Hi,
Is it possible to have a go to in Ruby without having a go to?
If yes, How?
Thanks again, You guys are the best. Maybe Eiffel will have a similar
support one day.
RK
----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
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"Roman K9" <litleguy@bendbroadband.com> schrieb im Newsbeitrag
news:uabvm0lrutuf59rls2vp7dvmscjk1e5rs5@4ax.com...
Hi,
Is it possible to have a go to in Ruby without having a go to?
If yes, How?
Thanks again, You guys are the best. Maybe Eiffel will have a similar
support one day.
RK
You might be able to do it with continuations (callcc) but I wonder what
you're cooking up there. Is this some kind of competition (putting "goto"
into languages that don't support it) or do you have a specific problem
that you think cannot be solved without "goto"?
Kind regards
robert
See if this is any help:
http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/78458
although it's more an academic exercise in understanding continuations
rather than something you'd actually want to use in practice.
Regards,
Brian,
Roman K9 ha scritto:
Hi,
Is it possible to have a go to in Ruby without having a go to?
If yes, How?
Thanks again, You guys are the best. Maybe Eiffel will have a similar
support one day.
RK
I guess my previous mail did'nt make it to the ml/ng:
def goto(cont)
cont.call(cont)
end
label= callcc{|k| k }
puts 'loop'
goto label
exit! #never arrive here
Everybody else has shown the black magic, so I'll take an easier approach. Are you aware of catch/throw?
James Edward Gray II
On Oct 15, 2004, at 6:04 AM, Roman K9 wrote:
Hi,
Is it possible to have a go to in Ruby without having a go to?
If yes, How?
Roman K9 wrote:
Is it possible to have a go to in Ruby without having a go to?
Thanks! Thanks a lot!
I was so careful to make sure I never even learned if Ruby _had_ a 'goto'
keyword, and now you go and post this!
catch/throw allow the creation of goto like behaviour, including
spaghetti code if abused.
Sam
Quoteing litleguy@bendbroadband.com, on Fri, Oct 15, 2004 at 08:04:28PM +0900:
Hi,
Is it possible to have a go to in Ruby without having a go to?
If yes, How?
Thanks again, You guys are the best. Maybe Eiffel will have a similar
support one day.
RK----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! >100,000 Newsgroups
---= East/West-Coast Server Farms - Total Privacy via Encryption =---
--- code ---
#!/home/ummaycoc/bin/ruby -w
# Number stuff down the side
# REM means remark (NO number)
# No number means continue last number
# \ is same as no number...
# -d debug mode.
class NRuby
def initialize(debug = false)
@line = 0
@next = nil
@debug = debug
end
def goto(line)
@next = line
end
def stop()
@next = nil
end
def NRuby.error(msg)
$stderr.puts("NRubyErr: #{msg}")
exit(-1)
end
def debug(code, line)
if @debug then
puts "NO CODE #{line}" unless code[line]
puts "**#{line}**\n#{code[line]}\n" if code[line]
end
end
def NRuby.read(input, start)
code, prev = Hash.new(false), start
input.each {|line|
doPrev = false
case line
when /^\s*REM(\s+|(\s*$))/i then ;
when /^\s*$/ then ;
when /^\s*(\d+)\s+(.*)$/ then prev = $1.to_i
code[prev] = [$2]
when /^\s*\\\s+(.*)$/ then doPrev, line = true, $1
else doPrev = true
end
error "No Previous Line!" if prev.nil? && doPrev
code[prev] = [] unless code.include? prev
code[prev] << line if doPrev
}
code.each_key {|key|
code[key] = code[key].join(" \n")
}
code
end
def execute(code)
lastline = code.keys.max
until @line.nil? || @line > lastline
debug(code, @line)
@next = nil
eval(code[@line]) if code[@line]
@line = @next || @line + 1
end
end
end
debug = false
if ARGV.length > 0 then
if ARGV.include? "-d" then
debug = true
ARGV.delete "-d"
end
end
@___nruby___, start = NRuby.new(debug), nil
if ARGV.length > 0 then
stdin_read, lines = false, nil
until ARGV.empty? do
arg = ARGV.shift
case arg
when /^-+h/i
$stderr.puts <<-END_HELP
#{File.basename($0)} [-z|-s num] [-d] [files+]
-z sets the first number label to zero - for unlabeled code at
beginning of program.
-s num sets the first number label to num. Same use as -z.
-d debug mode.
files list what files to read from. - is stdin.
If no inputs are given, a program is read from stdin and executed.
