MissingSourceFile no such file to load -- string

i use rails installer, when i add require 'string' in application_helper.rb, it shows the following errors,

E:/rails/INSTAN~1.0-W/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:496:in `require'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:342:in `new_constants_in'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:496:in `require'
app/helpers/application_helper.rb:1
app/controllers/application.rb:4
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:496:in `require'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:342:in `new_constants_in'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:496:in `require'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:203:in `load_without_new_constant_marking'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:203:in `load_file'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:342:in `new_constants_in'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:202:in `load_file'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:94:in `require_or_load'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:60:in `depend_on'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:442:in `require_dependency'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/helpers.rb:176:in `default_helper_module!'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/helpers.rb:191:in `send!'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/helpers.rb:191:in `inherited'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:203:in `load_without_new_constant_marking'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:203:in `load_file'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:342:in `new_constants_in'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:202:in `load_file'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:94:in `require_or_load'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:60:in `depend_on'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:442:in `require_dependency'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:141:in `prepare_application'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:178:in `send!'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:178:in `run_callbacks'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:175:in `each'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:175:in `send!'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:175:in `run_callbacks'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:114:in `dispatch'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:126:in `dispatch_cgi'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:9:in `dispatch'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/rails.rb:76:in `process'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/rails.rb:74:in `synchronize'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/rails.rb:74:in `process'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:159:in `process_client'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:158:in `each'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:158:in `process_client'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:285:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:285:in `initialize'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:285:in `new'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:285:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:268:in `initialize'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:268:in `new'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:268:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/configurator.rb:282:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/configurator.rb:281:in `each'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/configurator.rb:281:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/mongrel_rails:128:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/command.rb:212:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/mongrel_rails:281
E:/rails/INSTAN~1.0-W/ruby/bin/mongrel_rails:19:in `load'
E:/rails/INSTAN~1.0-W/ruby/bin/mongrel_rails:19
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:496:in `require'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:342:in `new_constants_in'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:496:in `require'
app/helpers/application_helper.rb:1
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:203:in `load_without_new_constant_marking'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:203:in `load_file'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:342:in `new_constants_in'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:202:in `load_file'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:94:in `require_or_load'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems开发者_开发技巧/activesupport-2.0.2/lib/active_support/dependencies.rb:60:in `depend_on'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:442:in `require_dependency'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/helpers.rb:176:in `default_helper_module!'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/helpers.rb:191:in `send!'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/helpers.rb:191:in `inherited'
app/controllers/application.rb:4
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:203:in `load_without_new_constant_marking'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:203:in `load_file'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:342:in `new_constants_in'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:202:in `load_file'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:94:in `require_or_load'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:60:in `depend_on'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:442:in `require_dependency'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:141:in `prepare_application'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:178:in `send!'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:178:in `run_callbacks'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:175:in `each'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:175:in `send!'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:175:in `run_callbacks'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:114:in `dispatch'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:126:in `dispatch_cgi'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:9:in `dispatch'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/rails.rb:76:in `process'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/rails.rb:74:in `synchronize'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/rails.rb:74:in `process'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:159:in `process_client'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:158:in `each'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:158:in `process_client'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:285:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:285:in `initialize'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:285:in `new'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:285:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:268:in `initialize'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:268:in `new'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel.rb:268:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/configurator.rb:282:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/configurator.rb:281:in `each'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/configurator.rb:281:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/mongrel_rails:128:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/lib/mongrel/command.rb:212:in `run'
E:/rails/INSTAN~1.0-W/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/mongrel_rails:281
E:/rails/INSTAN~1.0-W/ruby/bin/mongrel_rails:19:in `load'
E:/rails/INSTAN~1.0-W/ruby/bin/mongrel_rails:19
This error occurred while loading the following files:
   string

What are you trying to achieve?

There is no gem or standard module called 'string' in Ruby (String is a built in class and you don't need to require anything to be able to use it).

It looks like it all work as designed.

There is nothing like require 'string' in ruby.In order to use string you can directly go for it with no concerns of the error. Thanx