S
S. Robert James
What is the "returning" keyword? It's usually used with a block, but I
can't find what it is.
can't find what it is.
W
Wilson Bilkovich
It's not a keyword; it is a method added by the ActiveSupport library.
More here: http://weblog.jamisbuck.org/2006/10/27/mining-activesupport-object-returning
S
S. Robert James
Thanks.
Wow! That's an example of clever code. The code's less clear, no
shorter, and confusing to someone not familiar with this new method -
and for what? To be able to show off cool meta programming?
I think Rails is great, but someone needs to remind people that "clever
code" is an insult.
Wow! That's an example of clever code. The code's less clear, no
shorter, and confusing to someone not familiar with this new method -
and for what? To be able to show off cool meta programming?
I think Rails is great, but someone needs to remind people that "clever
code" is an insult.
T
Trans
S. Robert James said:
I disagree. It's not an uncommon to see the pattern:
def foo
o = Somthing.new
# muckaround with o
return o
end
The #returning method provides the same kind of "block orientation" we
use with files.
def foo
returning Something.new do |o|
# muckaround with o
end
end
In simple cases, sure, it's no dig deal. But in more complex cases it
lends to readability b/c it tells us what we're after from the start.
T.
D
dblack
HI --
Hang on a second. I know that there's a vogue for snideness and
"rants" these days, but please -- try not to be swept along by the
tide.
If you know Sam, who committed the #returning method, you'll know that
there's literally no possibility that he's "showing off cool meta
programming". If you don't know Sam, come to a Rails conference some
time and introduce yourself. You can also check out his best-known
work, a JavaScript library called Prototype. It ships with Rails, and
has currency and popularity well beyond Rails.
In general, remember that when you participate in this forum, you're
not sitting in a darkened theater making wisecracks to images on a
screen. Rather, you're among colleagues and fellow practitioners, an
astounding number of whom are willing and able to discuss technical
matters intelligently and enthusiastically with you. It's not just a
matter of not flinging insults at people who might actually hear you
(though that's part of it). It's also about taking advantage of the
knowledge and, most importantly, the collegiality available to you
here if you choose not to spurn it.
David
--
David A. Black | (e-mail address removed)
Author of "Ruby for Rails" [1] | Ruby/Rails training & consultancy [3]
DABlog (DAB's Weblog) [2] | Co-director, Ruby Central, Inc. [4]
[1] http://www.manning.com/black | [3] http://www.rubypowerandlight.com
[2] http://dablog.rubypal.com | [4] http://www.rubycentral.org
Hang on a second. I know that there's a vogue for snideness and
"rants" these days, but please -- try not to be swept along by the
tide.
If you know Sam, who committed the #returning method, you'll know that
there's literally no possibility that he's "showing off cool meta
programming". If you don't know Sam, come to a Rails conference some
time and introduce yourself. You can also check out his best-known
work, a JavaScript library called Prototype. It ships with Rails, and
has currency and popularity well beyond Rails.
In general, remember that when you participate in this forum, you're
not sitting in a darkened theater making wisecracks to images on a
screen. Rather, you're among colleagues and fellow practitioners, an
astounding number of whom are willing and able to discuss technical
matters intelligently and enthusiastically with you. It's not just a
matter of not flinging insults at people who might actually hear you
(though that's part of it). It's also about taking advantage of the
knowledge and, most importantly, the collegiality available to you
here if you choose not to spurn it.
David
--
David A. Black | (e-mail address removed)
Author of "Ruby for Rails" [1] | Ruby/Rails training & consultancy [3]
DABlog (DAB's Weblog) [2] | Co-director, Ruby Central, Inc. [4]
[1] http://www.manning.com/black | [3] http://www.rubypowerandlight.com
[2] http://dablog.rubypal.com | [4] http://www.rubycentral.org
A
ara.t.howard
nothing clever about it afaikt - made sense instantly: it's a factory method.
i use this idiom in code all the time
def m
ret = Array.new
...
return ret
end
or even
doesn't make sense for short methods, but once they reach 20/30 lines and have
complex logic is really nice to see up front what a method returns. it's the
same reason some people prefer
char *hostname();
over
def hostname()
a refinement of
def m
Object.new.instance_eval{
configure @object
self
}
end
which can make debugging hard due to having two scopes in the method body
in summary you know at a glace what's being returned - that's quite useful
sometimes.
-a
S
S. Robert James
I still maintain that this is clever code. Every new (pseudo)keyword
comes at a cost, of having to learn (and keep in your head) something
new. They have to justify their cost by truly cleaning up the code -
and I haven't seen an example of that yet.
