Revert "Colorize error part more"

This reverts commit c7f3c22.

lib/irb/color.rb

@@ -56,7 +56,7 @@ module Color
         on_tstring_content: [[RED],                   ALL],
         on_tstring_end:     [[RED],                   ALL],
         on_words_beg:       [[RED],                   ALL],
-        ERROR:              [[RED, REVERSE],          ALL],
+        on_parse_error:     [[RED, REVERSE],          ALL],
       }
     rescue NameError
       # Give up highlighting Ripper-incompatible older Ruby
@@ -66,16 +66,9 @@ module Color
 
     class Lexer < Ripper::Lexer
       if method_defined?(:token)
-        def self.lex(code)
-          new(code).parse.sort_by {|elem| elem.pos.dup << elem.event}
+        def on_parse_error(mesg)
+          @buf.push Elem.new([lineno(), column()], __callee__, token(), state())
         end
-
-        def on_error(mesg)
-          # :ERROR comes before other :on_ symbols
-          @buf.push Elem.new([lineno(), column()], :ERROR, token(), state())
-        end
-        alias compile_error on_error
-        alias on_parse_error on_error
       end
     end
 
@@ -117,43 +110,33 @@ def colorize_code(code)
         symbol_state = SymbolState.new
         colored = +''
         length = 0
-        pos = [1, 0]
 
-        Lexer.lex(code).each do |elem|
+        Lexer.new(code).parse.sort_by(&:pos).each do |elem|
           token = elem.event
           str = elem.tok
           expr = elem.state
           in_symbol = symbol_state.scan_token(token)
-          next if ([elem.pos[0], elem.pos[1] + str.bytesize] <=> pos) <= 0
-          Reline::Unicode.escape_for_print(str).each_line do |line|
-            if seq = dispatch_seq(token, expr, str, in_symbol: in_symbol)
+          if seq = dispatch_seq(token, expr, str, in_symbol: in_symbol)
+            Reline::Unicode.escape_for_print(str).each_line do |line|
               colored << seq.map { |s| "\e[#{s}m" }.join('')
               colored << line.sub(/\Z/, clear)
-            else
-              colored << line
-            end
-            if line.end_with?("\n")
-              pos[0] += 1
-              pos[1] = 0
-            else
-              pos[1] += line.bytesize
             end
+          else
+            colored << Reline::Unicode.escape_for_print(str)
           end
-          length += str.bytesize
+          length += str.length
         end
 
         # give up colorizing incomplete Ripper tokens
-        return code if length != code.bytesize
+        return code if length != code.length
 
         colored
       end
 
       private
 
       def dispatch_seq(token, expr, str, in_symbol:)
-        if token == :ERROR
-          TOKEN_SEQ_EXPRS[token][0]
-        elsif in_symbol
+        if in_symbol
           [YELLOW]
         elsif TOKEN_KEYWORDS.fetch(token, []).include?(str)
           [CYAN, BOLD]