From: SonOfLilit <sonoflilit@...>
Date: 2007-02-18T04:41:34+09:00
Subject: Re: Help with customising the IRB prompt

I was a bit unclear, so let me give an example:

class Hashlike < Hash
  def [] (key)
    return " " * $indentation_level if key == :PROMPT_I
    super
  end
end


IRB.conf[:PROMPT][:INDENTS] = Hashlike.new( # can I pass a Hash to Hash.new ?
 :PROMPT_I => "#{%i.times {print '  '}} >> ",
 :PROMPT_S => "#{%i.times {print '  '}} >> ",
 :PROMPT_C => "#{%i.times {print '  '}} >> ",
 :RETURN => "=> %s\n"

You might be able to achieve a similar effect with a Hash and a
default block, I don't remember it's syntax.


Aur Saraf


On 2/17/07, SonOfLilit <sonoflilit@gmail.com> wrote:
> This is a constant so you cannot just assign it a dynamic value.
>
> If you really want, you can assign it an instance of a class that
> exposes an interface similar to that of a Hash but acts dynamically.
>
> You'd still need to somehow get the value of "%i", whatever that is
> (I'm not familiar with IRB configuration but I know it's very hard to
> achieve this with Ruby so I just guess you meant @i or something (if
> I'm wrong, sorry)).
>
> You might as well just modify a few lines of IRB code, I guess.
>
> By the way, printf() like formatitng in Ruby has a great syntax:
>
> "%f" % 0.1
> "%d %d" % [1, 2]
>
> (String could be dynamic, Numerics could be dynamic, Array could be dynamic).
>
>
> Have a look at the  Adopt-a-newbie thread here in the mailing list :-)
>
>
> Aur Saraf
>
> On 2/17/07, Peter B. <peter.bunyan@googlemail.com> wrote:
> > Hi, I'm new to this newsgroup, so I'm not sure if this is the right
> > place to ask.
> >
> > Ok, so what I'm trying to do is customise the IRB prompt in a rather
> > complicated way: I want to print %i*2 (or even just %i) spaces at the
> > beginning of each line of prompt. Here was my best attempt (not sure
> > if there's a better way to format this for Usenet):
> >
> > IRB.conf[:PROMPT][:INDENTS] = {
> >   :PROMPT_I => "#{%i.times {print '  '}} >> ",
> >   :PROMPT_S => "#{%i.times {print '  '}} >> ",
> >   :PROMPT_C => "#{%i.times {print '  '}} >> ",
> >   :RETURN => "=> %s\n"
> > }
> >
> > So, what I want it do is like this:
> >
> >  >> if "Jim" == "Fred"
> >    >> print "Ruby Sucks!"
> >    >> else
> >    >> print "Ruby is cool!"
> >    >> end
> >  >> print "And you know it!"
> >
> > But obviously, It tries to work out the value of the #{ } as soon as
> > it's set, not when it's displayed, after the %i has been gsub'd for
> > displaying. So, I get an error thrown at me.
> >
> > Does anybody know how to do this? Maybe some printf() trickery?
> >
> > Thanks in advance.
> >
> >
> >
>