END_HELP
exit(-1)
when '-'
NRuby.error "Already read from stdin." if stdin_read
stdin_read = true
lines = $stdin.readlines
when '-z'
start = 0
when '-s'
NRuby.error "No argument given with -s." if ARGV.empty?
start = ARGV.shift
NRuby.error "Argument to -s must be integer." unless start =~ /-?\d+$/
start = start.to_i
else
NRuby.error "#{arg} doesn't exist..." unless FileTest.exists?(arg)
NRuby.error "#{arg} isn't a file..." unless FileTest.file?(arg)
NRuby.error "#{arg} isn't readable..." unless FileTest.readable?(arg)
lines = File.readlines(arg)
end
lines ||= $stdin.readlines
lines.each {|l| l.chomp!}
@___nruby___.execute(NRuby.read(lines, start))
end
else
lines = $stdin.readlines.map {|l| l.chomp}
if lines.nil? || lines.empty? then
NRuby.error "No input given."
else
@___nruby___.execute(NRuby.read(lines, start))
end
end
--- a usage ---
[ummaycoc@queen ummaycoc]$ echo '
10 x = 1
11 x += 1
12 puts x
15 goto 18 if x == 10
16 goto 11
18 puts "done"
stop' | nruby
2
3
4
5
6
7
8
9
10
done
[ummaycoc@queen ummaycoc]$
--- usage 2 & 3 ---
[ummaycoc@queen bin]$ echo 'puts "hi"' | nruby
NRubyErr: No Previous Line!
[ummaycoc@queen bin]$ echo 'puts "hi"' | nruby -z
hi
[ummaycoc@queen bin]$
-------------------------------
--
There's no word in the English language for what you do to a dead
thing to make it stop chasing you.
Hi everyone,
Thanks for the evil info.
I did not mean to force the GOTO taboo on Ruby. Just wanted to know.
Thanks again,
RK
On Mon, 18 Oct 2004 07:57:44 +0900, Sam Roberts <sroberts@uniserve.com> wrote:
catch/throw allow the creation of goto like behaviour, including
spaghetti code if abused.Sam
Quoteing litleguy@bendbroadband.com, on Fri, Oct 15, 2004 at 08:04:28PM +0900:
Hi,
Is it possible to have a go to in Ruby without having a go to?
If yes, How?
Thanks again, You guys are the best. Maybe Eiffel will have a similar
support one day.
RK----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! >100,000 Newsgroups
---= East/West-Coast Server Farms - Total Privacy via Encryption =---
----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! >100,000 Newsgroups
---= East/West-Coast Server Farms - Total Privacy via Encryption =---
Matt Maycock wrote:
[snip]
--- a usage ---
[ummaycoc@queen ummaycoc]$ echo '
10 x = 1
11 x += 1
12 puts x
15 goto 18 if x == 10
16 goto 11
18 puts "done"
stop' | nruby
2
3
4
5
6
7
8
9
10
done
That's just...wrong. Wow. 
Thanks for the enlightenment, Matt!
- Jamis
--
Jamis Buck
jgb3@email.byu.edu
http://www.jamisbuck.org/jamis
class NRuby
...
def execute(code)
...
eval(code[@line]) if code[@line]
The trouble with that is that you are *recompiling* each line as you run it.
I would expect that to make it very slow.
That's why my BASIC-like attempt at RubyTalk:78458 used continuations, but
in two passes: first read through all the lines generating continuations but
not executing the blocks; then set a flag which lets them execute, and then
start again at the top (no central loop). The two-pass approach is needed so
that forward gotos work.
Admittedly it doesn't enforce numeric ordering of lines; if you do
line(10) { x }
line(30) { y }
line(20) { z }
then they will be executed in the sequence x, y, z. [Although as I wrote it,
the line with the lowest number is used as the starting point for execution]
Regards,
Brian.
In article <e86cebfb041015073631769f2f@mail.gmail.com>,
Matt Maycock <ummaycoc@gmail.com> wrote:
[ Unholy morphing of Ruby into Basic deleted]
_ Man, that's just evil....
_ Booker C. Bense
10 x = 1
11 x += 1
12 puts x
15 goto 18 if x == 10
16 goto 11
18 puts "done"
Ewwwwww…lol... reminds me of walking into Radio Shack stores
as a kid and typing
10 PRINT "TRS-80 SUCKS"
20 GOTO 10
There's no word in the English language for what you do to a dead
thing to make it stop chasing you.
"dismember" ?
(Is woodchipper one word? 
Regards,
Bill
From: "Matt Maycock" <ummaycoc@gmail.com>
Actually, I made the fatal mistake of leaving some of that code in the
middle of a fix (a few months ago). Here's the good stuff:
http://www.cs.drexel.edu/~ummaycoc/nruby
(was changing how stop() works, and taking care of a case of the -z
and -s i arguments (beginning line empty...))
