Strange behaviour of Perl RegExp in Javascript engine

[heilu]

I'm using UE 13.10a+1.

Glad to have got a powerfull scripting engine - I never liked UE Macros as "programming language" - I've found that the Perl regular expression engine within Javascript behaves very strange.
First I've wondered, why there is an extra object/method to use:

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UltraEdit.activeDocument.findReplace.regExp = true;
UltraEdit.activeDocument.findReplace.find

while Javascript implementations in browsers or MS-Scripting host since years allow RegExp objects to be created with

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new RegExp("expr","flags")   or with   /expr/flags

I've even tried them, without error messages, but also without success.

Then I tried to write a little script to create proper idented javascript object from my Firefox "sessionstore.js", where the identation should be increased after the characters "{[(" and decreased before "}])". The first try was:

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UltraEdit.columnModeOff;
UltraEdit.hexOff;
UltraEdit.perlReOn;
UltraEdit.activeDocument.findReplace.regExp = true;
UltraEdit.activeDocument.findReplace.find("\[|\]");


It found only occurences of "|"

Next I tried character classes:

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UltraEdit.activeDocument.findReplace.find(/[\[\]{}{)]/);

did nothing - and no error.

Next try:

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UltraEdit.activeDocument.findReplace.find("[\[\]{}()]");

told me: "You have entered an invalid expression".
The identical regular expression entered in the Find dialog (with Perl regExp enabled) WORKS

Next try:

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UltraEdit.activeDocument.findReplace.find("[\[{}()]");

worked as expected.

Next try:

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UltraEdit.activeDocument.findReplace.find("[\]{}()]");

worked as expected.

Last try:

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UltraEdit.activeDocument.findReplace.find("[\[\]]");

did nothing - and no error.

Anything I've overseen?

[Bego]

You forgot to escape the backslash for Javascript.
I'm in a hurry, but a fast example:

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UltraEdit.activeDocument.findReplace.find("[|\\\\]");

will finf | and \ as you expected

[heilu]

Hi Bego,
thanks for your feedback. But I do not want to find | or \, but brackets/braces. The "|" was ment as alteration, the "\" to quote the characters with special meaning in RegExp i.e. "\[" and "\]" in classes, "\(" and "\)" outside!
But thanks anyway ...

[heilu]

Thanx again,

you pointed met into the right direction.
The correct syntax is:

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UltraEdit.activeDocument.findReplace.find("[\\[\\]{}()]");

The "\\" is never not necessary in Perl or in JS when using the "/" delimiter, indicating that you work on a RegExp and not a plain text string.
I would prefer syntax from my first post with ".find( /[\[\]{}()]/ ), it indicates directly that I want to have a RegExp.

Regards, Ulf

[mjcarman]

The "\\" is never not necessary in Perl

Yes, well, you aren't programming in Perl. Regular expressions aren't first-class objects in JavaScript.

I would prefer syntax from my first post with ".find( /[\[\]{}()]/ ), it indicates directly that I want to have a RegExp.

Sounds good to me. Send a feature request to IDM.

[Bego]

@heilu: Nice to hear that I pointed you in the right direction by answering your mail 50% correctly
Now I got more time to read...

mj: You got my vote too! It is boring to test a regexp and then have to convert it to "script-style" :-/

greetz, Bego

[jorrasdk]

And my vote too for the feature request.

I'm also tired of this escaping \ in regexp when using UE. You'll see me use this trick in the scripts I post in this forum to ease the copy and pasting of Regexp's:

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UltraEdit.perlReOn();

// Assign a helper prototype function for the RegExp object:
RegExp.prototype.toUEregexp = function() { return this.toString().replace(/^\/|\/$/g, ""); }; /* remove starting and ending / as UE does not recognize these for regexp */

// setup a regexp variale:
var myPerlRegExp = /[\[\]{}()]/;

// then use this in the UE find together with the prototype function:
UltraEdit.activeDocument.findReplace.find(myPerlRegExp.toUEregexp);

[SamHasler]

Regular expressions aren't first-class objects in JavaScript.

They are in some implementations