From: Intransition <transfire@...>
Date: 2011-11-14T11:30:33+09:00
Subject: Binding#with

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Binding#with

    def with(_local_variables)
      eval("Proc.new{ |#{_local_variables.keys.join(',')}| binding 
}").call(*_local_variables.values)
    end

Try it:

    b = binding.with(:a=>1)
    b.eval('a')  #=> 1

Now, it there a way to add a "yield" to the binding? I tried:

  def with(_local_variables, &_yields)
    eval("lambda{ |#{_local_variables.keys.join(',')},&yields| binding 
}").call(*_local_variables.values, &_yields)
  end

    b = binding.with{ |x| x+x}
    b.eval('yields[1]')  #=> 2

but

    b.eval('yield(1)')  #=> Error




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<div>Binding#with</div><div><br></div><div>&nbsp; &nbsp; def with(_local_va=
riables)</div><div>&nbsp; &nbsp; &nbsp; eval("Proc.new{ |#{_local_variables=
.keys.join(',')}| binding }").call(*_local_variables.values)</div><div>&nbs=
p; &nbsp; end</div><div><br></div><div>Try it:</div><div><br></div><div>&nb=
sp; &nbsp; b =3D binding.with(:a=3D&gt;1)</div><div>&nbsp; &nbsp; b.eval('a=
') &nbsp;#=3D&gt; 1<br></div><div><br></div><div>Now, it there a way to add=
 a "yield" to the binding? I tried:</div><div><br></div><div><div>&nbsp; de=
f with(_local_variables, &amp;_yields)</div><div>&nbsp; &nbsp; eval("lambda=
{ |#{_local_variables.keys.join(',')},&amp;yields| binding }").call(*_local=
_variables.values, &amp;_yields)</div><div>&nbsp; end</div></div><div><br><=
/div><div><div style=3D"border-style: initial; border-color: initial; ">&nb=
sp; &nbsp; b =3D binding.with{ |x| x+x}</div><div style=3D"border-style: in=
itial; border-color: initial; ">&nbsp; &nbsp; b.eval('yields[1]') &nbsp;#=
=3D&gt; 2<br></div></div><div style=3D"border-style: initial; border-color:=
 initial; "><br></div><div style=3D"border-style: initial; border-color: in=
itial; ">but</div><div style=3D"border-style: initial; border-color: initia=
l; "><br></div><div style=3D"border-style: initial; border-color: initial; =
">&nbsp; &nbsp; b.eval('yield(1)') &nbsp;#=3D&gt; Error<br></div><div style=
=3D"border-style: initial; border-color: initial; "><br></div><div style=3D=
"border-style: initial; border-color: initial; "><br></div><div><br></div>
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