permit empty string for ErrPrefix

[jchappelow]

The SetErrPrefix method introduced in #2023 is nice, but I wanted to set it to an empty string "", but discovered that this is treated the same as if you had not set it at all. For example, I want to print structured JSON with an "error" field or similar. To do this and return a non-zero exit code to the OS requires more hoop jumping unless I can remove teh prefix.

It would be preferable if this were a *string field, which would allow setting it to an empty string.

Another unexpected aspect of the prefix, is that a space is always inserted because it is applied with c.PrintErrln(c.ErrPrefix(), err.Error()). Perhaps at this spot, it could simply run c.PrintErrln(err.Error()) if we find that c.ErrPrefix() is ""? This way the prefix field could remain a string (no pointer).

[diegolara93]

@jchappelow Hi I am thinking about how to do this and I was wondering if you would like a variable such as "HideErrPrefix" that you can set to true and it will auto set the prefix to the empty string or just simply be able to set the prefix to "" and not change anything else?

[jchappelow]

@jchappelow Hi I am thinking about how to do this and I was wondering if you would like a variable such as "HideErrPrefix" that you can set to true and it will auto set the prefix to the empty string or just simply be able to set the prefix to "" and not change anything else?

Either works, yeah. For the latter, that's what I'm getting at here:

Another unexpected aspect of the prefix, is that a space is always inserted because it is applied with c.PrintErrln(c.ErrPrefix(), err.Error()). Perhaps at this spot, it could simply run c.PrintErrln(err.Error()) if we find that c.ErrPrefix() is ""? This way the prefix field could remain a string (no pointer).

The use of c.PrintErrln(c.ErrPrefix(), err.Error()) always doesn't permit full control of the error output.