gsub with match replacement

[James R. Leu]

I'm trying to convert

"12:34" => "12:34"

(I know there is a CGI module with unescapeHTML(), I'm working in a
ruby environment that does not allow for additions of modules)

I'm trying:

"12:34".gsub(/&#(\d+);/,'\1'.to_i.chr)

But I get "1234"

Can anyone explain what I'm doing wrong?

BTW I know I can do:

"12:34".gsub(/&#(\d+);/) do
Integer($1).chr
end

but for some reason in the ruby environment I'm working in
I get 'Undefined method Integer for main:Object'

 

[Carlos]

I'm trying to convert

"12:34" => "12:34"

(I know there is a CGI module with unescapeHTML(), I'm working in a
ruby environment that does not allow for additions of modules)

I'm trying:

"12:34".gsub(/&#(\d+);/,'\1'.to_i.chr)

But I get "1234"

Can anyone explain what I'm doing wrong?

When ruby is about to call method #gsub, it evaluates the arguments.
The second argument is '\1'.to_i.chr -> 0.chr -> "\000".

BTW I know I can do:

"12:34".gsub(/&#(\d+);/) do
Integer($1).chr
end

but for some reason in the ruby environment I'm working in
I get 'Undefined method Integer for main:Object'

It's very strange that you get that error (works here). Maybe you can try
with $1.to_i.chr, as before.