How do I replace a group of reserved chars into " " in Ruby on Rails?

Question

I want to replace the following reserved chars into spaces:

+ - & | ! ( ) { } [ ] ^ " ~ * ? : \

This is my code, but it doesn't work. Did I miss anything?

keyword = keyword.gsub(/\\+-&\\|!\\(\\)\\{\\}\\[\\]\\^"~\\*\\?:\\\\/, ' ')

Answer 1

Here's a benchmark showing the speed difference between gsub and tr:

require 'benchmark'
require 'pp'

STR = '+ - & | ! ( ) { } [ ] ^ " ~ * ? : \\'
LONG_STR = STR * 1_000
N = 1_000

puts `ruby -v`

pp STR.gsub(/[+&|!(){}\[\]^"~*:?\\-]/, ' ')
pp STR.tr('-+&|!(){}[]^"~*?:\\', ' ')

Benchmark.bm(5) do |b|
  b.report('gsub') { N.times { LONG_STR.gsub(/[+&|!(){}\[\]^"~*:?\\-]/, ' ') } }
  b.report('tr') { N.times { LONG_STR.tr('+&|!(){}[]^"~*:?\\-', ' ') } }
end

And the output:

ruby 1.8.7 (2012-02-08 patchlevel 358) [universal-darwin12.0]
"                                   "
"                                   "
          user     system      total        real
gsub  13.300000   0.190000  13.490000 ( 13.524779)
tr     0.080000   0.010000   0.090000 (  0.090045)

ruby 1.9.3p392 (2013-02-22 revision 39386) [x86_64-darwin12.2.0]
"                                   "
"                                   "
            user     system      total        real
gsub   17.890000   0.040000  17.930000 ( 18.016657)
tr      0.270000   0.000000   0.270000 (  0.283021)

ruby 2.0.0p0 (2013-02-24 revision 39474) [x86_64-darwin12.2.0]
"                                   "
"                                   "
            user     system      total        real
gsub    7.310000   0.020000   7.330000 (  7.361403)
tr      0.140000   0.010000   0.150000 (  0.145816)

It's interesting that 1.8.7 out-performed 1.9.3. I suspect it's because of the addition of multibyte character support in 1.9+.

I've done several benchmarks with 2.0 and have been very happy with the speed improvements I've seen.

Answer 2

This is what tr is for:

keyword.tr '-+&|!(){}[]^"~*?:\\', " "
#=> "                                   "