[QBS] What is the semantic difference between Rule and Transformer?

[Joerg Bornemann]

On 08-Nov-14 14:40, Smirnov Vladimir wrote:

> So I can imagine that Rule wraps some Transformer's functionality. But
> why don't just use only Rules? What can i do with Transformer that Rule
> couldn't cover?

Like Tim already mentioned, rules are triggered by matching file tags, 
transformers OTOH have file paths as input.
Rules can be seen as templates for transformers, or as a generalization.

The only thing you can't do with rules is producing artifacts out of 
thin air, like Stéphane wrote. But it would be possible to enable rules 
that have no input file tags. Shall we? :)

In qmake land transformers are similar to QMAKE_EXTRA_TARGETS and rules 
are like QMAKE_EXTRA_COMPILERS.


BR,

Joerg