[ruby-trunk - Feature #5554][Open] A method that applies self to a Proc if self is a Symbol

Issue #5554 has been reported by Tsuyoshi Sawada.


Feature #5554: A method that applies self to a Proc if self is a Symbol
http://redmine.ruby-lang.org/issues/5554

Author: Tsuyoshi Sawada
Status: Open
Priority: Normal
Assignee:
Category:
Target version:

Often, you want to apply a Proc to self if self is a Symbol, but not do
anything if otherwise. In this case, something I call Object#desymbolize
may be convenient:

proc = ->sym{
    case sym
    when :small_icon  then "16pt"
    when :medium_icon then "32pt"
    when :large_icon  then "64pt"
    end
}
:small_icon.desymbolize(&proc) => "16pt"
"18pt".desymbolize(&proc) => "18pt"

An implementation may be as follows:

class Object
def desymbolize; self end
end
class Symbol
def desymbolize ≺ pr.call(self) end
end

なかだです。

(11/11/03 3:51), Tsuyoshi Sawada wrote:

"18pt".desymbolize(&proc) => "18pt"

"often"というのは疑問がありますし、特にSymbolに関係する機能とも思えませ
ん。Hashではどうでしょうか。

desymbol = Hash.new {|h, k| k}
desymbol[:small_icon] = “16pt”
desymbol[:medium_icon] = “32pt”
desymbol[:large_icon] = “64pt”

desymbol[:small_icon] #=> “16pt”
desymbol[“18pt”] #=> “18pt”

Issue #5554 has been updated by Tsuyoshi Sawada.

本当は、意図したのは、どのようなSymbolがあるか簡単には分からない場合、もしくは別のところで関連するメソッドが定義されていて、Symbolの一覧を複数の場所で更新しなければならなくなる場合で、例えば次のような場合です:

proc =>sym{some_method_chain.send(sym)}  # sym can be :foo, :bar, 

…, which are defined elsewhere

でも、中田さんのおっしゃているのも分かります。

Feature #5554: A method that applies self to a Proc if self is a Symbol
http://redmine.ruby-lang.org/issues/5554

Author: Tsuyoshi Sawada
Status: Open
Priority: Normal
Assignee:
Category:
Target version:

Often, you want to apply a Proc to self if self is a Symbol, but not do
anything if otherwise. In this case, something I call Object#desymbolize
may be convenient:

proc = ->sym{
    case sym
    when :small_icon  then "16pt"
    when :medium_icon then "32pt"
    when :large_icon  then "64pt"
    end
}
:small_icon.desymbolize(&proc) => "16pt"
"18pt".desymbolize(&proc) => "18pt"

An implementation may be as follows:

class Object
def desymbolize; self end
end
class Symbol
def desymbolize ≺ pr.call(self) end
end

Issue #5554 has been updated by Yukihiro M…

Status changed from Open to Feedback

ごめんなさい。「本当に意図したのは」という部分の意図が読み取れません。
どのような局面でどのように嬉しいか(たとえば劇的にシンプルに記述できるから)を表現してください。
ただ単に「こんな風に書きたいと私が感じる」だとたぶん不十分です。
自分でメソッド定義するかActiveSupportに提案すれば良いわけで。

Feature #5554: A method that applies self to a Proc if self is a Symbol
http://redmine.ruby-lang.org/issues/5554

Author: Tsuyoshi Sawada
Status: Feedback
Priority: Normal
Assignee:
Category:
Target version:

Often, you want to apply a Proc to self if self is a Symbol, but not do
anything if otherwise. In this case, something I call Object#desymbolize
may be convenient:

proc = ->sym{
    case sym
    when :small_icon  then "16pt"
    when :medium_icon then "32pt"
    when :large_icon  then "64pt"
    end
}
:small_icon.desymbolize(&proc) => "16pt"
"18pt".desymbolize(&proc) => "18pt"

An implementation may be as follows:

class Object
def desymbolize; self end
end
class Symbol
def desymbolize ≺ pr.call(self) end
end

Issue #5554 has been updated by mame (Yusuke E.).

Status changed from Feedback to Rejected

長期間フィードバックがない+望み薄と思われるので閉じます。


Yusuke E. [email protected]

Feature #5554: A method that applies self to a Proc if self is a Symbol
https://bugs.ruby-lang.org/issues/5554#change-33200

Author: sawa (Tsuyoshi Sawada)
Status: Rejected
Priority: Normal
Assignee:
Category:
Target version:

Often, you want to apply a Proc to self if self is a Symbol, but not do
anything if otherwise. In this case, something I call Object#desymbolize
may be convenient:

proc = ->sym{
    case sym
    when :small_icon  then "16pt"
    when :medium_icon then "32pt"
    when :large_icon  then "64pt"
    end
}
:small_icon.desymbolize(&proc) => "16pt"
"18pt".desymbolize(&proc) => "18pt"

An implementation may be as follows:

class Object
def desymbolize; self end
end
class Symbol
def desymbolize ≺ pr.call(self) end
end

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