[XeTeX] Contextual shaping

[Simon Cozens]

On 27/11/2013 21:46, Khaled Hosny wrote:
> measure_native_node is called by the WEB code (called set_native_metrics
> there), check xetex.web for "collect_native:", that is where bulk of the
> work is done. Check also "@<Merge sequences of words using AAT".

Aha, I see it now, I think! Reading the WEB documentation for native_word_node 
helped.

So a run of letter characters in the same font are assembled into a 
native_word_node by collect_native, and then shaped by set_native_metrics. 
That makes sense - thanks!