From: Jacob Fugal <lukfugl@...>
Date: 2006-02-03T09:17:48+09:00
Subject: Re: Seeking the Ruby way

On 2/2/06, ara.t.howard@noaa.gov <ara.t.howard@noaa.gov> wrote:
> On Fri, 3 Feb 2006, Jacob Fugal wrote:
> > I'm curious why you decided to make `count` its own lambda when:
> >
> >  1) It's only ever used once
> >  2) The block that uses it has only one statement, namely the call to `count`
> >  3) count and the block to CSV::open have the same signature
>
> it's for abstraction only.

<snip>

> basically i find
>
>    {{{{}}}}
>
> tough to read sometimes and factor out things using lambda.  it's rare that it
> acutally ends up being the the only thing left as in this case - but here you
> are quite right that it can be compacted.

Yeah, I agree. I often use similar abstraction techniques for
readability. My brain just has the tendency to refactor code inwards
as well as outwards when an abstraction seems extraneous.

> >  CSV::open(path,"r"){|row| sum[row.last.to_s[0,6]] += 1}
>
> but i disagree here.  people, esp nubies will look at that and say - what?
> whereas reading
>
>    count = lambda{|row| sum[row.last.to_s[0,6]] += 1}
>
>    ... count[row] ...
>
> is pretty clear.  i often us variable as comments to others and myself.

Again, agreed. In this case though I don't think the abstraction of
naming sum[...] += 1 as count is a necessary one. If I were to
refactor part of the complex expression

  sum[row.last.to_s[0,6]] += 1

to improve readability, it would be the index:

  identifier_prefix = lambda{ |row| row.last.to_s[0,6] }
  ... sum[identifier_prefix[row]] += 1 ...

> what does this do:
>
>    password = "#{ sifname }_#{ eval( ((0...256).to_a.map{|c| c.chr}.sort_by{rand}.select{|c| c =~ %r/[[:print:]]/})[0,4].join.inspect ) }"
>
> hard to say huh?

Ick, yes, I'd definitely split that into chunks. :)

> how about this?
>
>    four_random_printable_chars = eval( ((0...256).to_a.map{|c| c.chr}.sort_by{rand}.select{|c| c =~ %r/[[:print:]]/})[0,4].join.inspect )
>    password = "#{ sifname }_#{ four_random_printable_chars }"
>
> ugly (yes i'm hacking like crazy today) but at least anyone reading it (most
> importantly me) knows what i'm trying to do if not how!

If you say so... ;)

Jacob Fugal