Escape carriage return when round-tripping

Previously the carriage return character ("\r") was not round-tripped
properly.

This will cause a warning on the (upcoming) Ruby 2.1.0 as a plain
carriage return that is not at end-of-line is treated as a space.

lib/kpeg/string_escape.kpeg

@@ -7,6 +7,7 @@
 segment = < /[\w ]+/ > { text } # Don't use \s because that matchs \n
         | "\\" { "\\\\" }
         | "\n" { "\\n" }
+        | "\r" { "\\r" }
         | "\t" { "\\t" }
         | "\b" { "\\b" }
         | "\"" { "\\\"" }

lib/kpeg/string_escape.rb

@@ -363,7 +363,7 @@ def self.rule_info(name, rendered)
   # :stopdoc:
   def setup_foreign_grammar; end
 
-  # segment = (< /[\w ]+/ > { text } | "\\" { "\\\\" } | "\n" { "\\n" } | "\t" { "\\t" } | "\b" { "\\b" } | "\"" { "\\\"" } | < . > { text })
+  # segment = (< /[\w ]+/ > { text } | "\\" { "\\\\" } | "\n" { "\\n" } | "\r" { "\\r" } | "\t" { "\\t" } | "\b" { "\\b" } | "\"" { "\\\"" } | < . > { text })
   def _segment
 
     _save = self.pos
@@ -429,12 +429,12 @@ def _segment
 
       _save4 = self.pos
       while true # sequence
-        _tmp = match_string("\t")
+        _tmp = match_string("\r")
         unless _tmp
           self.pos = _save4
           break
         end
-        @result = begin;  "\\t" ; end
+        @result = begin;  "\\r" ; end
         _tmp = true
         unless _tmp
           self.pos = _save4
@@ -447,12 +447,12 @@ def _segment
 
       _save5 = self.pos
       while true # sequence
-        _tmp = match_string("\b")
+        _tmp = match_string("\t")
         unless _tmp
           self.pos = _save5
           break
         end
-        @result = begin;  "\\b" ; end
+        @result = begin;  "\\t" ; end
         _tmp = true
         unless _tmp
           self.pos = _save5
@@ -465,12 +465,12 @@ def _segment
 
       _save6 = self.pos
       while true # sequence
-        _tmp = match_string("\"")
+        _tmp = match_string("\b")
         unless _tmp
           self.pos = _save6
           break
         end
-        @result = begin;  "\\\"" ; end
+        @result = begin;  "\\b" ; end
         _tmp = true
         unless _tmp
           self.pos = _save6
@@ -482,20 +482,38 @@ def _segment
       self.pos = _save
 
       _save7 = self.pos
+      while true # sequence
+        _tmp = match_string("\"")
+        unless _tmp
+          self.pos = _save7
+          break
+        end
+        @result = begin;  "\\\"" ; end
+        _tmp = true
+        unless _tmp
+          self.pos = _save7
+        end
+        break
+      end # end sequence
+
+      break if _tmp
+      self.pos = _save
+
+      _save8 = self.pos
       while true # sequence
         _text_start = self.pos
         _tmp = get_byte
         if _tmp
           text = get_text(_text_start)
         end
         unless _tmp
-          self.pos = _save7
+          self.pos = _save8
           break
         end
         @result = begin;  text ; end
         _tmp = true
         unless _tmp
-          self.pos = _save7
+          self.pos = _save8
         end
         break
       end # end sequence
@@ -603,7 +621,7 @@ def _embed
   end
 
   Rules = {}
-  Rules[:_segment] = rule_info("segment", "(< /[\\w ]+/ > { text } | \"\\\\\" { \"\\\\\\\\\" } | \"\\n\" { \"\\\\n\" } | \"\\t\" { \"\\\\t\" } | \"\\b\" { \"\\\\b\" } | \"\\\"\" { \"\\\\\\\"\" } | < . > { text })")
+  Rules[:_segment] = rule_info("segment", "(< /[\\w ]+/ > { text } | \"\\\\\" { \"\\\\\\\\\" } | \"\\n\" { \"\\\\n\" } | \"\\r\" { \"\\\\r\" } | \"\\t\" { \"\\\\t\" } | \"\\b\" { \"\\\\b\" } | \"\\\"\" { \"\\\\\\\"\" } | < . > { text })")
   Rules[:_root] = rule_info("root", "segment*:s { @text = s.join }")
   Rules[:_embed_seg] = rule_info("embed_seg", "(\"\#\" { \"\\\\\#\" } | segment)")
   Rules[:_embed] = rule_info("embed", "embed_seg*:s { @text = s.join }")

test/test_kpeg_string_escape.rb

@@ -0,0 +1,42 @@
+require 'minitest/autorun'
+require 'kpeg'
+require 'kpeg/string_escape'
+
+class TestKPegStringEscape < Minitest::Test
+
+  def test_bell
+    assert_equal '\b', parse("\b")
+  end
+
+  def test_carriage_return
+    assert_equal '\r', parse("\r")
+  end
+
+  def test_newline
+    assert_equal '\n', parse("\n")
+  end
+
+  def test_quote
+    assert_equal '\\\\\"', parse('\\"')
+  end
+
+  def test_slash
+    assert_equal '\\\\', parse('\\')
+  end
+
+  def test_tab
+    assert_equal '\t', parse("\t")
+  end
+
+  def parse(str, embed = false)
+    se = KPeg::StringEscape.new(str)
+
+    rule = (embed ? 'embed' : nil)
+
+    se.raise_error unless se.parse(rule)
+
+    se.text
+  end
+
+end
+