syntax question

syntax question

[Ray Andrews]

${${(z)string}[1]}

... that does what I expect, and it's readable, however I'm curious why 
this does not say the same thing:

${(z)string[1]}

... How can that mean anything different?  It seems to just sorta get to 
the point more quickly and given the " (z) " it seem unintuitive that it 
would only print the first character just as:

${string[1]}

... does.  So in the second line the " (z) " seems to do nothing.  I'd 
expect the first two lines to be semantically the same and the third 
line to be a single character.  Is this explainable?  I know it's a 
nit-pick but I'd like to understand it.

Re: syntax question

[Bart Schaefer]

On Wed, Mar 21, 2018 at 4:15 PM, Ray Andrews <rayandrews@eastlink.ca> wrote:
> ${${(z)string}[1]}
>
> ${(z)string[1]}
>
> ... How can that mean anything different?

Operator precedence.  The second one is equivalent to
${(z)${string[1]}}, as you observed.

Re: syntax question

[Sebastian Gniazdowski]

On 22 marca 2018 at 02:30:52, Bart Schaefer (schaefer@brasslantern.com) wrote:
> On Wed, Mar 21, 2018 at 4:15 PM, Ray Andrews wrote:
> > ${${(z)string}[1]}
> >
> > ${(z)string[1]}
> >
> > ... How can that mean anything different?
> 
> Operator precedence. The second one is equivalent to
> ${(z)${string[1]}}, as you observed.

Also, better to use (Az), utilizing your underrated patch, because:

% a='abcd'
% echo ${${(z)a}[1]}
a

-- 
Sebastian Gniazdowski
psprint /at/ zdharma.org

syntax question

[Ray Andrews]

If I have a variable who's name is partially constructed from the 
contents of another variable:

        eval "t$bb="
        eval "echo \$t$bb"

... the above handles it all fine, but is there a simpler syntax?  I 
understand that most/much of what 'eval' does can be written more elegantly.