SyntaxEditor hangs - SyntaxEditor for Windows Forms Forum

Posted 16 years ago by Barry Ahrens - Member of Technical Staff, Teledyne Scientific

Version: 4.0.0274

Do I have an infinite loop or something in my language that I have implemented? When using the editor with the following rules, the editor hangs/locks up when I type something like

"KEYWORD1 veryveryveryveryveryverylongstringvariable , F"

As soon as I hit the "F" key, the application hangs. I have narrowed it down to the 2nd rule below. The 1st rule is NOT causing the problem. As you are experts in the parsing rules, do you see a problem in the 2nd rule?

Thanks very much!

1st rule: This works fine.......


        <!-- Flags F -->
        <ExplicitPatternGroup TokenKey="Token1" Style="Style1" LookBehind="(KEYWORD1) {WhitespaceMacro}+ " LookAhead="{NonWordMacro}" CaseSensitivity="Sensitive">
          <ExplicitPatterns>
            F0 F1 F2 F3 F4 F5 F6 
          </ExplicitPatterns>
        </ExplicitPatternGroup>

2nd rule: This is Not OK:


    <ExplicitPatternGroup TokenKey="Token2" Style="Style2" LookBehind="(KEYWORD2) {WhitespaceMacro}+ ({WordMacro}+ {WhitespaceMacro}*)+ [,]+ {WhitespaceMacro}* " LookAhead="{NonWordMacro}" CaseSensitivity="Sensitive">
                    <ExplicitPatterns>
                        F7 F8 F9 
                    </ExplicitPatterns>
                </ExplicitPatternGroup>

Comments (1)

Posted 16 years ago by Actipro Software Support - Cleveland, OH, USA

Hi Barry,

Yes your LookBehind could cause a lot of extra backwards parsing overhead the way you have it. Whenever you start adding lots of '+' or '*' regular expressions, you add processing. And as you add multiple instances of them, you are starting to exponentially add procesing.

In your case you are allowing many levels of words and whitespaces which is probably where it is getting locked up since it is scanning those constantly. You really should simplify your LookBehind or find another way to do it, and that definitely will help.

Actipro Software Support

The latest build of this product (v24.1.0) was released 2 months ago, which was after the last post in this thread.

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