Here is a function generalized to work for any pair, building on dfepstein's function. I *think* it works, did limited testing. Try to find errors please. I'm curious to see benchmarking on this with long strings, if it works.
-- Peter Peter M. Brigham pmb...@gmail.com http://home.comcast.net/~pmbrig ------------------ function offsetPair str,tIndex,a,b -- str cannot be more than one line -- returns the offset of b matching the occurrence of a at char tIndex in str -- if (char tIndex of str) <> a then returns empty -- error -- if a or b are not in str then returns 0 -- if tIndex = empty then assumes the first occurrence of a -- if a or b = empty then assumes parentheses search if a = empty then put "(" into a if b = empty then put ")" into b put offsets(a,str) into openParens put offsets(b,str) into closeParens if openParens = 0 then return 0 if closeParens = 0 then return 0 if tIndex = empty then return firstOffsetPair(a,b,str) if tIndex is not among the items of openParens then return empty -- char tIndex of str <> a put howmany(a,char 1 to tIndex-1 of str) into openBefore put length(char 1 to tIndex-1 of str) into lengthBefore put char tIndex to -1 of str into workingStr put item -openBefore of closeParens into tempCloseIndex delete char tempCloseIndex to -1 of workingStr put firstOffsetPair(a,b,workingStr) into theCloseIndex return tIndex,(theCloseIndex + lengthBefore) end offsetPair function firstOffsetPair a,b,str -- from dfepstein -- str cannot be more than one line -- returns first instance of char a && "matching" instance of char b in str, or 0 if no a or empty if no match put offset(a,str) into ca if ca = 0 then return 0 put numToChar(7) into char 1 to ca of str set lineDelimiter to a set itemDelimiter to b repeat with i = 1 to the number of items in str if i = the number of lines in item 1 to i of str then return ca+length(item 1 to i of str) end repeat return empty end firstOffsetPair function offsets str,container,includeOverlaps -- returns a comma-delimited list of all the offsets of str in container -- returns 0 if not found -- third param is optional: -- offsets("xx","xxxxxx") returns "1,3,5" not "1,2,3,4,5" -- ie, by default, overlapping offsets are not counted -- if you want overlapping offsets then pass "true" in 3rd param if str is not in container then return 0 if includeOverlaps = empty then put false into includeOverlaps put empty into offsetList put 0 into startPoint repeat put offset(str,container,startPoint) into thisOffset if thisOffset = 0 then exit repeat add thisOffset to startPoint put startPoint & comma after offsetList if not includeOverlaps then add length(str)-1 to startPoint end if end repeat return item 1 to -1 of offsetList -- delete trailing comma end offsets function howmany tg,container -- how many tg = <target string> is in container -- note that howmany("00","000000") returns 3, not 5 -- if you want to allow overlapping matches, use: -- number of items of offsets(tg,container,"true") -- (see offsets() function) -- requires getDelimiters() put getDelimiters(container) into divChar replace tg with divChar in container set the itemdelimiter to divChar put the number of items of container into h if char -1 of container = divChar then return h -- trailing delimiter is ignored return h-1 end howmany function getDelimiters tText,nbr -- returns a cr-delimited list of <nbr> characters -- not found in the variable tText -- use for delimiters for, eg, parsing CSV files -- usage: put getDelimiters(CSVtext,2) into tDelims -- put line 1 of tDelims into lineDivider -- put line 2 of tDelims into itemDivider -- etc. if nbr = empty then put 1 into nbr -- default 1 delimiter put "2,3,4,5,6,7,8" into baseList -- could use other non-printing ASCII values put the number of items of baseList into maxNbr if nbr > maxNbr then return "Error: max" && maxNbr && "delimiters." repeat with tCount = 1 to nbr put true into failed repeat with i = 1 to the number of items of baseList put item i of baseList into testNbr put numtochar(testNbr) into testChar if testChar is not in tText then -- found one, store and get next delim put false into failed put testChar into line tCount of delimList exit repeat end if end repeat if failed then put the number of lines of delimList into nbrFound if nbr = 1 then return "Cannot get delimiter!" else if nbrFound = 0 then return "Cannot get any delimiters!" else return "Can only get" && nbrFound && "delimiters!" end if end if delete item i of baseList end repeat return delimList end getDelimiters ---------------------- On Jul 29, 2013, at 4:15 PM, dunb...@aol.com wrote: > > Hmmm. > > > I read the original post as finding the "closing parenthesis ... of a pair" > > > "Any pair?" > > > This seems to indicate that all nested parens have to be parsed as a whole. > If you want to find a particular > related couple, you have to use the correct ordered pair derived from the > function. > > > It is much simpler to find the first ")" and work backward. But that would > preclude nested parens, since the > firstmost and innermost pair would be the only one found. You cannot find > that kind of first "pair" and also > include nested pairs. That first pair is always minimally small. > > > The function could be easily modified to list all pairs within any designated > pair, of course. > > > > Anyway, it was fun to play with. > > > Craig > > > -----Original Message----- > From: Peter Haworth <p...@lcsql.com> > To: How to use LiveCode <use-livecode@lists.runrev.com> > Sent: Mon, Jul 29, 2013 1:15 pm > Subject: Re: Finding matched parentheses > > > On Mon, Jul 29, 2013 at 9:07 AM, <dunb...@aol.com> wrote: > >> I tired your script on the string: >> >> >> >> aa(ss)(xx)(yy) >> >> >> >> it only returned the parens bracketing "ss" >> > > I Think that's what he wants to do - just find the position of the first > set of parentheses, taking nested parens into account. But not sure..... > > Personally, I'd use the regex that Thierry posted a couple of days back. > No recursion involved and one line of code does the job. > > Pete > lcSQL Software <http://www.lcsql.com> > _______________________________________________ > 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