Regexp grouping question

ruby-talk
1

Hi

I'm trying to remove unecessary white space around equals signs and
after semicolons

compressed = "foo = bar; red = herring;"
compressed = compressed.gsub(/\s*([=;])\s*/,"#$1")
puts compressed

produces
foobarredherring

but I would like it to produce
foo=bar;red=herring;

Seems like the #$1 is not working. I also tried #{$1} but that didn't
work either.

Any ideas?

Thanks,
Peter

2

compressed = "foo = bar; red = herring;"
compressed = compressed.gsub(/\s*([=;])\s*/,'\1')

I believe #$1 is evalued *before* gsub is executed and hence fails.
gsub sets the variable and uses \1, \2, \3 in the replacement string
to correspond.

···

On 4/1/06, petermichaux@gmail.com <petermichaux@gmail.com> wrote:

Hi

I'm trying to remove unecessary white space around equals signs and
after semicolons

compressed = "foo = bar; red = herring;"
compressed = compressed.gsub(/\s*([=;])\s*/,"#$1")
puts compressed

produces
foobarredherring

but I would like it to produce
foo=bar;red=herring;

Seems like the #$1 is not working. I also tried #{$1} but that didn't
work either.

Any ideas?

Thanks,
Peter

3

unknown wrote:

Hi

I'm trying to remove unecessary white space around equals signs and
after semicolons

compressed = "foo = bar; red = herring;"
compressed = compressed.gsub(/\s*([=;])\s*/,"#$1")
puts compressed

produces
foobarredherring

but I would like it to produce
foo=bar;red=herring;

Seems like the #$1 is not working. I also tried #{$1} but that didn't
work either.

Any ideas?

Thanks,
Peter

This thread has been *very helpful*. Thank you!

What if the input syntax allows spaces in the field values?

Possible input:
foo = high bar jump ; red = pickled herring ;

And, let's remove leading and trailing white space.

Desired results:
foo=high bar jump;red=pickled herring;

···

--
Posted via http://www.ruby-forum.com/\.

4

Chris Alfeld wrote:

compressed = "foo = bar; red = herring;"
compressed = compressed.gsub(/\s*([=;])\s*/,'\1')

I believe #$1 is evalued *before* gsub is executed and hence fails.
gsub sets the variable and uses \1, \2, \3 in the replacement string
to correspond.

Thank you!

Peter

5

If you want to use $1, $2, $3, etc. with gsub, you can use the block form:

compressed.gsub(regexp) { |matched_string| $1 }

···

On Apr 1, 2006, at 4:28 PM, petermichaux@gmail.com wrote:

Chris Alfeld wrote:

compressed = "foo = bar; red = herring;"
compressed = compressed.gsub(/\s*([=;])\s*/,'\1')

I believe #$1 is evalued *before* gsub is executed and hence fails.
gsub sets the variable and uses \1, \2, \3 in the replacement string
to correspond.

Thank you!

Peter