I was wanting to print, a true|false type text
based on a boolean.
What first came to mine was using an array holding the
false & true values (in that order) and indexed by the
((value)) as 0=false, !0=true since arithmetic evals
yield true or false depending on whether the expression
evaluates to non-zero or zero, respectively.
Then I wondered if there was a way to do that w/o arrays,
and wondered about this possible syntax:
printf "%s\n" ${(yes no)[(($expr))]}
I know it doesn't currently work that way, but is there
any syntax-confusion-related reason why it couldn't?
Currently, input:
unset a
a=(yes no)
#for y/n conditions:
declare -i y=0 n=1
printf "%s, %s\n" "${a[((y))]}" "${a[((n))]}"
yields:
yes, no
The extra (()) are really superfluous if you ensure the value
in [] evals to <0|1> in the opposite sense that it would in (()),
or just reversing the list order of the T/F values in the array:
unset a
a=(no yes); declare -i y=0 n=1
printf "%s, %s\n" "${a[!y]}" "${a[!n]}"
yes, no
Would there be a syntax conflict in allowing an array initializer list
in-place of 'a'? like (53 chars):
printf "%s, %s\n" "${(no yes)[!y]}" "${(no yes)[!n]}"
Obviously, the whole thing could be wrapped in a sub, but
that would incur a process fork w/every yes/no as well as
the array assignment (to be safe), i.e. (103 chars):
yn() { declare -a ny=(no yes); printf "%s" "${ny[$# && !$1]}"; }
printf "%s, %s\n" "$(yn $y)" "$(yn $n)"
Anyway -- was mostly interested in whether or not something like that
might be possible to add (or allow) as a feature enhancement?
Since the list-form generates a syntax error, I can't see allowing it
to be a compatibility problem in any existing, working scripts -- which
would seem to "ok" it from a syntax POV. Would it be too hard to
implement given that the array-initializer syntax seems to be limited
to being an initialization-value for an array?
