Hi,

I'm fairly new to regex. I know that the * is a greedy match. This is currently giving me undesired results. How do I rewrite the regex below so it will match up to the first } symbol it encounters.

To put this in context, I'm writing a regex based syntax highlighter. Here is sample code I am having trouble with:

   function MyFunc: {$ifdef FPC}longword{$else}word{$endif};

The following regex matches the first { symbol up until the last } symbol. :-( I obviously want it to stop at the first } it encounters.

This is the regex I'm currently using:

\s*\{\$.*\}

Any regex wizards that could help me here?

Regards,
- Graeme -

Try this:
\{.*[^\}]\}

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ik wrote

Try this: \{.*[^\}]\}

thanks for the quick response, but that doesn't seem to work either. You can try with Lazarus IDE's Find dialog. Just tick the "Regular expression" checkbox, and untick everything else. My code uses the same regex engine as Lazarus IDE does.

You left out the $ symbol after the first { symbol, but even so the following still matches too much.

\{\$.*[^\}]\}

I also tried this...

\{\$.*[^\{]\}

still no luck.

Regards,
- Graeme -

can you please explain again what you are looking for ? the content inside the curly braces after the $ sign ?

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Ah, I found it. TRegExpr supports the non-greedy syntax, so I changed the above regex to read:

\{\$.*?\}

*? makes it non-greedy. :-)

Regards,
- Graeme -

Only on Perl like syntax, not on POSIX regex.

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Graeme Geldenhuys wrote

On 08/10/2011 05:21 PM, ik wrote: > Try this: > \{.*[^\}]\} thanks for the quick response, but that doesn't seem to work either.

...

without testing, from memory

All the above have

.* => any
then try to match ONE not "}"

So either use ( omit spaces, they are for readability)

\{ \$ .*? \}

or
\{ \$ [^ \} ]* \}

\{\$.*?\} in preg dialect

matches:
17:{$ifdef FPC}
37:{$else}
48:{$endif}

Ludo

Martin wrote

or ?\{ ?\$ ? ? [^ ?\} ?]* ? ?\}

Thanks Martin, the above syntax makes more sense to me, and is more readable. I tried it and it works perfectly for what I wanted.