Cryptic Error message with scope(failure) and AA
Is this known?
I've heard there are many problems with associative arrays.
dmd 2.063
---
module scopefailtest;
int[char] AAarray;
void main(string[] args)
{
AAarray = ['a':1, 'b':2, 'c':3];
foreach(aa; AAarray)
{
scope(failure)continue;
aa = 32;
}
}
---
dmd output
Error: cannot implicitly convert expression (0) of type int to
void
Works without scope(failure)
Works with non Associative Array
No helpful description.
No file or line number.
Very hard to find.
Re: Cryptic Error message with scope(failure) and AA
On Saturday, 29 June 2013 at 20:45:12 UTC, Anthony Goins wrote:
Is this known?
I've heard there are many problems with associative arrays.
dmd 2.063
---
module scopefailtest;
int[char] AAarray;
void main(string[] args)
{
AAarray = ['a':1, 'b':2, 'c':3];
foreach(aa; AAarray)
{
scope(failure)continue;
aa = 32;
}
}
---
dmd output
Error: cannot implicitly convert expression (0) of type int to
void
Works without scope(failure)
Works with non Associative Array
No helpful description.
No file or line number.
Very hard to find.
Seems like there are several levels of wrong actually: What do
you expect scope(failure)continue to do exactly?
It compiles, but it doesn't make much sense?
When I run this code:
void main(string[] args)
{
foreach(aa; 0 .. 3)
{
scope(failure){writeln(error);continue;}
writeln(aa);
throw new Exception();
}
}
I get:
0
error
1
error
2
error
Which is wrong, since a scope(failure) is not supposed to catch
the exception. In this case, the continue short-circuits the
compiler generated rethrow.
DMD is on to something, because if you replace failure with
exit or success, then it complains with: Error: continue is
not inside a loop.
Re: Cryptic Error message with scope(failure) and AA
On Saturday, June 29, 2013 23:26:33 monarch_dodra wrote: Which is wrong, since a scope(failure) is not supposed to catch the exception. In this case, the continue short-circuits the compiler generated rethrow. I thought that there was a bug report on that (probably suggesting that the compiler make such a continue illegal), but I can't find it right now. - Jonathan M Davis
Re: Cryptic Error message with scope(failure) and AA
Jonathan M Davis: I thought that there was a bug report on that (probably suggesting that the compiler make such a continue illegal), but I can't find it right now. If you can't find it, it's better to file it because it's better to have a bug two times in Bugzilla than no times. Bye, bearophile
Re: Cryptic Error message with scope(failure) and AA
On 06/29/2013 02:26 PM, monarch_dodra wrote: DMD is on to something, because if you replace failure with exit or success, then it complains with: Error: continue is not inside a loop. Hmmm... 'continue' and others are disallowed only for scope(exit) and scope(success): http://dlang.org/statement.html#ScopeGuardStatement A scope(exit) or scope(success) statement may not exit with a throw, goto, break, continue, or return; nor may it be entered with a goto. Ali
Re: Cryptic Error message with scope(failure) and AA
Seems like there are several levels of wrong actually: What do you expect scope(failure)continue to do exactly? I was reading an array of files (Document[string]). Stuck the scope(failure)continue in late at night apparently to skip reading files that no longer exist. Forgot about it. Still don't remember doing it. Next day tried to build my project (30+ files). I had no clue what was going on given the error message. The problem for me was not the error itself but the message. Thanks for the reply. Didn't realize there was a problem with 'continue' from a scopeguard.
