Re: history expansion

[Peter Stephenson <pws@csr.com>]

Roman Neuhauser wrote:
>     not knowing the internals of the history expansion, what is the
>     probability of nested expansion appearing in zsh?

It doesn't look *that* difficult, but it's not completely trivial (some
of the state is currently kept in global variables) so it's a bit of
work for a feature which only appeals to the few who like lines like

  !!:s/!!3/!-2:s,foo,bar,/

but if anyone thinks they're good at making code recursive it might be
an interesting project.  Your starting point is getsubsargs() and
hdynread2() in hist.c.  (I'm making the optimistic assumption that the
character input mechanism is already robust enough to handle it.)

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


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