Anyone have an interesting or idiomatic usage of Struct?
Other than the obvious usage for on-the-fly attr reader/writer
objects, what else can you do with this?
One use case that came to mind was for managing CSV files (esp. w/
headers). You could create a Struct for the file, using the header
row from the file, passing a block to the new method to add a method
to initialize it based on an array (as returned from the csv reader).
Anyone have a cool usage?
Joe at CodeGear
I really like the way you think:
#!/usr/bin/env ruby -w
require "rubygems"
require "faster_csv"
require "pp"
Name = Struct.new(:first, :last)
names = [Name.new("James", "Gray"), Name.new("Joe")]
csv = FCSV.dump(names)
puts <<END_CSV
CSV
On Feb 16, 2007, at 7:30 PM, Joe at CodeGear wrote:
One use case that came to mind was for managing CSV files (esp. w/
headers). You could create a Struct for the file, using the header
row from the file, passing a block to the new method to add a method
to initialize it based on an array (as returned from the csv reader).
===
#{csv}
END_CSV
END_RUBY
pp reloaded
# >> CSV
# >> ===
# >> class,Name
# >> first=,last=
# >> James,Gray
# >> Joe,
# >>
# >> Ruby
# >> ====
# >> [#<struct Name first="James", last="Gray">,
# >> #<struct Name first="Joe", last=nil>]
__END__
James Edward Gray II
I was naming regular expressions with it roughly like this
Fields=Struct.new(:a,:b,:c)
/(x*)(y*)(z*)/ === whatever
named= Fields.new( *Regexp.last_match.captures )
Cheers
Robert
On 2/17/07, Joe at CodeGear <jmcglynn@codegear.com> wrote:
Anyone have an interesting or idiomatic usage of Struct?
Other than the obvious usage for on-the-fly attr reader/writer
objects, what else can you do with this?One use case that came to mind was for managing CSV files (esp. w/
headers). You could create a Struct for the file, using the header
row from the file, passing a block to the new method to add a method
to initialize it based on an array (as returned from the csv reader).Anyone have a cool usage?
Joe at CodeGear
--
We have not succeeded in answering all of our questions.
In fact, in some ways, we are more confused than ever.
But we feel we are confused on a higher level and about more important things.
-Anonymous
At work I need to process different bits of information stored in csv format. I use OpenStruct modified to create new propertied from strings that I read from the file headers. I don't have the code here, but can get it if anyone is interested.
I find this method very useful as then I can work with the properties I require, but the code doesn't fall over when the format of the files changes (not that that would happen without anyone telling me first... 
)
Cheers,
Dave
On 17/02/2007, at 12:30 PM, Joe at CodeGear wrote:
Anyone have an interesting or idiomatic usage of Struct?
Other than the obvious usage for on-the-fly attr reader/writer
objects, what else can you do with this?One use case that came to mind was for managing CSV files (esp. w/
headers). You could create a Struct for the file, using the header
row from the file, passing a block to the new method to add a method
to initialize it based on an array (as returned from the csv reader).Anyone have a cool usage?
Joe at CodeGear
Ooh, that's quite cool. Thanks for sharing that! 
On Feb 17, 1:39 am, "Robert Dober" <robert.do...@gmail.com> wrote:
I was naming regular expressions with it roughly like this
Fields=Struct.new(:a,:b,:c)
/(x*)(y*)(z*)/ === whatever
named= Fields.new( *Regexp.last_match.captures )
That's one way of doing it. There was a discussion not too long ago of
doing it with the MatchData itself. Something like (tested, works):
class MatchData
def name_captures(*names)
meta = (class << self; self; end)
names.each_with_index { |name,index|
meta.send(:define_method, name) { captures[index] }
}
self
end
end
named = /(x*)(y*)(z*)/.match(whatever).name_captures(:a, :b, :c)
--Greg
On Sun, Feb 18, 2007 at 12:00:15AM +0900, Phrogz wrote:
On Feb 17, 1:39 am, "Robert Dober" <robert.do...@gmail.com> wrote:
> I was naming regular expressions with it roughly like this
>
> Fields=Struct.new(:a,:b,:c)
> /(x*)(y*)(z*)/ === whatever
> named= Fields.new( *Regexp.last_match.captures )Ooh, that's quite cool. Thanks for sharing that!
My pleasure
Robert
On 2/17/07, Phrogz <gavin@refinery.com> wrote:
On Feb 17, 1:39 am, "Robert Dober" <robert.do...@gmail.com> wrote:
> I was naming regular expressions with it roughly like this
>
> Fields=Struct.new(:a,:b,:c)
> /(x*)(y*)(z*)/ === whatever
> named= Fields.new( *Regexp.last_match.captures )Ooh, that's quite cool. Thanks for sharing that!
That seems a little bit heavy. I was thinking to extend
RegularExpressions so that the names could be bound to the Regexp for
one and than just thought that I do not have enough usecases.
AFAIK Ruby 2 will have named captures and I am not really smart enough to handle
alternatives and nesting so I let it be...
Cheers
Robert
On 2/17/07, Gregory Seidman <gsslist+ruby@anthropohedron.net> wrote:
On Sun, Feb 18, 2007 at 12:00:15AM +0900, Phrogz wrote:
> On Feb 17, 1:39 am, "Robert Dober" <robert.do...@gmail.com> wrote:
> > I was naming regular expressions with it roughly like this
> >
> > Fields=Struct.new(:a,:b,:c)
> > /(x*)(y*)(z*)/ === whatever
> > named= Fields.new( *Regexp.last_match.captures )
>
> Ooh, that's quite cool. Thanks for sharing that!That's one way of doing it. There was a discussion not too long ago of
doing it with the MatchData itself. Something like (tested, works):class MatchData
def name_captures(*names)
meta = (class << self; self; end)
names.each_with_index { |name,index|
meta.send(:define_method, name) { captures[index] }
}
self
end
endnamed = /(x*)(y*)(z*)/.match(whatever).name_captures(:a, :b, :c)
--Greg
--
We have not succeeded in answering all of our questions.
In fact, in some ways, we are more confused than ever.
But we feel we are confused on a higher level and about more important things.
-Anonymous