improvements from #perl6; added working examples

Author: perlpilot

misc/perl6advent-2010/articles/feed.pod

@@ -8,23 +8,30 @@ or written code similar to this:
 In this construction, the data flows from the C<@original> array which
 feeds into the C<grep>, and that, in turn, feeds into the C<map>, and
 then into the C<sort>, and then finally, the result is assigned to the
-C<@new> array. Because they each take a list as their final
-parameter, simply by juxtposition, the data feeds from one operation
+C<@new> array.  Because they each take a list as their final parameter,
+Simply by juxtposition, the data feeds leftward from one operation
 to the next.
 
 Perl 6, on the other hand, makes this idea of data flowing from one
 operation to another explicit by introducing the I<feed operator>. The
-above Perl 5 code would be written like this in Perl 6:
+above Perl 5 code could be written like this in Perl 6:
 
     my @new <== sort { ... } <== map { ... } <== grep { ... } <== @original;
 
-So, what do we gain from this? Normally, when reading code, you read
-from left to right. In the original Perl 5 code you would read from left
-to right until you realize that you're dealing with constructions where
-the direction of flow is right to left, then you jump to the end and
-follow the processing in a right-to-left manner. In Perl 6 there is now
-a prominent syntactic marker that clues you in to the leftward flowing
-nature of the data.
+Note that tmtowtdi is alive and well in Perl 6.  You could have also
+written much the same as in Perl 5:
+
+    my @new = sort { ... }, map { ... }, grep { ... }, @original;
+
+The only difference would be the addition of commas.
+
+So, what do we gain from these feed operators?  Normally, when reading
+code, you read from left to right.  In the original Perl 5 code you
+would read from left to right until you realize that you're dealing with
+constructions where the direction of flow is right to left, then you
+jump to the end and follow the processing in a right-to-left manner.  In
+Perl 6 there is now a prominent syntactic marker that clues you in to
+the leftward flowing nature of the data.
 
 Still, the right-to-left nature of this code is somewhat troublesome.
 It may not seem so onerous if all of the code fits on one line as
@@ -33,8 +40,20 @@ C<sort> were little longer. Finding the end of the statement could be a
 bit annoying.
 
 Luckily, Perl 6 has another feed operator that allows you to write the
-same statement in a left-to-right fashion:
+same code in a left-to-right fashion:
 
     @original ==> grep { ... } ==> map { ... } ==> sort { ... }  ==> my @new;
 
+This works exactly the same as before only the direction of flow has been changed.
+
+
+Here are a couple of examples of real, working Perl 6 code using the
+feed operators:
+
+    my @random-nums = (1..100).pick(*);
+    my @odds-squared <== sort <== map { $_ ** 2 } <== grep { $_ % 2 } <== @random-nums;
+    say @odds-squared.join(" ");
 
+    my @rakudo-people = <scott patrick carl moritz jonathan jerry stephen>;
+    @rakudo-people ==> grep { /at/ } ==> map { .ucfirst } ==> my @who-its-at;
+    say @who-its-at.join(" ");