Add Reline.pre_input_hook interface

lib/reline.rb

@@ -68,6 +68,14 @@ module Reline
     @@completion_proc = p
   end
 
+  @@pre_input_hook = nil
+  def self.pre_input_hook
+    @@pre_input_hook
+  end
+  def self.pre_input_hook=(p)
+    @@pre_input_hook = p
+  end
+
   @@dig_perfect_match_proc = nil
   def self.dig_perfect_match_proc
     @@dig_perfect_match_proc
@@ -155,6 +163,7 @@ module Reline
     @@line_editor.output = @@output
     @@line_editor.completion_proc = @@completion_proc
     @@line_editor.dig_perfect_match_proc = @@dig_perfect_match_proc
+    @@line_editor.pre_input_hook = @@pre_input_hook
     @@line_editor.retrieve_completion_block = method(:retrieve_completion_block)
     @@line_editor.rerender
 

lib/reline/line_editor.rb

@@ -9,6 +9,7 @@ class Reline::LineEditor
   attr_reader :line
   attr_accessor :confirm_multiline_termination_proc
   attr_accessor :completion_proc
+  attr_accessor :pre_input_hook
   attr_accessor :dig_perfect_match_proc
   attr_writer :retrieve_completion_block
   attr_writer :output