numeric.c: improves Float#round rdoc [ci skip]

* numeric.c (flo_round): [DOC] improves Float#round documentation
  to better highlight the half keyword.  [Fix GH-1541]

Author:    Evan Brodie <brodie.evan@gmail.com>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58190 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

doc/contributors.rdoc

@@ -57,6 +57,9 @@ Oliver M. Bolzer
 Alexey Borzenkov
 * a patch for mkmf.rb
 
+Evan Brodie
+* a patch for documentation of Float#round
+
 Richard Brown
 * a patch for configure.in
 

numeric.c

@@ -2215,7 +2215,7 @@ rb_int_truncate(VALUE num, int ndigits)
 
 /*
  *  call-seq:
- *     float.round([ndigits])  ->  integer or float
+ *     float.round([ndigits] [, half: symbol])  ->  integer or float
  *
  *  Rounds +float+ to a given precision in decimal digits (default 0 digits).
  *
@@ -2242,13 +2242,20 @@ rb_int_truncate(VALUE num, int ndigits)
  *     34567.89.round(2)  #=> 34567.89
  *     34567.89.round(3)  #=> 34567.89
  *
- *  If <code>half:</code> optional keyword is given, just-half number
+ *  If the <code>half:</code> optional keyword is given, just-half number
  *  will be rounded according to that value.
  *  Supported values for this keyword are follows.
  *
  *  * <code>:up</code> or +nil+: the result will be rounded away from zero
  *  * <code>:even</code>: the result will be rounded to nearest even number
  *  * <code>:down</code>: the result will be rounded close to zero
+ *
+ *     2.5.round(half: :up)   #=> 3
+ *     2.5.round(half: :even) #=> 2
+ *     2.5.round(half: :down) #=> 2
+ *     3.5.round(half: :up)   #=> 4
+ *     3.5.round(half: :even) #=> 4
+ *     3.5.round(half: :down) #=> 3
  */
 
 static VALUE