On Sep 8, 2009, at 7:14 AM, Steven Jenkins wrote:
>
> Luke Kanies wrote:
>> Can you go into a bit more detail on the various repercussions of
>> this?
>>
>> I understand the idea, but we don't really do it anywhere else right
>> now, and I'm wondering if this is a theme we should start adopting,
>> or
>> what.
>>
>> If it is, then it should probably be in many places, not just this
>> one, right?
>>
>
> The basic idea is to use a Functional programming style so that you
> can use the
> results of one computation as the input to another. Using a Unix
> shell example,
> it's a lot like using unix pipes: e.g.,
>
> grep some-pattern /var/spool/some-log | sort | uniq -c | sort -nr |
> tail -1
>
> instead of
>
> grep some-pattern /var/spool/some-log > a.out
> sort a.out > b.out
> uniq -c b.out > c.out
> sort -nr c.out > d.out
> tail -1 d.out
>
> Note that Rails also uses this style; e.g., it's common to see
> things like
>
> total = Product.find(product_list).sum(&:price)
This isn't a terribly good example (since Product.find returns an
instance of Product and then sum returns a number), but I understand
what you mean.
>
> where the result of one method is the object that is used for the
> subsequent method.
>
> I haven't looked all through the Puppet source for this, but, yes,
> it would be
> good to be done everywhere, not just this one file. It would be a
> technically
> straightforward task to do (just tedious). I'd suggest either
> putting together
> a set of Redmine tasks, and perhaps to put it aside and apply for a
> Google
> Summer of Code student next year if no one has gotten to it by Feb/
> March.
I guess my main question is when this would be used, but I suppose
it's 'any method whose return you don't care about'?
>
> Steven Jenkins
> End Point Corporation
>
>> On Sep 3, 2009, at 10:57 AM, Steven Jenkins wrote:
>>
>>> ---
>>> lib/puppet/indirector/facts/facter.rb | 8 +-------
>>> lib/puppet/node/facts.rb | 5 ++++-
>>> spec/unit/indirector/facts/facter.rb | 4 ++--
>>> spec/unit/node/facts.rb | 24 +++++++++++++++
>>> +--------
>>> 4 files changed, 23 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/lib/puppet/indirector/facts/facter.rb b/lib/puppet/
>>> indirector/facts/facter.rb
>>> index 9df71fc..62ac3ed 100644
>>> --- a/lib/puppet/indirector/facts/facter.rb
>>> +++ b/lib/puppet/indirector/facts/facter.rb
>>> @@ -64,13 +64,7 @@ class Puppet::Node::Facts::Facter <
>>> Puppet::Indirector::Code
>>>
>>> # Look a host's facts up in Facter.
>>> def find(request)
>>> - result = Puppet::Node::Facts.new(request.key,
>>> Facter.to_hash)
>>> -
>>> - result.add_local_facts
>>> - result.stringify
>>> - result.downcase_if_necessary
>>> -
>>> - result
>>> + Puppet::Node::Facts.new(request.key,
>>> Facter.to_hash).add_local_facts.stringify.downcase_if_necessary
>>> end
>>>
>>> def save(facts)
>>> diff --git a/lib/puppet/node/facts.rb b/lib/puppet/node/facts.rb
>>> index dca435c..861214a 100755
>>> --- a/lib/puppet/node/facts.rb
>>> +++ b/lib/puppet/node/facts.rb
>>> @@ -24,6 +24,7 @@ class Puppet::Node::Facts
>>> def add_local_facts
>>> values["clientversion"] = Puppet.version.to_s
>>> values["environment"] ||= Puppet.settings[:environment]
>>> + self
>>> end
>>>
>>> def initialize(name, values = {})
>>> @@ -34,12 +35,13 @@ class Puppet::Node::Facts
>>> end
>>>
>>> def downcase_if_necessary
>>> - return unless Puppet.settings[:downcasefacts]
>>> + return self unless Puppet.settings[:downcasefacts]
>>>
>>> Puppet.warning "DEPRECATION NOTICE: Fact downcasing is
>>> deprecated; please disable (20080122)"
>>> values.each do |fact, value|
>>> values[fact] = value.downcase if value.is_a?(String)
>>> end
>>> + self
>>> end
>>>
>>> # Convert all fact values into strings.
