Hello,
I'm a just beginner to ruby and impressed by the possibility to test
code in irb. Today I wrote a line of code in irb and it behaved as I
expected. But when I inserted it in my program and executed with ruby,
the code-block didn't worke. Maybe you could tell me why.
It asked me in irb depending on the size of 'a' for some input and
replaced a part (I used the Regular Expression /<\w*>/) of the string
'a' with my input.
But if I use this line in a program, the part 'gets.chomp' seems to be
ignored. The result is no change on String 'a'.
I've no explanation for this strange behaviour, I hope you can give me
a hint. Maybe the whole line is rubbish and there is a lot better way
to do the job?
Hello,
I'm a just beginner to ruby and impressed by the possibility to test
code in irb. Today I wrote a line of code in irb and it behaved as I
expected. But when I inserted it in my program and executed with ruby,
the code-block didn't worke. Maybe you could tell me why.
The line
a.scan(reg_exp).each {|w| print "#{w.to_s}: "
w is already a string.
; a.sub!(reg_exp,
gets.chomp)}
To me, it doesn't make sense to change the string
while you are scanning it.
Try this:
a = "foo <trew> bar <tich>"
reg_exp = /<\w*>/
a.gsub!(reg_exp) { |w| print "#{w}: "; gets.chomp }
p a
···
It asked me in irb depending on the size of 'a' for some input and
replaced a part (I used the Regular Expression /<\w*>/) of the string
'a' with my input.
But if I use this line in a program, the part 'gets.chomp' seems to be
ignored. The result is no change on String 'a'.
I've no explanation for this strange behaviour, I hope you can give me
a hint. Maybe the whole line is rubbish and there is a lot better way
to do the job?
I don't know if this is the problem here, but:
"gets" might not do exactly what you think it does...
Try changing it to "$stdin.gets".
Read:
$ ri Kernel#gets
That's what you use now...
and:
$ ri IO#gets
That's what you call with $stdin.gets.
HTH,
Stefan
···
On Sunday 30 July 2006 21:05, naPOLeon wrote:
Hello,
I'm a just beginner to ruby and impressed by the possibility to
test code in irb. Today I wrote a line of code in irb and it
behaved as I expected. But when I inserted it in my program and
executed with ruby, the code-block didn't worke. Maybe you could
tell me why.
It asked me in irb depending on the size of 'a' for some input and
replaced a part (I used the Regular Expression /<\w*>/) of the
string 'a' with my input.
But if I use this line in a program, the part 'gets.chomp' seems to
be ignored. The result is no change on String 'a'.
your right, gsub! is a better way to do what I want. But your solution
doesn't work, either. I think ruby has a problem by invoking gets.chomp
(by the way Stefan, it made for me no difference to use $stdin.gets
instead of gets )-: in a block. I hope you know a workaround (I tried
to write ..do..end instead of {}, but it doesn't changed anything in
the behaviour of my program)
thanks,
naPOLeon
William James wrote:
···
naPOLeon wrote:
> Hello,
> I'm a just beginner to ruby and impressed by the possibility to test
> code in irb. Today I wrote a line of code in irb and it behaved as I
> expected. But when I inserted it in my program and executed with ruby,
> the code-block didn't worke. Maybe you could tell me why.
>
> The line
>
> a.scan(reg_exp).each {|w| print "#{w.to_s}: "
w is already a string.
> ; a.sub!(reg_exp,
> gets.chomp)}
To me, it doesn't make sense to change the string
while you are scanning it.
Try this:
a = "foo <trew> bar <tich>"
reg_exp = /<\w*>/
a.gsub!(reg_exp) { |w| print "#{w}: "; gets.chomp }
p a
>
> It asked me in irb depending on the size of 'a' for some input and
> replaced a part (I used the Regular Expression /<\w*>/) of the string
> 'a' with my input.
> But if I use this line in a program, the part 'gets.chomp' seems to be
> ignored. The result is no change on String 'a'.
>
> I've no explanation for this strange behaviour, I hope you can give me
> a hint. Maybe the whole line is rubbish and there is a lot better way
> to do the job?
>
> Thanks,
> naPOLeon