On May 11, 2008, at 5:00 PM, Jeff Johnson wrote:

>
> In Yet Other Words:
>    Is a --queryformat pipeline a pipeline of extractors or  
> transformers?
>
> Patterns and lua wait on deciding the fundamental design issue.  
> Meanwhile
> I'm pretty pleased with the implementation so far, even if there  
> are likely huge
> flaws with type coercion and in-band error reporting (I'm sure I'm  
> gonna hear
> bugs about both of those issues).
>
> Also: Perhaps '|' rather than ':' is a better pipeline element  
> separator so that URI's
> (with embedded ':') can be used in tag format extension parameters.  
> But I haven't a clue atm ...
>

Hmmm, I likely answered my own question by writing it down.

I can have it both ways if I use ':' as an "extractor" format,
and '|' (just like in shell) as a "transformer" format, with an
explicit syntax marker external to the format extension.

A few more implementation details like whether the end-point sink of  
a mixed
extractor/transformer queryformat pipeline should be the analogue of / 
dev/stdout
or /dev/null, but I think having both extractors/transformers in a -- 
queryformat pipeline
with explcit syntax marker can be done (and is useful).

If I'm lucky, I'll be able to sort the in-band vs out-of-band
error reporting too (think: stdout == in-band, stderr == out-of-band,  
for shell scripts)
with something similar. Hmm perhaps a trailing ':' or '|' with an  
empty format token
explicitly, and appropriate defaults implicitly ...

73 de Jeff