$foo{bar}[ blat(\%foo) ] = { a => 'fool' };

##</code><code>##

foo$ bar {} foo%\ blat [] (a => 'fool') {} =;

# or, if you feel better binding things a little closer...

foo$ bar{} (foo%\ blat)[] (a => 'fool'){} =;

##</code><code>##

foo$ x$[]  # $foo[$x]

##</code><code>##

foo$ x$[] =  # $foo = [$x]

##</code><code>##

# what is:
foo$ x$[] y$[] =;

# is it...
$foo[$x] = [$y];

# or...
$foo = [$x][$y];

# it can't be the second (since that's a syntax error)