Finding matched parentheses

[Peter Haworth]

This appears to work:

get matchChunk(<string>,".*\(.*(\)).*",tstart,tEnd)

tStart and tEnd will both contain the offset of the closing paren

You'd have to build the regex on the fly if you want to match any pair of
characters but the regex for square brackets is

".*\[.*(\]).*"

Pete
lcSQL Software <http://www.lcsql.com>


On Thu, Jul 25, 2013 at 5:17 PM, David Epstein <dfepstein at comcast.net>wrote:

> Has anyone scripted a function that will locate the closing parenthesis
> (or bracket, etc.) of a pair?  Below is my effort.  Reports of its
> limitations or simpler alternatives (regex?) are invited.
>
> David Epstein
>
> function offsetPair a,b,str, at z
>   -- returns offset(a,str) and loads in z offset(b,str) where b is the
> "matching" member of the pair;
>   -- returns 0 if there is no a, empty if there is no match
>
>   if a is not in str then return 0
>   if b is not in str then return empty
>   put 0 into b4 -- skipped characters
>   put 0 into na -- number (ordinal) of the a hit
>   put 0 into nb
>   repeat
>     put offset(a,str,b4) into ca -- character position of a
>     put offset(b,str,b4) into cb -- character position of a
>     if ca = 0 and na < nb then return empty
>     if cb = 0 and nb < na then return empty
>     -- only take note of the first hit:
>     put empty into hitCase -- default
>     if ca > 0 and (ca < cb or cb = 0) then put "a" into hitCase
>     if cb > 0 and (cb < ca or ca = 0) then put "b" into hitCase
>     if hitCase = "a" then
>       add 1 to na
>       put ca+b4 into aca[na] -- absolute char position of a hit number na
>       put aca[na] into b4
>     else if hitCase = "b" then
>       add 1 to nb
>       put cb+b4 into acb -- absolute char position of most recent b hit
>       put acb into b4
>     else return empty
>     if na = nb then -- we have a match
>       put acb into z
>       return aca[1]
>     end if
>   end repeat
>   return empty
> end offsetPair
>
> ______________________________**_________________
> use-livecode mailing list
> use-livecode at lists.runrev.com
> Please visit this url to subscribe, unsubscribe and manage your
> subscription preferences:
> http://lists.runrev.com/**mailman/listinfo/use-livecode<http://lists.runrev.com/mailman/listinfo/use-livecode>
>