* array.c: Document #<=> return values and formatting

* bignum.c: ditto
* file.c: ditto
* object.c: ditto
* numeric.c: ditto
* rational.c: ditto
* string.c: ditto
* time.c: ditto


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39418 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

9 files changed, 73 insertions, 40 deletions

diff --git a/ChangeLog b/ChangeLog
index 699e3a3d85..2b5e6aa67c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+Sat Feb 23 12:35:00 2013  Zachary Scott  <zachary@zacharyscott.net>
+
+	* array.c: Document #<=> return values and formatting
+	* bignum.c: ditto
+	* file.c: ditto
+	* object.c: ditto
+	* numeric.c: ditto
+	* rational.c: ditto
+	* string.c: ditto
+	* time.c: ditto
+
 Sat Feb 23 10:50:00 2013  Zachary Scott  <zachary@zacharyscott.net>
 
 	* array.c (rb_ary_diff, rb_ary_and, rb_ary_or): Document return order
diff --git a/array.c b/array.c
index ba93a050ed..84c386cefa 100644
--- a/array.c
+++ b/array.c
@@ -3703,6 +3703,8 @@ recursive_cmp(VALUE ary1, VALUE ary2, int recur)
  *  Comparison --- Returns an integer (+-1+, +0+, or <code>+1</code>) if this
  *  array is less than, equal to, or greater than +other_ary+.
  *
+ *  +nil+ is returned if the two values are incomparable.
+ *
  *  Each object in each array is compared (using the <=> operator).
  *
  *  Arrays are compared in an "element-wise" manner; the first two elements
diff --git a/bignum.c b/bignum.c
index 8601d80342..54dd75cf89 100644
--- a/bignum.c
+++ b/bignum.c
@@ -1520,9 +1520,11 @@ rb_integer_float_eq(VALUE x, VALUE y)
  *  call-seq:
  *     big <=> numeric   -> -1, 0, +1 or nil
  *
- *  Comparison---Returns -1, 0, or +1 depending on whether <i>big</i> is
- *  less than, equal to, or greater than <i>numeric</i>. This is the
- *  basis for the tests in <code>Comparable</code>.
+ *  Comparison---Returns -1, 0, or +1 depending on whether +big+ is
+ *  less than, equal to, or greater than +numeric+. This is the
+ *  basis for the tests in Comparable.
+ *
+ *  +nil+ is returned if the two values are incomparable.
  *
  */
 
diff --git a/file.c b/file.c
index 69b5a7cf4b..6742cf022e 100644
--- a/file.c
+++ b/file.c
@@ -326,8 +326,10 @@ static struct timespec stat_mtimespec(struct stat *st);
  *  call-seq:
  *     stat <=> other_stat    -> -1, 0, 1, nil
  *
- *  Compares <code>File::Stat</code> objects by comparing their
- *  respective modification times.
+ *  Compares File::Stat objects by comparing their respective modification
+ *  times.
+ *
+ *  +nil+ is returned if the two values are incomparable.
  *
  *     f1 = File.new("f1", "w")
  *     sleep 1
diff --git a/numeric.c b/numeric.c
index 5c629d79c9..fe85d6cc31 100644
--- a/numeric.c
+++ b/numeric.c
@@ -1038,10 +1038,10 @@ num_eql(VALUE x, VALUE y)
 
 /*
  *  call-seq:
- *     num <=> other  ->  0 or nil
+ *     number <=> other  ->  0 or nil
  *
- *  Returns zero if <i>num</i> equals <i>other</i>, <code>nil</code>
- *  otherwise.
+ *  Returns zero if +number+ equals +other+, otherwise +nil+ is returned if the
+ *  two values are incomparable.
  */
 
 static VALUE
@@ -1129,13 +1129,15 @@ rb_dbl_cmp(double a, double b)
 
 /*
  *  call-seq:
- *     flt <=> real  ->  -1, 0, +1 or nil
+ *     float <=> real  ->  -1, 0, +1 or nil
+ *
+ *  Returns -1, 0, +1 or nil depending on whether +float+ is less than, equal
+ *  to, or greater than +real+. This is the basis for the tests in Comparable.
  *
- *  Returns -1, 0, +1 or nil depending on whether <i>flt</i> is less
- *  than, equal to, or greater than <i>real</i>. This is the basis for
- *  the tests in <code>Comparable</code>.
  *  The result of <code>NaN <=> NaN</code> is undefined, so the
  *  implementation-dependent value is returned.
+ *
+ *  +nil+ is returned if the two values are incomparable.
  */
 
 static VALUE
@@ -3042,10 +3044,11 @@ fix_equal(VALUE x, VALUE y)
  *  call-seq:
  *     fix <=> numeric  ->  -1, 0, +1 or nil
  *
- *  Comparison---Returns -1, 0, +1 or nil depending on whether
- *  <i>fix</i> is less than, equal to, or greater than
- *  <i>numeric</i>. This is the basis for the tests in
- *  <code>Comparable</code>.
+ *  Comparison---Returns -1, 0, +1 or nil depending on whether +fix+ is less
+ *  than, equal to, or greater than +numeric+. This is the basis for the tests
+ *  in  Comparable.
+ *
+ *  +nil+ is returned if the two values are incomparable.
  */
 
 static VALUE
diff --git a/object.c b/object.c
index 76ff316543..3da19cdf3d 100644
--- a/object.c
+++ b/object.c
@@ -1540,13 +1540,14 @@ rb_mod_gt(VALUE mod, VALUE arg)
 
