From: Matthew Smillie <M.B.Smillie@...>
Date: 2005-11-24T20:37:49+09:00
Subject: Re: ruby error messages

On Nov 24, 2005, at 8:01, Sam Joseph wrote:

> Hi there,
>
> Is the meaning of the ruby error messages defined anywhere? E.g. I get
> something like:
>
> NameError: uninitialized constant Blah
>
> and maybe you'll tell me it's self explanatory, but it would be  
> nice to
> look through a list of errors and read more about what they mean. I
> searched the web and asked on ruby-lang irc channel but haven't turned
> up anything yet.

Sounds like a decent wiki page.

What it means is that something Ruby considers a constant is being  
used without being initialised, which I suppose is obvious.

The less-obvious bit is "something Ruby considers a constant" which  
is "an identifier that starts with an uppercase letter".  All class  
and module names, for instance.  (Forgive me if that's a little  
amorphous - I don't have a language grammar to poke through for the  
actual definition).

So, for this error, I would look for typos, particularly in  
assignment statements (as one poster mentioned), but also in class  
definitions - maybe you defined your class as "Balh" when you meant  
"Blah".  For particularly tricky cases, you can get a list of  
constants via 'Module.constants'.

matthew smillie.