Rails - Jan 2008 - What does the ' & ' mean when associated to a block?

I have a function that is defined as such:

def rubyfunc( &block )
    ...
end

Its called by "interface.rubyfunc" (Where obviously interface is a
class)


Can anyone give me an explanation of what the "&"-sign is and in
general
what the parameter is when I call it from an empty function?
-- 
Posted via http://www.ruby-forum.com/.

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the syntax of ''&'' comes from the c/c++ lang and means that
the variable
''block'' is not a parameter in the normal list.

''block'' would take a ruby variable

while ''&block'' takes a block of code

The function would be called like this

rubyfunc do |some_param|
 puts param.to_s
end

where the do/end is becomes a Proc object and gets stored in the &block 
arg

& must be used on the last argument in the function definition.

An instance of a Proc object can be executed via
<var_name>.call(<args>)

note that the do/end can be substituted with {} but should only be used 
on single line blocks ie.

rubyfunc{ puts ''hello'' }

-K

p.s. this is a ruby syntax question and should be posted on the ruby 
forum in the future.
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