*** parse.y.1.9.3-p0	2011-11-12 15:42:07.000000000 +0900
--- parse.y	2011-11-12 15:41:18.000000000 +0900
***************
*** 682,688 ****
--- 682,690 ----
  %token <num>  tREGEXP_END
  
  %type <node> singleton strings string string1 xstring regexp
+ %type <node> yaml
  %type <node> string_contents xstring_contents regexp_contents string_content
+ %type <node> yaml_contents
  %type <node> words qwords word_list qword_list word
  %type <node> literal numeric dsym cpath
  %type <node> top_compstmt top_stmts top_stmt
***************
*** 735,740 ****
--- 737,743 ----
  %token tAMPER		/* & */
  %token tLAMBDA		/* -> */
  %token tSYMBEG tSTRING_BEG tXSTRING_BEG tREGEXP_BEG tWORDS_BEG tQWORDS_BEG
+ %token tYAML_BEG
  %token tSTRING_DBEG tSTRING_DVAR tSTRING_END tLAMBEG
  
  /*
***************
*** 2616,2621 ****
--- 2619,2625 ----
  primary		: literal
  		| strings
  		| xstring
+ 		| yaml
  		| regexp
  		| words
  		| qwords
***************
*** 3905,3910 ****
--- 3909,3926 ----
  		    }
  		;
  
+ yaml		: tYAML_BEG yaml_contents tSTRING_END
+ 		    {
+ 		    /*%%%*/
+ 			NODE *node = $2;
+ 			if (!node) node = NEW_STR(STR_NEW0());
+ 			$$ = NEW_CALL(node, rb_intern("__yaml__"), 0)
+ 		    /*%
+ 			$$ = dispatch1(xstring_literal, $2);
+ 		    %*/
+ 		    }
+ 		;
+ 
  regexp		: tREGEXP_BEG regexp_contents tREGEXP_END
  		    {
  		    /*%%%*/
***************
*** 4098,4103 ****
--- 4114,4137 ----
  		    }
  		;
  
+ yaml_contents	: /* none */
+ 		    {
+ 		    /*%%%*/
+ 			$$ = 0;
+ 		    /*%
+ 			$$ = dispatch0(xstring_new);
+ 		    %*/
+ 		    }
+ 		| yaml_contents string_content
+ 		    {
+ 		    /*%%%*/
+ 			$$ = literal_concat($1, $2);
+ 		    /*%
+ 			$$ = dispatch2(xstring_add, $1, $2);
+ 		    %*/
+ 		    }
+ 		;
+ 
  regexp_contents: /* none */
  		    {
  		    /*%%%*/
***************
*** 5383,5388 ****
--- 5417,5423 ----
  #define STR_FUNC_QWORDS 0x08
  #define STR_FUNC_SYMBOL 0x10
  #define STR_FUNC_INDENT 0x20
+ #define STR_FUNC_YAML   0x40
  
  enum string_type {
      str_squote = (0),
***************
*** 5392,5398 ****
      str_sword  = (STR_FUNC_QWORDS),
      str_dword  = (STR_FUNC_QWORDS|STR_FUNC_EXPAND),
      str_ssym   = (STR_FUNC_SYMBOL),
!     str_dsym   = (STR_FUNC_SYMBOL|STR_FUNC_EXPAND)
  };
  
  static VALUE
--- 5427,5434 ----
      str_sword  = (STR_FUNC_QWORDS),
      str_dword  = (STR_FUNC_QWORDS|STR_FUNC_EXPAND),
      str_ssym   = (STR_FUNC_SYMBOL),
!     str_dsym   = (STR_FUNC_SYMBOL|STR_FUNC_EXPAND),
!     str_yaml   = (STR_FUNC_YAML|STR_FUNC_EXPAND)
  };
  
  static VALUE
***************
*** 5859,5864 ****
--- 5895,5901 ----
      rb_encoding *enc = *encp;
      char *errbuf = 0;
      static const char mixed_msg[] = "%s mixed within %s source";
+     int yaml_dotlen = 0;
  
  #define mixed_error(enc1, enc2) if (!errbuf) {	\
  	size_t len = sizeof(mixed_msg) - 4;	\
***************
*** 5878,5883 ****
--- 5915,5932 ----
      } while (0)
  
      while ((c = nextc()) != -1) {
+         if (func == str_yaml) {
+             if (c == '.') {
+                 yaml_dotlen++;
+                 if (yaml_dotlen == 3) {
+                     //return -1;
+                     return 1;
+                 }
+             }
+             else {
+                 yaml_dotlen = 0;
+             }
+         }
  	if (paren && c == paren) {
  	    ++*nest;
  	}
***************
*** 6037,6042 ****
--- 6086,6094 ----
  
      tokfix();
      set_yylval_str(STR_NEW3(tok(), toklen(), enc, func));
+     if (func == str_yaml) {
+         quote->nd_func = -1;
+     }
  
  #ifdef RIPPER
      if (!NIL_P(parser->delayed)) {
***************
*** 6048,6054 ****
  	parser->tokp = lex_p;
      }
  #endif
! 
      return tSTRING_CONTENT;
  }
  
--- 6100,6106 ----
  	parser->tokp = lex_p;
      }
  #endif
!  
      return tSTRING_CONTENT;
  }
  
***************
*** 7135,7140 ****
--- 7187,7200 ----
  	    lex_state = EXPR_ARG;
  	    return tLAMBDA;
  	}
+ 	if (c == '-') {
+ 	    c = nextc();
+ 	    if (c == '-') {
+ 		lex_strterm = NEW_STRTERM(str_yaml, c, 0);
+ 		return tYAML_BEG;
+ 	    }
+ 	    pushback('-');
+ 	}
  	if (IS_BEG() || (IS_SPCARG(c) && arg_ambiguous())) {
  	    lex_state = EXPR_BEG;
  	    pushback(c);