Modifying findGrep results when using lookaheads/lookbehinds [JS][CS6]

Question

Dear all,
I am thinking about a search/replace script (JS) in which the user is able to choose in a GUI to which elements of a findGrep()-array a changeGrep() method should be applied to. All in all that should be an easy thing to do.
The only thing I am wondering about is dealing with lookaheads and lookbehinds. Assuming the findWhat expression to be " (?=!)" to find a single unwanted space in front of an exclamation mark. Please understand this just as a simple example, it is obvious that you can do that kind of simple search without using a lookahead. The findGrep array will contain the pointer to the found space. If the user decides to remove the space and applies the changeGrep method on it, no changes will be made because the exclamation mark is not stored in the findGrep array and hence changeGrep method will not match the space.
So I am thinking of extending the pointer/selection before using changeGrep to include the exclamation mark in order to successfully apply changeGrep. But maybe there is a more straight solution I am not aware of?
Would be glad to read your point of view here.
Thank you very much!
Jan

Answer 1

HH_BFS wrote:
Hey pixxxel schubser,
many thanks for your reply! I think I am causing confusion when not showing any code. The script still is an idea, so there is nothing to present. But maybe these lines will illustrate my problem. And to underline it, please let me tell again, that my question adresses doing specific changes when using lookaheads/lookbehinds in general. The given bloody example with space and exclamation mark is really just an simple illustration.
//now (in my opinion) the problem: 
//but found[0] only contents " " (space). so the changeGrep method will not match, because the "!" is missing. Nothing changes. 
//it is clear to me that this happens because the findGrep method finds matching content in which the changeGrep tries a second find with replace. that can not work well. 
//so i would be happy, if i could just give up the findGrep method and tell the changeGrep method only to change i.e. the first (or second ... or whatever) match. But I think that is not possible. 
A little suggestion:
// required: opened document with one text frame
// with contents e.g. The search for the "h" in the middle of the first "the"
// and show text before and behind (in Javascript-Console)
var aDoc = app.activeDocument;
var aTF = aDoc.textFrames[0];
var found = aTF.contents.match(/(\w+ )(t)(h)(e)( \w+)/);
$.writeln(found);
$.writeln(RegExp.$1 + "  |  " + RegExp.$2 + "  |  " + RegExp.$3 + "  |  " + RegExp.$4 + "  |  " + RegExp.$5 );
Try it out. This will be sometimes complicated for the programmer (I mean you ), but perhaps one possible way to go.
Have fun