--
There's no word in the English language for what you do to a dead
thing to make it stop chasing you.
--- code ---
#!/usr/bin/env ruby
# Number stuff down the side
# REM means remark (NO number)
# No number means continue last number
# \ is same as no number...
# -d debug mode.
class NRuby
def initialize(debug = false)
@line = 0
@next = nil
@debug = debug
end
def goto(line)
@next = line
end
def stop()
@next = :stop
end
def NRuby.error(msg)
$stderr.puts("NRubyErr: #{msg}")
exit(-1)
end
def debug(code, line)
if @debug then
puts "NO CODE #{line}" unless code[line]
puts "**#{line}**\n#{code[line]}\n" if code[line]
end
end
def NRuby.read(input, start)
code, prev = Hash.new(false), start
input.each {|line|
doPrev = false
case line
when /^\s*REM(\s+|(\s*$))/i then ;
when /^\s*$/ then ;
when /^\s*(\d+)\s+(.*)$/ then prev = $1.to_i
code[prev] = [$2]
when /^\s*\\\s+(.*)$/ then doPrev, line = true, $1
else doPrev = true
end
error "No Previous Line!" if prev.nil? && doPrev
unless prev.nil? then
code[prev] = [] unless code.include? prev
code[prev] << line if doPrev
end
}
code.each_key {|key|
code[key] = code[key].join(" \n")
}
code
end
def execute(code)
lastline = code.keys.max
until @line == :stop || @line > lastline
debug(code, @line)
@next = nil
eval(code[@line]) if code[@line]
@line = @next || @line + 1
end
end
end
debug = false
if ARGV.length > 0 then
if ARGV.include? "-d" then
debug = true
ARGV.delete "-d"
end
end
@___nruby___, start = NRuby.new(debug), nil
if ARGV.length > 0 then
stdin_read, lines = false, nil
until ARGV.empty? do
arg = ARGV.shift
case arg
when /^-+h/i
$stderr.puts <<-END_HELP
#{File.basename($0)} [-z|-s num] [-d] [files+]
-z sets the first number label to zero - for unlabeled code at
beginning of program.
-s num sets the first number label to num. Same use as -z.
-d debug mode.
files list what files to read from. - is stdin.
If no inputs are given, a program is read from stdin and executed.
END_HELP
exit(-1)
when '-'
NRuby.error "Already read from stdin." if stdin_read
stdin_read = true
lines = $stdin.readlines
when '-z'
start = 0
when '-s'
NRuby.error "No argument given with -s." if ARGV.empty?
start = ARGV.shift
NRuby.error "Argument to -s must be integer." unless start =~ /-?\d+$/
start = start.to_i
else
NRuby.error "#{arg} doesn't exist..." unless FileTest.exists?(arg)
NRuby.error "#{arg} isn't a file..." unless FileTest.file?(arg)
NRuby.error "#{arg} isn't readable..." unless FileTest.readable?(arg)
lines = File.readlines(arg)
end
lines ||= $stdin.readlines
lines.each {|l| l.chomp!}
@___nruby___.execute(NRuby.read(lines, start))
end
else
lines = $stdin.readlines.map {|l| l.chomp}
if lines.nil? || lines.empty? then
NRuby.error "No input given."
else
@___nruby___.execute(NRuby.read(lines, start))
end
end
-------------
Dismember a dead thing? It will now follow you in parts!
Woodchipper doesn't count. You can't woodchipper a dead thing, same
as that you can't automobile it (you could woodchip it, or run over
it...)
Trust me - there isn't a word. But there should be!
~Me!
--
There's no word in the English language for what you do to a dead
thing to make it stop chasing you.
Dezombify.
On 2004-10-15, Bill Kelly <billk@cts.com> wrote:
There's no word in the English language for what you do to a dead
thing to make it stop chasing you.
"dismember" ?
You're right, there isn't ONE word. That's because everyone knows YOU SHOOT IT
IN THE HEAD!
(unless your talking about demonized dead things, but then there is little
hope anyway.)
T.
On Friday 15 October 2004 03:17 pm, Matt Maycock wrote:
Dismember a dead thing? It will now follow you in parts!
Woodchipper doesn't count. You can't woodchipper a dead thing, same
as that you can't automobile it (you could woodchip it, or run over
it...)Trust me - there isn't a word. But there should be!
How about "hug"?
-- Markus
On Sat, 2004-10-16 at 06:49, Curt wrote:
On 2004-10-15, Bill Kelly <billk@cts.com> wrote:
>> There's no word in the English language for what you do to a dead
>> thing to make it stop chasing you.