}
    this.eval = function (code) {
      try {
	return this.eval2(code);
      } catch (e) {
	var msg = code.substr(0,128);
	if(msg.length >= 125) msg += "...";
	puts(e);
	var msg = e+'\n        while executing\n"'+msg+'"';
	for(var i = this.level; i > 0; i--)
	  msg += '\n        invoked from within\n"'+this.levelcall[i]+'"'
	this.setVar("::errorInfo", msg);

      }
    }
    this.eval2 = function(code) {
      this.code  = this.OK;
      var parser = new TclParser(code);
      var args   = [];
      var first  = true;

	for (var i = 2; i < args.length; i++) str += args[i].toString();
        interp.setVar(vname, str);
        return str;
      });
    this.registerCommand("break", function (interp, args) {
        interp.code = interp.BRK;
        return;









      });
    this.registerCommand("cd", function (interp, args) {
	this.arity(args, 1, 2);
	var dir = process.env.HOME;
	if (args.length == 2) dir = args[1].toString();
	process.chdir(dir);
	return;

        var r = args[1];
        interp.code = interp.RET;
        return r;
    });
    this.registerCommand("set", function (interp, args) {
        this.arity(args, 2, 3);
        var name = args[1];

        if (args.length == 3) interp.setVar(name, args[2]);
        return interp.getVar(name);
    });
    this.registerCommand("source", function (interp, args) {
        this.arity(args, 2);
        interp.script = args[1].toString();
        try {
	  var data = fs.readFileSync(interp.script).toString();
        } catch(e) {
	  throw 'couldn\' read file "'+interp.script+'": no such file or directory';}

	var res    = interp.eval(data);
	interp.script = "";
	return res;
      });
    this.registerCommand("split", function (interp, args) {
        this.arity(args, 2, 3);
        var str = args[1].toString();
        var sep = " ";
        if (args.length == 3) sep = args[2].toString();
	var res = [], e;
        var tmp = str.split(sep);
	for(var i in tmp) {
	  e = tmp[i];
	  if(e == "") e = "{}";
	  res.push(e);
	}
	return res.join(" ");
      });
    this.registerSubCommand("string", "compare", function (interp, args) {
        this.arity(args, 3);
	var a = args[1].toString();
	var b = args[2].toString();

	  return;
        }
        base = cmd[0].toString();
        cmd.shift();
        interp.registerSubCommand(base, cmd.join(" "), eval(args[2].toString()));
        return;
      });
    this.math = function (name, a, b) {
      switch (name) {
      case "+":  return a + b;
      case "-":  return a - b;
      case "*":  return a * b;
      case "/":  return a / b;
      case "%":  return a % b;
      case "<":  return a < b? "1":"0";
      case ">":  return a > b? "1":"0";
      case "==": return a == b? "1":"0";
      case "!=": return a != b? "1":"0";
      default:   throw "Unknown operator: '"+name+"'";
      }
    }
    var ops = ["+","-","*","/","%","<",">","==","!="];
    for (var i in ops)
      this.registerCommand(ops[i],function (interp, args) {
	  this.arity(args, 3);
	  var name = args[0].toString();
	  var a    = interp.objectify(args[1]);
	  var b    = interp.objectify(args[2]);
	  if (name == '==') 
	    return new TclObject(a.toString() == b.toString()?"1":"0","BOOL");
	  if (name == '!=') 
	    return new TclObject(a.toString() != b.toString()?"1":"0","BOOL");
	  
	  var x = a.getNumber();
	  var y = b.getNumber();
	  if (a.isInteger() && b.isInteger())
	    return new TclObject(interp.math(name, x, y),"INTEGER");
	  if (a.isReal() && b.isReal())
	    return new TclObject(interp.math(name, x, y),"REAL");
	  return new TclObject(interp.math(name, args[1].toString(), 
					   args[2].toString()));
        });
    this.mkList = function(x) {
      var list = [];
      for (var name in x) {list.push(name);}
      return list;
    }
    this.objectify = function (text) {
      if (text == null) text = "";

  this.SEP = 0;
  this.STR = 1;
  this.EOL = 2;
  this.EOF = 3;
  this.ESC = 4;
  this.CMD = 5;
  this.VAR = 6;
  this.text  = text;
  this.start = 0;
  this.end   = 0;
  this.insidequote = false;
  this.index = 0;
  this.len = text.length;
  this.type = this.EOL;
  this.cur = this.text.charAt(0);
  this.getText = function () {
    return this.text.substring(this.start,this.end+1);
  }
  this.parseString = function () {
    var newword = (this.type==this.SEP ||
		   this.type == this.EOL || this.type == this.STR);
    if (newword && this.cur == "{") return this.parseBrace();
    else if (newword && this.cur == '"') {
      this.insidequote = true;
      this.feedchar();
    }
    this.start = this.index;
    while (true) {
      if (this.len == 0) {
	this.end = this.index-1;
	this.type = this.ESC;
	return this.OK;
      }
      if (this.cur == "\\") {
	//if (this.len >= 2) this.feedSequence();
      }
      else if ("$[ \t\n\r;".indexOf(this.cur)>=0) {
	if ("$[".indexOf(this.cur)>=0 || !this.insidequote) {
	  this.end = this.index-1;
	  this.type = this.ESC;
	  return this.OK;
	}
      }
      else if (this.cur == '"' && this.insidequote) {
	this.end    = this.index-1;
	this.type = this.ESC;
	this.feedchar();
	this.insidequote = false;
	return this.OK;
      }
      this.feedchar();
    }
    return this.OK;
  }
  this.parseList = function () {
    var level = 0;
    this.start = this.index;
    while (true) {
      if (this.len == 0) {
	this.end  = this.index;
	this.type = this.EOL;
	return;
      }
      switch (this.cur) {
      case "\\":
	if (this.len >= 2) this.feedSequence();
	break;
      case " ": case "\t": case "\n": case "\r":
	if (level > 0) break;
	this.end  = this.index - 1;
	this.type = this.SEP;
	this.feedchar();
	return;
      case '{': level++; break;