>>> @@ -47,6 +49,7 @@ class Puppet::Node::Facts
>>> values.each do |fact, value|
>>> values[fact] = value.to_s
>>> end
>>> + self
>>> end
>>>
>>> private
>>> diff --git a/spec/unit/indirector/facts/facter.rb b/spec/unit/
>>> indirector/facts/facter.rb
>>> index ea68f63..9903912 100755
>>> --- a/spec/unit/indirector/facts/facter.rb
>>> +++ b/spec/unit/indirector/facts/facter.rb
>>> @@ -57,7 +57,7 @@ describe Puppet::Node::Facts::Facter do
>>> it "should add local facts" do
>>> facts = Puppet::Node::Facts.new("foo")
>>> Puppet::Node::Facts.expects(:new).returns facts
>>> - facts.expects(:add_local_facts)
>>> + facts.expects(:add_local_facts).returns facts
>>>
>>> @facter.find(@request)
>>> end
>>> @@ -65,7 +65,7 @@ describe Puppet::Node::Facts::Facter do
>>> it "should convert all facts into strings" do
>>> facts = Puppet::Node::Facts.new("foo")
>>> Puppet::Node::Facts.expects(:new).returns facts
>>> - facts.expects(:stringify)
>>> + facts.expects(:stringify).returns facts
>>>
>>> @facter.find(@request)
>>> end
>>> diff --git a/spec/unit/node/facts.rb b/spec/unit/node/facts.rb
>>> index a6e227a..44fb931 100755
>>> --- a/spec/unit/node/facts.rb
>>> +++ b/spec/unit/node/facts.rb
>>> @@ -9,26 +9,34 @@ describe Puppet::Node::Facts, "when indirecting"
>>> do
>>> @facts = Puppet::Node::Facts.new("me")
>>> end
>>>
>>> + it "add_local_facts should return an instance of
>>> Puppet::Node::Facts" do
>>> + @facts.add_local_facts.class.should == Puppet::Node::Facts
>>> + end
>>> +
>>> + it "stringify should return an instance of Puppet::Node::Facts"
>>> do
>>> + @facts.stringify.class.should == Puppet::Node::Facts
>>> + end
>>> +
>>> + it "downcase_if_necessary should return an instance of
>>> Puppet::Node::Facts" do
>>> + @facts.downcase_if_necessary.class.should ==
>>> Puppet::Node::Facts
>>> + end
>>> +
>>> it "should be able to convert all fact values to strings" do
>>> @facts.values["one"] = 1
>>> - @facts.stringify
>>> - @facts.values["one"].should == "1"
>>> + @facts.stringify.values["one"].should == "1"
>>> end
>>>
>>> it "should add the Puppet version as a 'clientversion' fact when
>>> adding local facts" do
>>> - @facts.add_local_facts
>>> - @facts.values["clientversion"].should ==
>>> Puppet.version.to_s
>>> + @facts.add_local_facts.values["clientversion"].should ==
>>> Puppet.version.to_s
>>> end
>>>
>>> it "should add the current environment as a fact if one is not
>>> set when adding local facts" do
>>> - @facts.add_local_facts
>>> - @facts.values["environment"].should == Puppet[:environment]
>>> + @facts.add_local_facts.values["environment"].should ==
>>> Puppet[:environment]
>>> end
>>>
>>> it "should not replace any existing environment fact when adding
>>> local facts" do
>>> @facts.values["environment"] = "foo"
>>> - @facts.add_local_facts
>>> - @facts.values["environment"].should == "foo"
>>> + @facts.add_local_facts.values["environment"].should ==
>>> "foo"
>>> end
>>>
>>> it "should be able to downcase fact values" do
>>> --
>>> 1.6.3.3
>>>
>>>
>>
>>
>
>
> >
--
Never esteem anything as of advantage to you that will make you break
your word or lose your self-respect. -- Marcus Aurelius Antoninus
---------------------------------------------------------------------
Luke Kanies | http://reductivelabs.com | http://madstop.com
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