* ext/digest/digest.c: Add documentation for Digest.

  [Feature #10452][ruby-core:66001][ci skip]
  * remove HMAC from list of digest algorithms,
  * add MD5 in list of digest algorithms,
  * add information about writing a C digest implementation using Digest::Base,
  * add documentation for Digest::Base public methods.
* ext/digest/md5/md5init.c: add examples for MD5.
* ext/digest/rmd160/rmd160init.c: add examples for Digest::RMD160.
* ext/digest/sha1/sha1init.c: add examples for Digest::SHA1.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56455 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 20 insertions, 0 deletions

diff --git a/ext/digest/md5/md5init.c b/ext/digest/md5/md5init.c
index a6afedef69..41f966fa7b 100644
--- a/ext/digest/md5/md5init.c
+++ b/ext/digest/md5/md5init.c
@@ -22,9 +22,29 @@ static const rb_digest_metadata_t md5 = {
 };
 
 /*
+ * Document-class: Digest::MD5 < Digest::Base
  * A class for calculating message digests using the MD5
  * Message-Digest Algorithm by RSA Data Security, Inc., described in
  * RFC1321.
+ *
+ * MD5 calculates a digest of 128 bits (16 bytes).
+ *
+ * == Examples
+ *  require 'digest'
+ *  
+ *  # Compute a complete digest
+ *  Digest::MD5.hexdigest 'abc'      #=> "90015098..."
+ *
+ *  # Compute digest by chunks
+ *  md5 = Digest::MD5.new               # =>#<Digest::MD5>
+ *  md5.update "ab"
+ *  md5 << "c"                           # alias for #update
+ *  md5.hexdigest                        # => "90015098..."
+ *
+ *  # Use the same object to compute another digest
+ *  md5.reset
+ *  md5 << "message"
+ *  md5.hexdigest                        # => "c13557f2..."
  */
 void
 Init_md5(void)