From: Eivind Eklund <eeklund@...>
Date: 2007-06-22T19:24:21+09:00
Subject: Re: avoiding nil.methodcalls short and cheap

On 6/22/07, Thorsten Rossner <rossnet@gmx.de> wrote:
> Hi,
>
> I often have to check if a methodcall A is not returning nil before
> calling another method on the return value of the methodcall A. I'm
> looking for a short and cheap (avoiding to call method A two times like
> in this example where xmltag.get_text is method A:
> textvalue = xmltag.get_text.value if xmltag.get_text

Variations using just logic operators and conditionals - I think the
last two are probably best (though it vary by context)

# Short, unclear
textvalue = xmltag.get_text
textvalue &&= textvalue.value

# With if
textvalue = textvalue.value if textvalue = xmltag.get_text

# Longer, clearer
if textvalue = xmltag.get_text
  textvalue = textvalue.value
end

# Re-using the variable, one-line
textvalue = xmltag.get_text and textvalue = textvalue.value

# With new variable, possibly the cleanest
textvalue = (text = xmltag.get_text and text.value)

# You can also redefine the object in question
def xmltag.get_text_value
   text = get_text && text.value
end
textvalue = xmltag.get_text_value




> )
> The ideal solution would be a oneliner with only little complexity
> calling method A just one time. Am I using the wrong approach here
> anyway?
>
> Thanks,
> .tr!
>
> --
> Posted via http://www.ruby-forum.com/.
>
>


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