set -o nounset; foo=(); print ${foo:#bar}

set -o nounset; foo=(); print ${foo:#bar}

[Roman Neuhauser]

hello,

i encountered a behavior i don't like and would like to get rid of. :)

  roman@wrench ~ 0 1074 0 > print $ZSH_VERSION
  5.0.5
  roman@wrench ~ 0 1075 0 > set -o nounset
  roman@wrench ~ 0 1076 0 > foo=()
  roman@wrench ~ 0 1077 0 > print $foo

  roman@wrench ~ 0 1078 0 > print ${foo:#bar}
  zsh: foo: parameter not set
  roman@wrench ~ 0 1079 1 > 

the problematic part is ${foo:#bar} triggering nounset.  FMPOV it *is*
set (but null), so i'd say the observed behavior is a bug.

is it fixable?  or is there at least a good workaround?  (stuffing the
array with a sentry is not a good workaround.)

-- 
roman

Re: set -o nounset; foo=(); print ${foo:#bar}

[Bart Schaefer]

On Sep 6,  8:47pm, Roman Neuhauser wrote:
}
}   roman@wrench ~ 0 1078 0 > print ${foo:#bar}
}   zsh: foo: parameter not set
}   roman@wrench ~ 0 1079 1 > 
} 
} the problematic part is ${foo:#bar} triggering nounset.  FMPOV it *is*
} set (but null), so i'd say the observed behavior is a bug.

This seems to be ${name:#word} being confused with ${name:?word} where
the ":" means to treat an empty parameter as unset.  This also affects
the newer ${name:^word} form.

} is it fixable?

I don't immediately see a simple code change that would do so, but I'm
sure it can eventually be fixed.

} or is there at least a good workaround?  (stuffing the
} array with a sentry is not a good workaround.)

You can use ${foo##bar(#e)} with extendedglob, I think, but it may
depend on context.  Without extendedglob I don't see a good way.

Re: set -o nounset; foo=(); print ${foo:#bar}

[Roman Neuhauser]

# schaefer@brasslantern.com / 2014-09-06 12:34:33 -0700:
> I don't immediately see a simple code change that would do so, but I'm
> sure it can eventually be fixed.

cool!  btw will this be tracked somewhere?

> You can use ${foo##bar(#e)} with extendedglob, I think, but it may
> depend on context.  Without extendedglob I don't see a good way.

(reminder to self: (#e) is like $ in REs)

thanks a lot!  extendedglob is fine and the workaround works perfectly.

-- 
roman