Expand on negated char classes. Closes #40.

lib/Language/regexes.pod

@@ -284,6 +284,24 @@ write between the C< [ ] > is the backslashed forms for character classes.
     / <[02468]>
     # because the first one also contains "weird" unicodey digits
 
+To negate a character class, put a C<-> after the opening angle:
+
+    say 'no quotes' ~~ /  <-[ " ]> + /;  # matches characters except "
+
+A common pattern for parsing quote-delimited strings involves negated
+character classes:
+
+    say '"in quotes"' ~~ / '"' <-[ " ]> * '"'/;
+
+This first matches a quote, then any characters thare aren't quotes, and then
+a quote again. The meaning of C<*> and C<+> in the examples above are
+explained in L<section Quantifier|#Quantifier>.
+
+Just as you can use the C<-> for both set difference and for negation of a
+single value, you can also explicitly put a C<+> in front:
+
+    / <+[123]> /  # same as <[123]>
+
 =head1 Quantifier
 
 A quantifier makes a preceding atom match not exactly once, but rather a