Merge pull request #305 from gfldex/master

add example for hyperoperator with user defined operator

doc/Language/operators.pod

@@ -223,6 +223,32 @@ C<%outer »+» %inner;>   only keys of %inner that exist in %outer will occur in
     my %inner = 1,2 Z=> <x z>; 
     say %outer «~» %inner; # {"1" => "ax", "2" => "bz"}
 
+Hyper operators can take user defined operators as its operator argument.
+
+    sub pretty-file-site (Int $size --> Str) {
+        # rounding version of infix:</>(Int,Int)
+        sub infix:<r/>(Int \i1, Int \i2) {
+            round(i1 / i2, 0.1)
+        }
+    
+        # we build a vector of fractions of $size and zip that with the fitting prefix
+        for $size «[r/]« (2**60, 2**50, 2**40, 2**30, 2**20, 2**10)
+                  Z      <EB     PB     TB     GB     MB     KB> -> [\v,\suffix] {
+            # starting with the biggest suffix, we take the first that is 0.5 of that suffix or bigger
+            return v ~ ' ' ~ suffix if v > 0.4
+        }
+        # this be smaller or equal then 0.4 KB
+        return $size.Str;
+    }
+    
+    for 60, 50, 40, 30, 20, 10 -> $test {
+        my &a = { (2 ** $test) * (1/4, 1/2, 1, 10, 100).pick * (1..10).pick };
+        print pretty-file-site(a.Int) xx 2, ' ';
+    }
+
+    # OUTPUT: «10 EB 4 EB 2 PB 5 PB 0.5 PB 4 TB 300 GB 4.5 GB 50 MB 200 MB 9 KB 0.6 MB»
+
+
 =head2 Reduction Operators
 
 Reduction operators apply any infix operator, surrounded by C<[> and C<]>,