From: Meinrad Recheis <meinrad.recheis@...>
Date: 2006-03-05T04:23:02+09:00
Subject: Re: Symbols

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On 3/4/06, Servando Garcia <garcia.servando@gmail.com> wrote:
>
> Hello all .
>     I am a newbie to Ruby. I have been reading everything I can get my
> hands on about Ruby. I understand what a symbol is and how it saves
> memory space. I just can not seem to find any good reason to use one. I
> am sure I am missing something. Would some one please show me a good
> working example for using a symbol, please not the "Foo Bar" example
> again.
>
>
> Sam
>

hi Sam.
symbols are a coding style instrument:

personally, i use symbols whereever i want to refer to method names, as key=
s
in hashes or as other constant identifiers.

symbols as constant identifiers that need not be initialized are nicer than
code like this:

LAYOUT_CONSTANTS=3D[
  LAYOUT_RIGHT=3D0,
  LAYOUT_LEFT=3D1,
...
]

or even:

LAYOUT_CONSTANTS=3D[
  LAYOUT_RIGHT=3D"LAYOUT_RIGHT",
  LAYOUT_LEFT=3D"LAYOUT_LEFT",
...
]

code snippets that illustrate my coding style using symbols:

> if object.respond_to? :a_method
>
> { :key =3D> "value" }
>
> subject.do_something( sideeffect=3D:notify)

you could use strings instead, but this kind of coding style enhances code
readability, because if you see a symbol you automatically associate it wit=
h
methods, variables, and constant expressions and the symbol syntax
differentiates these from normal (data-)strings.
i think i don't need to tell you guys why good coding styles are important
in software engineering :)
-- henon

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