Ruby regex to replace character sequence

Question

So I have this string

x = "{"1"=>"test","2"=>"Another=>Test","3"=>"Another=>One"}"

and I want to replace the rocket symbol that is beside a character to a pipe symbol. so the result is

x = "{"1"=>"test","2"=>"Another|Test","3"=>"Another|One"}"

I have this code right now

if x =~ /(=>\w)/).present?
    x.match(/=>\w/) do |match|
      #loop through matches and replace => with |
    end
end

So basically my question is how do I loop through a matched by regex and replace the rocket sign to a pipe?

That string looks like the string representation of a Ruby hash. Where do you get the string from? I did you consider working on the original Ruby hash? — spickermann
– spickermann, Commented Mar 7, 2019 at 17:26
@SergioTulentsev yes but I dont want to replace =>T to | I just wanted to replace => to a | if it matches the regex /=>\w/ — stuckoverflow24
– stuckoverflow24, Commented Mar 7, 2019 at 17:30
@stuckoverflow24: ah, I see. In this case, you could use a positive lookahead (assert presence without including it in the match). Look it up. — Sergio Tulentsev
– Sergio Tulentsev, Commented Mar 7, 2019 at 17:31
I'm specifically asking for the code in your question to match, exactly, what you're trying to deal with. Right now that's not valid Ruby code. — tadman
– tadman, Commented Mar 7, 2019 at 18:01

Schwern · Accepted Answer · 2019-03-07 18:59:13Z

2

gsub with a positive look-ahead will do it.

x = %q[{"1"=>"test","2"=>"Another=>Test","3"=>"Another=>One"}]
x.gsub!(%r{=>(?=\w)}, '|')
puts x

A look-ahead (or look-behind) matches, but does not include that bit in the match.

Though I think %r{=>(?=[^"])}, a => which is not in front of a quote, is more correct.

x = %q[{"1"=>"what about => a space?","2"=>"Or=>(this)"}]
x.gsub!(%r{=>(?=[^"])}, '|')
puts x

answered Mar 7, 2019 at 18:59

Schwern

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