[Rails] Re: Combine if and do in a single line?
Frederick Cheung wrote:
> {} binds more tightly than do..end - in some cases this can lead to
> your block being passed to the 'wrong' method:
Interesting, makes sense.
Personally, that's one reason I don't like making method calls without
parens, or doing anything else that relies on non-obvious
order-of-evaluation-binding just to save a couple of parens.
foo( bar {} )
or
foo( bar do
end )
will both do the same thing. Although the latter is kind of weird style,
if I need a multi-line block for bar, I'd personally just use a
temporary var instead.
result = bar do
end
foo(result)
But everyone's got their own style, I guess. Of course you COULD use
{||} with multi-lines too, but it would also be stylistically weird in
my opinion in that case.
foo bar {|a|
stuff
more stuff
}
That's just weird. And if I DID it, I'd still want to put parens in
around foo's argument, which would make it even weirder looking.
Jonathan
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[Rails] Re: Combine if and do in a single line?
On May 30, 7:03 pm, Marnen Laibow-Koser wrote:
> Jonathan Rochkind wrote:
>
> [...]
>
> > The {| | } and the 'do' syntaxes are interchangeable in all ways.
>
> Almost. I've run across a couple of cases where one works and the other
> doesn't -- one creates a Proc and the other doesn't, or something like
> that.
{} binds more tightly than do..end - in some cases this can lead to
your block being passed to the 'wrong' method:
def foo(x)
puts "foo #{block_given?}"
end
def bar
puts "bar #{block_given?}"
end
running foo bar {} outputs
bar true
foo false
but running
foo bar do
end
outputs
boo false
foo true
Fred
> But that's vanishingly rare, and 99 times out of 100, you will
> not go wrong to treat them as interchangeable.
>
> > More
> > of a Ruby question than a Rails one.
>
> Yup.
>
> Best,
> --
> Marnen Laibow-Koserhttp://www.marnen.org
> mar...@marnen.org
> --
> Posted viahttp://www.ruby-forum.com/.
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[Rails] Re: Combine if and do in a single line?
Jonathan Rochkind wrote:
[...]
> The {| | } and the 'do' syntaxes are interchangeable in all ways.
Almost. I've run across a couple of cases where one works and the other
doesn't -- one creates a Proc and the other doesn't, or something like
that. But that's vanishingly rare, and 99 times out of 100, you will
not go wrong to treat them as interchangeable.
> More
> of a Ruby question than a Rails one.
Yup.
Best,
--
Marnen Laibow-Koser
http://www.marnen.org
mar...@marnen.org
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[Rails] Re: Combine if and do in a single line?
Mario Gr wrote:
> Is there a way to combine if and do into a single line?
>
> items.each do |item| if current_user.admin?
> #do stuff
> end
>
> Thanks!
Freddy Andersen wrote:
> items.each { |item| item.stuff? } if current_user.admin?
Which you actually COULD write like this too, but I'm not sure if it
would be considered easily readable:
items.each do |item|
#do stuff
end if current_user.admin?
The {| | } and the 'do' syntaxes are interchangeable in all ways. More
of a Ruby question than a Rails one.
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[Rails] Re: Combine if and do in a single line?
items.each { |item| item.stuff? } if current_user.admin?
On May 27, 6:17 pm, Mario Gr wrote:
> Is there a way to combine if and do into a single line?
>
> items.each do |item| if current_user.admin?
> #do stuff
> end
>
> Thanks!
> --
> Posted viahttp://www.ruby-forum.com/.
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