Clarify requirements of <=>

A return value of <=> is automatically converted to -1, 0, or 1, so
other values can be returned.  [Misc #15630]

1 files changed, 7 insertions, 6 deletions

diff --git a/compar.c b/compar.c
index dbd4bce96d..3d06592692 100644
--- a/compar.c
+++ b/compar.c
@@ -95,7 +95,7 @@ cmpint(VALUE x, VALUE y)
  *     obj > other    -> true or false
  *
  *  Compares two objects based on the receiver's <code><=></code>
- *  method, returning true if it returns 1.
+ *  method, returning true if it returns a value greater than 0.
  */
 
 static VALUE
@@ -110,7 +110,7 @@ cmp_gt(VALUE x, VALUE y)
  *     obj >= other    -> true or false
  *
  *  Compares two objects based on the receiver's <code><=></code>
- *  method, returning true if it returns 0 or 1.
+ *  method, returning true if it returns a value greater than or equal to 0.
  */
 
 static VALUE
@@ -125,7 +125,7 @@ cmp_ge(VALUE x, VALUE y)
  *     obj < other    -> true or false
  *
  *  Compares two objects based on the receiver's <code><=></code>
- *  method, returning true if it returns -1.
+ *  method, returning true if it returns a value less than 0.
  */
 
 static VALUE
@@ -140,7 +140,7 @@ cmp_lt(VALUE x, VALUE y)
  *     obj <= other    -> true or false
  *
  *  Compares two objects based on the receiver's <code><=></code>
- *  method, returning true if it returns -1 or 0.
+ *  method, returning true if it returns a value less than or equal to 0.
  */
 
 static VALUE
@@ -209,8 +209,9 @@ cmp_clamp(VALUE x, VALUE min, VALUE max)
 /*
  *  The Comparable mixin is used by classes whose objects may be
  *  ordered. The class must define the <code><=></code> operator,
- *  which compares the receiver against another object, returning -1,
- *  0, or +1 depending on whether the receiver is less than, equal to,
+ *  which compares the receiver against another object, returning
+ *  a value less than 0, 0, or a value greater than 0, depending on
+ *  whether the receiver is less than, equal to,
  *  or greater than the other object. If the other object is not
  *  comparable then the <code><=></code> operator should return +nil+.
  *  Comparable uses <code><=></code> to implement the conventional