets str,cntr > -- returns a comma-delimited list of > -- all the offsets of str in cntr > put "" into oList > put 0 into startPoint > repeat > put offset(str,cntr,startPoint) into os > if os = 0 then exit repeat > add os to startPoint > put startPoint & "," after oList > end repeat > if oList = "" then return "0" > return item 1 to -1 of oList > end offsets > > function lineOffsetsAll str,cntr > -- returns a comma-delimited list of > -- all the lineoffsets of str in cntr > # (returns a line number for ALL instances) > put offsets(str,cntr) into charList > if charList = "0" then return "0" > put the number of items of charList into nbr > put "" into oList > repeat for each item n in charList > put the number of lines of (char 1 to n of cntr) \ > & "," after oList > end repeat > return item 1 to -1 of oList > end lineOffsetsAll > > # added by Devin Asay > function lineOffsets pStr,pSearchTxt > # (returns only unique line numbers) > put empty into tList > put 0 into tStartLine > repeat > put lineOffset(pStr,pSearchTxt,tStartLine) into tLineNum > if tLineNum = 0 then exit repeat > add tLineNum to tStartLine > put tStartLine & "," after tList > end repeat > if tList is empty then return "0" > return item 1 to -1 of tList > end lineOffsets > > Hope this helps. > > Devin > > Devin Asay > Director > Office of Digital Humanities > Brigham Young University > > _______________________________________________ > 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
