Update charted to 0.4.8 and roll

packages/petitparser/lib/lisp.dart

-/// This package contains a simple grammar and evaluator for LISP.
-///
-/// The code is reasonably complete to run and evaluate reasonably complex
-/// programs from the console and from the web browser.
-library petitparser.lisp;
-
-import 'dart:collection';
-import 'petitparser.dart';
-
-part 'src/lisp/cons.dart';
-part 'src/lisp/environment.dart';
-part 'src/lisp/grammar.dart';
-part 'src/lisp/name.dart';
-part 'src/lisp/natives.dart';
-part 'src/lisp/parser.dart';
-part 'src/lisp/standard.dart';
-
-/// The standard lisp parser definition.
-final lispParser = new LispParser();
-
-/// The evaluation function.
-eval(Environment env, expr) {
-  if (expr is Cons) {
-    return eval(env, expr.head)(env, expr.tail);
-  } else if (expr is Name) {
-    return env[expr];
-  } else {
-    return expr;
-  }
-}
-
-/// Evaluate a cons of instructions.
-evalList(Environment env, expr) {
-  var result = null;
-  while (expr is Cons) {
-    result = eval(env, expr.head);
-    expr = expr.tail;
-  }
-  return result;
-}
-
-/// The arguments evaluation function.
-evalArguments(Environment env, args) {
-  if (args is Cons) {
-    return new Cons(eval(env, args.head), evalArguments(env, args.tail));
-  } else {
-    return null;
-  }
-}
-
-/// Reads and evaluates a [script].
-evalString(Parser parser, Environment env, String script) {
-  var result = null;
-  for (var cell in parser.parse(script).value) {
-    result = eval(env, cell);
-  }
-  return result;
-}