From: Dark Ambient <sambient@...>
Date: 2006-07-12T03:18:55+09:00
Subject: Re: blocks and procs

------=_Part_169784_31275581.1152641929103
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

oops...this is the error:

rb:32:in `select': wrong number of arguments (0 for 1) (ArgumentError)

On 7/11/06, Dark Ambient <sambient@gmail.com> wrote:
>
> Good example.  Also because it's rails centric (something I'd eventually
> like to get to)
> I am running into some select errors though , via the select statement.
> If your up to reading it through (I don't find any typos matched against
> your code), if not that is fine as the explanation helped me.
>
> class ClientDB
>   Record = Struct.new(:client_name, :location, :projects)
>
>   def initialize
>     @records = [ Record.new("Gray Productions", "Oklahoma",
>                       ["Ruby Quiz", "Rails Extensions"] ),
>                       Record.new( "Serenity Crew", "Deep Space",
>                       ["Ship Enhancements"] ),
>                       Record.new( "Neo", "Hollywood",
>                       ["Rails interface for the Matrix"] ) ]
>                     end # end of method
>
>     def select( query )
>       # parse query String
>       rules = Hash[*query.split(/\s*AND\s*/).map do |rule|
>         rule.split(/\s*=\s*/).map { |value| value.sub(/^['"](.+)['"]$/,
> '\1') }
>         end.flatten ]
>
>       #match records
>       @records.select { |record| block_given? and yield record }
>         rules.all? { |field, value| record.send(field) == value }
>
>
>     end # end of method
>
> end # end of class
>
>   require "pp"
>   db = ClientDB.new
>   pp db.select { |record| record.client_name != "Gray Productions" }
>   pp db.select { |record| record.client_name +~ /crew/i }
>   pp db.select { |record| record.projects.size == 1 }
>   pp db.select { |record| record.projects.include? "Ruby Quiz" }
>
> --------
>
>
> On 7/11/06, James Edward Gray II < james@grayproductions.net> wrote:
> >
> > On Jul 11, 2006, at 11:55 AM, Dark Ambient wrote:
> >
> > > Just curious, I'm just learning about Procs, and have already
> > > looked at
> > > using blocks.
> > > Are they very close in the way they function.  It seems that way to
> > > me.
> > > Perhaps I'm wrong.
> > > Is one favoured above the other ?
> >
> > I see David has already answered your question here, but just in case
> > it helps I wrote about this on my blog a while back:
> >
> > http://blog.grayproductions.net/articles/2006/01/05/code-as-a-data-type
> >
> > James Edward Gray II
> >
> >
>

------=_Part_169784_31275581.1152641929103--