On 2011-01-31 0:50, Alex Folland wrote:
On 2011-01-30 21:47, Vladimir Panteleev wrote:
On Mon, 31 Jan 2011 03:57:44 +0200, Alex Folland <lexlex...@gmail.com>
wrote:
I wrote this little program to test for regular expression matches. I
compiled it with in Windows with DMD 2.051 through Visual Studio 2010
with Visual D. It crashes if regexbuf is just the single character,
"*". Why? Shouldn't it match the entire string?
"*" in regular expressions means 0 or more instances of the previous
entity:
http://www.regular-expressions.info/repeat.html
It doesn't make sense at the start of an expression. ".*" is the regexp
that matches anything[1].
std.regex probably can't handle invalid regexps very well. Note that
std.regex is a new module that intends to replace the older std.regexp,
but still has some problems.
Okay, so that particular regex is invalid. Yeah, it still shouldn't
crash. You're right. How should I prevent my program from crashing
without fixing std.regex (code I definitely don't trust myself to
touch)? Would the Scope statement be useful? I still can't figure out
exactly what it does. I tried using scope(exit)writeln("Bad regex.");
just before my foreach loop, but it still crashes. I then tried changing
"exit" to "failure", but that didn't help either; same behavior. Am I
using scope wrong?
Yeah, you nitwit. You didn't realize that scope(failure) doesn't
prevent the program from exiting and throwing an exception. It merely
runs the code inside itself before throwing an exception and exiting.
However, one can use scope(failure){writeln("Bad regex");break;} to
prevent an actual crash and just write "Bad regex"! I expected that it
would break automatically out of scope. I was wrong. Anyway, this is
beautiful. I love D. Haha.
