function err_exit
{
print -u2 -n "\t"
print -u2 -r ${Command}[$1]: "${@:2}"
let Errors+=1
}
alias err_exit='err_exit $LINENO'
Command=${0integer Errors=0
{
x=abc
x+=def ;} 2> /dev/null
if [[ $x != abcdef ]]
then err_exit 'abc+def != abcdef'
fi
integer i=3
{ i+=4;} 2> /dev/null
if (( i != 7 ))
then err_exit '3+4!=7'
fi
iarray=( one two three )
{ iarray+= (four five six) ;} 2> /dev/null
if [[ ${iarray[@]} != 'one two three four five six' ]]
then err_exit 'index array append fails'
fi
unset iarray
iarray=one
{ iarray+= (four five six) ;} 2> /dev/null
if [[ ${iarray[@]} != 'one four five six' ]]
then err_exit 'index array append to scalar fails'
fi
typeset -A aarray
aarray=( [1]=1 [3]=4 [xyz]=xyz )
aarray+=( [2]=2 [3]=3 [foo]=bar )
if [[ ${aarray[3]} != 3 ]]
then err_exit 'associative array append fails'
fi
if [[ ${then err_exit 'number of elements of associative array append fails'
fi
point=(x=1 y=2)
point+=( y=3 z=4)
if [[ ${point.y} != 3 ]]
then err_exit 'compound append fails'
fi
unset foo
foo=one
foo+=(two)
if [[ ${foo[@]} != 'one two' ]]
then err_exit 'array append to non array variable fails'
fi
exit $((Errors))