 /*
  *  call-seq:
- *     mod <=> other_mod   -> -1, 0, +1, or nil
+ *     module <=> other_module   -> -1, 0, +1, or nil
  *
- *  Comparison---Returns -1 if <i>mod</i> includes <i>other_mod</i>, 0 if
- *  <i>mod</i> is the same as <i>other_mod</i>, and +1 if <i>mod</i> is
- *  included by <i>other_mod</i>. Returns <code>nil</code> if <i>mod</i>
- *  has no relationship with <i>other_mod</i> or if <i>other_mod</i> is
- *  not a module.
+ *  Comparison---Returns -1, 0, +1 or nil depending on whether +module+
+ *  includes +other_module+, they are the same, or if +module+ is included by
+ *  +other_module+. This is the basis for the tests in Comparable.
+ *
+ *  Returns +nil+ if +module+ has no relationship with +other_module+, if
+ *  +other_module+ is not a module, or if the two values are incomparable.
  */
 
 static VALUE
diff --git a/rational.c b/rational.c
index 0cba54e281..a78b3202ec 100644
--- a/rational.c
+++ b/rational.c
@@ -1024,10 +1024,12 @@ nurat_expt(VALUE self, VALUE other)
 
 /*
  * call-seq:
- *    rat <=> numeric  ->  -1, 0, +1 or nil
+ *    rational <=> numeric  ->  -1, 0, +1 or nil
  *
  * Performs comparison and returns -1, 0, or +1.
  *
+ * +nil+ is returned if the two values are incomparable.
+ *
  *    Rational(2, 3)  <=> Rational(2, 3)  #=> 0
  *    Rational(5)     <=> 5               #=> 0
  *    Rational(2,3)   <=> Rational(1,3)   #=> 1
diff --git a/string.c b/string.c
index 3d4fd37b5a..cbfac397fc 100644
--- a/string.c
+++ b/string.c
@@ -2358,20 +2358,22 @@ rb_str_eql(VALUE str1, VALUE str2)
 
 /*
  *  call-seq:
- *     str <=> other_str   -> -1, 0, +1 or nil
+ *     string <=> other_string   -> -1, 0, +1 or nil
  *
- *  Comparison---Returns -1 if <i>other_str</i> is greater than, 0 if
- *  <i>other_str</i> is equal to, and +1 if <i>other_str</i> is less than
- *  <i>str</i>. If the strings are of different lengths, and the strings are
- *  equal when compared up to the shortest length, then the longer string is
- *  considered greater than the shorter one. In older versions of Ruby, setting
- *  <code>$=</code> allowed case-insensitive comparisons; this is now deprecated
- *  in favor of using <code>String#casecmp</code>.
+ *
+ *  Comparison---Returns -1, 0, +1 or nil depending on whether +string+ is less
+ *  than, equal to, or greater than +other_string+.
+ *
+ *  +nil+ is returned if the two values are incomparable.
+ *
+ *  If the strings are of different lengths, and the strings are equal when
+ *  compared up to the shortest length, then the longer string is considered
+ *  greater than the shorter one.
  *
  *  <code><=></code> is the basis for the methods <code><</code>,
- *  <code><=</code>, <code>></code>, <code>>=</code>, and <code>between?</code>,
- *  included from module <code>Comparable</code>.  The method
- *  <code>String#==</code> does not use <code>Comparable#==</code>.
+ *  <code><=</code>, <code>></code>, <code>>=</code>, and
+ *  <code>between?</code>, included from module Comparable. The method
+ *  String#== does not use Comparable#==.
  *
  *     "abcdef" <=> "abcde"     #=> 1
  *     "abcdef" <=> "abcdef"    #=> 0
@@ -7946,9 +7948,15 @@ sym_succ(VALUE sym)
 /*
  * call-seq:
  *
- *   str <=> other       -> -1, 0, +1 or nil
+ *   symbol <=> other_symbol       -> -1, 0, +1 or nil
+ *
+ * Compares +symbol+ with +other_symbol+ after calling #to_s on each of the
+ * symbols. Returns -1, 0, +1 or nil depending on whether +symbol+ is less
+ * than, equal to, or greater than +other_symbol+.
+ *
+ *  +nil+ is returned if the two values are incomparable.
  *
- * Compares _sym_ with _other_ in string form.
+ * See String#<=> for more information.
  */
 
 static VALUE
diff --git a/time.c b/time.c
index 765dc31194..77cac95621 100644
--- a/time.c
+++ b/time.c
@@ -3334,10 +3334,12 @@ time_subsec(VALUE time)
  *  call-seq:
  *     time <=> other_time -> -1, 0, +1 or nil
  *
- *  Comparison---Compares _time_ with +other_time+.
- *  The return value is ++1+ if _time_ is greater than
- *  +other_time+, +0+ if _time_ is equal to +other_time+ and
- *  +-1+ if _time_ is smaller than +other_time+.
+ *  Comparison---Compares +time+ with +other_time+.
+ *
+ *  -1, 0, +1 or nil depending on whether +time+ is less  than, equal to, or
+ *  greater than +other_time+.
+ *
+ *  +nil+ is returned if the two values are incomparable.
  *
  *     t = Time.now       #=> 2007-11-19 08:12:12 -0600
  *     t2 = t + 2592000   #=> 2007-12-19 08:12:12 -0600