[#377882] remove array bracket — Kamarulnizam Rahim <niezam54@...>

Hi when i run my script, the output is as followed:

18 messages 2011/02/02

[#378046] Setter method for Hash value — Rolf Pedersen <rolfhsp@...>

Hi

20 messages 2011/02/03
[#378052] Re: Setter method for Hash value — Brian Candler <b.candler@...> 2011/02/03

Rolf Pedersen wrote in post #979431:

[#378056] Re: Setter method for Hash value — Rolf Pedersen <rolfhsp@...> 2011/02/03

Hi Brian (and others who have contributed with suggestions along the same

[#378144] C extension: How to check if a VALUE is still alive (not being GC'ed)? — Iñaki Baz Castillo <ibc@...>

Hi, I'm coding an async DNS resolver for EventMachine based on udns (a

13 messages 2011/02/05
[#378171] Re: C extension: How to check if a VALUE is still alive (not being GC'ed)? — Tony Arcieri <tony.arcieri@...> 2011/02/06

On Sat, Feb 5, 2011 at 4:02 PM, I=F1aki Baz Castillo <ibc@aliax.net> wrote:

[#378179] Re: C extension: How to check if a VALUE is still alive (not being GC'ed)? — Iñaki Baz Castillo <ibc@...> 2011/02/06

2011/2/6 Tony Arcieri <tony.arcieri@medioh.com>:

[#378199] Choosing an office suite — Hilary Bailey <my77elephants@...>

I am trying to decide which office suite to choose from. The only

30 messages 2011/02/07
[#378229] Re: Choosing an office suite — Phillip Gawlowski <cmdjackryan@...> 2011/02/07

On Mon, Feb 7, 2011 at 11:15 AM, Hilary Bailey <my77elephants@gmail.com> wrote:

[#378202] making hash key from arrays — Arihan Sinha <arihan_sinha@...>

Hi All,

11 messages 2011/02/07

[#378254] "permission denied" happening too often — Peter Bailey <pbailey@...>

Hello,

15 messages 2011/02/08
[#378256] Re: "permission denied" happening too often — Anurag Priyam <anurag08priyam@...> 2011/02/08

> I've got Ruby scripts that have been working fine for years now. But,

[#378257] Re: "permission denied" happening too often — Markus Schirp <mbj@...> 2011/02/08

You can also try to strace your script. In the logs you'll find the system

[#378259] Re: "permission denied" happening too often — Peter Bailey <pbailey@...> 2011/02/08

Markus Schirp wrote in post #980289:

[#378307] undefined class/module YAML::PrivateType - Error — "Priya D." <dharsininitt@...>

Hi,

11 messages 2011/02/09

[#378341] System calls with ` in parameters — "Gerad S." <geradstemke@...>

Hi All,

12 messages 2011/02/09

[#378618] Defining class methods — Tony Arcieri <tony.arcieri@...>

It seems there are 3 ways of defining class methods (at least in common

12 messages 2011/02/16

[#378685] LiveAST: a pure Ruby 1.9.2 library obtaining live abstract syntax trees — "James M. Lawrence" <quixoticsycophant@...>

= LiveAST

13 messages 2011/02/18

[#378753] posix_mq : Problem installing on HPUX — Tadeusz Bochan <tad.bochan@...>

Hello,

13 messages 2011/02/20

[#378890] a, b = Array.new(2).map!{|x| data.dup} — Stefan Salewski <mail@...>

I think I can replace this code

19 messages 2011/02/23
[#378892] Re: a, b = Array.new(2).map!{|x| data.dup} — niklas | brueckenschlaeger <niklas@...> 2011/02/23

Are you sure you can't rework your code to *not* copy data 5x? I assume

[#378899] Re: a, b = Array.new(2).map!{|x| data.dup} — Stefan Salewski <mail@...> 2011/02/23

On Thu, 2011-02-24 at 07:00 +0900, niklas | brueckenschlaeger wrote:

[#378941] Automatic question generator libs in Ruby Language — Sniper Abandon <sathish.salem.1984@...>

is there any Automatic question generator libraries in Ruby Language ?

