From b3ec381ed12b039cede8386b80ad2cb11c0af03d Mon Sep 17 00:00:00 2001
From: Marius Gavrilescu <marius@ieval.ro>
Date: Sat, 23 Jun 2018 20:50:56 +0300
Subject: [PATCH] Also write documentation

---
 lib/Digest/HighwayHash.pm | 38 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/lib/Digest/HighwayHash.pm b/lib/Digest/HighwayHash.pm
index e69ad0a..201886d 100644
--- a/lib/Digest/HighwayHash.pm
+++ b/lib/Digest/HighwayHash.pm
@@ -34,12 +34,21 @@ Digest::HighwayHash - XS fast strong keyed hash function
   say join ' ', @{highway_hash256([1, 2, 3, 4], 'hello')};
   # 8099666330974151427 17027479935588128037 4015249936799013189 10027181291351549853
 
+  my $state = Digest::HighwayHash->new([1, 2, 3, 4]);
+  $state->append('he');
+  $state->append('llo');
+  say join ' ', @{$state->finish128};
+  # 3048112761216189476 13900443277579286659
+
 =head1 DESCRIPTION
 
 HighwayHash is a fast and strong keyed hash function, documented at
 L<https://github.com/google/highwayhash>.
 
-Three functions are exported by this module, all by default:
+This module has a procedural interface (used to hash an entire
+message) and an OO interface (used to hash a message bit by bit). The
+procedural interface is made of three functions, all exported by
+default:
 
 =over
 
@@ -62,6 +71,33 @@ The key must be a 4-element arrayref, with each element either a
 number or (on Perls without 64-bit numbers) a L<Math::Int64> object. The result is an array of exactly four numbers or (on Perls without 64-bit numbers) L<Math::Int64> objects.
 
 
+=back
+
+The OO interface has these methods:
+
+=over
+
+=item Digest::HighwayHash->B<new>(I<\@key>)
+
+Initialize a new C<Digest::HighwayHash> state with a given key. The
+B<append> method will be called with this state and parts of the
+message, and then one of the B<finish*> methods will be called to
+compute the result.
+
+=item $state->B<append>(I<$input>)
+
+Append I<$input> to the message to be hashed by $state.
+
+=item $state->B<finish64>
+
+=item $state->B<finish128>
+
+=item $state->B<finish256>
+
+Compute and return the 64-bit, 128-bit, or respectively 256-bit
+HighwayHash of this state. The return values are the same as in the
+procedural interface.
+
 =back
 
 =head1 SEE ALSO
-- 
2.30.2