[variables] try to clarify the difference between item and list assig…

…nment

lib/variables.pod

@@ -14,12 +14,12 @@ the documentation in L<List>.
 
 =begin table
 
-    Sigil   Type constraint          Default type  Flattens
-    =====   ===============          ============  ========
-    $       Mu (no type constraint)  Any           No
-    &       Callable                 Callable      No
-    @       Positional               Array         Yes
-    %       Associative              Hash          Yes
+    Sigil   Type constraint          Default type  Flattens  Assignment
+    =====   ===============          ============  ========  ==========
+    $       Mu (no type constraint)  Any           No        item
+    &       Callable                 Callable      No        item
+    @       Positional               Array         Yes       list
+    %       Associative              Hash          Yes       list
 
 =end table
 
@@ -29,14 +29,23 @@ Examples:
     my @array  = 1, 2, 3;   # Array-variable with three elements
     my %hash   = London => 'UK', Berlin => 'Germany';
 
-Assignment to C<%> and C<@>-sigiled variables is special-cased
-syntactically. Instead of replacing the variable on the left-hand side with
-those of the right-hand side, it empties the variable, and fills it
-again with the values from the right-hand side.
+There are two types of assignment, I<item assignment> and I<list assignment>.
+Both use the equal sign C<=> as operator. The distinction wheter a C<=>
+means item or list assignment is based on the syntax of the left-hand side.
+(TODO: explain in detail, or do that in L<operators>).
 
-    my $item = (1, 2); say $item.WHAT;   # Parcel()
-    my @arr  = (1, 2); say @arr.WHAT;    # Array()
-    my %hash = (1, 2); asy %hash.WHAT;   # Hash()
+Item assignment places the value from the right-hand side into the variable
+(container) on the left.
+
+List assignment leaves the choice of what to do to the variable on the left.
+
+For example L<Array> variables (C<@> sigil) empty themselves on list assignment, and then
+put all the values from the right-hand side into themselves. Contrary to item
+assignment, it means that the type of the variable on the left always stays
+C<Array>, regardless of the type of the left-hand side.
+
+Note that the item assignment has tighter precedence than list assigment, and
+also tighter than the comma. See L<operators> for more details.
 
 =head1 Twigils