add option to disable to the input completer (ref #1123).

CHANGELOG.md

@@ -23,6 +23,7 @@
 * `whereami` is now aliased to `@`
 * default configuration(Pry.config) lazy loads its values. (#1096)
 * require of 'readline' is delayed until Pry.start() has been called for the first time. (#1117)
+* add option to disable input completer through `_pry_.config.completer = nil`
 
 #### Bug fixes, etc.
 * `binding.pry` inside `.pryrc` file now works, with some limitations (@richo / #1118)

lib/pry/pry_instance.rb

@@ -40,6 +40,7 @@ class Pry
 
   extend Pry::Config::Convenience
   config_shortcut *Pry::Config.shortcuts
+  EMPTY_COMPLETIONS = [].freeze
 
   # Create a new {Pry} instance.
   # @param [Hash] options
@@ -131,6 +132,7 @@ class Pry
   # @param [String] input What the user has typed so far
   # @return [Array<String>] Possible completions
   def complete(input)
+    return EMPTY_COMPLETIONS unless config.completer
     Pry.critical_section do
       config.completer.call input, :target => current_binding,
         :pry => self,