Document next/last with a value in 6.e

doc/Language/control.rakudoc

@@ -1210,6 +1210,22 @@ for @x -> $x {
 
 prints "1245".
 
+You can also use C<last> in a C<map>: the above example then looks
+like:
+
+=begin code
+my @x = 1, 2, 3, 4, 5;
+print @x.map: -> $x {
+    next if $x == 3;
+    $x
+}
+=end code
+
+prints "1 2 4 5" because a space is added between entries of a C<Seq>
+when it is stringified.  Note that that C<print> was not put inside
+the block of the C<map>, as it generally considered bad practice to
+run a C<map> for its side-effects (in this case, the C<print>.
+
 If the L<C<NEXT> phaser|/language/phasers#NEXT> is present, it runs
 before the next iteration:
 
@@ -1229,6 +1245,20 @@ while ($i < 10) {
 # OUTPUT: «1 is odd.␤3 is odd.␤5 is odd.␤7 is odd.␤9 is odd.␤»
 =end code
 
+In version 6.e.PREVIEW (available as of the 2021.07 Rakudo compiler
+release), it is also possible to return a value with the C<next>
+statement.  This is particularly useful when using it in a C<map>:
+
+=begin code
+my @x = 1, 2, 3, 4, 5;
+print @x.map: -> $x {
+    next 42 if $x == 3;
+    $x
+}
+=end code
+
+prints "1 2 42 4 5".
+
 In a L<whenever|/language/concurrency#index-entry-whenever>
 block, C<next> immediately exits the block for the current value:
 
@@ -1250,7 +1280,6 @@ last statement values returns C<Empty> for the iterations they run on.*
 The C<last> command immediately exits the loop in question.
 
 =begin code
-
 my @x = 1, 2, 3, 4, 5;
 for @x -> $x {
     last if $x == 3;
@@ -1260,6 +1289,22 @@ for @x -> $x {
 
 prints "12".
 
+You can also use C<last> in a C<map>: the above example then looks
+like:
+
+=begin code
+my @x = 1, 2, 3, 4, 5;
+print @x.map: -> $x {
+    last if $x == 3;
+    $x
+}
+=end code
+
+prints "1 2" because a space is added between entries of a C<Seq> when
+it is stringified.  Note that that C<print> was not put inside the
+block of the C<map>, as it generally considered bad practice to run
+a C<map> for its side-effects (in this case, the C<print>.
+
 If the L<C<LAST> phaser|/language/phasers#LAST> is present, it runs
 before exiting the loop:
 
@@ -1280,8 +1325,22 @@ while ($i < 10) {
 # OUTPUT: «The last number was 5.␤»
 =end code
 
-*Since version 6.d, the C<last> command in a loop that collects its last
-statement values returns C<Empty> for the iterations they run on.*
+Since version 6.d, the C<last> command in a loop that collects its last
+statement values returns C<Empty> for the iterations they run on.
+
+In version 6.e.PREVIEW (available as of the 2021.07 Rakudo compiler
+release), it is also possible to return a value with the C<last>
+statement.  This is particularly useful when using it in a C<map>:
+
+=begin code
+my @x = 1, 2, 3, 4, 5;
+print @x.map: -> $x {
+    last 42 if $x == 3;
+    $x
+}
+=end code
+
+print "1 2 42".
 
 =head1 X<redo|Control flow,redo>