From: Marc-Andre Lafortune <redmine@...>
Date: 2009-10-25T07:33:09+09:00
Subject: [ruby-core:26284] [Feature #2265] Matrix#empty? [patch]

Feature #2265: Matrix#empty? [patch]
http://redmine.ruby-lang.org/issues/show/2265

Author: Marc-Andre Lafortune
Status: Open, Priority: Normal
Assigned to: Keiju Ishitsuka, Category: lib

Now that the Matrix library handles well empty matrices, how about a new instance method #empty?

diff --git a/lib/matrix.rb b/lib/matrix.rb
index b577ef3..45ef25e 100644
--- a/lib/matrix.rb
+++ b/lib/matrix.rb
@@ -386,6 +386,14 @@ class Matrix
   #++
 
   #
+  # Returns +true+ if this is an empty matrix, i.e. if the number of rows
+  # or the number of columns is 0.
+  #
+  def empty?
+    column_size == 0 || row_size == 0
+  end
+
+  #
   # Returns +true+ if this is a regular matrix.
   #
def regular?
@@ -924,7 +932,7 @@ class Matrix
  # Overrides Object#to_s
  #
  def to_s
-    if row_size == 0 || column_size == 0
+    if empty?
      "Matrix.empty(#{row_size}, #{column_size})"
    else
      "Matrix[" + @rows.collect{|row|
@@ -939,7 +947,7 @@ class Matrix
  # Overrides Object#inspect
  #
  def inspect
-    if row_size == 0 || column_size == 0
+    if empty?
      "Matrix.empty(#{row_size}, #{column_size})"
    else
      "Matrix#{@rows.inspect}"


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