* lib/csv.rb (CSV::{Row,Table}#{each,delete_if}): returns an enumerator

  if no block is given. [ruby-core:75346] [Feature #11058]

* test/csv/test_row.rb: add test for above.

* test/csv/test_table.rb: ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56083 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,12 @@
+Wed Sep  7 14:56:59 2016  Kazuki Tsujimoto  <kazuki@callcc.net>
+
+	* lib/csv.rb (CSV::{Row,Table}#{each,delete_if}): returns an enumerator
+	  if no block is given. [ruby-core:75346] [Feature #11058]
+
+	* test/csv/test_row.rb: add test for above.
+
+	* test/csv/test_table.rb: ditto.
+
 Wed Sep  7 14:50:01 2016  Kazuki Tsujimoto  <kazuki@callcc.net>
 
 	* gems/bundled_gems: update to power_assert 0.3.1.

lib/csv.rb

@@ -431,7 +431,11 @@ def delete(header_or_index, minimum_index = 0)
     #
     # This method returns the row for chaining.
     #
+    # If no block is given, an Enumerator is returned.
+    #
     def delete_if(&block)
+      block or return enum_for(__method__) { size }
+
       @row.delete_if(&block)
 
       self  # for chaining
@@ -500,13 +504,15 @@ def field?(data)
 
     #
     # Yields each pair of the row as header and field tuples (much like
-    # iterating over a Hash).
+    # iterating over a Hash). This method returns the row for chaining.
     #
-    # Support for Enumerable.
+    # If no block is given, an Enumerator is returned.
     #
-    # This method returns the row for chaining.
+    # Support for Enumerable.
     #
     def each(&block)
+      block or return enum_for(__method__) { size }
+
       @row.each(&block)
 
       self  # for chaining
@@ -822,7 +828,11 @@ def delete(index_or_header)
     #
     # This method returns the table for chaining.
     #
+    # If no block is given, an Enumerator is returned.
+    #
     def delete_if(&block)
+      block or return enum_for(__method__) { @mode == :row or @mode == :col_or_row ? size : headers.size }
+
       if @mode == :row or @mode == :col_or_row  # by index
         @table.delete_if(&block)
       else                                      # by header
@@ -845,7 +855,11 @@ def delete_if(&block)
     #
     # This method returns the table for chaining.
     #
+    # If no block is given, an Enumerator is returned.
+    #
     def each(&block)
+      block or return enum_for(__method__) { @mode == :col ? headers.size : size }
+
       if @mode == :col
         headers.each { |header| block[[header, self[header]]] }
       else

test/csv/test_row.rb

@@ -209,9 +209,20 @@ def test_delete
     # by header
     assert_equal(["C", 3], @row.delete("C"))
 
-    # using a block
+  end
+
+  def test_delete_if
     assert_equal(@row, @row.delete_if { |h, f| h == "A" and not f.nil? })
-    assert_equal([["A", nil]], @row.to_a)
+    assert_equal([["B", 2], ["C", 3], ["A", nil]], @row.to_a)
+  end
+
+  def test_delete_if_without_block
+    enum = @row.delete_if
+    assert_instance_of(Enumerator, enum)
+    assert_equal(@row.size, enum.size)
+
+    assert_equal(@row, enum.each { |h, f| h == "A" and not f.nil? })
+    assert_equal([["B", 2], ["C", 3], ["A", nil]], @row.to_a)
   end
 
   def test_fields
@@ -281,6 +292,16 @@ def test_each
 
     # verify that we can chain the call
     assert_equal(@row, @row.each { })
+
+    # without block
+    ary = @row.to_a
+    enum = @row.each
+    assert_instance_of(Enumerator, enum)
+    assert_equal(@row.size, enum.size)
+    enum.each do |pair|
+      assert_equal(ary.first.first, pair.first)
+      assert_equal(ary.shift.last, pair.last)
+    end
   end
 
   def test_enumerable

test/csv/test_table.rb

@@ -220,6 +220,17 @@ def test_each
     # verify that we can chain the call
     assert_equal(@table, @table.each { })
 
+    # without block
+    enum = @table.each
+    assert_instance_of(Enumerator, enum)
+    assert_equal(@table.size, enum.size)
+
+    i = 0
+    enum.each do |row|
+      assert_equal(@rows[i], row)
+      i += 1
+    end
+
     ###################
     ### Column Mode ###
     ###################
@@ -231,6 +242,17 @@ def test_each
       assert_equal(@table[header], column)
     end
 
+    # without block
+    enum = @table.each
+    assert_instance_of(Enumerator, enum)
+    assert_equal(@table.headers.size, enum.size)
+
+    headers = @table.headers
+    enum.each do |header, column|
+      assert_equal(headers.shift, header)
+      assert_equal(@table[header], column)
+    end
+
     ############################
     ### One Shot Mode Change ###
     ############################
@@ -363,6 +385,24 @@ def test_delete_if_row
     END_RESULT
   end
 
+  def test_delete_if_row_without_block
+    ######################
+    ### Mixed/Row Mode ###
+    ######################
+    enum = @table.delete_if
+    assert_instance_of(Enumerator, enum)
+    assert_equal(@table.size, enum.size)
+
+    # verify that we can chain the call
+    assert_equal(@table, enum.each { |row| (row["B"] % 2).zero? })
+
+    # verify resulting table
+    assert_equal(<<-END_RESULT.gsub(/^\s+/, ""), @table.to_csv)
+    A,B,C
+    4,5,6
+    END_RESULT
+  end
+
   def test_delete_if_column
     ###################
     ### Column Mode ###
@@ -378,6 +418,25 @@ def test_delete_if_column
     END_RESULT
   end
 
+  def test_delete_if_column_without_block
+    ###################
+    ### Column Mode ###
+    ###################
+    @table.by_col!
+
+    enum = @table.delete_if
+    assert_instance_of(Enumerator, enum)
+    assert_equal(@table.headers.size, enum.size)
+
+    assert_equal(@table, enum.each { |h, v| h > "A" })
+    assert_equal(<<-END_RESULT.gsub(/^\s+/, ""), @table.to_csv)
+    A
+    1
+    4
+    7
+    END_RESULT
+  end
+
   def test_values_at
     ##################
     ### Mixed Mode ###