[Dancer-users] User-friendly errors on YAML parsing failures (was: Re: dancer croaking with a strange error in config.yml)

[damien krotkine]

On 15 November 2011 10:46, sawyer x <xsawyerx at gmail.com> wrote:
> On Tue, Nov 15, 2011 at 11:42 AM, damien krotkine <dkrotkine at gmail.com>
> wrote:
>>
>> try to parse the config file. If it fails, try to parse the error
>> message sent by YAML, and extract the line / column from the message.
>> It's usually reported accurately. Then 2 cases : if Carp::Verbose is
>> false (general case), perform a croak (not a confess), with a human
>> message saying " failed to parse config file '$filename', at line 42,
>> column 12. Take extra care to spaces and tabs, blabla".
>> If Carp::Verbose is true, then do a confess instead, appending the
>> full YAML message.
>
> Disagree. We shouldn't be trying to parse error messages of other modules.
> You cannot be sure it will be consistent between versions or between engines
> or between modules.
>
> We should be outputting a "Reading your configuration file failed. This was
> the error message: $msg\n"
> Something like that, no more.

Well, if the YAML error message is short enough and explicit enough,
sure. But if it's a pile of 500 stack traces, it's not going to help.
Also, YAML tend to have criptic concept like BAD_BLOCKS, which the
user has to translate into "huh, probably a wrong character".

Imho this is what causes the issues. Don't you agree ?