    while (true) {
      if (this.len == 0) break;
      if (this.cur == "[" && blevel == 0)
	level++;
      else if (this.cur == "]" && blevel == 0) {
	level--;
	if (level == 0) break;
      } else if (this.cur == "\\") {
	this.feedSequence();
      } else if (this.cur == "{") {
	blevel++;
      } else if (this.cur == "}") {
	if (blevel != 0) blevel--;
      }
      this.feedchar();
    }

    this.setPos(this.end+1);
    return this.OK;
  }
  this.parseBrace = function () {
    var level = 1;
    this.feedcharstart();
    while (true) {
      if (this.len > 1 && this.cur == "\\") {
	this.feedSequence();

      } else if (this.len == 0 || this.cur == "}") {
	level--;
	if (level == 0 || this.len == 0) {
	  this.end = this.index-1;
	  if (this.len > 0) this.feedchar();
	  this.type = this.STR;
	  return this.OK;
	}

      }
      if (this.cur == "#" && this.type == this.EOL) {
	this.parseComment();
	continue;
      }
      return this.parseString();
    }

    return this.OK; // unreached
  }
  this.feedSequence = function () {
    //return;
    if (this.cur != "\\") throw "Invalid escape sequence";
    var cur = this.steal(1);
    //puts("enter feedSequence, text: "+this.text+" cur: "+cur);
    var specials = {};
    specials.a = "\a";
    specials.b = "\b";
    specials.f = "\f";
    specials.n = "\n";
    specials.r = "\r";
    specials.t = "\t";
    specials.v = "\v";
    switch (cur) {
    case 'u':
      var hex = this.steal(4);
      if (hex != Tcl.isHexSeq.exec(hex))
	throw "Invalid unicode escape sequence: "+hex;
      cur = String.fromCharCode(parseInt(hex,16));
      break;
    case 'x':

      var hex = this.steal(2);
      puts("enter case x, hex: '"+hex+"'");
      if (hex != Tcl.isHexSeq.exec(hex))
	throw "Invalid unicode escape sequence: "+hex;
      cur = String.fromCharCode(parseInt(hex,16));
      //puts("hex: "+hex.toString()+" cur: "+cur);

      break;
    case "a": case "b": case "f": case "n":
    case "r": case "t": case "v":
      cur = specials[cur];
      break;
    default:
      if ("0123456789".indexOf(cur) >= 0) {

e.g. {append x bar}     -> foobar

proc sum args {expr [join $args +]}
e.g. {sum 1 2 3} -> 6
#native sum2 {function (interp, args) {return eval(args.join("+"));}}
#e.g. {sum2 2 3 4} -> 9






e.g. {concat {a b} {c d}} -> {a b c d}

e.g. {set d [dict create a 1 b 2 c 3]} -> {a 1 b 2 c 3}
e.g. {dict exists $d c} -> 1
e.g. {dict exists $d x} -> 0
e.g. {dict get $d b}    -> 2
e.g. {dict keys $d}     -> {a b c}

e.g. {set x 0xFF; expr {$x+0}} -> 255
e.g. {expr 0376}               -> 254
e.g. {set x 0375; expr $x}     -> 253
e.g. {expr {$x}}   -> 253
e.g. {expr 6 * 7}  -> 42
e.g. {expr 1 == 2} -> 0
e.g. {expr 1 < 2}  -> 1




e.g. {expr !0}     -> 1
e.g. {expr !42}    -> 0
e.g. {set x 3}     -> 3
e.g. {expr $x+1}   -> 4
e.g. {expr {$x+1}} -> 4
e.g. {set x a; set y b; expr {$x == $y}} -> 0
e.g. {expr {$x != $y}} -> 1




set forres ""
e.g. {for {set i 0} {$i < 5} {incr i} {append forres $i}; set forres} -> 01234
e.g. {foreach i {a b c d e} {append foreachres $i}; set foreachres}   -> abcde

e.g. {format %x 255} -> ff
e.g. {format %X 254} -> FE

e.g. {llength $x}         -> 4
e.g. {lindex $x 2}        -> c
e.g. {lrange $x 1 2}      -> {b c}
e.g. {lreverse {a b c}}   -> {c b a}
e.g. {lsearch $x b}       -> 1
e.g. {lsearch $x y}       -> -1
e.g. {lsort {z x y}}      -> {x y z}






e.g. {regexp {X[ABC]Y} XAY}    -> 1
e.g. {regexp {X[ABC]Y} XDY}    -> 0
e.g. {regsub {[A-C]+} uBAAD x} -> uxD 

e.g. {split "a b  c d"}     -> {a b {} c d}
e.g. {split " a b  c d"}     -> {{} a b {} c d}

e.g. {string length ""}       -> 0
e.g. {string length foo}      -> 3
e.g. {string range hello 1 3} -> ell
e.g. {string tolower Tcl}     -> tcl
e.g. {string toupper Tcl}     -> TCL
e.g. {string trim " foo "}    -> foo

#e.g. {set x a.\x62.c} -> a.b.c ;# severe malfunction, breaks test suite operation :(

puts "total $total tests, passed $passed, failed $fail"
#----------- clean up variables used in tests
foreach var [info vars] {
    set pos [lsearch $vars $var] ;# expr can't substitute commands yet
    set neq [string compare $var vars]
    if {$var != "vars" && $pos < 0} {unset $var}
}
unset vars var pos neq
puts "vars now: [info vars]"
puts "[llength [info commands]] commands implemented"