[ruby/irb] Remove dead code (https://github.com/ruby/irb/pull/554)

* Remove unused ATTR_TTY and ATTR_PLAIN constants

They were added in https://github.com/ruby/irb/commit/d7d26b51bf47a52e4e2339e2ad509ace74f0e4c7

But the references were removed in https://github.com/ruby/irb/commit/1c76845cca59635bb0cf386ced721e34b25d7410

Co-authored-by: Alexandre Terrasa <alexandre.terrasa@shopify.com>

* Remove unused MethodExtender module

It was added in https://github.com/ruby/irb/commit/6cc5d718d7045952ef61d504d624f7e70ce828be
but it's not used anywhere.

Co-authored-by: Alexandre Terrasa <alexandre.terrasa@shopify.com>

* Remove unused IRB.irb_at_exit

It's not used after https://github.com/ruby/irb/commit/aaf4eb4e9830ae71240ca5d2047c5e3ad20a4044

Co-authored-by: Alexandre Terrasa <alexandre.terrasa@shopify.com>

* Remove unused InputCompletor.ignored_modules

It was added in https://github.com/ruby/irb/commit/88311ce3c84251e6f420246cd14efc96e00888be
but the reference was removed in https://github.com/ruby/irb/commit/78c74d24254145a39c4d30168dbcd87dbbbc66dc

* Remove unused TracerLoadError constant

This constant was added in https://github.com/ruby/irb/commit/cb50fa3738121e4d829cb05b4bcb0d5fb43760c5
but never referenced.

---------

https://github.com/ruby/irb/commit/7de0234325

Co-authored-by: Alexandre Terrasa <alexandre.terrasa@shopify.com>

3 files changed, 0 insertions, 80 deletions

diff --git a/lib/irb/completion.rb b/lib/irb/completion.rb
index c21ebfbdbd..6a7e04264a 100644
--- a/lib/irb/completion.rb
+++ b/lib/irb/completion.rb
@@ -450,30 +450,5 @@ module IRB
         end
       end
     end
-
-    def self.ignored_modules
-      # We could cache the result, but this is very fast already.
-      # By using this approach, we avoid Module#name calls, which are
-      # relatively slow when there are a lot of anonymous modules defined.
-      s = {}
-
-      scanner = lambda do |m|
-        next if s.include?(m) # IRB::ExtendCommandBundle::EXCB recurses.
-        s[m] = true
-        m.constants(false).each do |c|
-          value = m.const_get(c)
-          scanner.call(value) if value.is_a?(Module)
-        end
-      end
-
-      %i(IRB RubyLex).each do |sym|
-        next unless Object.const_defined?(sym)
-        scanner.call(Object.const_get(sym))
-      end
-
-      s.delete(IRB::Context) if defined?(IRB::Context)
-
-      s
-    end
   end
 end
diff --git a/lib/irb/ext/tracer.rb b/lib/irb/ext/tracer.rb
index 2d20cd3821..5fde3409cf 100644
--- a/lib/irb/ext/tracer.rb
+++ b/lib/irb/ext/tracer.rb
@@ -9,7 +9,6 @@ begin
 rescue LoadError
   $stderr.puts "Tracer extension of IRB is enabled but tracer gem doesn't found."
   module IRB
-    TracerLoadError = true
     class Context
       def use_tracer=(opt)
         # do nothing
diff --git a/lib/irb/extend-command.rb b/lib/irb/extend-command.rb
index 5020b1e5cd..e68b79daa7 100644
--- a/lib/irb/extend-command.rb
+++ b/lib/irb/extend-command.rb
@@ -371,58 +371,4 @@ module IRB # :nodoc:
 
     CE.install_extend_commands
   end
-
-  # A convenience module for extending Ruby methods.
-  module MethodExtender
-    # Extends the given +base_method+ with a prefix call to the given
-    # +extend_method+.
-    def def_pre_proc(base_method, extend_method)
-      base_method = base_method.to_s
-      extend_method = extend_method.to_s
-
-      alias_name = new_alias_name(base_method)
-      module_eval %[
-        alias_method alias_name, base_method
-        def #{base_method}(*opts)
-          __send__ :#{extend_method}, *opts
-          __send__ :#{alias_name}, *opts
-        end
-      ]
-    end
-
-    # Extends the given +base_method+ with a postfix call to the given
-    # +extend_method+.
-    def def_post_proc(base_method, extend_method)
-      base_method = base_method.to_s
-      extend_method = extend_method.to_s
-
-      alias_name = new_alias_name(base_method)
-      module_eval %[
-        alias_method alias_name, base_method
-        def #{base_method}(*opts)
-          __send__ :#{alias_name}, *opts
-          __send__ :#{extend_method}, *opts
-        end
-      ]
-    end
-
-    # Returns a unique method name to use as an alias for the given +name+.
-    #
-    # Usually returns <code>#{prefix}#{name}#{postfix}<num></code>, example:
-    #
-    #     new_alias_name('foo') #=> __alias_of__foo__
-    #     def bar; end
-    #     new_alias_name('bar') #=> __alias_of__bar__2
-    def new_alias_name(name, prefix = "__alias_of__", postfix = "__")
-      base_name = "#{prefix}#{name}#{postfix}"
-      all_methods = instance_methods(true) + private_instance_methods(true)
-      same_methods = all_methods.grep(/^#{Regexp.quote(base_name)}[0-9]*$/)
-      return base_name if same_methods.empty?
-      no = same_methods.size
-      while !same_methods.include?(alias_name = base_name + no)
-        no += 1
-      end
-      alias_name
-    end
-  end
 end