From: William James <w_a_x_man@...>
Date: 2008-09-03T13:19:31+09:00
Subject: Re: How would this Perl script look in Ruby?

On Aug 28, 7:23 am, Avinash Magar <avinash.ma...@gmail.com> wrote:
> Can somebody please me tell the way to write this script in Ruby?
>
> ;---------------------------------------
> #!/bin/env perl
>
> use strict;
> use Data::Dumper;
>
> #; define some message templates here
> my $message_templates = [
>     'adm has _QTY_ _CAR_ cars',
>     'ssn had _QTY_ _CAR_ cars',
> ];
>
> #; value map
> my %value_map = (
>     '_CAR_' => {
>         'order' => 'rand',
>         'vals' => [qw(bentley merc bmw audi porsche ford honda lexus)]
>         },
>     '_QTY_' => {
>         'order' => 'rand',
>         'vals' => [1..10]
>         }
> );
>
> # using 'random_msg_stub and val generators from %value_map
> sub get_next_random_msg {
>     my ($next_msg, $val_map) = @_;
>
>     my $m = &$next_msg();
>     while (my($vk, $v) = each (%value_map)) {
>         my ($nval) = $v->{gen}->();
>         $m =~ s/$vk/$nval/g;
>     }
>     $m;
>
> }
>
> # return $arrya[$last + 1] elem of array; $last is remembered across
> invocations
> sub get_seq_val_generator {
>     my $a = $_[0];
>     my $last = 0;
>     return sub {
>         $last = 0 if ($last == scalar @$a);
>         $$a[$last++];
>     };
>
> }
>
> # return random elem of array
> sub get_random_val_generator {
>     my $arr = shift;
>     return sub { return $arr->[ rand @$arr] };
>
> }
>
> #; let's generate value generator foreach value in 'value_map
> while (my($vk, $v) = each (%value_map)) {
>     if ($v->{order} eq 'seq') {
>         $v->{gen} = get_seq_val_generator($v->{vals});
>     } elsif ($v->{order} eq 'rand') {
>         $v->{gen} = get_random_val_generator($v->{vals});
>     } else {
>         die "Invalid value order in value_map\n";
>     }
>
> }
>
> my ($get_next_random_msg_stub) =
> get_random_val_generator($message_templates);
>
> while (1) {
>     print get_next_random_msg($get_next_random_msg_stub, \%value_map),
> "\n\n";
>
> }
>
> 1;
>
> ;--------------------------------------------------

message_templates =
  'adm has _QTY_ _CAR_ cars',
  'ssn had _QTY_ _CAR_ cars'

get_rand = proc{|a| a[ rand( a.size ) ] }
$last = -1
get_seq  = proc{|a| $last = $last.next % a.size; a[$last] }

value_map = {
  '_CAR_' => [ get_seq,
      %w(bentley merc bmw audi porsche ford honda lexus) ],
  '_QTY_' => [ get_rand, (1..10).to_a ]
}

while true do
  puts get_rand[ message_templates ].gsub( /_.*?_/ ){|s|
    prc, list = value_map[ s ]
    prc[ list ] }
end


--- output ---
ssn had 1 honda cars
ssn had 10 lexus cars
adm has 2 bentley cars
adm has 6 merc cars
adm has 4 bmw cars
adm has 4 audi cars
ssn had 7 porsche cars
adm has 3 ford cars
ssn had 5 honda cars
adm has 10 lexus cars
ssn had 7 bentley cars
adm has 6 merc cars
...