However, I do accept that my words were out of tact, and could have,
and should have, been said politely. I stand corrected - thanks for
pointing that out.
comes at a cost, of having to learn (and keep in your head) something
new. They have to justify their cost by truly cleaning up the code -
and I haven't seen an example of that yet.
However, I do accept that my words were out of tact, and could have,
and should have, been said politely. I stand corrected - thanks for
pointing that out.
A
ara.t.howard
that is a reasonable thing to say - imho you'd need something like this to do
so
def factory
returning Object.new do |o|
o.property_0 = 'value_0'
o.property_1 = 'value_1'
o.property_2 = 'value_2'
o.property_3 = 'value_3'
o.property_4 = 'value_4'
o.property_5 = 'value_5'
o.property_6 = 'value_6'
o.property_7 = 'value_7'
o.property_8 = 'value_8'
o.property_9 = 'value_9'
o.property_10 = 'value_10'
o.property_11 = 'value_11'
o.property_12 = 'value_12'
o.property_13 = 'value_13'
o.property_14 = 'value_14'
o.property_15 = 'value_15'
o.property_16 = 'value_16'
o.property_17 = 'value_17'
o.property_18 = 'value_18'
o.property_19 = 'value_19'
o.property_20 = 'value_20'
o.property_21 = 'value_21'
o.property_22 = 'value_22'
o.property_23 = 'value_23'
o.property_24 = 'value_24'
o.property_25 = 'value_25'
o.property_26 = 'value_26'
o.property_27 = 'value_27'
o.property_28 = 'value_28'
o.property_29 = 'value_29'
o.property_30 = 'value_30'
o.property_31 = 'value_31'
o.property_32 = 'value_32'
o.property_33 = 'value_33'
o.property_34 = 'value_34'
o.property_35 = 'value_35'
o.property_36 = 'value_36'
o.property_37 = 'value_37'
o.property_38 = 'value_38'
o.property_39 = 'value_39'
o.property_40 = 'value_40'
o.property_41 = 'value_41'
o.property_42 = 'value_42'
o.property_43 = 'value_43'
o.property_44 = 'value_44'
o.property_45 = 'value_45'
o.property_46 = 'value_46'
o.property_47 = 'value_47'
o.property_48 = 'value_48'
o.property_49 = 'value_49'
o.property_50 = 'value_50'
o.property_51 = 'value_51'
o.property_52 = 'value_52'
o.property_53 = 'value_53'
o.property_54 = 'value_54'
o.property_55 = 'value_55'
o.property_56 = 'value_56'
o.property_57 = 'value_57'
o.property_58 = 'value_58'
o.property_59 = 'value_59'
o.property_60 = 'value_60'
o.property_61 = 'value_61'
o.property_62 = 'value_62'
o.property_63 = 'value_63'
o.property_64 = 'value_64'
o.property_65 = 'value_65'
o.property_66 = 'value_66'
o.property_67 = 'value_67'
o.property_68 = 'value_68'
o.property_69 = 'value_69'
o.property_70 = 'value_70'
o.property_71 = 'value_71'
o.property_72 = 'value_72'
o.property_73 = 'value_73'
o.property_74 = 'value_74'
o.property_75 = 'value_75'
o.property_76 = 'value_76'
o.property_77 = 'value_77'
o.property_78 = 'value_78'
o.property_79 = 'value_79'
o.property_80 = 'value_80'
o.property_81 = 'value_81'
o.property_82 = 'value_82'
o.property_83 = 'value_83'
o.property_84 = 'value_84'
o.property_85 = 'value_85'
o.property_86 = 'value_86'
o.property_87 = 'value_87'
o.property_88 = 'value_88'
o.property_89 = 'value_89'
o.property_90 = 'value_90'
o.property_91 = 'value_91'
o.property_92 = 'value_92'
o.property_93 = 'value_93'
o.property_94 = 'value_94'
o.property_95 = 'value_95'
o.property_96 = 'value_96'
o.property_97 = 'value_97'
o.property_98 = 'value_98'
o.property_99 = 'value_99'
o.property_100 = 'value_100'
o.property_101 = 'value_101'
o.property_102 = 'value_102'
o.property_103 = 'value_103'
o.property_104 = 'value_104'
o.property_105 = 'value_105'
o.property_106 = 'value_106'
o.property_107 = 'value_107'
o.property_108 = 'value_108'
o.property_109 = 'value_109'
o.property_110 = 'value_110'
o.property_111 = 'value_111'
o.property_112 = 'value_112'
o.property_113 = 'value_113'
o.property_114 = 'value_114'
o.property_115 = 'value_115'
o.property_116 = 'value_116'
o.property_117 = 'value_117'
o.property_118 = 'value_118'
o.property_119 = 'value_119'
