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From: Intransition on 5 Jul 2010 19:29
I have a registry (array) of CLI classes. Each class has a class
method cli() that returns an array of strings or regular expressions
to match against ARGV to see if it is the chosen cli. Eg.

class FooList << CLIBase
def self.cli ; ['foo', 'list'] ; end
...
end

So if someone puts on the command line:

$ foo list

Then the above class would match for it. I wrote the algorithm to
handle this, but I think it's Ugh-ly. Wondering if the smart folk here
might play a game of golf on it.

def command(argv)
lookup = registry.map{ |cc| [cc, cc.cli] }.sort{ |a,b| b[1].size
<=> a[1].size }
x = lookup.find do |cc, cli|
t = true
cli.each_with_index do |r, i|
t = t && (r === argv[i])
end
t
end
cmdc = x[0]
argv = argv[x[1].size..-1]
return cmdc, argv
end

From: Joel VanderWerf on 6 Jul 2010 00:46
Intransition wrote:
> def command(argv)
> lookup = registry.map{ |cc| [cc, cc.cli] }.sort{ |a,b| b[1].size
> <=> a[1].size }
> x = lookup.find do |cc, cli|
> t = true
> cli.each_with_index do |r, i|
> t = t && (r === argv[i])
> end
> t
> end
> cmdc = x[0]
> argv = argv[x[1].size..-1]
> return cmdc, argv
> end

Untested:

def command(argv)
lookup = registry.sort_by {|cc| cc.cli.size}
cmdc = lookup.find do |cc|
cc.cli.zip(argv).all? do |r,arg|
r === arg
end
end
return cmdc, argv[cmdc.cli.size..-1]
end

The following (assuming it works!) would be more compact still:

class Symbol
alias old_to_proc to_proc
def to_proc
case self
when :=== # etc.
proc {|x,y| x === y}
else
old_to_proc
end
end
end

def command(argv)
lookup = registry.sort_by {|cc| cc.cli.size}
cmdc = lookup.find do |cc|
cc.cli.zip(argv).all?(&:===)
end
return cmdc, argv[cmdc.cli.size..-1]
end


From: Martin DeMello on 6 Jul 2010 07:24
On Tue, Jul 6, 2010 at 4:59 AM, Intransition <transfire(a)gmail.com> wrote:
>
>   def command(argv)
>      lookup = registry.map{ |cc| [cc, cc.cli] }.sort{ |a,b| b[1].size
> <=> a[1].size }

at the least this should be registry.map {|cc| [cc, cc.cli]}.sort_by
{|a| -a[1].size}

also, you're never using cc, so why carry it around?

lookup = registry.map {|cc| cc.cli}.sort_by {|cli| -cli.size}

and using the ever-handy symbol.to_proc

lookup = registry.map(&:cli).sort_by(&:size).reverse

>      x = lookup.find do |cc, cli|
>        t = true
>        cli.each_with_index do |r, i|
>          t = t && (r === argv[i])
>        end
>        t
>      end

# untested
lookup.find do |cli|
cli.zip(argv).inject(true) {|e, (i, j)| e && (i === j)}
end

>      cmdc = x[0]
>      argv = argv[x[1].size..-1]
>      return cmdc, argv
>    end

martin

From: Intransition on 12 Jul 2010 20:49
Thanks Joel and Martin. Amazingly concise answers -- it's amazes me
sometimes how small a piece of code can get in Ruby :-)

I haven't gotten back to the particular code I need this for yet which
is why I haven't responded until now, but should be back to it soon
and I'll let you know how it worked out.

From: w_a_x_man on 12 Jul 2010 23:20
On Jul 6, 6:24 am, Martin DeMello <martindeme...(a)gmail.com> wrote:
> On Tue, Jul 6, 2010 at 4:59 AM, Intransition <transf...(a)gmail.com> wrote:
>
> >   def command(argv)
> >      lookup = registry.map{ |cc| [cc, cc.cli] }.sort{ |a,b| b[1].size
> > <=> a[1].size }
>
> at the least this should be registry.map {|cc| [cc, cc.cli]}.sort_by
> {|a| -a[1].size}
>
> also, you're never using cc, so why carry it around?
>
> lookup = registry.map {|cc| cc.cli}.sort_by {|cli| -cli.size}
>
> and using the ever-handy symbol.to_proc
>
> lookup = registry.map(&:cli).sort_by(&:size).reverse
>
> >      x = lookup.find do |cc, cli|
> >        t = true
> >        cli.each_with_index do |r, i|
> >          t = t && (r === argv[i])
> >        end
> >        t
> >      end
>
> # untested
> lookup.find do |cli|
>   cli.zip(argv).inject(true) {|e, (i, j)| e && (i === j)}
> end

lookup.find{|cli| cli == argv[0,cli.size] }


>
> >      cmdc = x[0]
> >      argv = argv[x[1].size..-1]
> >      return cmdc, argv
> >    end
>
> martin

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