20 messages 2011/02/24
[#379058] Re: Automatic question generator libs in Ruby Language — Sniper Abandon <sathish.salem.1984@...> 2011/02/27

suppose if i have a paragraph (arround 250 words)

[#379172] Re: Automatic question generator libs in Ruby Language — Shadowfirebird <shadowfirebird@...> 2011/03/01

> i want to get all the possible question from that paragraph

[#379174] Re: Automatic question generator libs in Ruby Language — Peter Zotov <whitequark@...> 2011/03/01

On Tue, 1 Mar 2011 19:31:36 +0900, Shadowfirebird wrote:

[#379175] Re: Automatic question generator libs in Ruby Language — Adam Prescott <mentionuse@...> 2011/03/01

On Tue, Mar 1, 2011 at 10:55 AM, Peter Zotov <whitequark@whitequark.org>wrote:

[#379177] Re: Automatic question generator libs in Ruby Language — Peter Zotov <whitequark@...> 2011/03/01

On Tue, 1 Mar 2011 20:02:13 +0900, Adam Prescott wrote:

[#379179] Re: Automatic question generator libs in Ruby Language — Adam Prescott <mentionuse@...> 2011/03/01

On Tue, Mar 1, 2011 at 12:28 PM, Peter Zotov <whitequark@whitequark.org>wrote:

[#378949] why is $1 in a grep() equal to nil? — 7stud -- <bbxx789_05ss@...>

class DataSource

16 messages 2011/02/24
[#378953] Re: why is $1 in a grep() equal to nil? — Eric Christopherson <echristopherson@...> 2011/02/25

On Thu, Feb 24, 2011 at 2:59 PM, 7stud -- <bbxx789_05ss@yahoo.com> wrote:

[#378958] parsing rule for this code? — 7stud -- <bbxx789_05ss@...>

1)

11 messages 2011/02/25

[#379000] Symbol#to_proc helping out with #select to beat Scala-s solution — Jarmo Pertman <jarmo.p@...>

Hey!

9 messages 2011/02/25

[#379074] finding a tag in a binary file — rob stanton <tnotnats@...>

I have a binary file in which I'd like to find multiple strings of 10

12 messages 2011/02/27

Symbol#to_proc helping out with #select to beat Scala-s solution

From: Jarmo Pertman <jarmo.p@...>
Date: 2011-02-25 21:15:23 UTC
List: ruby-talk #379000
Hey!

I had a discussion with my colleague about Java lacking decent
collection API. This is indeed true. One of the main reasons is that
there's no lambda and no closures in Java. The problem has been tried
to leverage with external libraries, but they're failing in my mind.

Check out the following example in lambdaj [1]:
with(sales).retain(having(on(Sale.class).getValue(),greaterThan(50000))).extract(on(Sale.class).getBuyer()).sort(on
(Person.class).getAge());

It is just awful. So my colleague created the same example in Scala:
sales.filter(_.value > 50000).map(_.buyer).sortBy(_.age)

He also created it in Ruby:
sales.find_all{|sale| sale.value > 50000}.map{|sale|
sale.buyer}.sort_by{|buyer| buyer.age}

I polished it by using Ruby 1.9 syntax and find_all alias called
select:
sales.select{|sale| sale.value > 50000}.map(&:buyer).sort_by(&:age)

It's still whopping 12 characters longer. So i decided to use
different block variable - more Scala-like underscore:
sales.select{|_| _.value > 50000}.map(&:buyer).sort_by(&:age)

Still 6 characters longer. Even if i'd be able to use syntax like
this, i'd win only 2 characters:
sales.select(&:value > 50000).map(&:buyer).sort_by(&:age)

My first question is, is there any meaningful way to shorten my
#select call by not creating any additional methods to my Sale class?
One solution would be to just create a method "good" and use it:
class Sale
  def good
    value > 50000
  end
end

sales.select(&:good).map(&:buyer).sort_by(&:age)

I'd call it cheating though because the next step could be to use
alias_method to create one-character-length aliases to Enumerable
methods.

I'm thinking that one possible way to shorten my calls would be to use
instance-eval in #select, #map and #sort_by so i could do it like
this:
sales.select{value > 50000}.map{buyer}.sort_by{age}

Any other ideas how to beat a statically typed language with this
concrete example? :)

[1] - http://code.google.com/p/lambdaj

Jarmo Pertman
-----
IT does really matter - http://www.itreallymatters.net

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