o.property_120 = 'value_120'
o.property_121 = 'value_121'
o.property_122 = 'value_122'
o.property_123 = 'value_123'
o.property_124 = 'value_124'
o.property_125 = 'value_125'
o.property_126 = 'value_126'
o.property_127 = 'value_127'
end
end
-a
D
dblack
Hi --
Wow, you must feel very strongly about this
David
--
David A. Black | (e-mail address removed)
Author of "Ruby for Rails" [1] | Ruby/Rails training & consultancy [3]
DABlog (DAB's Weblog) [2] | Co-director, Ruby Central, Inc. [4]
[1] http://www.manning.com/black | [3] http://www.rubypowerandlight.com
[2] http://dablog.rubypal.com | [4] http://www.rubycentral.org
^^
Wow, you must feel very strongly about this
David
--
David A. Black | (e-mail address removed)
Author of "Ruby for Rails" [1] | Ruby/Rails training & consultancy [3]
DABlog (DAB's Weblog) [2] | Co-director, Ruby Central, Inc. [4]
[1] http://www.manning.com/black | [3] http://www.rubypowerandlight.com
[2] http://dablog.rubypal.com | [4] http://www.rubycentral.org
D
David Vallner
--------------enigB2FE51E3FFE57140EC51D562
Content-Type: text/plain; charset=ISO-8859-1
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^(Foo new) name: 'fred';
surname: 'flintstone';
wife: wilma;
yourself.
I think that one's on the top of my list of Little Smalltalk Features I
Miss. No pseudokeywords, no having to bend setters / add_whatever
methods backwards, or decide in the library whether to return self or
the added object / setter value.
David Vallner
--------------enigB2FE51E3FFE57140EC51D562
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Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
^(Foo new) name: 'fred';
surname: 'flintstone';
wife: wilma;
yourself.
I think that one's on the top of my list of Little Smalltalk Features I
Miss. No pseudokeywords, no having to bend setters / add_whatever
methods backwards, or decide in the library whether to return self or
the added object / setter value.
David Vallner
--------------enigB2FE51E3FFE57140EC51D562
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L
Louis J Scoras
It's not a new keyword though, it's simply a method and a very useful
one at that. In my opinion, the intention comes off pretty clearly,
and if not there is always the documentation.
Consider how many times you see the idiom:
def foo
o = Object.new
o.mutate!
o
end
The fact that you see that so much is just crying out for an
additional abstraction, and that's what 'returning' provides.
In fact, something like this could be helpful in other scenarios as
well. Take Enumerable#inject for example. Many times you are just
making changes to the state parameter and returning that at the end of
the block. Try something like this:
module Enumerable
def injecting(s)
inject(s) do |k, i|
yield(k, i); k
end
end
end
Say you want to count letters--
some_text.inject(Hash.new(0)) {|h,l| h[l] +=1; h}
vs
some_text.injecting(Hash.new(0) {|h,l| h[l] += 1}
It's not about being clever, or saving some typing (as this example
shows, its the same about of characters). It's about abstracting away
repeated patterns; that's almost always a win in my book.
P
Peña, Botp
:From =3D> "Louis J Scoras [mailto:[email protected]]"
# module Enumerable
# def injecting(s)
# inject(s) do |k, i|
# yield(k, i); k
# end
# end
# end
#=20
# Say you want to count letters--
#=20
# some_text.inject(Hash.new(0)) {|h,l| h[l] +=3D1; h}
#=20
# vs
#=20
# some_text.injecting(Hash.new(0) {|h,l| h[l] +=3D 1}
clever indeed.
+1 on my-bag-of-tricks. =20
thanks for the tip.
kind regards -botp
# module Enumerable
# def injecting(s)
# inject(s) do |k, i|
# yield(k, i); k
# end
# end
# end
#=20
# Say you want to count letters--
#=20
# some_text.inject(Hash.new(0)) {|h,l| h[l] +=3D1; h}
#=20
# vs
#=20
# some_text.injecting(Hash.new(0) {|h,l| h[l] +=3D 1}
clever indeed.
+1 on my-bag-of-tricks. =20
thanks for the tip.
kind regards -botp