From: Sharon Phillips <phillipsds@...>
Date: 2007-03-13T07:46:08+09:00
Subject: Re: OpenStruct,, know what keys are set


On 13/03/2007, at 6:59 AM, Aaron Smith wrote:

> Jan Friedrich wrote:
>> o = OpenStruct.new
>> o.foo = 2
>> o.bar = 4
>> o.marshal_dump # => {:foo=>2, :bar=>4}
>> o.marshal_dump.keys # => [:foo, :bar]
>>
>> regards,
>> Jan
>
> nice one, that's faster..

marshal_dump returns @table, so marshal_dump.keys == @table.keys  
except that @table is not accessable from outside OpenStruct.
http://www.ruby-doc.org/stdlib/libdoc/ostruct/rdoc/classes/ 
OpenStruct.html
Click on the [Source] link to see the code behind these methods.

Note that some of your examples here return symbols (2 and 5) whilst  
3 and 4 take an extra step of transforming these into strings.

Looks like you're having fun :)
Dave

> require 'ostruct'
> require 'benchmark'
>
> class OpenStruct
>   def keys_added
>     @table.keys.map{|k| k.to_s}
>   end
> end
>
> lady = OpenStruct.new
> 0.upto(10) do |i|
>   eval("lady.cat#{i} = i")
>   #puts eval("lady.cat#{i}")
> end
>
> Benchmark.bm do |x|
>   x.report("Find all keys 1"){
>     0.upto(100000) do
>       lady.methods(false).grep(/[^=]$/)
>     end
>   }
>
>   x.report("Find all keys 2"){
>     0.upto(100000) do
>       lady.instance_variable_get("@table").keys
>     end
>   }
>
>   x.report("Find all keys 3"){
>     0.upto(100000) do
>       lady.keys_added
>     end
>   }
>
>
>   x.report("Find all keys 4"){
>     0.upto(100000) do
>       lady.instance_variable_get("@table").keys.map{|k| k.to_s }
>     end
>   }
>
>   x.report("Find all keys 5"){
>     0.upto(100000) do
>       lady.marshal_dump.keys
>     end
>   }
> end
>
> user     system      total        real
> Find all keys 1  4.110000   0.010000   4.120000 (  4.151098)
> Find all keys 2  0.160000   0.000000   0.160000 (  0.153028)
> Find all keys 3  0.870000   0.010000   0.880000 (  0.884275)
> Find all keys 4  0.900000   0.000000   0.900000 (  0.897666)
> Find all keys 5  0.130000   0.000000   0.130000 (  0.137231)
>
> -- 
> Posted via http://www.ruby-forum.com/.
>