Re: "Put" in Ruby

From	Robert Klemme <shortcutter@googlemail.com>
Newsgroups	comp.lang.ruby
Subject	Re: "Put" in Ruby
Date	2016-04-16 01:50 +0200
Message-ID	<dndd1lFd67gU1@mid.individual.net> (permalink)
References	<d720c9a9-3943-45d9-83a1-ff3cf224aaef@googlegroups.com>

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On 15.04.2016 17:23, Cai Gengyang wrote:

> First off, puts is not a function. It's sole purpose is to have a
> side-effect (printing something to the console), whereas functions
> cannot have side-effects ... that's the definition of "function",
> after all.

More precisely this is _one_ definition of function.  Other context are 
more liberal and will include functions with side effects.

> Ruby doesn't have functions. It only has methods. Thus, puts is a
> method.
>
> Is this true ?

If you apply a strict definition, yes.  Every method can have side 
effects - but it does not need to.  There is no way to declare a "thing" 
in Ruby to be a function without side effects.

> So basically, 'puts' is just a "thing" to enable
> printing something to the console ...

It is a method with the side effect of writing a character 
representation of its arguments to whatever file descriptor 0 (usually 
called "stdout") points to.  Additionally there are some formatting 
tricks, i.e. newlines will be inserted between output of arguments.

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

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Thread

"Put" in Ruby Cai Gengyang <gengyangcai@gmail.com> - 2016-04-15 08:23 -0700
  Re: "Put" in Ruby Sebastian Christ <rudolfo.christ@gmail.com> - 2016-04-15 20:57 +0200
    Re: "Put" in Ruby Robert Klemme <shortcutter@googlemail.com> - 2016-04-16 01:45 +0200
      Re: "Put" in Ruby Sebastian Christ <rudolfo.christ@gmail.com> - 2016-04-16 11:52 +0200
        Re: "Put" in Ruby Robert Klemme <shortcutter@googlemail.com> - 2016-04-16 13:40 +0200
  Re: "Put" in Ruby Robert Klemme <shortcutter@googlemail.com> - 2016-04-16 01:50 +0200
  Re: "Put" in Ruby Kaz Kylheku <545-066-4921@kylheku.com> - 2016-04-16 01:39 +0000

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