gistfile1.txt

require_dependency 'vendor/plugins/blacklight/app/controllers/catalog_controller.rb'

class CatalogController < ApplicationController
        
# prepend_before_filter :transform_syntax

    def solr_search_params(extra_controller_params={})
        solr_parameters = super extra_controller_params
        my_parameters = solr_parameters.clone
        if my_parameters.key? :q
            my_parameters[:q] = my_parameters[:q].gsub(/\S+/) { |match|
                if match.include? ':' or match.index('=') != 0
                    match
                else
                    match.sub("=", "#{Blacklight.config[:nosyn_field]}:")
                end
            }
        end
        return my_parameters
    end

    
end
~ 

irb(main):006:0> a = "foo"
=> "foo"
irb(main):007:0> b = a
=> "foo"
irb(main):008:0> a.gsub!(/foo/, "New one!")
=> "New one!"
irb(main):009:0> a
=> "New one!"
irb(main):010:0> b
=> "New one!"
irb(main):014:0> a === b
=> true

gsub! actually changes the string object itself, both 'a' and 'b' point to the same string object, mutating it means it's different for both, because there's only one string there, and you've changed it. vs:

irb(main):011:0> x = "foo"
=> "foo"
irb(main):012:0> y = x
=> "foo"
irb(main):013:0> x = x.gsub(/foo/, "New one!")
=> "New one!"
irb(main):016:0> y
=> "foo"

x and y no longer point to the same string object, because instead of mutating that obj with gsub!, you created a new string based on the old with gsub, and assigned it to x.

irb(main):017:0> x === y
=> false