Pull whitespace skipping out into a shared method

lib/ahem/lexer.rb

   end
 
   def get_token
-    return Token.new(TokenKinds::EOF) if at_end
+    skip_whitespace
 
-    @position += 1 while !at_end && @source.slice(@position).match(/\s/)
+    return Token.new(TokenKinds::EOF) if at_end
 
     source = @source.slice(@position..-1)
 
   def scan_all
     tokens = Array.new
     until at_end
-      if @source.slice(@position).match(/\s/)
-        @position += 1
-      else
-        tokens << get_token
-      end
+      tokens << get_token
     end
     tokens << Token.new(TokenKinds::EOF)
-    tokens
   end
 
   private
 
+  def skip_whitespace
+    while !at_end && @source[@position].match(/\A\s/)
+      @position += 1
+    end
+  end
+
   def at_end
     @position == @source.size
   end